The headline warned that a mother’s stress during pregnancy is passed on to the baby. My friend was under a lot of pressure at work, and she began to worry. Was she permanently harming her baby by not going on early maternity leave? I encouraged her to take a deep breath. The study she had seen was done on rats, not humans.
(Yes, I looked it up — what are friends for?)
The rats’ stress during pregnancy consisted of two things: daily restraint stress — a euphemism for putting an animal in a container no bigger than its body, with minimal holes for ventilation — and forced swimming, or making a rat tread water until it starts to drown. As much pressure as my friend felt at work, it was nothing like this.
When you look at human studies, it becomes clear that stress during pregnancy is not always harmful.
A 2011 review of over a hundred studies found that only severe stress, such as surviving a terrorist attack or being homeless during pregnancy, increased the risk of preterm birth and low birth weight. Higher levels of daily stress and hassles did not.
Some degree of stress during pregnancy may even benefit the baby.
For example, researchers at Johns Hopkins University found that women who reported greater stress during pregnancy had babies born with superior brain development and higher heart rate variability, a biological measure of resilience to stress. The exposure to a mom’s stress hormones in the womb teaches a baby’s developing nervous system how to handle stress.
So my friend needn’t have panicked. Yes, she might have been passing her stress on to her baby — but that stress might have been making her baby resilient.
— The Upside of Stress (Kelly McGonigal), Loc. 853–65