LABOR AND BIRTH AT RISK (Preterm, Postterm
Labour, Preterm
Premature Rupture of Membranes, Distocia). Nursing Care during Labour
and delivery with risk Factors.
LEARNING
OBJECTIVES
• Differentiate
between preterm birth and low birth weight.
• Identify
the risk factors for preterm labor.
• Discuss
current interventions to prevent preterm birth.
•
Discuss the use of tocolytics and antenatal glucocorticoids in preterm labor and birth.
•
Examine the effects of prescribed bed rest on pregnant women and their families.
Discuss
the criteria for evaluating the nursing care of women experiencing labor and
birth complications.
Describe
the care of a woman experiencing postterm
pregnancy.
KEY
TERMS AND DEFINITIONS
amniotic fluid
embolism (AFE) Embolism resulting from amniotic fluid entering
the maternal bloodstream during labor and birth after rupture of membranes;
often fatal to the woman if it is a pulmonary embolism
antenatal glucocorticoids Medications
administered to the mother for the purpose of accelerating fetal lung maturity
when there is increased risk for preterm birth between 24 and 34 weeks of
gestation
augmentation of labor Stimulation
of ineffective uterine contractions after labor has started spontaneously but
is not progressing satisfactorily
Bishop
score Rating system to evaluate inducibility
(ripeness) of the cervix; a higher score increases the likelihood of a
successful induction of labor
cephalopelvic
disproportion (CPD) Condition in which the infant's head
is of such a shape, size, or position that it cannot pass through the mother's
pelvis or the maternal pelvis is too small, abnormally shaped, or deformed to
allow the passage of a fetus of average size
cesarean birth Birth of a fetus by an incision through
the abdominal wall and uterus
chorioamnionitis Inflammatory
reaction in fetal membranes to bacteria or viruses in the amniotic fluid, which
then become infiltrated with polymorphonuclear leukocytes
dysfunctional labor Abnormal
uterine contractions that prevent normal progress of cervical dilation, effacement,
or descent
dystocia Prolonged,
painful, or otherwise difficult birth caused by various conditions associated with
the five factors affecting labor (powers, passage, passenger, maternal
position, and maternal emotions)
external cephalic
version (ECV) Turning of the fetus to a vertex presentation by
external exertion of pressure on the fetus through the maternal
abdomen
forceps-assisted birth Vaginal
birth in which forceps (i.e., curved-bladed instruments) are used to assist in
the birth of the fetal head
hypertonic uterine
dysfunction Uncoordinated, painful, frequent uterine
contractions that do not cause cervical dilation and effacement; primary dysfunctional
labor
hypotonic uterine
dysfunction Weak, ineffective uterine contractions usually occurring
in the active phase of labor; often related to cephalopelvic
disproportion or malposition of the fetus; secondary uterine
inertia
oxytocin Hormone
produced by the posterior pituitary gland that stimulates uterine contractions and
the release of milk in the mammary glands (let-down reflex); oxytocics are medications that mimic the uterine
stimulating action of oxytocin
postterm
pregnancy Pregnancy
prolonged past 42 weeks of gestation
precipitous labor Rapid
or sudden labor lasting less than 3 hours from the onset of uterine
contractions to complete birth of the fetus
premature
rupture of membranes (PROM) Rupture of the amniotic sac and
leakage of amniotic fluid beginning at least 1 hour before the onset of labor
at any gestational age
preterm birth Birth occurring before the
completion of 37 weeks of gestation
preterm labor Cervical
changes and uterine contractions occurring between 20 weeks and 37 weeks of
pregnancy
preterm premature
rupture of membranes (PPROM) PROM that occurs before 37 weeks of gestation
prolapse
of the umbilical cord Protrusion of the umbilical cord in
advance of the presenting part
shoulder dystocia Condition in which the head is born
but the anterior shoulder cannot pass under the pubic arch
therapeutic rest Administration
of analgesics and implementation of comfort/relaxation measures to decrease
pain and induce rest for management of hypertonic uterine dysfunction
tocolytics Medications
used to suppress uterine activity and relax the uterus in cases of hyperstimulation or preterm labor
trial of labor
(TOL) Period of observation to determine whether a laboring
woman is likely to be successful in progressing to a vaginal birth
vacuum-assisted birth Birth involving attachment of a
vacuum cap to the fetal head (occiput) and applying
negative pressure to assist in birth of the fetus
vaginal birth after
cesarean (VBAC) Giving birth vaginally after having had a
previous cesarean birth
When complications arise during labor and birth, risk of
perinatal morbidity and mortality increases.
Some complications are anticipated, especially if the mother is identified as
high risk during the antepartum period; others are unexpected or
unforeseen. The woman, her family, and the obstetric team can feel devastated
when things go wrong. Nurses must recognize these feelings if they are to provide
effective support. It is crucial for nurses to understand the normal birth
process to prevent and detect deviations from normal labor and birth and to
implement nursing measures when complications arise. Optimal care of the
laboring woman, fetus, and family experiencing complications is possible only
when the nurse and other members of the obstetric team use their knowledge and skills
in a concerted effort to provide care. This chapter focuses on the problems of
preterm labor and birth, dystocia, and postterm pregnancy and obstetric emergencies.
PRETERM LABOR AND BIRTH
Preterm
labor is defined as cervical changes and uterine contractions
occurring between 20 and 37 weeks of pregnancy. Preterm birth is any birth
that occurs before the completion of 37 weeks of pregnancy (American College of
Obstetricians and Gynecologists & American Academy of Pediatrics, 1997).
Preterm labor and birth are the most serious complications of pregnancy because
they lead to approximately 90% of all neonatal deaths, with more than 75% of
these deaths occurring in infants born at fewer than 32 weeks of gestation.
