STRESSFUL LIFE EVENTS RAISE RISK

We asked over 2000 mothers about 3 stressful life events occurring around conception or in early pregnancy: death, divorce/separation and job loss.

	At least 1 major event was reported by 27% of the mothers whose babies did not have birth defects.
	Stressful life events were 30%-50% more common among mothers whose babies had any of the birth defects studied: oral clefts, heart, neural tube and limb defects.
	The difference was not driven by other known risk factors for birth defects such as obesity, smoking or binge drinking.
	The study did not examine possible lifestyle changes or coping behaviors that may have influenced risk.
	Because this study looked at only 3 stressful life events, results cannot be generalized to stress in other situations—whether from a different major event, chronic stress or the stress of daily life.

HOW MIGHT STRESSFUL LIFE EVENTS BE LINKED TO BIRTH DEFECTS?

At least 2 other population-based studies to date have linked birth defects and major stressful life events. Although the ways stressful life events might influence prenatal development are not yet well understood, they may include:

	Physical effects. Stress is known to cause physiological changes which may alter blood flow to the uterus.
	Behavior changes. Stressful life events may reduce healthy activities such as eating a nutritious diet or taking multivitamins. Stress may also trigger risk-raising behaviors like cigarette smoking or binge drinking.
	Shared underlying cause. Stressful life events may be a marker for other risk factors, rather than being directly linked to birth defects risk. For example, low socioeconomic status—a risk factor for some birth defects—may predispose an individual to life events such as job loss.