Maternal prepregnancy waist circumference and BMI in relation to gestational weight gain and breastfeeding behavior: the CARDIA study

Abstract

Background: Studies suggest that gestational weight gain (GWG) and breastfeeding behavior may influence long-term maternal abdominal fat mass. However, this could be confounded by abdominal fat mass before pregnancy because it is unknown whether abdominal fat mass, independently of body size, affects GWG and breastfeeding behavior.

Objective: We investigated how maternal prepregnancy fat distribution, described by waist circumference (WC) and body mass index (BMI), is associated with GWG and breastfeeding behavior.

Design: We analyzed 1371 live births to 1024 women after enrollment in the Coronary Artery Risk Development in Young Adults study (1985-1996). For each birth, maternal prepregnancy BMI and WC were measured at year 0 (baseline), 2, 5, or 7 examinations. Recalled GWG and breastfeeding behavior were collected at years 7 and 10. GWG was analyzed by using linear regression and breastfeeding behavior by using logistic regression and discrete-time logistic regression.

Results: Adjusted for potential confounders, a 1-cm larger WC adjusted for BMI was associated with a 0.19-kg (95% CI: -0.29-, -0.10-kg) lower GWG. In contrast, a 1-unit higher BMI adjusted for WC was associated with a 0.27-kg (95% CI: 0.06-, 0.47-kg) higher GWG. The OR for ever breastfeeding compared with never breastfeeding was 0.93 (95% CI: 0.90, 0.97) per 1-cm larger WC after adjustment for BMI, whereas it was 1.10 (95% CI: 1.02, 1.19) per 1-unit higher BMI adjusted for WC.

Conclusions: Maternal prepregnancy body size was differently associated with GWG and breastfeeding behavior depending on the location of the fat mass. Thus, maternal fat distribution may be a more important determinant of GWG and breastfeeding behavior than BMI alone.

Trial registration: ClinicalTrials.gov NCT00005130.

Keywords: breastfeeding; fat distribution; gestational weight gain; maternal; prepregnancy.

FIGURE 1

Flow diagram of sample selection criteria for the CARDIA study, 1985–1996. A birth was defined as a delivery after 20 wk of gestation. CARDIA, Coronary Artery Risk Development in Young Adults.

FIGURE 2

Difference in GWG according to centimeter deviation from the predicted waist circumference for a given BMI. The reference value is set to 0; to the left side is a lower waist circumference than predicted by BMI, and to the right side is a larger than predicted waist circumference. The solid line shows the estimated difference in GWG, and the dotted line the 95% CIs. Adjusted for race, study center, gestational age, child birth weight, time from prepregnancy measure to conception, and maternal prepregnancy height, age, parity, marital status, education, work status, smoking, physical activity, alcohol intake, and intake of fat, protein, carbohydrate, and fiber. GWG, gestational weight gain.

FIGURE 3

The OR for ever compared with never breastfeeding according to centimeter deviation from the predicted waist circumference for a given BMI. The reference value is set to 0; to the left side is a lower waist circumference than predicted by BMI, and to the right side is a larger than predicted waist circumference. The solid line shows the OR, and the dotted line the 95% CIs. Adjusted for race, study center, gestational age, child birth weight, time from prepregnancy measure to conception, and maternal prepregnancy height, age, parity, marital status, education, work status, smoking, physical activity, alcohol intake, and intake of fat, protein, carbohydrate, and fiber.