Despite decreasing infant mortality rates in the
PRETERM BIRTH VERSUS LOW BIRTH WEIGHT
Although
they have distinctly different meanings, the terms preterm birth and low
birth weight are often used interchangeably. Preterm birth describes length
of gestation (i.e., less than 37 weeks), whereas low birth weight describes only
weight at the time of birth (i.e., 2500 g or less). Low birth weight is far
easier to measure than preterm birth, and thus in many settings and
publications, low birth weight has been used as a substitute term for preterm
birth. Preterm birth, however, is a more dangerous health condition for an
infant because length of time in the uterus correlates with immaturity of body
systems. Low-birth-weight babies can be, but are not necessarily, preterm; low
birth weight can be caused by conditions other than preterm birth, such as
intrauterine growth restriction (IUGR), a condition of fetal undergrowth not
necessarily correlated with initiation of labor.
The
incidence of preterm birth in the
PREDICTING PRETERM LABOR AND BIRTH
The
known risk factors for preterm birth are shown in
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DEMOGRAPHIC
RISKS • Nonwhite race • Age (<17, >35) • Low socioeconomic status • Unmarried • Less than high school education BIOPHYSICAL
RISKS • Previous preterm labor or birth • Second-trimester abortion (more than two
spontaneous or therapeutic); still births • Grand multiparity;
short interval between pregnancies <1 year since last birth); family
history of preterm labor and birth • Progesterone deficiency • Uterine anomalies or fibroids; uterine
irritability • Cervical incompetence, trauma, shortened
length • Exposure to DES or other toxic substances • Medical diseases (e.g., diabetes,
hypertension, anemia) • Small stature (< 119 cm in height;
<45.5 kg or underweight for height) • Current pregnancy risks: • Multifetal
pregnancy • Hydramnios • Bleeding • Placental problems (e.g., placenta previa, abruption placentae) • Infections (e.g., pyelonephritis,
recurrent urinary tract infections, asymptomatic bacteriuria,
bacterial vaginosis, chorioamnionitis) • Pregnancy-induced hypertension • Premature rupture of the membranes • Fetal anomalies • Inadequate plasma volume expansion; anemia BEHAVIORAL-PSYCHOSOCIAL
RISKS • Poor nutrition; weight loss or low weight
gain • Smoking (>10 cigarettes a day) • Substance abuse (e.g., alcohol; illicit
drugs, especially cocaine) • Inadequate prenatal care • Commutes of more than 1V2 hours each way • Excessive physical activity (heavy physical
work, prolonged standing, heavy lifting, young child care) •
Excessive lifestyle stressors |
Biochemical markers
The
two most common biochemical markers used in an effort to predict who might
experience preterm labor are fetal fibronectin and
salivary estriol. Fetal fibronectins
are glycoproteins found in plasma and produced during
fetal life. They appear in the cervical canal early in pregnancy, and then
again in late pregnancy. Their appearance between 24 and 34 weeks of gestation
could predict preterm labor. The negative predictive value of fetal fibronectins is high (up to 95%). The positive predictive
value of the fetal fibronectin test is lower (25% to
40%) (
Salivary
estriol is a form of estrogen produced by the fetus that
is present in plasma at 9 weeks of gestation. Levels of salivary estriol have been shown to increase before preterm birth.
Specimens of salivary estriol are collected by the
woman in the home; the testing is done every 2 weeks for approximately 10
weeks. This marker also has a high negative predictive value (98%) and a lower
positive predictive value (7% to 25%) (
Endocervical length
Some
studies have suggested that a shortened cervix precedes preterm labor and can
be determined by ultrasound measurement (Crane et al., 1997). A shortened
cervical length of less than 30 mm in a singleton pregnancy can predict some
instances of preterm labor. When a woman has a short cervix combined with a
positive fetal fibronectin result, her risk for
spontaneous preterm birth is substantially higher than for women positive for
only one marker or none at all (Goldenberg et al., 2000).
Causes of preterm labor and birth
The cause of
preterm labor is unknown and is assumed to be multifactorial
(Goldenberg & Rouse, 1998; Maloni, 2000) (
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MATERNAL
BEHAVIORS Smoking Substance use
(alcohol or illegal drugs) Poor nutrition Work/fatigue Short interpregnancy interval Sexual activity MATERNAL
CHARACTERISTICS Young or old age Previous preterm
birth Short stature Short cervix Uterine anomalies Diethylstilbestrol
exposure Prematurely
dilated cervix Low prepregnancy weight African-American Unmarried Low socioeconomic
status Victim of
domestic violence OTHER FACTORS Inadequate
support systems Stress Uterine
irritability Multiple
gestation Late or no
prenatal care Preterm premature
rupture of membranes Anemia Infection Catecholamine
release Decreased
progesterone production Decidual cell disruption Prostaglandin
synthesis Cytokine release |
|
Bacterial vaginosis 40%
increased risk Syphilis and
gonorrhea 50% increased risk Asymptomatic bacteriuria 50% increased risk |
Not
all preterm births can or even should be prevented. Approximately 25% of all
preterm births are iatrogenic; that is, babies are intentionally delivered
prematurely be cause of pregnancy complications that put the life or health of
the fetus or mother in danger, not because of preterm labor. Another 25% of all
preterm births are preceded by spontaneous rupture of the membranes followed by
labor. These preterm births are not known to be preventable. Approximately 50%
of preterm births, therefore, are possibly amenable to prevention efforts and
are considered idiopathic preterm births (Goldenberg & Rouse, 1998).
Sociodemographic factors such
as poverty, low educational level, lack of social support, smoking, little or
no prenatal care, domestic violence, and stress are thought to contribute to
the 50% of preterm births that may be preventable (Curry, Perrm,
& Wall, 1998; McFarlane & Gondolf, 1998; Moore
& Freda, 1998). If prenatal care programs are to be effective in reducing
the rate of preterm labor and birth, they must address these sociodemographic factors and develop strategies to attract
all women to participate, including those at high risk for preterm labor (Maloni, 2000). Addressing the factors that contribute to
preterm labor and birth can produce significant results. For example, Janke (1999) found that when women at risk for preterm
birth participated in a daily program of relaxation to reduce stress and
anxiety, they experienced prolonged pregnancies and gave birth to larger newborns
with significantly longer gestations.
