Literature Review

Higher Rate of Loss in Unplanned Pregnancies for Women With Epilepsy

The risk of fetal loss is greater if the interval between pregnancies is under one year.


Unplanned pregnancy among women with epilepsy is associated with twice the risk of spontaneous fetal loss (SFL) when compared with women with epilepsy who planned their pregnancy, according to results from a retrospective study published online ahead of print October 15 in JAMA Neurology.

“This analysis adds the finding that unplanned pregnancy may increase the risk of SFL in women with epilepsy and identifies pregnancy planning, maternal age, and interpregnancy interval as significant modifiable variables,” said Andrew G. Herzog, MD, a neurologist at the Harvard Neuroendocrine Unit at Beth Israel Deaconess Medical Center in Wellesley, Massachusetts, and colleagues.

Andrew G. Herzog, MD

The Epilepsy Birth Control Registry

The researchers examined results from a web-based survey completed by 1,144 women in the Epilepsy Birth Control Registry (EBCR) between 2010 and 2014. Respondents provided data on contraception use, pregnancy history, and antiepileptic drug (AED) treatment. Patients were between ages 18 and 47 (mean, 28.5). Approximately 8.7% of the cohort were minorities, and 39.8% had household incomes of $25,000 or less.

Pregnancy history data included number of pregnancies, number of planned or unplanned pregnancies, AED type used during pregnancies, and pregnancy outcomes such as live birth, induced abortion, and SFL. Patients were categorized as receiving no therapy, monotherapy, or polytherapy. AED use was further subdivided into no AED, enzyme-inducing AED, non–enzyme-inducing AED, enzyme-inhibiting AED, glucuronidated AED, and mixed.

Most Pregnancies Were Unplanned

Of 794 pregnancies, 530 (66.8%) were unplanned and 264 (33.2%) were planned. Outcomes included 473 live births (59.6%), 141 induced abortions (17.8%), and 180 SFLs (22.7%). Among patients who did not have an induced abortion, SFL risk was higher if the pregnancy was unplanned (137 patients, 35.0%), compared with planned (43 patients, 16.4%) The risk ratio (RR) of SFL was 2.14. According to a regression analysis, SFL risk was higher for patients where “planning was entered alone” in unplanned pregnancies (odds ratio [OR], 2.75), as well as when adjusted for AED category, maternal age, and interpregnancy interval (OR, 3.57).

There was an association between maternal age (OR, 0.957) and risk of SFL. Risk was lower in the 18- to 27-year-olds (118 patients; 29.5%; RR, 0.57) and 28- to 37-year-olds (44 patients; 20.8%; RR, 0.40), compared with the under-18 group (15 patients, 51.7%). Risk of SFL was related to interpregnancy interval (OR, 2.878). This risk was greater if the interpregnancy interval was under one year (56 patients, 45.9%), compared with one year (56 patients, 22.8%) or higher (RR, 2.02).

The Epilepsy Foun-dation and Lundbeck funded the study. Dr. Herzog reports grants, and two coauthors received salary support from grants, from the two organizations.

—Jeff Craven

Suggested Reading

Herzog AG, Mandle HB, MacEachern DB. Association of unintended pregnancy with spontaneous fetal loss in women with epilepsy: findings of the Epilepsy Birth Control Registry. JAMA Neurol. 2018 Oct 15 [Epub ahead of print].

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