A mother’s stress during pregnancy and even prior to conception may result in a higher likelihood of preterm birth, as well as the child being more susceptible to faster aging, according to two recent studies out of the University of California, Los Angeles.

The research detailed how stress levels before and during pregnancy can result in an “intergenerational transmission of stress” that can lead to numerous health complications.

One study, published in Psychoneuroendocrinology, found that an elevated level of prenatal maternal stress correlates with an adverse impact on the baby’s telomeres, which are small pieces of DNA at the ends of chromosomes. Shorter telomeres are linked with an increased risk of being diagnosed with cardiovascular disease, metabolic disorders and certain types of cancer earlier in life.

The researchers found that negative effects on telomere length were the strongest following a high period of stress in the third trimester. The study’s lead author, Judith Carroll, an associate professor of psychiatry and biobehavioral sciences at UCLA, also noted that “stressors are ongoing throughout pregnancy. Nonetheless, the third trimester may be a sensitive period for some aspects of fetal development.”

The other research, which was published this summer in the Annals of Behavioral Medicine, found that mothers who face high stress during the period of time before conception had shorter pregnancies than those who did not report such stressors. The study followed 360 mothers from low-income, racially diverse areas, and collected data regarding environmental stressors such as financial and employment concerns, relationship issues and discrimination, among others.

Carroll noted that much of the preexisting research into maternal stress has been concentrated in higher-income, primarily white areas that are more easily accessible for studies. That research has shown that stress has many adverse effects on pregnancies, and the scope of the studies is now expanding into other populations.

“There is no reason to think this does not affect every woman,” Carroll said.

However, the difference is that resources to support pregnant or pre-pregnant women who are experiencing stressors in lower-income areas tend to be scarce, said Nicole Mahrer, the lead author of the study in the Annals of Behavioral Medicine, who conducted the research as a postdoctoral scholar at UCLA and who is now a professor at the University of La Verne. The resource inequalities between demographics and income levels can be a barrier for expecting mothers to get the help they need during such a sensitive time, especially amid the current pandemic, Mahrer said.

“The health inequalities in this country have been apparent for years and are now coming more to the forefront in light of the current pandemic,” Mahrer said. “For example, our prior work has shown that Black and Latina women may experience more stress related to pregnancy compared to white women. These inequities are likely getting exacerbated with the inordinate burden placed on communities of color related to COVID-19.”

While there are state-funded programs throughout the U.S. that help to promote healthy pregnancies, and an increasing amount of online resources to combat prenatal mental health struggles, Christine Dunkel Schetter, a senior author on both studies, said that there is still work to be done to address the issue.

“Despite all our efforts as a society to promote [healthy] pregnancies, stress, anxiety and depression are very high — especially now — and more needs to be done to address this in women in pregnancy and preconception,” Dunkel Schetter said.

Both studies highlighted that not only is managing stress during pregnancy key to producing healthy offspring, but that a high level of stress even before conception can be harmful to the health of both mother and child.

“Not only do we know definitively that feeling stress, anxiety and depression in pregnancy is detrimental at high levels to mothers and their children from these and other studies, but we know now that preconception health is important for a healthy pregnancy,” Carroll said. “There is a continuity implied here from preconception to pregnancy and then to offspring. This intergenerational transmission of stress has long-term consequences that will last for generations to come.”

The study published in the November issue of Psychoneuroendocrinology, titled “Prenatal maternal stress prospectively relates to shorter child buccal cell telomere length,” was authored by Judith Carroll, University of California, Los Angeles; Nicole Mahrer, UCLA and University of La Verne; Madeleine Shalowitz, NorthShore University HealthSystem; Sharon Ramey, Virginia Tech; and Christine Dunkel Schetter, UCLA. 

The study “Maternal Stress Before Conception Is Associated with Shorter Gestation,” published July 20 in the Annals of Behavioral Medicine, was authored by Nicole Mahrer, UCLA and University of La Verne; Christine Guardino, Dickinson College; Calvin Hobel, Cedars-Sinai; and Christine Dunkel Schetter, UCLA.