CARE MANAGEMENT
Assessment and Nursing Diagnoses
Because
all pregnant women must be considered at risk for preterm labor (as they are
for any other pregnancy complication), nursing assessment begins at the time of
entry to prenatal care. Because the onset of preterm labor is often insidious
and can be easily mistaken for normal discomforts of pregnancy, it is essential
that nurses teach pregnant women how to detect the early symptoms of preterm
labor (
Pregnant
women need to be taught what to do if the symptoms of preterm labor occur. Some
women wait hours or days before contacting a health care provider after preterm
labor symptoms have begun (Freston et al., 1997).
Waiting too long to see a health care provider could result in inevitable
preterm birth without the benefit of the administration of antenatal glucocorticoids. In this event the neonate is born at
higher risk for respiratory distress syndrome and intraventricular
hemorrhage. Nursing diagnoses relevant for women at risk for preterm birth
include the following:
• Deficient
knowledge related to
-recognition of preterm labor symptoms
• Risk for
maternal or fetal injury related to
-preterm labor and birth
• Impaired
mobility related to
-prescribed bed rest
• Anticipatory
grieving related to
-preterm labor and birth
Expected Outcomes of Care
Expected
outcomes include that the woman will do the following:
• Learn the
symptoms of preterm labor and be able to assess herself and her need for
intervention
• Follow
teaching suggestions and call her physician or nurse-midwife if symptoms occur
• Not
experience preterm symptoms, or if she does, she will take appropriate action
• Maintain
her pregnancy for at least 37 completed weeks
• Give birth
to a healthy, term infant
Plan of Care and
Interventions
Prevention
Prevention
strategies that address risk factors associated with preterm labor and birth
are less costly in human and financial terms than the high-tech and often
lifelong care required by preterm infants and their families. Programs aimed at
health promotion and disease prevention that encourage healthy lifestyles for the
population in general and women of childbearing age in particular should be
developed in an effort to prevent preterm labor and birth (Heaman,
Sprague, & Stewart, 2001). One of the most important nursing interventions aimed
at preventing preterm birth is the education of pregnant women about the early
symptoms of preterm labor, so that if the symptoms occur the woman can be
referred promptly to her physician or nurse-midwife for more intensive care.
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UTERINE ACTIVITY • Uterine
contractions more frequent than every 10 minutes
persisting for 1 hour or more • Uterine
contractions may be painful or painless DISCOMFORT • Lower abdominal
cramping similar to gas pains; may be accompanied by diarrhea • Dull,
intermittent low back pain (below the waist) • Painful,
menstrual-like cramps • Suprapubic pain or pressure • Pelvic pressure
or heaviness • Urinary
frequency VAGINAL DISCHARGE • Change in
character and amount of usual discharge: thicker (mucoid)
or thinner (watery), bloody, brown or colorless, increased amount, odor • Rupture of amniotic membranes |
.files/image002.gif)
Fig, 1 Nurse teaching woman signs and symptoms of
preterm labor. (Courtesy Marjorie
Pyle, RNC, Lifecircle,
Early
recognition and diagnosis
Early
recognition of preterm labor is essential to successfully implement
interventions such as tocolytic therapy and
administration of antenatal glucocorticoids.
According to the
Lifestyle
modifications
Nurses
caring for women who exhibit symptoms of preterm labor should question the
woman about whether she has symptoms when engaged in any of the following activities:
• Sexual activity
• Riding long distances in automobiles, trains,
or buses
• Carrying heavy loads such as laundry, groceries,
or a small child
• Standing more than 50% of the time
• Heavy housework
• Climbing stairs
• Hard physical work
• Being unable to stop and rest when tired
If
symptoms occur when the woman is engaged in any of these activities, the woman
should consider what she was doing when the symptoms began, and then consider stopping
those activities until 37 weeks of pregnancy when preterm birth is no longer a
risk. Counseling about lifestyle modification should be individualized; only women
who have symptoms of preterm labor when they are engaged in certain activities
need to alter their lifestyles. There are no specific rules for which
activities are safe for pregnant women and which are not. Each pregnant woman
must understand which lifestyle factors might be contributing to her symptoms
and be taught to modify only those factors. Sexual activity, for instance, is
not prohibited during pregnancy. If, however, symptoms of preterm labor occur
after sexual activity, that activity may need to be curtailed until 37 weeks of
gestation.
Bed
rest
Bed rest is a
commonly used intervention for the prevention of preterm birth. There is no
evidence in the literature to support the efficacy of this intervention,
however. Maloni and colleagues (1993) have shown that
there are deleterious effects of bed rest on women: after 3 days there is
decreased muscle tone, weight loss, calcium loss, and glucose intolerance.
Weeks of bed rest lead to bone demineralization, constipation, fatigue,
isolation, anxiety, and depression (
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MATERNAL EFFECTS (PHYSICAL) • Weight loss • Muscle wasting, weakness • Bone demineralization and calcium
loss • Decreased plasma volume and
cardiac output • Increased clotting tendency; risk
for thrombophlebitis • Alteration in bowel function • Sleep disturbance, fatigue • Prolonged postpartum recovery MATERNAL EFFECTS (PSYCHOSOCIAL) • Loss of control associated with
role reversals • Dysphoria—anxiety,
depression, hostility, and anger • Guilt associated with difficulty
complying with activity restriction and inability to meet role
responsibilities • Boredom, loneliness • Emotional lability
(mood swings) EFFECTS ON SUPPORT SYSTEM • Stress associated with role
reversals, increased responsibilities, and disruption of family routines • Financial strain associated with
loss of maternal income and cost of treatment • Fear and anxiety regarding the
well-being of the mother and fetus |
Home
care
Bed
rest, although frequently prescribed, is not a benign intervention and has
furthermore never been shown to decrease preterm birthrates (Maloni, 1998). Women who are at high risk for preterm birth
commonly are told that it would be best if they were at home on bed rest for weeks
or months. The home care of the woman at risk for preterm birth is a challenge
for the nurse, who needs to assist the woman and her family in dealing with the
many difficulties faced by families in which one member must be incapacitated.
