DALLAS — Obese women may be at increased risk for postpartum depression, new research suggests.
In a prospective analysis of 1,282 women who gave birth to singleton infants at term, nearly 30% of women with a prepregnancy body mass index (BMI) of 30 kg/m
The study is the first to use a validated screening tool to evaluate the risk of postpartum depression (PPD) by maternal BMI strata, according to the researchers, who used a score of 12 or more on the Edinburgh Postnatal Depression Screen to define a positive PPD screen.
Women at the extremes of BMI and those with greater weight gains in pregnancy were also at increased risk for PPD, Dr. Yvette LaCoursiere and colleagues at the University of Utah, Salt Lake City, reported in a poster at the annual meeting of the Society for Maternal-Fetal Medicine.
A positive PPD screen was reported in 18.7% of underweight women (BMI below 18.5), 12.7% of normal-weight (BMI 18.5–24.9), 15.9% of overweight women (BMI 25–29.9), 17.6% with class I obesity (BMI 30–34.9), 28% with class II obesity (BMI 35–39.9), and 29.4% with class III obesity (BMI greater than or equal to 40). The number of women in each BMI stratum was: 115, 724, 256, 116, 43, and 31, respectively, with incomplete data available on 3.
BMI remained a risk factor for PPD even after the researchers controlled for maternal age (mean 27 years), race (86% white, 9% Hispanic), parity (two children), education (mean 14 years), and stressors including financial, traumatic, partner associated, and emotional.
“We're not screening women aggressively for postpartum depression, in general,” Dr. LaCoursiere said in an interview. “When I look at how this changed my practice, if I have women who are obese before delivery I have them come back at a 2-week visit and make sure they get a screening test because they have a very high chance of developing depression.”
Weight gain during pregnancy also influenced a woman's chance of becoming depressed. A positive PPD screen was observed for 9.6% of normal-weight women who gained 24 pounds or less, 11% of those who gained 25–34 pounds, and 16% of those who gained more than 35 pounds. The rates were similar in overweight women (12%, 13.6%, and 20%, respectively), but did not increase in a stepwise fashion in the mildly obese (23%, 9%, and 21%, respectively). There were too few women with class II and III obesity to analyze.
Contrary to expectations, normal-weight women are more likely than are obese women to exceed the recommended pregnancy weight gain of 25–35 pounds, with obese women typically gaining only about 16–24 pounds during pregnancy, Dr. LaCoursiere said.
The modified Body Shape Questionnaire (BSQ) was also used, and revealed that poor body image was associated with obesity and weight gain during pregnancy. Scores on the BSQ increased significantly with increasing BMI strata (32, 39, 44, 48, 51, and 49; P less than .05).
Only 54% of physicians discussed mood during the postpartum visit, and 26% addressed weight, Dr. LaCoursiere said. Fewer than 30 women reported that their evaluation of mood was conducted with a written tool. During pregnancy, 77% of providers addressed weight and 53% discussed mood. “We [should] make this part of the nursing system so a woman has to answer a survey when she first comes through the door, so the doctor has the information in hand. Another thing that's tough for OBs is what to do with that result when you find it. Most should feel comfortable treating at least mild depression and knowing what resources are available and whom to refer to.”
In all, 50 women (4%) reported using alcohol during pregnancy, 224 (17.4%) had a history of depression, 109 (8.5%) had a history of PPD, 23 (2%) had a history of other psychiatric diagnoses, and 175 (14%) had a family history of other psychiatric diagnoses. The percentage of women with a history of depression or PPD seems high, but the data may be inflated because they are self-reported and thus do not necessarily reflect those who accessed care and were treated, Dr. LaCoursiere said.