Adverse pregnancy or birth outcomes did not differ among more than 400 women with MS, when compared with more than 2,000 women without the disease, according to a new study of women in British Columbia, Canada. Mia L. van der Kop, MSc, Helen Tremlett, PhD and colleagues (University of British Columbia, Vancouver) report their findings in Annals of Neurology (published online: June 27, 2011).
Background: MS often occurs in women of childbearing age. When young women receive a diagnosis of MS, they frequently have questions about the effects of the disease on childbearing—and vice versa. Studies undertaken over the past several decades allow health professionals to provide answers to many of these questions. Read more about pregnancy and reproduction issues in MS.
There is no evidence that MS impairs fertility or leads to an increased number of spontaneous abortions, stillbirths or congenital malformations. Several studies of large numbers of women have repeatedly demonstrated that pregnancy, labor, delivery and the incidence of fetal complications are no different in women who have MS than in control groups without the disease.
The Study: With funding from the Canadian Institute of Health Research, investigators gathered data from the British Columbia MS Clinics’ database and the British Columbia Perinatal Database Registry, which captures nearly all births in the province. They analyzed 432 births to women with MS and 2975 births to women without MS from 1998 to 2009, looking at gestational age, birth weight, assisted vaginal delivery, and Caesarean section. Thanks to having access to both databases, this unique study was able to explore clinical factors in the women with MS, examining age at MS onset, disease duration, disability levels and other factors.
The results show that overall, women with MS did not differ in pregnancy outcomes from women who did not have MS. The mean birth weight and gestational age of babies did not differ, and women with MS were not at a greater risk of adverse deliveries, including Caesarean section and assisted vaginal delivery.
There was a slightly elevated risk of adverse delivery outcomes among women with MS and greater levels of disability, but this difference was not statistically significant. The authors comment that further study is needed to determine whether women with greater disability require closer monitoring during pregnancy.
This study differed from similar efforts, in that the investigators were able to control for “confounding factors” that might affect pregnancy and birth outcomes, such as gestational hypertension, diabetes, obstetrical history, and body mass index. In fact, the results show that mothers who had MS were more often overweight or obese. Because a high body mass index is associated with adverse pregnancy and birth outcomes in general, the authors suggest that women with MS should be counseled to optimize their weight when planning a pregnancy.
Read more about pregnancy and MS.