The scope of care given to women in their homes could range from occasional
visits to monitor the maternal and fetal condition to daily telephone
consultation and reading of uterine monitoring strips. Families, who are often
anxious regarding the health status of the mother and baby, may need help in
learning how to organize time and space or restructure family routines so that
the pregnant woman can remain a part of family activity while still maintaining
bed rest. It is also important for the nurse to work toward assisting all the
family members to explore their feelings regarding the anxieties of preterm
labor and help them to share their feelings with each other (Maloni, Brezinski-Tomasi, &
Johnson, 2001) (Fig. 2 and Box 6) (see Self-Care box).
.files/image004.gif)
Fig.
2 Woman at home on restricted activity for preterm labor prevention. Note how
she has arranged her daytime resting area so that needed items are close at
hand. (Courtesy Amy Turner,
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• Schedule brief
play periods throughout the day. • Keep a few
favorite toys in a box or basket close to the bed or couch. • Read to the child(ren). • Put puzzles
together. • Watch videos,
play video games (remote control for TV is ideal). • Play cards or
board games. • Color in
coloring books. • Cut out
pictures from magazines and paste on cardboard. • Play bed
basketball with a soft (sponge) ball or rolled up sock and a trash can or
empty laundry basket. |
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Patient Instructions for Self-Care Suggested Activities for Women on Bed Rest • Set a routine
for daily activities (e.g., getting dressed, moving from the bedroom to a
"day bed rest place," having social time, eating meals,
self-monitoring fetal and uterine activity) • Do passive
exercises as allowed • Review
childbirth education information or have a childbirth class at home, if this
can be arranged • Plan menus and
make up grocery shopping lists • Shop by phone • Read books
about high risk pregnancy or other topics • Keep a journal
of the pregnancy • Keep a calendar
of your progress • Reorganize
files, recipes, household budget • Update address
book • Do mending,
sewing • Listen to
audiotapes, watch videos orTV • Do crossword
puzzles, jigsaw puzzles, etc. • Do craft
projects; make something for the baby • Put pictures in
photo albums • Call a friend,
family member, or support person each day or use email • Treat yourself
to a facial, manicure, neck massage, or other special treat when you need a
lift |
Horns
uterine activity monitoring
Home
care agencies provide home uterine monitoring services for women diagnosed with
preterm labor (Fig. 3). However, from the body of research over the past 15
years, researchers have concluded that home uterine activity monitoring does
not prevent preterm birth, and its prohibitive cost makes it an unacceptable
intervention in the larger scheme of prenatal care (Dyson et al., 1998; Maloni, 2000). The use and effectiveness
of home uterine activity monitoring remains controversial (Roberts &
Morrison, 1998). Some research suggests that it is the nursing care
offered by the home care nurse that helps women the most (lams, Johnson, &
O'Shaughnessy, 1988; Moore et al., 1998).
.files/image006.gif)
Fig. 3 Home uterine activity
monitoring. Tocodynamometer is in
place at center of abdomen below umbilicus. Recording unit and transmitter are
on bedside table. (Courtesy Michael S. Clement, MD,
Suppression
of uterine activity
Tocolytics. Should
preterm labor occur, women are usually admitted to the hospital for assessment;
fetal monitoring; cervical/vaginal cultures; and assessment of cervical status,
amniotic fluid leakage, and maternal temperature (an early sign of chorioamnionitis). The initiation
of tocolytic therapy might be considered at this
time. Tocolytics have been the subject of research
since the late 1970s (Viamantes, 1996). At first, it
was thought that use of tocolytic therapy could
prolong a threatened pregnancy indefinitely; research has demonstrated that a
gain of 24 hours to several days is the best outcome that can be expected (Goldenberg
& Rouse, 1998; Maloni, 2000). It is now thought
that the best reason to use tocolytics is that they afford
the opportunity to begin administering antenatal glucocorticoids
to accelerate fetal lung maturity and reduce the severity of sequelae in infants born preterm (Enkin
et al., 2001; Goldenberg & Rouse, 1998).
