Ideally, if a woman wants the lowest-possible risk of complications, she should wait at least 18 months after giving birth to get pregnant again, a new study says. But that same study found that the risk isn’t much higher if she conceives within 12 months of her first child.
These findings could have particular relevance for older women, said study lead Laura Schummers, a postdoctoral fellow at the University of British Columbia’s department of family practice.
For women who delay childbearing until the age of 35, “These women tend to more closely space their subsequent pregnancies,” she said.
“From other studies it seems like that is likely due to them feeling like they’re under a bit of a time crunch,” she said. They’re trying to conceive before they become infertile, she suggested, and trying to have children before they face an increased risk of complications due to their age.
The study, published in JAMA Internal Medicine, looked at 148,544 pregnancies in British Columbia over 10 years. “We found that first, for women of all ages, pregnancies conceived within 12 months of a live birth have increased risks,” Schummers said.
These included things like maternal mortality or severe morbidity, infant death, preterm delivery and having children that were small for their gestational age.
Women over 35 who conceived a second child less than 12 months after giving birth faced increased risks to themselves, while younger women faced increased risks to their infant.
But after 12 months, those risks lessened, the researchers found. “We found that the optimum spacing was 18 months. That was the moment with the lowest risk,” Schummers said.
“But the risks between 12 and 24 months were very similar to those at 18 months.”
Although she cautions that it’s just one study and can’t be relied upon to change clinical practice, “From the findings of our study we would be comfortable recommending that women try to conceive at 12 months, up to 24,” Schummers said.
Figuring out how to space out your pregnancies is a complicated decision, according to Dr. Yolanda Kirkham, an obstetrician gynecologist at Women’s College Hospital and St. Joseph’s Health Centre in Toronto.
“I think there are a lot of factors that people need to take into consideration when they’re thinking about their own plan.”
Canadian women are having children much older than they used to, she said. “For a lot of us in big cities like Toronto, almost half of our practice is over 35 years old.”
This comes with difficulties getting pregnant and higher risks of miscarriage, along with additional issues like risks of chromosomal problems — such as Down’s syndrome — or higher chances of things like gestational diabetes or high blood pressure.
Then there are the social and personal considerations. “This discussion about age is very important, but keeping that in mind, everyone has to take into consideration their life stage and where they are, whether it’s financially or in their career, whether they have resources.”
“No time is a good time. You could say the opposite, and anytime is a good time.”
The study’s findings could help reassure women who feel that time crunch or have an unplanned pregnancy soon after giving birth, she said. But, she recommends that women discuss their decision with their doctor as it will be different for everyone.
“Whether these are planned pregnancies, whether your current child has any difficulties or disabilities that might make it harder for you to cope with another child. Finances, child care, whether or not they’re still breastfeeding. Sleep and fatigue status,” she said. “These would all come into play as well.”