Women with psychiatric illness who become pregnant are more likely to have adverse obstetric outcomes if they are obese, new research suggests

Among women with psychiatric disorders, obesity was associated with a significantly higher risk for major malformations, as well as gestational diabetes, compared to control persons of normal weight, Marlene P. Freeman, MD, Massachusetts General Hospital, Boston, told Medscape Medical News.

"Women with psychiatric disorders represent an at-risk population for pregnancy. They also have a higher rate of obesity than the general population, and we know that obesity also increases the risk of obstetrical and neonatal complications. But that is a factor that we can potentially address in terms of decreasing risk," she said.

At-Risk Population

The investigators prospectively collected data from pregnant women aged 18 to 45 years who were enrolled in the Massachusetts General Hospital National Pregnancy Registry for Psychiatric Medications. The data related to the patients' conditions during the patient's during pregnancy until 6 months postpartum.

Of the 584 participants, 252 were of normal weight, 170 were overweight, and 162 were obese. The unadjusted odds ratio of major malformations in infants born to obese vs normal-weight mothers was 3.19 (95% confidence interval [CI], 0.79 – 12.95).

Obese and overweight women were at significantly higher risk for gestational diabetes. In obese women, the odds ratio (OR) was 3.81 (95% CI, 1.29 – 7.84; P = .009); in overweight women, the OR was 3.4 (95% CI, 1.49 – 7.76; P = .004).

Among obese women, there was a trend for higher rates of hypertension (P = .2) and cesarian delivery (P = .055), compared with normal-weight women.Other outcomes, including preeclampsia, stay in the neonatal intensive care unit, and preterm birth, did not differ significantly between the groups.

"This is already an at-risk population, and we would like to emphasize to healthcare providers that obesity is another risk that these patients have to contend with. There is often a lot of concern about potential exposure to psychiatric medication, but we also want to raise awareness about other factors, such as obesity, which can greatly impact pregnancy outcomes in the population we treat," Freeman said.

Patient Education Critical

"It's very important for everyone to maintain a healthy weight because of the health risks, but it is particularly so for our psychiatric patients who are on medications which can sometimes promote weight gain, such as the atypical antipsychotics that are commonly used in bipolar disorder and schizophrenia," Crystal Clark, MD, Northwestern University Feinberg School of Medicine, Chicago, Illinois, told Medscape Medical News.

"I discuss the importance of healthy diets, warn about gestational diabetes from too much weight gain, which has complications for the fetus, but sometimes the message is difficult to get across, partly because of the timing of when I am actually introduced to a patient," she said.

"It's an important standard of care, but I don't think this is done in every physician's office, because sometimes when people come to me, they have not had that prior education. I believe healthcare providers should provide education to these women and advise about healthy exercise and the dangers of excessive weight gain during pregnancy. It's definitely doable," she said.