The
use of tocolysis to suppress preterm labor has
increased 50%, from 1.6% in 1990 to 2.4% in 1999 (Ventura et al., 2001). The
medications most commonly used for this purpose are magnesium sulfate, ritodrine, terbutaline, indomethacin, and nifedipine. Ritodrine is the only medication approved by the U.S. Food
and Drug Administration (FDA) specifically for the purpose of cessation of uterine
contractions. The other drugs are used for this purpose on an
"unlabeled" basis (i.e., drugs known to be effective for a specific
purpose though not specifically developed and tested for this purpose). There
are important contraindications to the use of all tocolytics
(
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MATERNAL Severe
pregnancy-induced hypertension or eclampsia Active vaginal
bleeding Intrauterine
infection Cardiac disease Medical or
obstetric condition that contraindicates continuation of pregnancy FETAL Estimated
gestational age over 37 weeks Dilation over 4
cm Fetal demise Lethal fetal
anomaly Chorioamnionitis Acute fetal
distress Chronic ILJGR |
|
BOX 8 Nursing Care for Women Receiving Tocolytic Therapy Explain the
purpose and side effects of tocolytic therapy to
woman and her family. Position woman on
her side to enhance placental perfusion and reduce pressure on the cervix. Monitor maternal
vital signs, FHR, and labor status according to hospital protocol and
professional standards. Assess mother and
fetus for signs of adverse reactions related to the tocolytic
being administered. Determine maternal fluid balance by measuring
daily weight and intake and output (I&O). Limit fluid
intake to 2500 to 3000 ml/day, especially if a beta-adrenergic agonist is
being administered. Provide
psychosocial support and opportunities for women and family to express feelings
and concerns. Offer comfort
measures as required. Encourage diversional activities and
relaxation techniques. |
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Table 1 Medication Guide: Tocolitic Therapy for preterm Labor |
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MEDICATION/ ACTION |
DOSAGE AND ROUTE |
ADVERSE REACTIONS |
NURSING CONSIDERATIONS |
|
Ritodrine (Yutopar) Beta-adrenergic agonist Relaxes smooth muscles,
inhibiting uterine activity and causing bronchodilation
|
Mix 150 mg in 500
ml isotonic intravenous solution Attach to
controller pump and piggyback to primaryinfusion Begin infusion at
0.05 to 0.1 mg/min Increase rate by 0.05 mg q10min until contractions stop,
intolerable adverse reactions develop, or a maximum dose of 0.35 mg/min is
reached Maintain effective dose for 12 to
24 hr |
Intravenous
adverse reactions: • Shortness of
breath, coughing, tachypnea, pulmonary edema • Tachycardia,
palpitations, skipped beats • Chest pains • Hypotension • Tremors,
dizziness, nervousness • Muscle cramps
and weakness • Headache • Hyperglycemia; hypokalemia • Nausea and
vomiting • Fetal
tachycardia Oral adverse reactions: • Significant
adverse effects are rare • Gl
distress |
Women should be
screened with ECG before therapy begins; maternal heart disease and
hypertension are contraindications Use cautiously if
woman has type 1 diabetes or hyperthyroidism Validate that
woman is in PTL and is over 20 weeks of gestation Assess woman and
fetus before and after each rate increase and following frequency of agency
protocol Discontinue
infusion and notify physician if • Maternal heart
rate greater than 120 to 140 beats/min; dysrhythmias,
chest pain • BP is less than
90/60 mm Hg • Fetal heart
rate greater than 180 beats/min Ensure that propranolol (Inderal) is
available to reverse adverse effects related to cardiovascular function |
|
Terbutaline*
(Brethine) Beta-adrenergic agonist
Relaxes smooth muscles,
inhibiting uterine activity and causingbronchodilation |
Subcutaneous
injection: • 0.25 mg q30min
for 2 hr • Maximum dose: 0.5 mg q4-6h Subcutaneous pump: • Maintenance
dose 0.05-0.1 mg/hr • Bolus: 0.25 mg
q4-6h according to contraction pattern • 3 mg/24 hr |
Similar to ritodrine |
Teach woman and
family: • Assessment
measures: pulse, BP, respiratory effort, insertion site for infection, signs
of PTL and adverse reactions of terbutaline • Who to call if
problems or concerns arise • Site care and
pump maintenance • Activity restrictions
Arrange for follow-up |
|
Magnesium*
sulfate CNS depressant; relaxes smooth muscles including uterus |
Mix 40 g in 1000
ml intravenous solution, piggyback to primary infusion, and administer loading
dose or bolus of 4-6 g using controller pump over 15 to 20 min Continue
maintenance infusion at 1 g/hr, increasing to a maximum 3 g/hr until contractions
stop or intolerable adverse reactions develop |
During loading
dose: • Hot flushes,
sweating, nausea and vomiting, drowsiness, and blurred vision; usually
subside when loading dose is completed Intolerable
adverse reactions: • Respiratory
rate less than 12 breaths/min • Absent DTRs • Severe
hypotension • Extreme muscle
weakness • Urine output
less than 25-30 ml/hr • Serum magnesium
level of 10 mEq/L or greater |
Assess woman and
fetus before and after each rate increase and following frequency of agency
protocol Monitor serum magnesium levels; therapeutic level should range
between 4 and 7.5 mEq/L Discontinue
infusion and notify physician if intolerable adverse reactions occur Ensure that
calcium gluconate is available for emergency administration
to reverse magnesium sulfate toxicity Limit IV fluid
intake to 125 ml/hr |
|
Nifedipine* (Procardia; Adalat) Calcium channel blocker;
relaxes smooth muscles including the uterus by blocking calcium entry |
nitial dose: 10-20 mg Maintenance dose: 10 to 20 mg q4-6h PO |
Transient tachycardia, palpitations Hypotension Dizziness, headache. nervousness Peripheral edema Fatigue Nausea Facial flushing |
Do not use with
magnesium sulfate Assess woman and
fetus according to agency protocol being alert for adverse reactions Do not use
sublingual route |
|
Indomethacin* Prostaglandin inhibitor;
relaxes uterine smooth muscle |
Initial dose: 50
mg (orally or rectally) Maintenance dose: 25-50 mg, q4-6h for 24-48 hr (PO) |
Facial flushing Maternal: nausea
and vomiting, dyspepsia, dizziness, oligohyramnios Fetal: premature
closure of ductus arteriosus Neonate: bronchopulmonary dysplasia, respiratory distress syndrome,
intracranial hemorrhage, necrotizing enterocolitis,
hyperbilirubinemia |
Used when other
methods fail; never used after 35 weeks of gestation Do not use for
women with bleeding potential Fetal assessment:
amniotic fluid level; function of ductus arteriosus |
Magnesium
sulfate is the most commonly used tocolytic agent,
although its exact mechanism of action on uterine muscle is unclear. Because it
acts as a central nervous system depressant, it has been used for decades for seizure
control in women with preeclampsia; it began to be used for tocolysis
in the 1970s (lams, 2002). At the onset of preterm labor, magnesium sulfate is
administered via an intravenous infusion. Terbutaline,
0.25 mg, may be injected subcutaneously before the initiation of the magnesium
sulfate infusion and then administered again by subcutaneous pump as the infusion
is discontinued (see Table 1).
Ritodrine and terbutaline, beta-adrenergic agonist medications for tocolysis, work by relaxing smooth muscle. When used, ritodrine is usually administered intravenously as one of
the first steps in suppressing preterm labor. Terbutaline
is most commonly administered by a subcutaneous injection of 0.25 mg to
suppress uterine hyperactivity or by a subcutaneous pump. Effectiveness of pump
therapy in prolonging gestation is controversial (Guinn et al., 1998).
