NYC Gazette

Oxytocin, a hormone recognized for its roles in childbirth and maternal bonding, may also influence pregnancy by delaying embryo development under stress, according to a new study on rodents. Researchers at NYU Langone Health found that the hormone can pause an embryo's growth after conception during times of maternal stress.

The study focused on diapause, a process where an embryo halts its development before attaching to the uterus lining. This phenomenon is observed in various species such as armadillos and seals and is believed to help mothers conserve resources by delaying birth until conditions are favorable.

The research indicated that lactation-induced stress could trigger diapause. In mice, pregnancy duration extended by about a week when nursing occurred simultaneously with gestation. The delay was linked to increased oxytocin levels during lactation. Laboratory tests showed that small doses of oxytocin delayed embryo implantation by up to three days.

“Our findings shed light on the role of oxytocin in diapause,” said Moses V. Chao, PhD, from NYU Grossman School of Medicine. “Because of this newfound connection, it is possible that abnormalities in the production of this hormone could play roles in infertility, premature or delayed birth, and miscarriage.”

Published online March 5 in Science Advances' special issue on women’s health, the report also explored how embryos react to oxytocin surges through receptors on trophectoderm cells surrounding them.

Dr. Robert Froemke emphasized understanding factors contributing to fertility issues: “Having a deeper understanding of the factors that contribute to these problems may allow experts to better address them in the future.” Future research will examine how cell growth resumes post-diapause and its effects on offspring health.

While promising results were noted in mice studies, Dr. Froemke cautioned about differences between human and rodent reproductive processes. The study did not evaluate other hormones like estrogen or progesterone concerning diapause.

Funding came from National Institutes of Health grants T32MH019524, NS107616, and HD088411. Besides Drs. Chao and Froemke, contributors included Luisa Schuster; Habon Issa; Janaye Stephens; Michael Cammer; Latika Khatri; Maria Alvarado-Torres; Jie Tong; Orlando Aristizábal; Youssef Z. Wadghiri; Sang Yong Kim; Catherine Pei-ju Lu; Silvana Valtcheva; Jessica Minder led as former NYU Langone graduate student now at University of California Berkeley.

NYU Langone Health stands out for quality patient outcomes with low mortality rates nationwide—ranked No.1 academic medical center thrice consecutively by Vizient Inc., while U.S News & World Report ranks nine specialties among top five nationally—with comprehensive services across multiple locations generating $14 billion revenue annually including tuition-free medical schools plus extensive NIH-backed research enterprise exceeding $1 billion active awards yearly.