The average duration of pregnancy in the United States is shorter than in European countries

Maternal health outcomes continue to deteriorate in the United States, where maternal and infant mortality rates far exceed rates in European and other wealthy nations. Today, a new study by researchers from Boston University School of Public Health (BUSPH) and Beth Israel Deaconess Medical Center (BIDMC), affiliated with Harvard Medical School, provides insight into how organizational structures Hospitals and maternity care personnel in the United States can affect childbirth. process and possibly contribute to adverse birth outcomes.

Published in the journal PLOS ONEthe study analyzed gestational age patterns and timing of home and hospital births in three high-income countries: the United States, which adopts a model of maternity care that relies heavily on obstetricians and clinical interventions, and England and the Netherlands, which rely primarily on midwives. who provide low intervention maternity care.

The results show that the average duration of pregnancies in the United States has steadily decreased by more than half a week between 1990 and 2020, from 39.1 weeks to 38.5 weeks, and that pregnancies in the United States are on average shorter than pregnancies in England and the Netherlands. In 2020, only 23% of births in the United States took place at 40 weeks or more, compared to 44% of births in the Netherlands and 40% of births in England. The gestational age pattern for home births was the same in all three countries.

In all three countries, the researchers also looked at the timing of delivery by time of day for home and vaginal deliveries in hospitals, and then repeated this analysis, limiting the comparison with vaginal deliveries. in a hospital setting without interventions such as induction or augmentation of labor that could possibly alter the timing.

In England and the Netherlands, home and hospital births took place at similar times of the day, peaking in the early morning hours between 1 a.m. and 6 a.m.

But in the United States, there was a notable difference in the timing of births between the two settings: home births peaked in the same early morning hours as home births in other countries. By contrast, hospital deliveries — even those without intervention that might affect the natural pattern at the time — largely occurred during clinical staff’s normal working hours of 8 a.m. to 5 p.m.

The paper is the first international study using large datasets to compare gestational age and time of birth in three high-income countries; most previous research has focused on data from individual hospitals or countries. Given the superior childbirth outcomes of England and the Netherlands, the authors say their findings suggest that American models of maternity care could benefit from organizational change that places less emphasis on active management. and clinical labor and allows the birthing process to follow a natural course.

“Our multi-country analysis shows that the United States is an outlier in the distribution of gestational age and timing of low-intervention hospital births,” says Dr. Eugene Declercq, study leader and corresponding author, professor of community health sciences at BUSPH. “There is a lesson to be learned from countries with more positive maternity outcomes than the United States in that hospital staffing and operational plans conform more closely to natural patterns of birth timing and pregnancy. gestational age rather than trying to tailor the timing of birth to organizational needs.”

The study included nationally representative, publicly available birth data from all three countries, including data on more than 3.8 million births in the United States and 156,000 births in the Netherlands in 2014, and over 56,000 births in England from 2008 to 2010. The researchers looked at the timing of home and hospital births for births that occurred between 37 and 42 weeks.

“Each system is perfectly designed to achieve the results it achieves,” says Dr. Neel Shah, lead study author, Maven Clinic Chief Medical Officer and Visiting Scientist at BIDMC. “The alarming results of the U.S. maternal health care system demand greater attention to its design. Our study shows that compared to other high-income countries, U.S. hospitals can be designed to center clinician convenience more than needs of people giving birth.