Stress and pregnancy

Pregnancy is a time of many changes for a woman: in her body, in her emotions and in the life of her family. As welcome as these changes may be, they often add new stresses to the lives of busy pregnant women who already face many demands at home and at work.

Too much stress can be uncomfortable for anyone. In the short term, a high level of stress can cause fatigue, sleeplessness, anxiety, poor appetite or overeating, headaches and backaches. When a high level of stress continues for a long period, it may contribute to potentially serious health problems, such as lowered resistance to infections, high blood pressure and heart disease. High levels of stress also may pose some special risks for pregnant women.

Most women cope well with the emotional and physical changes of pregnancy and other stresses in their lives. A pregnant woman who feels she is coping well with stress (taking good care of herself, feeling energized rather than drained, and functioning well at home and work) probably does not face health risks from stress.

Pregnant women who are concerned about the level of stress in their lives should discuss their feelings with their partner, family or friends. These individuals can often provide support, which can help reduce stress. A pregnant woman who is having trouble coping with stress also can ask her health care provider to refer her to resources in her community that can help her take steps to reduce and cope with stress.

What types of stress may affect pregnancy outcome?
Routine stresses, such as work deadlines and traffic delays, probably don’t contribute much to pregnancy complications. Stress is not all bad. When managed properly, a little stress can provide us with the drive to meet new challenges.

But certain types of severe or long-lasting stress may pose a risk in pregnancy. Some studies suggest that women who experience negative life events, such as divorce, death in the family, serious illness or loss of a job, may be at increased risk of having a premature (born before 37 completed weeks of pregnancy) and/or low birthweight (less than 5½ pounds) baby (1, 2). However, most women who experience negative life events do not have adverse pregnancy outcomes. A recent study found that maternal chacteristics including depression, panic disorder, drug use, domestic violence and having two or more medical conditions were associated with high levels of stress during pregnancy (3).

Women who experience a catastrophic event during pregnancy also may be at increased risk of having a premature and/or low-birthweight baby. One study found that pregnant women who worked within 2 miles of the World Trade Center in New York on September 11, 2001, had significantly shorter gestations and significantly smaller babies than women who worked farther from the site (1, 4). Another study found that pregnant women who experienced a major earthquake had shorter gestations than women who did not experience the event (5). The timing of the event may influence pregnancy outcome. Studies suggest that women who experienced the World Trade Center attack or an earthquake in the first trimester of pregnancy tended to deliver earlier than women who experienced these catastrophic events later in pregnancy (1, 4, 5).

Chronic stress may play a role in adverse pregnancy outcomes. A recent study found that low-income women with chronic stress (resulting from difficulty obtaining food, caring for a child with a chronic illness or being unemployed) were at increased risk of having a low-birthweight baby (6).

Racism is another form of chronic stress that may contribute to pregnancy problems. African-American women may experience stress from racism throughout their lifetime. This may help explain why African-American women are more likely to deliver premature and low-birthweight babies than women from other racial/ethnic groups (1).

Some women may experience serious chronic stress over the pregnancy itself, possibly increasing their risk of adverse pregnancy outcomes (1, 2). These women may be especially worried about the health of their baby or about how they will cope with labor and delivery. They should discuss their concerns with their health care provider, who can refer them to a mental health professional, if needed.

Most women who experience severe stress in pregnancy have healthy, full-term babies. Some women may be more vulnerable than others to the effects of stress in pregnancy due to physical or other risk factors (2).

What are the risks of high stress levels in pregnancy?
A number of studies suggest that high levels of stress in pregnancy may contribute to premature birth and low birthweight (1, 2). Babies born too small and too soon are at increased risk for health problems during the newborn period, lasting disabilities (such as mental retardation and cerebral palsy) and even death.

How may stress contribute to adverse pregnancy outcomes?
Researchers do not completely understand how stress may contribute to adverse pregnancy outcomes. However, certain stress-related hormones may play a role. For example, stress may contribute to preterm labor by triggering the release of a hormone called corticotropin-releasing hormone (CRH). CRH, which is produced by the brain and the placenta, is closely tied to labor. It prompts the body to release chemicals called prostaglandins, which help trigger uterine contractions.

Severe or prolonged stress may interfere with the functioning of the immune system. This could cause a pregnant woman to be more susceptible to infections involving the uterus. Uterine infections are an important cause of premature birth, especially those occurring at less than 28 weeks of pregnancy (1).

Stress may affect a woman’s behavior. Some women react to stress by smoking cigarettes, drinking alcohol or taking illicit drugs, all of which have been linked to premature birth, low birthweight and other pregnancy complications (1). Use of alcohol and certain illicit drugs increases the risk of birth defects.

Does a high level of stress in pregnancy have long-term effects on the baby (besides any caused by prematurity and low birthweight)?
Some studies suggest that high levels of stress in pregnancy may affect a child’s mental and emotional development (7, 8). Maternal stress may contribute to learning problems, such as difficulty paying attention, and to increased anxiety and fearfulness (7, 8). It is not known how maternal stress may cause these problems. However, some studies suggest that stress-related hormones in the mother’s blood may cross the placenta and affect the fetus’s developing brain (8).

