Anxiety during pregnancy can lead to earlier births, study finds

The study, which examined the relationship between pregnancy length and different measures of anxiety, could help doctors understand when and how best to screen for anxiety during pregnancy to help prevent preterm birth.

"Anxiety about a current pregnancy is a potent psychosocial state that may affect birth outcomes," said lead study author Christine Dunkel Schetter, PhD, of the University of California Los Angeles. "These days, depressive symptoms are assessed in many clinic settings around the world to prevent complications of postpartum depression for mothers and children. This and other studies suggest that we should also be assessing anxiety in pregnant women."

The study was published in the journal Health Psychology.

Previous research has found that up to one in four pregnant women has clinically elevated anxiety symptoms and that anxiety can be a risk factor for preterm birth, or birth before 37 weeks of pregnancy. However, those studies have used a variety of measures of anxiety and have looked at both general anxiety and pregnancy-specific anxiety, which includes worries about childbirth, parenting and the baby's health. Researchers have also measured anxiety at different points in pregnancy, from early to late pregnancy and most often in the second trimester.

To sort out these various effects of timing and anxiety type, the researchers examined data from a diverse sample of 196 pregnant women in Denver and Los Angeles who took part in the Healthy Babies Before Birth study. Forty-five percent of the women identified as non-Hispanic white, 36% as Hispanic white, 10% as Asian and 9% as Black or African American.

The researchers administered four different anxiety scales to the women, in both the first and the third trimesters of their pregnancies. One was a five-question screener for general anxiety and three were specific to pregnancy: a 10-question and a four-question scale of pregnancy-related anxiety, and a nine-question assessment of a broader range of pregnancy-related stressors, such as medical care and worries about taking care of a newborn.

The researchers found that participants' scores on all three scales of pregnancy-related anxiety were interrelated, suggesting that the scales measure the same underlying thing.

They also found that pregnancy-related anxiety in the third trimester was most strongly associated with earlier births. However, general anxiety in the first trimester also contributed to risk for early birth. One possibility, according to the researchers, is that general anxiety early in pregnancy could predispose women to be anxious later in pregnancy about such issues as medical risks, the baby, labor and delivery, and parenting. The results held even when adjusted for the actual medical risk of the women's pregnancies.

"Although not all women who begin pregnancy with general anxiety symptoms will later experience pregnancy-specific anxiety, our results suggest that women who do follow this progression are likely to be especially at risk for earlier delivery," Dunkel Schetter said.

The results suggest that doctors should screen women for general anxiety early in pregnancy, she added, just as they commonly screen for depression, and that women who score high could be monitored for increases in anxiety and possible intervention later in pregnancy.

Further research should continue to explore reasons that pregnancy anxiety is linked to birth timing, including stress-related neuroendocrine changes, inflammation and health behaviors, according to Dunkel Schetter.

"Increasing precision in our understanding of both the risks and mechanisms of the effects of pregnancy anxiety on gestational length can improve our ability to develop, test and implement interventions to address the pressing public health issue of preterm birth," she said.