Advanced-age pregnancies, particularly after 35, carry elevated risks for maternal and infant health. Researchers from Harvard T.H. Chan School of Public Health in Boston and the University of British Columbia in Vancouver analyzed data from 148,544 Canadian pregnancies, including birth certificates and hospitalization records. Their findings: Women aged 35 and older should wait at least 12 months—and ideally 12 to 18 months—between pregnancies to minimize the risk of death or severe complications during pregnancy or childbirth.
Among women over 35 who conceived just 6 months after their previous birth, the risk of death or serious complications stood at 1.2% (12 cases per 1,000 pregnancies). Extending the interval to 18 months reduced this to 0.5% (5 per 1,000). Preterm birth rates (before 37 weeks) were also higher at shorter intervals: 6% (60 per 1,000) versus 3.4% after 18 months. These risks may stem from insufficient maternal recovery or factors like limited prenatal care in unplanned pregnancies. "Taking appropriate postpartum contraception or abstaining from unprotected sex" is key, advises Harvard's Professor Sonia Hernandez-Diaz. Share this evidence-based guidance with friends planning closely spaced families.
