Labor and Birth at Risk

Labor and Birth at Risk

Kitty Cashion

Key Terms and Definitions

Web Resources

Additional related content can be found on the companion website at image

W hen complications arise during labor and birth, the risk of perinatal morbidity and mortality increases. Some complications are anticipated, especially if the woman is identified as high risk during the antepartum period; others are unexpected or unforeseen. A crucial responsibility for nurses is 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 competent and compassionate care. This chapter focuses on the problems of preterm labor and birth, dystocia, postterm pregnancy, and obstetric emergencies.

Preterm Labor and Birth image

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 gestation (Iams & Romero, 2007). It occurs in approximately 12.8% of all live births, and the rate has been increasing for the last several years. Preterm birth is the major unsolved problem in perinatal medicine today (Iams, Romero, & Creasy, 2009).

Approximately 75% of all preterm births are termed late preterm births because they occur between 34 and 36 weeks of gestation. Although these babies experience significant complications, the great majority of infant deaths and the most serious morbidity occur among the 16% of all preterm infants who are born before 32 weeks of gestation (Iams et al., 2009). See Chapters 18 and 24 for more discussion of problems related to late preterm birth.

Preterm Birth versus Low Birth Weight

Although they have distinctly different meanings, the terms preterm birth or prematurity and low birth weight were often used interchangeably in the past. Preterm birth describes the length of gestation (i.e., less than 37 weeks regardless of the weight of the infant), whereas low birth weight describes only weight at the time of birth (i.e., ≤2500 g). Because birth weight was far easier to determine than gestational age, in many settings and publications, low birth weight was used as a substitute term for preterm birth. Preterm birth, however, is a more dangerous health condition for an infant than low birth weight because a decreased 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 inadequate fetal growth not necessarily correlated with initiation of labor. On the other hand, infants born at a preterm gestation can weigh more than 2500 g at birth. Today, thanks to advances in pregnancy dating, outcomes related to gestational age can be increasingly distinguished from outcomes related to birth weight (Iams et al., 2009).

The incidence of preterm birth in developed countries has increased mainly as a result of more late preterm births and multifetal gestations. An increased use of assisted reproductive technologies has led to the rise in multifetal gestations (Iams et al., 2009). An increasing willingness on the part of health care providers to end the pregnancy when maternal or obstetric conditions threaten the health of mother or fetus after 32 to 34 weeks of gestation also contributes to the rise in preterm births (Iams & Romero, 2007).

Increasingly, preterm births are being divided into two categories, spontaneous and indicated. Spontaneous preterm births occur after an early initiation of the labor process. Conditions such as preterm labor with intact membranes, preterm premature rupture of membranes (preterm PROM), cervical insufficiency, or amnionitis often result in preterm birth. Approximately 75% of all preterm births in the United States are spontaneous (Iams et al., 2009). Box 22-1 lists risk factors for the development of spontaneous preterm birth.

Indicated preterm births, on the other hand, occur as a means to resolve maternal or fetal risk related to continuing the pregnancy. Approximately 25% of all preterm births in the United States are indicated because of medical or obstetric conditions that affect the mother, the fetus, or both. An increase in the number of indicated preterm births accounts for much of the recent rise in late preterm births (Iams et al., 2009). Box 22-2 lists common causes of indicated preterm births.

The remainder of this section deals with spontaneous preterm labor and birth.

Predicting Spontaneous Preterm Labor and Birth

A history of previous preterm birth, multiple gestation, bleeding after the first trimester of pregnancy, and a low maternal body mass index have been shown to be major risk factors for spontaneous preterm birth (Iams & Romero, 2007). Other risk factors include non-Caucasian race (especially African-American), low socioeconomic and educational status, living with chronic stress, smoking, substance abuse, physically demanding working conditions, and periodontal disease (Iams et al., 2009). A recent study found that perceived levels of stress measured at 28 weeks of gestation in African-American women experiencing preterm labor were higher in those who gave birth prematurely than in those whose pregnancies reached term (Gennaro, Shults, & Garry, 2008). In addition, the risk for preterm birth appears to be genetically related. Relatives of women who were born prematurely or gave birth prematurely also have an increased risk for spontaneous preterm birth (Iams et al., 2009).

