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Stress in Pregnancy
Claire Mazzia, BSc & Kelsey McLaughlin, PhD

A certain level of stress is a normal part of daily life for all pregnant women. However, the Canadian Maternity Experiences Survey reported that 12.5% of women found most days in the year before childbirth very stressful.

 

Can a pregnant woman’s stress levels impact the health of the mother and her baby?

What are hormones and how are they related to stress?

 

Our bodies respond to our surroundings through hormones. Hormones are chemical messengers produced by endocrine glands to regulate how our bodies function and behave. Some hormones affect growth and development of the body, others have an impact on sexual function, mood and metabolism.

 

Endocrine glands are located throughout the body, including:

  • Brain: hypothalamus, pineal and pituitary glands

  • Neck: thyroid and parathyroid glands

  • Abdomen: pancreas and adrenal glands

  • The ovaries and testes contain hormone-secreting tissues

 

In situations of physical or psychological stress, the hormones in our body produce a ‘fight or flight response’. This is a reaction to put our body in a heightened state so we can be ready to respond to a threat. When we are in 'fight or flight mode', we can feel our breathing frequency and heart rate increase.

Importantly, stress hormones can cross from the mother’s circulation through the placenta into the baby’s circulation.

What are the major stress hormones?

Cortisol: increases the energy available in the form of fatty acids and sugar.

 

Epinephrine: increases blood flow to the muscles, increases heart rate and blood pressure, and stimulates the release of sugar into the blood for our muscles to use.

 

Norepinephrine: increases heart rate and the force of muscle contraction throughout the body, as well as increases blood glucose.

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Stress & pregnancy

Pregnant women are commonly recommended to reduce their stress levels during pregnancy. There are different kinds of stress that we can feel, including short- vs long-term stress, as well as physical vs psychological stress. Women can also experience stress that existed before she became pregnant, or pregnancy-specific stress. Every person defines stress differently, or has different thresholds of what they consider to be a stressor in their lives.

 

The impacts of short-term stress, or acute stress, on the health of moms and babies is especially difficult to study, and there is little data from human investigations available on this topic.

Here is an example of a study examining the short-term impacts of stress in pregnancy:

 

  • Fetal heart rate increases when pregnant women complete a stressful task and experience anxiety, supporting the close physiologic link between pregnant women and the developing baby

Impacts of long-term stress on pregnancy outcomes & fetal health

The impacts of long-term stress, or chronic stress, on pregnancy outcomes have been investigated more thoroughly. Many human and animal studies have determined that persistent or long-term stress in pregnant women can impact the health and development of the baby.

 

Stress throughout the pregnancy can have effects on pregnancy outcomes, as well as long-term effects on fetal health and development.

 

Here are some examples of studies examining the impacts of stress on pregnancy outcomes:

 

  • Stress during pregnancy is a risk factor for preterm birth, low birth weight and earlier gestational age at delivery

  • Chronic psychosocial stress during pregnancy, including food insecurity, a child with a chronic illness, household crowding and unemployment, doubles the risk of delivering a low birth weight baby

  • Perceived racism is a significant psychosocial stress that is linked with birthweight in African-American women

Here are some examples of studies examining the impacts of long-term stress on babies’ health:

  • Maternal stress experienced early in pregnancy is linked with rate of development  over the baby’s first year of life

  • Specific changes in brain morphology and an increased risk of schizophrenia have been described in children whose mothers reported significant stress during pregnancy

 

There is a significant amount of research in animal models to determine the link between maternal stress, pregnancy outcomes and fetal health. Scientists hypothesize that maternal stress causes disruptions in the maternal immune, endocrine and nervous system.

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Work Stress

Many pregnant women question if they should modify their work schedules and/or work load to reduce stress during pregnancy. 

 

A recent investigation determined that pregnant women who worked rotating shifts, night shifts and longer hours (more than 55 hours / week) were at increased risk of preterm delivery, lower birth weight, preeclampsia, gestational hypertension and miscarriage.

Further research is needed in this area to provide guidance to pregnant women.

Managing Stress in Pregnancy

The American Institute of Stress recommends a number of strategies to manage and reduce stress levels during pregnancy, including:

 

  • Identifying sources of stress in your life, and discuss with a partner, friend or health care provider

  • Ask your healthcare provider for recommendations regarding how to manage pregnancy-specific discomforts

  • Focus on staying as healthy as possible through maintaining a healthy diet, sleep habits and appropriate exercise

  • Develop a good support network, within your existing social circles or in your community

  • Ask for help from people you trust and don't be afraid to accept help

  • Try out some new activities that can help to reduce stress levels, such as prenatal yoga, massage and meditation

  • Educational childbirth and parenting classes in the community or online can be useful to reduce stress

  • Discuss options to reduce work-related stress with your employer

Summary

High levels of stress throughout pregnancy have been shown to impact pregnancy outcomes and babies' development. Pregnant women should monitor stress levels, and discuss strategies with healthcare providers to reduce stress levels.

Disclaimer

Every woman and every pregnancy is unique. Pregnant women should speak to their healthcare provider to ensure maternal and fetal safety. This article is meant to provide readers with current information and opinions. All medical and treatment decisions should be discussed with your healthcare provider.

This article was written by Claire Mazzia and Dr. Kelsey McLaughlin and edited by Dr. Kelsey McLaughlin and Dr. Melanie Audette.