Beta-adrenergic agonists have many maternal and fetal side effects and must
always be used with extreme caution and careful, conscientious nursing care.
Medication administration and nursing care are aimed at maintaining a
therapeutic level of medication and avoiding the most serious side effects
while maintaining optimal health of the fetus (see Table 1).
NURSE ALERT! Caution must be used when administering intravenous fluids
to women in preterm labor because this practice can increase the risk for tocolyticinduced pulmonary edema, especially when a betaadrenergic agonist is used. It is recommended that the
total oral and intravenous fluid intake in 24 hours should be restricted to
2400 to 3000 ml. Strict intake and output measurement, daily weight
determination, and assessment of pulmonary function should be instituted
(American College of Obstetricians and Gynecologists [ACOG], 1995a; Freda &
DeVore, 1996; Hill, 1995).
Indomethacin, a nonsteroidal antiinflammatory
medication, has been shown in some trials to cause a cessation of uterine
contractions by blocking the action of prostaglandins (Besinger
et al, 1991; Lehne, 2001). The severity of fetal side
effects associated with the use of indomethacin for tocolysis makes it less common than other classes of tocolytic drugs. However, Macones
and Robinson (1998) studied the risk of using indomethacin
versus the benefit of delayed birth in 1000 women and found that it was more beneficial
to the fetus for the mother to have received indomethacin
and the fetus to have gained gestational age than was preterm birth at 32 weeks
(see Table 1).
Nifedipine, a calcium
channel blocker, is another tocolytic agent that can
suppress contractions (Lehne, 2001; Read & Wellby, 1986). It works by inhibiting calcium from entering
smooth muscle cells, thus reducing uterine contractions. Despite mild maternal
side effects, this medication might be used less than other tocolytic
agents because of concerns about fetal side effects. When the tocolytic effects and maternal tolerance of nifedipine and ritodrine were
compared, no significant differences in length of delay of birth were found,
but significantly fewer maternal side effects occurred with nifedipine
(Garcia-Velasco & Gonzalez-Gonzalez, 1998) (see Table 1).
Promotion
of fetal lung maturity
Antenatal glucocorticoids.
Antenatal glucocorticoids given
as intramuscular injections to the mother accelerate fetal lung maturity. It is
viewed as a form of care
likely
to be beneficial (Enkin et al., 2001). This class of medications
also seems to decrease rates of intraventricular hemorrhage
in preterm infants (Goldenberg & Rouse, 1998). All women between 24 and 34
weeks of gestation should be given antenatal glucocorticoids
when preterm birth is threatened, unless there is a medical indication for immediate
delivery such as cord prolapse, chorioamnionitis,
or abruptio placentae. The
regimen for administration of antenatal glucocorticoids
is given in the Medication Guide.
|
Medication Guide Antenatal Glucocorticoid
Therapy with Betamethasone, Dexamethasone ACTION Stimulates fetal lung maturation by promoting release of enzymes that
induce production or release of lung surfactant. NOTE: The FDA has not approved
these medications for this use (i.e., this is an unlabeled use for
obstetrics). INDICATION To prevent or reduce the severity of respiratory distress syndrome in
preterm infants between 24 and 34 weeks of gestation DOSAGE AND ROUTE Betamethasone: 12 mg IM x 2 doses 12 hr
apart Dexamethasone: 6 mg IM x 2 doses 12 hr
apart May be repeated in 7 days if birth has not occurred. ADVERSE REACTIONS Possible maternal infection, pulmonary edema (if given with
/3-adrenergic medications), may worsen maternal condition (diabetes,
hypertension) NURSING CONSIDERATIONS Give deep IM in gluteal muscle. Teach signs
of pulmonary edema. Assess blood glucose levels and lung sounds. Do not give
if woman has infection. Use in women with PPROM not universally recommended. |
Management
of inevitable preterm birth
Labor
that has progressed to a cervical dilation of 4 cm is likely to lead to
inevitable preterm birth. Preterm births in tertiary care centers lead to
better neonatal and maternal outcomes. Women considered at risk for inevitable preterm
birth should be transferred quickly to such a facility to ensure the best
possible outcome. The first dose of antenatal glucocorticoids
should be given before transfer because these medications require 24 hours to
take effect.
Although
maternal transport helps ensure a better health outcome for the mother and the
baby, it may have complications. Women may be transported to tertiary care centers
far from home, making visits by the family difficult and increasing the anxiety
levels of the woman and her family.
Evaluation
Evaluation of
the nursing care provided for a woman at risk for preterm birth is based on the
expected outcomes of care (see Plan of Care).
PLAN OF CARE Preterm Labor
NURSING
DIAGNOSIS Deficient knowledge related to recognition of preterm
labor
Expected
Outcome Woman and significant other delineate the signs
and symptoms of preterm labor.
Nursing Interventions/Rationales
Assess
what the partners know about abnormal signs and symptoms during pregnancy to
identify areas of deficit.
Discuss
signs and symptoms that serve as warning signs of preterm labor so that the
woman or her partner has adequate information to identify problems early.
Provide
written supplemental materials that include a list of warning signs and
instructions regarding what to do if any of the listed signs occur so that
the couple can reinforce and review learning and act swiftly and appropriately should
a sign occur.
Discuss
and demonstrate how to assess and time the contractions to provide needed
skills to assess the signs of labor.
NURSING
DIAGNOSIS Risk for maternal/fetal injury related to recurrence
of preterm labor
Expected
outcomes Woman demonstrates ability to assess self and
fetus for signs of recurring labor; maternal-fetal well-being is maintained.
Nursing Interventions/Rationales
Teach
woman/partner how to monitor fetal and uterine contraction activity daily to
provide immediate evidence of a worsening condition.
