The rate of premature births has jumped over the last decade — mystifying doctors.
A preterm birth is any birth that occurs at or before the 37th week of pregnancy. Between 2014 and 2022, the Department of Health and Human Services recorded a 12% increase in preterm births according to a National Vital Statistics Report.
“The rate of preterm birth in the United States rose by more than one-third from 1981 to 2006. This rise prompted concern and a heightened awareness of the morbidities associated with births delivered at 34–36 weeks of gestation, or late preterm,” stated the report. “Late preterm births comprise about 70% of all preterm births and were the largest contributor to the overall preterm increase over the period. ... Late preterm and early-term births declined for several years from 2007 to 2014, but have been on the rise in recent years.”
As of 2022, just over 8.6% of all births are preterm. Early births – births that occur between 37-38 weeks of pregnancy – have also risen over the last eight years by 20%.
Simultaneously, the rate of full-term births declined by 6%.
“Globally, prematurity is the leading cause of death in children under the age of 5 years,” noted the World Health Organization. “Most preterm births happen spontaneously, but some are due to medical reasons such as infections, or other pregnancy complications that require early induction of labour or caesarean birth.”
Medical risk factors linked to preterm deliveries include preeclampsia or high blood pressure, intrahepatic cholestasis of pregnancy, and diabetes. Women who underwent in vitro fertilization (IVF), who do not gain enough weight during pregnancy, who have a significant amount of stress, who abuse substances while pregnant, who work long hours, or who stand excessively are also all believed to be at risk for preterm labor, according to March of Dimes.
In addition to death, babies born prematurely are more likely to develop anemia, apnea and infections. They are also at a higher risk of having learning disabilities and chronic health issues according to the Mayo Clinic. At birth, premature infants may have a low body temperature and trouble breathing.
“Although infants born preterm are at highest risk of morbidity and mortality, early-term birth is associated with poorer outcomes compared with full-term birth, and differences in outcomes are seen across the single-week full-term spectrum,” noted the National Vital Statistics Report. “Increases in births delivered preterm and early term were observed for all maternal age groups from 2014 to 2022. Although the largest changes were seen for mothers age 30 and older, the percent change for births delivered at less than full term ranged only from 15% (for the youngest mothers) to 20% (for the oldest mothers).”
The driving factor of the recent increase in preterm births is not immediately clear to the medical community. The Hill noted a recent study suggested that exposure to phthalates – otherwise known as the “everywhere chemical” used to make flexible plastic – caused 5% to 10% of preterm births in 2018.
“The chemicals are hormone disruptors that can impact how a developing fetus grows and how the placenta functions during pregnancy,” reported the outlet.
