Women with multiple sclerosis may not be at a higher risk of pregnancy complications such as gestational diabetes, emergency cesarean section, or stillbirth than women who do not have the disease, according to a new study. However, researchers found babies born to mothers with MS had a higher chance of being delivered by elective cesarean section or induced delivery, and being small for their age compared to babies of women who did not have the disease.

The study from the University of Copenhagen, in Denmark, involved 2,930 pregnant women with MS who were compared to 56,958 pregnant women without MS. All women gave birth between 1997 and 2016. Researchers found no difference in risk of several pregnancy complications between women with MS and women without it. No differences were found in risk of pre-eclampsia, gestational diabetes, placenta complications, emergency c-section, instrumental delivery, stillbirth, preterm birth, congenital malformations or low Apgar score. Apgar score is a test of a newborn's health, including measures like heart rate, reflexes and muscle tone immediately after birth.

Researchers found 401 of the 2,930 women with MS, or 14 percent, had an elective c-section, compared to 4,402 of the 56, 958 women without MS, or 8 percent, who had an elective c-section. After adjusting for other factors that could increase the likelihood of having an elective c-section, such as prior c-section and mother's age, women with MS were 89 percent more likely to have an elective c-section. Researchers also found women with MS were 15 percent more likely to have an induced delivery than women without the disease.

Women with MS were also found to be 29 percent more likely to have babies that were born small for their gestational age compared to women without MS. Overall, 3.4 percent of women with MS had babies small for their gestational age, compared to 2.8 percent of women without MS. Researchers found mothers with MS were 13 percent less likely to give birth to babies with signs of being deprived of oxygen, or asphyxia. Magyari said the higher prevalence of elective c-sections among women with MS most likely explains the corresponding lower odds of asphyxia.

A limitation of the study is the lack of data on the mothers' smoking, which could cause babies to be born small for their gestational age.

The study was published in Neurology Clinical Practice, an official journal of the American Academy of Neurology.