Maternal obesity increased preterm delivery risk
Click Here to Manage Email Alerts
Swedish researchers have found that maternal overweight and obesity during pregnancy increased the risk for preterm birth.
In their population-based cohort study of more than 1 million women with one live birth in Sweden between 1992 and 2010, Sven Cnattingius, MD, PhD, of Karolinska University Hospital, and colleagues examined data from the nationwide Swedish Medical Birth Register. They studied the potential link between early pregnancy BMI and risk for preterm delivery by gestational age and other factors of preterm delivery.
The risks for preterm deliveries were categorized into three outcomes: extremely preterm (22-27 weeks), very preterm (28-31 weeks) and moderately preterm (32-36 weeks). After this was established, the researchers filtered the preterm births into two additional groups: spontaneous (related to preterm contractions or preterm premature rupture of membranes) or medically indicated preterm delivery (cesarean delivery before onset of labor or induced onset of labor), the researchers wrote.
Of 1,599,551 deliveries with data on early pregnancy BMI, researchers wrote that 3,082 deliveries were extremely preterm, whereas 6,893 were very preterm, and 67,059 were labeled moderately preterm. Normal-weight women (BMI, 18.5 to <25) had a 0.17% rate of extremely preterm delivery, researchers wrote.
Furthermore, 0.21% of women with extremely preterm delivery had a BMI of 25 to <30 (OR= 1.26; 95% CI, 1.15-1.37), 0.27% had a BMI of 30 to <35 (OR=1.58; 95% CI, 1.39-1.79), 0.35% had a BMI of 35 to <40 (OR=2.01; 95% CI, 1.66-2.45) and 0.52% of women had a BMI of at least 40 (OR=2.99; 95% CI, 2.28-3.92) vs. normal-weight women.
“Our results showing dose-response associations between maternal overweight and obesity and risks of preterm delivery, especially of extremely preterm delivery, suggest that maternal overweight and obesity may have serious long-term consequences for infant health,” the researchers wrote.
Disclosure: One researcher reports an institutional grant or pending grant from the Swedish Research Council for Working Life and Social Health. All other researchers report no relevant financial disclosures.