Here's How Long You Should Really Wait Between Pregnancies, According to Research

Mothers should wait at least a year between giving birth and getting pregnant again, according to research published in JAMA Internal Medicine. This differs slightly with the World Health Organization’s guidelines, which recommend women wait between 18 and 24 months.

Smaller gaps between pregnancies can risk premature birth and infant mortality.

For the 2018 study, researchers observed 150,000 births in Canada and found that while getting pregnant less than 12 months after your previous pregnancy lead to increased maternal, fetal and infant risks, 12 to 18 months was the ideal time to wait between giving birth and becoming pregnant again.

“Our findings indicate a shorter optimal interval than previously thought for women of all ages,” the report states. “This finding may be reassuring particularly for older women who must weigh the competing risks of increasing maternal age with longer interpregnancy intervals against the risks of short interpregnancy intervals.”

Researchers hope the news will reassure women over 35 years old who are trying to grow their family. “Achieving that optimal one-year interval should be doable for many women and is clearly worthwhile to reduce complication risks,” senior study author Wendy Norman says.

The researchers also found all women, regardless of their age, who got pregnant less than 12 months after giving birth had pregnancies associated with more risks. There was only a risk for the mothers when they were older than 35, but in all cases their was a risk for the babies. The highest risk for babies was from women who were between 20 and 34 years old.

Women older than 35 who got pregnant six months after giving birth had a 1.2 percent risk of maternal mortality. Younger women who got pregnant six months after a previous birth had an 8.5 percent risk of premature labor. This dropped to 3.7 percent if they waited 18 months between pregnancies.

The American College of Obstetricians and Gynecologists is pretty aligned with these findings. It also suggests women should be advised to avoid interpregnancy periods of less than six months and "should be counseled on the risks and benefits of repeat pregnancy sooner than 18 months.”