Neurologic Disease and Pregnancy Outcomes

December 8, 2009
Victor Dostrow, MD

Some neurologic disorders increase the risk of problematic outcomes of pregnancy. Data on such associations have been scant, but this is beginning to change. For example, with regard to epilepsy, there are a number of pregnancy registries which track outcomes related to antiepileptic drug therapy. However, large trials and population studies are not common.

Some neurologic disorders increase the risk of problematic outcomes of pregnancy. Data on such associations have been scant, but this is beginning to change. For example, with regard to epilepsy, there are a number of pregnancy registries which track outcomes related to antiepileptic drug therapy. However, large trials and population studies are not common.

A recent study in Neurology adds to the literature base of such larger studies. The authors abstracted data over a four year period from the Nationwide Inpatient Sample, comprising data from 1,054 non-Federal hospitals in 37 states. Among the large set of data in the sample are maternal age, primary diagnosis and up to 14 secondary diagnoses. They compared outcomes in women with MS and epilepsy to those in women with diabetes, and controls. Data were then extrapolated to represent all deliveries in the U.S. over the 4 year study period.

The hospital database included 3,854,793 obstetric hospitalizations over the four years. This extrapolated to about 18.8 million obstetric hospitalizations in the entire U.S. over the period. By diagnosis, this extrapolated to (approximately): MS: 10,000; Epilepsy: 5,000; Diabetes: 190,000. Total deliveries by diagnosis were approximately: MS: 7,697; Epilepsy: 2,745; and diabetes: 112,650.

The outcomes are interesting. Mean maternal age at delivery was slightly older than the average (27.4 years) for women with MS (31.6) and diabetes (30.2), but younger for women with epilepsy (26.8). Antepartum hospitalizations (obstetric admission to hospital without delivery) were higher in women with the target disorders. In the general population, such hospitalizations were 18.8% of total hospitalizations. However, the percentage was higher for women with MS (23%), epilepsy (42%) and diabetes (40%). This was statistically significant: p<0.001.

Odd ratios of adverse outcomes were also higher in the neurologic disease groups. MS was associated with an increased risk of antenatal hospitalization (OR 1.3, 95% CI 1.2—1.5), IUGR (OR 1.7, 1.2–2.4) and delivery by cesarean section (OR 1.3, 1.1–1.4). The risks associated with epilepsy were even more elevated: antenatal hospitalization (OR 3.0 2.6–3.5), IUGR (OR 1.9, 1.2–3.3), and cesarean (OR 1.5, 1.3–1.9). By comparison, rates of all problems were also elevated in women with diabetes, with Cesarean delivery risk exceeding those for MS and epilepsy.

The authors find the results reassuring with regard to pregnancy and neurologic disease. The risks are elevated, but not unduly so. They also comment that their epilepsy data are probably more pessimistic compared with other data sets due to using diagnostic coding from hospital records rather than self-reporting. Antenatal hospitalizations would, for example, be more completely captured by their methodology. On the other hand, a limitation of note is that outpatient encounters were not captured, and thus early pregnancy teratogenic events would potentially be missed. Also noted: Women with mild epilepsy may not have been classified as having epilepsy in the database, causing them to not be included and thus skewing outcomes towards women with more active disease.

Overall, these data are reassuring for women with epilepsy or MS who wish to become pregnant. However, it is still prudent to counsel such women that planning pregnancy allows for optimization of pharmacotherapy, which further reduces risk of adverse pregnancy outcomes.