Have
woman/partner report rupture of membranes, vaginal bleeding, cramping, pelvic
pressure, or low backache to appropriate health care resource immediately because
such symptoms are signs of labor.
If
home uterine activity monitoring is to be used, teach woman/partner how to use
the monitoring device and how to transmit the data to the health care provider
via telephone to enhance correct use of monitoring device and increase the
accuracy of detection of early labor.
Have
woman monitor her weight, diet, fluid intake, and vital signs on a daily basis to
evaluate for potential problems.
Limit
activities to bed rest with bathroom privileges to decrease the likelihood
of onset of labor.
Use
a side-lying position to enhance placental perfusion.
Abstain
from sexual intercourse and nipple stimulation because such activities may
stimulate uterine contractions.
Practice
relaxation techniques to decrease uterine tone and decrease anxiety and
stress.
Take
tocolytic or other medications per physician's orders
to inhibit uterine contractions.
Teach
woman/partner about and have them report any medication side effects
immediately to prevent medicationinduced complications.
Have
family arrange for alternative strategies in carrying out the woman's usual
roles and functions to decrease stress and limit temptations to increase
activity.
If
small children are part of the household, encourage family to make alternative
arrangements for child care to enhance woman's adherence to bed rest
protocol.
NURSING
DIAGNOSIS Anxiety related to preterm labor and potentially
premature neonate
Expected
outcome Feelings and symptoms of fear/anxiety abate.
Nursing Interventions/Rationales
Provide a calm, soothing atmosphere and teach family to provide
emotional support to facilitate coping.
Encourage
verbalization of fears to decrease intensity of emotional response.
Involve woman
and family in the home management of her condition to promote a greater
sense of control.
Help the
woman identify and use appropriate coping strategies and support systems to
reduce fear/anxiety.
Explore the
use of desensitization strategies such as progressive muscle relaxation, visual
imagery, or thought stopping to reduce fear-related emotions and related
physical symptoms.
NURSING
DIAGNOSIS Deficient diversions! Activity related to imposed bed
rest
Expected
outcome Verbalization of diminished feelings of boredom.
Nursing Interventions/Rationales
Assist
woman to creatively explore personally meaningful activities that can be
pursued from the bed to ensure activities that have meaning, purpose, and
value to the individual.
Maintain
emphasis on personal choices of the woman because doing so promotes control
and minimizes imposition of routines by others.
Evaluate
what support and system resources are available in the environment to assist
in providing diversional activities.
Explore
ways for the woman to remain an active participant in home management and
decision making to promote control.
Engage
support of family and friends in carrying out chosen activities and making
necessary environmental alterations to ensure success.
Teach
woman about stress management and relaxation techniques to help manage
tension of confinement.
PRETERM PREMATURE RUPTURE OF MEMBRANES
Premature
rupture of membranes (PROM) is the rupture of the amniotic sac
and leakage of amniotic fluid beginning at least 1 hour before the onset of
labor at any gestational age. Preterm premature rupture of membranes (PPROM)
(i.e., membranes rupture before 37 weeks of gestation) occurs in up to 25%
of all cases of preterm labor. Infection often precedes PPROM, but the etiology
of PPROM remains unknown. PPROM is diagnosed after the woman complains of
either a sudden gush of fluid from the vagina or a slow leak of fluid from the
vagina.
Infection
is the serious side effect of PPROM that makes it a major complication of
pregnancy. Chorioamnionitis is an intraamniotic infection of the chorion
and amnion that is potentially life threatening for the fetus and the woman.
Most cases of intrauterine infection respond well to antibiotics, yet sepsis
can occur and can lead to maternal death. Fetal complications from chorioamnionitis include congenital pneumonia, sepsis, and
meningitis (Mercer & Lewis, 1997). Even in the absence of infection, PPROM
can precipitate cord prolapse or cause oligohydramnios leading to cord compression, potentially lifethreatening complications for the fetus.
CARE MANAGEMENT
When
PPROM is suspected, strict sterile technique should be used in any vaginal
examination to avoid introduction of infection. A Nitrazine
or fern test is used to determine whether the discharge is amniotic fluid (see
Chapter 14, Procedure Box: Tests for Rupture of Membranes, p. 326). A woman
with this diagnosis is often cared for at home, with more frequent visits to
her physician or nurse-midwife. Expectant management will continue as long as
there are no signs of infection or fetal distress. Nursing support of the woman
and her family is critical at this time. She is often anxious about the health
of her baby and may fear that she was responsible in some way for the membrane rupture.
The nurse needs to encourage expression of feelings and concerns, provide
information, and make referrals as needed (Weitz,
2001).
Frequent
biophysical profiles are performed to determine fetal health status and
estimate amniotic fluid volume. The woman with PPROM should also be taught how to
count fetal movements daily because a slowing of fetal movement has been shown
to be a precursor to severe fetal compromise. Several methods are commonly used
to count fetal movements; one method for fetal movement counting is described
in the Self-Care box (Freda et al., 1993). Antenatal glucocorticoids
may be administered if chorioamnionitis is absent
(ACOG, 1998; Weitz, 2001).
Vigilance
for signs of infection is a major part of the nursing care and patient
education following PPROM. The woman needs to be taught how to keep her genital
area clean and that nothing should be introduced into her vagina. Signs of
infection (e.g., fever, foul-smelling vaginal discharge, rapid pulse) should be
reported to the physician or nurse-midwife immediately. Prophylactic antibiotic
therapy may be ordered because it improves perinatal
outcome (ACOG, 1998).
POSTTERM PREGNANCY, LABOR, AND BIRTH
A postterm pregnancy, or prolonged pregnancy,
is one that extends beyond the end of week 42 of gestation, or 294 days from
the first day of the last menstrual period. The incidence of postterm pregnancy is estimated to be between 4% and 14%,
with an average of 10% (Cunningham et al, 2001).
