NEW YORK (Reuters Health) - Good news for women with multiple sclerosis (MS) who are pregnant or thinking about becoming pregnant. A study published Wednesday shows that while women with MS have a somewhat heightened risk of certain pregnancy complications, by and large, their pregnancies are as healthy as other women‘s.
Using a national database on nearly 19 million deliveries in the U.S., researchers found that women with MS had marginally higher risks of cesarean delivery and intrauterine growth restriction -- where a newborn’s weight is below the 10th percentile for his or her gestational age.
Among more than 10,000 women with MS who gave birth between 2003 and 2006, 42 percent had a C-section, compared with roughly 33 percent of women overall. Meanwhile, intrauterine growth restriction was seen in almost 3 percent, versus 2 percent of other women.
Still, the overall findings, published in the medical journal Neurology, are being seen as good news for women with MS -- a disorder that is more prevalent among women of childbearing age than any other group.
“I think these findings are quite reassuring for women with MS,” senior researcher Dr. Eliza F. Chakravarty, a rheumatologist at Stanford University School of Medicine in California, told Reuters Health in an email. “We found that the obstetric outcomes for women with MS were not terribly different from those seen in the general population.”
MS is believed to arise from an abnormal immune system attack on the body’s own myelin, a protective sheath surrounding nerve fibers in the brain and spine. This leads to symptoms such as muscle weakness, numbness, vision problems and difficulty with coordination and balance.
Years ago, women with MS were advised to avoid pregnancy, out of concern that it could exacerbate the disease. But studies in recent decades have shown that the opposite is true; many women see a remission in their symptoms during pregnancy -- possibly because immune system activity naturally declines and levels of anti-inflammatory corticosteroids naturally rise during pregnancy.
Much less has been known, however, about pregnancy complications in women with MS.
The current study included information on 10,055 pregnant women with MS, as well as 4,730 with epilepsy and 187,239 with diabetes -- two disorders already associated with higher risks of certain pregnancy complications.
Overall, women with either MS or epilepsy had elevated risks of C-section delivery and intrauterine growth restriction compared with U.S. women overall. They did, however, generally fare better than women with diabetes, who had higher rates of additional complications, like high blood pressure and premature rupture of the sac surrounding the fetus.
“When you combine our findings of relatively good pregnancy outcomes in women with MS with the large body of evidence that the underlying disease seems to improve during pregnancy,” Chakravarty said, “it strongly suggests that women should not necessarily be discouraged from becoming pregnant just because they have MS.”
That said, she added, some women may have additional issues that could make pregnancy higher-risk -- such as co-existing medical conditions, smoking or lack of access to good prenatal care.
Women who are planning on becoming pregnant also need to talk with their doctors about whether they should stop taking any of their MS medications. It is not known whether the so-called disease-modifying drugs often used for MS are safe during pregnancy, and research suggests that at least one -- beta-interferon -- may be associated with miscarriage.
Chakravarty noted that the drug methotrexate, sometimes used for MS, is known to cause birth defects.
SOURCE: Neurology, online November 18, 2009.