Many risk scoring systems have been developed in an attempt to determine which women might go into labor prematurely. None of these systems has been very successful, however, because at least 50% of all women who ultimately give birth prematurely have no identifiable risk factors (Iams & Romero, 2007; Iams et al., 2009). Therefore all women should be educated about prematurity not only in early pregnancy, but also in the preconceptional period.

Biochemical markers

Fetal fibronectin has been studied extensively and is currently marketed in the United States as a diagnostic test for preterm labor. Fetal fibronectin is a glycoprotein found in plasma produced during fetal life. The test is performed by collecting fluid from the woman’s cervix and vagina using a swab during a vaginal examination. Fetal fibronectin is normally present in cervical and vaginal fluid early in pregnancy and then again in late pregnancy.

The presence of fetal fibronectin during the late second and early third trimesters of pregnancy may be related to placental inflammation, which is thought to be one cause of spontaneous preterm labor. The presence of fetal fibronectin is not very sensitive as a predictor of preterm birth, however. Before 35 weeks of gestation a positive fetal fibronectin test predicts preterm birth only approximately 25% of the time. The test’s sensitivity may be better earlier in pregnancy. In one study the fetal fibronectin test predicted 65% of preterm births occurring before 28 weeks of gestation when it was performed between 22 and 24 weeks. The test is often used to predict who will not go into preterm labor because preterm birth is very unlikely to occur in women with a negative result. Use of the fetal fibronectin test in women who are at low risk for preterm birth as a screening tool is not recommended (Iams et al., 2009).

Causes of spontaneous preterm labor and birth

Infection is currently the only factor that has been definitely shown to cause preterm labor. Another proposed cause of preterm labor and birth is bleeding at the site of placental implantation in the uterus in the first or second trimester of pregnancy. The resulting uteroplacental ischemia or hemorrhage at the decidual layer of the placenta may somehow activate the preterm labor process. Intrauterine inflammation is associated with infection, uterine vascular compromise, and decidual hemorrhage, and may contribute to preterm labor. Maternal and fetal stress, uterine overdistention, allergic reaction, and a decrease in progesterone are other factors that may play a part in initiating preterm labor. That preterm labor is caused by multiple pathologic processes that eventually result in uterine contractions, cervical changes, or membrane rupture is becoming increasingly clear (Iams et al., 2009; Romero & Lockwood, 2009).

Two recent research studies suggest that recurrent preterm birth can be prevented in some women by administering prophylactic progesterone supplementation. In one study, women were given vaginal suppositories daily. In the other, women received weekly intramuscular injections of 17-alpha hydroxyprogesterone caproate. In both studies the risk of recurrent preterm birth was reduced by approximately one third. Exactly how progesterone works to prevent recurrent preterm birth is unclear; thus more study is necessary. Another important point to note is that prophylactic supplemental progesterone administration is recommended only for women who have previously given birth prematurely (Meis & Society for Maternal-Fetal Medicine, 2005; Romero & Lockwood, 2009).image

Care Management image

Because all pregnant women must be considered at risk for preterm labor, assessment regarding knowledge of this condition begins early in pregnancy and continues throughout the prenatal period. Nursing diagnoses, interventions, and expected outcomes of care will be established for each woman based on her assessment findings (see the Nursing Process box: Preterm Labor and the Nursing Care Plan box: Preterm Labor).

Nursing Process

Preterm Labor

Plan of Care and Interventions

• Teach the symptoms of preterm labor (see Box 22-3).

• Teach appropriate responses if symptoms of preterm labor occur (see Teaching for Self-Management: What to Do if Symptoms of Preterm Labor Occur).

• Administer medications (e.g., corticosteroids and tocolytics) as ordered (see Medication Guides).

• Assist the woman and her family in making lifestyle modifications, if necessary, to decrease the risk of preterm birth.

• Assist in making plans to transport the pregnant woman-fetus to a hospital that is capable of providing care for the infant if preterm birth appears likely.

• Prepare to assist with stabilization and initial care of a preterm infant if birth appears imminent.

Oct 8, 2016 | Posted by in NURSING | Comments Off on Labor and Birth at Risk

Full access? Get Clinical Tree

Get Clinical Tree app for offline access