Fifteen scientists from across NIEHS collaborated on a paper describing how various environmental chemicals can harm a woman’s health both during pregnancy and in the years that follow. The paper, published online in the Journal of Women’s Health, is part of a special issue on maternal health due out in late February. The National Institutes of Health Office of Research on Women’s Health coordinated the special issue.

Such information can underpin broader understanding of maternal illness and death, especially the long-term consequences of certain health conditions during pregnancy. Maternal health refers to pregnancy, childbirth, and the postpartum period.

The special journal issue was a year-long effort within the U.S. Department of Health and Human Services and in the greater scientific community. (Photo courtesy of Monkey Business Images / Shutterstock.com)

“We hope our paper will increase the clinicians’ awareness of the environment’s role in maternal health and point them to reputable sources for information they can share with their patients,” said Abee Boyles, Ph.D., a health scientist administrator at NIEHS.

Health inequality

Pregnant women may be exposed to harmful chemicals through polluted air and water, consumer products, and sometimes food.

Environmental health disparities are differences in disease cases that affect disadvantaged people. For example, Black, American Indian, and Alaska Native women in the U.S. are two to three times more likely to die from pregnancy-related causes than white women, according to a 2019 report from the Centers for Disease Control and Prevention (CDC).

“Health disparities are also considered an environmental justice issue to address,” said Boyles. “Different exposures contribute to the marked disparities in maternal morbidly and mortality that we observe.”

Maternal health findings

Lead author Boyles oversees grants for research on reproductive epidemiology, weather-related health impacts, and cancer epidemiology. (Photo courtesy of Steve McCaw / NIEHS)

The paper specifies chemicals in the environment that affect maternal health and pays special attention to racial and ethnic differences in outcomes.

• Hypertensive disorders of pregnancy(https://ntp.niehs.nih.gov/ntp/ohat/trap/mgraph/trap_final_508.pdf), such as high blood pressure and related liver and kidney damage are chief causes of maternal illness and death. Traffic-related air pollution may be a leading factor in these disorders.
• Traffic-related air pollution is also associated with infertility or increased pregnancy loss. Substances from this source are linked to fertility disorders and pregnancy complications.
• Women’s breast health is especially important during pregnancy. This condition marks the “last period of breast maturation in women but also the first developmental window for her offspring,” wrote the authors. Exposure to pesticides such as DDT are shown to increase breast cancer risk.
• Studies indicate that chemicals that interfere with the endocrine system, such as the phthalates and phenols often present in consumer products, may play a role in the development of uterine fibroids. These noncancerous tumors range in size from microscopic to several inches. African American women tend to develop uterine fibroids earlier in life and experience more severe symptoms than women of other races, according to the authors.
• Metabolic disorders during pregnancy, such as gestational diabetes, can affect a woman’s short- and long-term health. Looking further, the authors noted that chemicals that disrupt endocrine function may affect the body’s regulation of blood sugar levels or thyroid hormones.

“Pregnant women tend to worry about the effects of what they eat and other chemical exposures on their children, but they rarely consider the impacts on their own health from exposures during pregnancy,” noted Boyles.

Next steps

NIEHS scientists continue to research maternal health. But few studies have focused on how exposures during pregnancy affect the short- and long-term health of the mother.

To help fill that gap, NIEHS recently awarded seven research grants under the theme of pregnancy as a vulnerable time period for women’s health.

Citations:
Boyles AL, Beverly BE, Fenton SE, Jackson CL, Jukic AMZ, Sutherland VL, Baird DD, Collman GW, Dixon D, Ferguson KK, Hall JE, Martin EM, Schug TT, White AJ, Chandler KJ. 2020. Environmental factors involved in maternal morbidity and mortality. J Womens Health; doi:10.1089/jwh.2020.8855 [Online 18 Nov 2020].

Kioumourtzoglou MA, Raz R, Wilson A, Fluss R, Nirel R, Broday DM, Yuval, Hacker MR, McElrath TF, Grotto I, Koutrakis P, Weisskopf MG. 2019. Traffic-related air pollution and pregnancy loss. Epidemiology 30(1):4-10.

Mahalingaiah S, Hart JE, Laden F, Farland LV, Hewlett MM, Chavarro J, Aschengrau A, Missmer SA. 2016. Adult air pollution exposure and risk of infertility in the Nurses' Health Study II. Hum Reprod 31(3):638-647.

National Toxicology Program(https://ntp.niehs.nih.gov/ntp/ohat/trap/mgraph/trap_final_508.pdf). 2019. Systematic Review of Traffic-Related Air Pollution and Hypertensive Disorders of Pregnancy. NTP Monograph 7. Research Triangle Park, NC: National Toxicology Program.

Wu HC, Cohn BA, Cirillo PM, Santella RM, Terry MB. DDT exposure during pregnancy and DNA methylation alterations in female offspring in the Child Health and Development Study. 2020. Reprod Toxicol 92:138–147.

(Carol Kelly is managing editor for the NIEHS Office of Communications and Public Liaison.)