Women who wait at least 18 months between pregnancies have lower health risks, according to a new study published in JAMA Internal Medicine.
According to the study authors, this is the “most extensive evaluation of how the role of pregnancy spacing could be impacted by maternal age.” Furthermore, this is also the first study to look at the relationship between pregnancy spacing and maternal mortality or severe morbidity among members of a high-income country.
For the study, researchers evaluated approximately 150,000 Canadian health records of mothers and babies. They looked at birth records, billing codes, infertility rates, census records, and hospitalization data, to find any correlation between maternal mortality and severe morbidity. The team found that pregnancy intervals shorter than 18 months appear to be at the highest risk for adverse pregnancy outcomes.
Lead study author Laura Schummers advises, “Our study found increased risk to both mother and infant when pregnancies are closely spaced, including for women older than 35. The findings for older women are particularly important, as older women tend to more closely space their pregnancies and often do so intentionally.”
The study found that women over the age of 35 who conceived at six months following a birth had a 1.2 percent higher risk for maternal mortality or severe morbidity. By simply waiting 18 months, the researchers found this risk drops to 0.5 percent.
In addition, among younger women, the shorter waiting period could yield an 8.5 percent higher risk of “spontaneous preterm birth,” which is delivering prior to 37 weeks (and labor started on its own/was not induced). For those women under 35 who conceived after 18 months, the frequency dropped to 3.7 percent.
The study authors advise that this work confirms that different age groups [or women, in this case] face different health risks. The data, however, could also help us better understand the importance of proper family planning.
After all, Harvard University T.H. Chan School of Public Health professor of epidemiology Dr. Sonia Hernandez-Diaz commented, “Short pregnancy spacing might reflect unplanned pregnancies, particularly among young women.”
At the end of the day, then, UBC associate professor Dr. Wendy Norman advises: “Achieving that optimal one-year interval should be doable for many women, and is clearly worthwhile to reduce complication risk.”