Women who have had a C-section have a 10% decreased likelihood of conceiving again compared with those who had vaginal deliveries, a new study finds.

The researchers from the University of Bergen in Norway also determined that women who take at least a year to conceive are 21% more likely to be delivered by C-section compared to women who got pregnant in less than a year. 

“In our study, women with difficulty conceiving have a higher prevalence of pregnancy complications,” researcher Yeneabeba Sima, of the Department of Global Public Health and Primary Care at the University of Bergen, said in a statement.

“There is also a higher prevalence of chronic health issues like diabetes mellitus and high blood pressure among these women. However, the increased risk of having a C-section still existed for women who didn’t have these health issues,” she added.

The study findings were published in October in the American Journal of Obstetrics & Gynecology.

The researchers analyzed the time it took to conceive another child for the 42,379 mothers who participated in the Norwegian Mother, Father and Child Cohort Study (MoBa) linked to the Medical Birth Registry of Norway.

The MoBa questionnaire asked the women if they planned their subsequent pregnancy.

“For those who actively tried to have a baby, we examined the time it took for them to conceive,” Sima explained. “If they had tried for a year or more before getting pregnant, they were considered to have reduced fertility.”

Sima said the lower probability of conceiving a baby after having a C-section could be due to “underlying maternal conditions not registered in our data.”

She noted that reduced fertility following a C-section may not be a side effect of the surgical operation itself, which involves a doctor making incisions in the abdomen and the uterus to deliver the baby.

In the US in 2021, there were 1.17 million C-section births and 2.48 million vaginal deliveries, according to data from the Centers for Disease Control and Prevention.

That means that C-sections represented 32% of all US births in 2021.

A woman might undergo a C-section if her baby is in distress or in an unusual position; if labor isn’t progressing normally; or if she had a prior C-section.

The recovery time is typically longer for a C-section than a vaginal birth, and complications can include infection, blood loss, and organ injury.

Meanwhile, among 74,025 MoBa participants, 11% reported trying for more than one year to get pregnant.

These women were more likely to deliver via C-section.

“Maternal stress might be one reasonable explanation connecting challenges in conceiving and an elevated risk of labor difficulties, ultimately leading to a higher likelihood of C-section,” Sima said.