August 30, 2022
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A retrospective cohort study found that pregnant women living in rural United States were more likely to give birth before 39 weeks’ gestation than those living in rural counties.
The data published in American Journal of Obstetrics and Gynecologyalso showed that women in rural counties were less likely to give birth between 39 and 41 weeks of gestation.
“National safety and quality efforts are aimed at optimizing delivery timing in 39 weeks.” Oshinakachukuu mbataMD, An OB/GYN resident and colleague at the Oregon Health and Science University School of Medicine in Portland, Oregon, wrote: “Evidence to suggest that the 39-week rule reduces neonatal morbidity and mortality in deliveries after 39 weeks compared with deliveries earlier (defined as 37 weeks 0 days to 38 weeks 6 days). Surveys show widespread adherence to the initiative across the country, but it is unclear whether there are differences in adherence to the 39-week rule among rural women.”
Mbata and colleagues used limited use and linked vital statistics and National Center for Health Statistics infant mortality data and data on maternal counties of residence and delivery hospital counties to identify low-risk singleton pregnancies. created a cohort of .
Overall, researchers identified 3,010,183 women who met the inclusion criteria. Of these, 338,093 (11.2%) lived in rural counties.
Women living in rural areas were more likely to die at 36 weeks (3.2% vs. 2.9%), 37 weeks (7.9% vs. 7.6%) and 38 weeks (16.2% vs. 16.1%; all, P. < .001). The relative risk ratio for delivery at 36 weeks versus her 39 weeks was 1.03 for her in the rural county (95% CI, 1–1.05).
Conversely, the proportion of women living in rural counties who gave birth between 39 and 41 weeks of gestation was lower than their counterparts (72.7% vs 73.4%; P. < .001). The relative risk ratio for delivery at 40 weeks versus her 39 weeks was 0.83 for women living in rural counties (95% CI, 0.82–0.84).
“It is unclear whether these differences are a result of medical necessity, differences in the timing of spontaneous childbirth, or differences in application of the 39-week rule,” Mbata and colleagues concluded. “Additional research is needed to determine the cause of these differences, and the associated adverse effects are justified.”