How can a pregnant woman reduce stress?
Each pregnant woman needs to identify the personal and work-related sources of stress in her life and develop effective ways to deal with them. If she feels overwhelmed by stress, she should consult her health care provider.

Pregnancy-related discomforts (such as nausea, fatigue, frequent urination, swelling and backache) can be stressful, especially if a pregnant woman tries to do all the activities she did before pregnancy. She can help reduce her stress by recognizing that these symptoms are temporary and by asking her health care provider how to cope with them. A woman also can consider cutting back on unnecessary activities when she is uncomfortable.

Many pregnant women experience mood swings during pregnancy. These are caused by hormonal changes and are normal. However, mood swings may make it difficult for a pregnant woman to cope with stress.

A pregnant woman can cope better with the stresses in her life if she is healthy and fit. She should eat healthy foods; get plenty of sleep; avoid alcohol, cigarettes and drugs; and exercise regularly (with her health care provider’s OK). Exercise helps keep pregnant women fit, helps prevent some common discomforts of pregnancy (such as backache, fatigue and constipation) and relieves stress.

Having a good support network, including the pregnant woman’s partner, extended family and friends can help a pregnant woman relieve stress. A pregnant woman should ask for and accept help from people who are close to her. For example, they can help her with routine chores and childcare, talk with her about her feelings and concerns, or go with her to prenatal visits. Some studies suggest that having a good support network reduces a woman’s risk of having a low-birthweight baby (1).

A number of stress-reduction techniques can be helpful for pregnant women. These include yoga classes for pregnant women, biofeedback, meditation and guided mental imagery. A health care provider may be able to refer a pregnant woman to local classes or experts. Childbirth education classes teach relaxation techniques and help reduce anxiety by educating parents-to-be about what to expect during labor and delivery.

Does post-traumatic stress disorder affect pregnancy?
Some individuals who experience or witness a traumatic event, such as rape, combat, a natural disaster, terrorist attacks (such as the September 11 attack on the World Trade Center) or death of a loved one, develop post-traumatic stress disorder (PTSD). Affected individuals may experience severe anxiety, flashbacks of the event, nightmares, intense physical reactions to reminders of the event (such as palpitations and sweating) and other problems, such as startling easily.

Post-traumatic stress disorder is common during pregnancy. One study found that almost 8 percent of pregnant women are affected (9). Women with PTSD may be at increased risk for a number of pregnancy complications, including miscarriage, hyperemesis gravidarum (a severe form of pregnancy-related vomiting) and preterm labor (9). Affected women also are more likely to have risky health behaviors, such as smoking, drinking alcohol or drug use, that can contribute to pregnancy complications (10). Women who suspect that they have PTSD should discuss their symptoms with their health care provider or a mental health professional. There are a number of effective treatments, including talk therapies, that can ease symptoms.

References

1. Institute of Medicine Committee on Understanding Premature Birth and Assuring Healthy Outcomes, Board on Health Sciences Policy, Behrman, R.E., and Butler, A.S. (eds.). Preterm Birth: Causes, Consequences, and Prevention. Washington, DC, The National Academies Press, 2006.
2. American College of Obstetricians and Gynecologists (ACOG). Psychosocial Risk Factors: Perinatal Screening and Intervention. ACOG Committee Opinion, number 343, August 2006.
3. Woods, S.M., Melville, J.L., Guo, Y., Fan, M.-Y. & Gavin, A. Psychosocial Stress During Pregnancy. American Journal of Obstetrics and Gynecology, volume 202, number 1, pages 61.e1-61.e7, January 2010.
4. Lederman, S.A., et al. The Effects of the World Trade Center Event on Birth Outcomes among Term Deliveries at Three Lower Manhattan Hospitals. Environmental Health Perspectives, volume 112, number 17, December 2004, pages 1772-1778.
5. Glynn, L.M., et al. When Stress Happens Matters: Effects of Earthquake Timing on Stress Responsivity in Pregnancy. American Journal of Obstetrics and Gynecology, volume 184, number 4, March 2001, pages 637-642.
6. Borders, A.E.B., et al. Chronic Stress and Low Birthweight Neonates in a Low-Income Population of Women. Obstetrics and Gynecology, volume 109, number 2, part 1, February 2007, pages 331-338.
7. Bergman, K., et al. Maternal Stress During Pregnancy Predicts Cognitive Ability and Fearfulness in Infancy. Journal of the American Academy of Child and Adolescent Psychiatry, volume 46, number 11, November 2007, pages 1454-1463.
8. Talge, N.M., et al. Antenatal Maternal Stress and Long-Term Effects on Child Neurodevelopment: How and Why? Journal of Child Psychol Psychiatry, volume 48, number 3-4, March-April 2007, pages 245-261.
9. Cook, C.A.L., et al. Posttraumatic Stress Disorder in Pregnancy: Prevalence, Risk Factors, and Treatment. Obstetrics and Gynecology, volume 103, 2004, pages 710-717.
10. Morland, L., et al. Posttraumatic Stress Disorder and Pregnancy Health: Preliminary Update and Implications. Psychosomatics, volume 48, number 4, July-August 2007, pages 304-308.