Although risks for complications rise linearly with each year (Yaniv et al., 2011), it is important to realize that the majority of women over age 35 give birth to healthy infants. Differences in context and behavior may compensate for some of the risks of advanced maternal age. For example, longer use of oral contraceptives is associated with a lower risk of giving birth to a child with Down syndrome (Nagy, Győrffy, Nagy, & Rigó, 2013).
Figure 3.7 Birth Rates, by Selected Age of Mother, United States, 1990–2016
Source: Hamilton et al., 2017.
Figure 3.8 Maternal Age and Risk of Down Syndrome
Although the risk for Down syndrome increases dramatically with maternal age, most infants are born healthy, regardless of maternal age.
Source: Reprinted with permission from Down Syndrome: Prenatal Risk Assessment and Diagnosis, August 15, 2000, Vol 62, No 4, American Family Physician. Copyright © 2000 American Academy of Family Physicians. All Rights Reserved.
Thinking in Context 3.2
1 Referring to Bronfenbrenner’s bioecological model (see Chapter 1), identify factors at each bioecological level that may influence development in the womb.
2 Imagine that you are a health care provider conferring with a woman who is contemplating becoming pregnant. Give some examples of specific advice you would offer to help her promote a healthy pregnancy and baby.
Childbirth
At about 40 weeks of pregnancy, or 38 weeks after conception, childbirth, also known as labor, begins.
Labor
Labor progresses in three stages. The first stage of labor, dilation, is the longest. It typically lasts 8 to 14 hours for a woman having her first child; for later-born children, the average is 3 to 8 hours. Labor begins when the mother experiences regular uterine contractions spaced at 10- to 15-minute intervals. Initial contractions may feel like a backache or menstrual cramps or may be extremely sharp. The amniotic sac (“water”) may rupture at any time during this stage. The contractions, which gradually become stronger and closer together, cause the cervix to dilate so that the fetus’s head can pass through, as shown in Figure 3.9.
The second stage of labor, delivery, begins when the cervix is fully dilated to 10 cm and the fetus’s head is positioned at the opening of the cervix—known as “crowning.” It ends when the baby emerges completely from the mother’s body. It is during this stage that the mother typically feels an urge to push or bear down with each contraction to assist the birth process. Delivery can take from 30 minutes to an hour and a half.
In the third stage of labor, the placenta separates from the uterine wall and is expelled by uterine contractions. This typically happens about 5 to 15 minutes after the baby has emerged, and the process can take up to a half hour.
Medication During Delivery
Medication is administered in over 80% of births in the United States (Declercq, Sakala, Corry, Applebaum, & Herrlich, 2014). Several drugs are used during labor, with varying effects. Analgesics, such as tranquilizers, may be used in small doses to relieve pain and to help the mother relax. These drugs pass through the placenta to the fetus and are associated with decreases in heart rate and respiration (Hacker, Gambone, & Hobel, 2016). Newborns exposed to some medications show signs of sedation and difficulty regulating their temperature (Gabbe et al., 2016). Anesthesia is a painkiller that blocks sensations. General anesthesia (getting “knocked out”) blocks consciousness entirely; it is no longer used because it is transmitted to the fetus and can slow labor and harm the fetus. Today, the most common anesthetic is an epidural, in which a regional anesthetic drug is administered to a small space between the vertebrae of the lower spine. The woman’s lower body is numbed. There are several types of epidurals, with varying numbing effects ranging from immobilizing the lower body to numbing only the pelvic region, enabling the mother to move about (a so-called walking epidural). Epidurals, however, are associated with a longer delivery as they weaken uterine contractions and may increase the risk of a cesarean section, as discussed next (Gabbe et al., 2016; Herrera-Gómez et al., 2017).
Figure 3.9 Stages of Labor
Source: Adapted from Gerard J. Tortora and Bryan H. Derrickson, 2009.
Childbirth, also known as labor and delivery, progresses in three stages.
Pacific Press/Sipa USA/Newscom
Cesarean Delivery
Sometimes a vaginal birth is not possible because of concerns for the health or safety of the mother or fetus. For example, normally the baby’s head is the first part of the body to exit the vagina. A baby facing feet-first is said to be in a breech position, which poses risks to the health of the baby. Sometimes the obstetrician can turn the baby so that it is head-first. In other cases, a cesarean section, or C-section, is common. A cesarean section is a surgical procedure that removes the fetus from the uterus through the abdomen. About 32% of U.S. births were by cesarean section in 2016 (Martin, Hamilton, Osterman, Driscoll, & Drake, 2018). Cesarean sections are performed when labor progresses too slowly, the fetus is in breech position or transverse position (crosswise in the uterus), the head is too large to pass through the pelvis, or the fetus or mother is in danger (Jha, Baliga, Kumar, Rangnekar, & Baliga, 2015; Visscher & Narendran, 2014). Babies delivered by cesarean are exposed to more maternal medication and secrete lower levels of the stress hormones that occur with vaginal birth that are needed to facilitate respiration, enhance circulation of blood to the brain, and help the infant adapt to the world outside of the womb. Interactions between mothers and infants, however, are similar for infants delivered vaginally and by cesarean section (Durik, Hyde, & Clark, 2000).
Cultural Influences on Development
Cultural Differences in Childbirth