Many
pregnancies are misdiagnosed as prolonged. This can occur because (1) the pregnancy
is inaccurately dated because the woman has an irregular menstrual cycle
pattern, (2) an accurate date of the last menstrual period is unknown, or (3)
entry into prenatal care was delayed or did not occur. Interestingly, a woman
who experiences one postterm pregnancy is 30% to 40%
more likely to experience it again in subsequent pregnancies (Arulkumarian, 1997).
Clinical
manifestations of postterm pregnancy include maternal
weight loss, decreased uterine size, meconium in the
amniotic fluid, and advanced bone maturation of the fetal skeleton with an
exceptionally hard fetal skull (Gilbert & Harmon, 1998).
MATEMAL AND FETAL RISKS
Maternal
risks are often related to the birth of an excessively large infant. The woman
is at increased risk for dysfunctional labor; birth canal trauma, including
lacerations and extension of episiotomy related to vaginal birth; postpartum
hemorrhage; and infection. Interventions such as induction of labor with oxytocin, forcepsor vacuum-assisted
birth, and cesarean birth are more likely to be necessary. The woman also may
experience fatigue and psychologic reactions such as
depression, frustration, and feelings of inadequacy as she passes her estimated
date of birth (Arulkumarian, 1997; Freeman & Lagrew, 1996; Gilbert & Harmon, 1998).
Fetal
risks appear to be twofold. The first is the possibility of prolonged labor,
shoulder dystocia, birth trauma, and asphyxia from macrosomia. Macrosomia occurs
when the placenta continues to provide adequate nutrients to support fetal
growth after 40 weeks of gestation. It is estimated to occur in approximately
25% of prolonged pregnancies (Divon, 2002). The
second risk is the compromising effects on the fetus of an "aging"
placenta. Spellacy (1999) notes that placental function gradually decreases after 37
weeks of gestation. Amniotic fluid volume (AFV)
declines to approximately 800 ml by 40 weeks of gestation and to approximately
400 ml by 42 weeks of gestation. The resulting oligohydramnios
can lead to fetal hypoxia related to cord compression. If placental
insufficiency is present, there is a high likelihood of fetal distress
occurring during labor. Neonatal problems may include asphyxia, meconium aspiration syndrome, dysmaturity
syndrome, hypoglycemia, polycythemia, and respiratory
distress (Gilbert & Harmon, 1998).
CARE MANAGEMENT
The
management of postterm pregnancy is still
controversial. The induction of labor at 41 to 42 weeks is suggested by some
authorities as a means of reducing the rate of cesarean birth and stillbirth or
neonatal death (Hannah et al., 1996). Others follow a more individualized
approach, allowing the pregnancy to proceed to 43 weeks of gestation as long as
assessment of fetal well-being using a combination of tests is performed and
the results of the tests are normal (Searing, 2001).
LEGAL TIP Informed Consent Regarding Care During
Postterm Pregnancy
The woman with a postterm pregnancy should be
informed about the risks and benefits of both treatment and nontreatment.
The standard of practice for postterm pregnancy is to
begin antepartal surveillance (e.g., maternal
assessments and tests of fetal well-being) by 14 days after the EDB, no matter how the date was derived. The woman and her
physician or nursemidwife should mutually agree on a
plan of care (Wood, 1994).
Antepartum assessments
for postterm pregnancy may include daily fetal
movement counts, nonstress tests, amniotic fluid
volume assessments, contraction stress tests, biophysical profiles, and Doppler
flow measurements. The woman and her family should be fully informed regarding
the tests performed and the meaning of the results obtained.
The
amniotic fluid index should be greater than 8 with at least one pocket of
amniotic fluid greater than
Cervical
checks usually are performed weekly after 40 weeks of gestation to determine
whether the condition of the cervix is favorable for induction (9 or greater on
the Bishop score) (see Table 4). Vaginal secretions may be assessed for the
amount of fetal fibronectin; however results of
studies have been inconclusive (Divon, 2002). Amniocentesis
or amnioscopy may be performed to detect meconium in the amniotic fluid (Spellacy,
1999).
During
the postdate period the woman is encouraged to assess fetal activity daily,
assess for signs of labor, and keep appointments with her physician or
nurse-midwife (see Self-Care box). The woman and her family should be
encouraged to express their feelings about the prolonged pregnancy. Referral to
a support group or another supportive resource may be needed (Schmidt, 1999).
|
Patient Instructions for
Self-Care Postterm
Pregnancy Perform
daily fetal movement counts. Assess
for signs of labor. Call
your primary health care provider if your membranes rupture, or if you
perceive a decrease in or no fetal movement. Keep
appointments for fetal assessment tests or cervical checks. Come
to the hospital soon after labor begins. |
If
the woman's cervix is ripe, labor is usually induced with oxytocin.
If her cervix is not ripe, continued fetal surveillance or a cervical ripening
agent (e.g., prostaglandin insert or gel) may be administered followed by oxytocin induction (Gilbert & Harmon, 1998; Schmidt,
1999).
The
fetus of a woman with a postterm pregnancy should be
monitored electronically for a more accurate assessment of the FHR pattern. If oligohydramnios is pre sent, amnioinfusion
may be implemented to restore amniotic fluid volume and thereby maintain a
cushioning of the cord. Inadequate fluid volume leads to compression of the
cord, which results in fetal hypoxia that is reflected in variable or prolonged
deceleration patterns and passage of meconium. Amnioinfusion may also be used to prevent or minimize meconium aspiration syndrome by diluting amniotic fluid
thickened with meconium passed by a hypoxic fetus.
Maternal-fetal risks related to amnioinfusion,
although rare, can result from infection and overdistention
of the uterine cavity with infused fluid (Folsom, 1997; Gilbert & Harmon,
1998; Schmidt, 1997). Accurate assessment of the woman's labor pattern also is
important because dysfunctional labor is common (Spellacy,
1999).
Emotional
support is essential for the woman with a postterm
pregnancy and her family. A vaginal birth is anticipated, but the couple should
be prepared for a forcepsassisted, vacuum-assisted,
or cesarean birth if complications arise.