The relationship between antenatal body attitudes, pre-pregnancy body mass index, and gestational weight gain

Objectives: an estimated 50% of women experience excessive gestational weight gain (GWG). Maternal body attitudes are associated with GWG, however this relationship is complex and may differ based on pre-pregnancy body mass index (BMI) or gestational age. The aim of this study was to explore the moderating role of maternal pre-pregnancy BMI on the relationship between body attitudes in early-to-mid and late pregnancy and GWG. Design/Participants: pregnant women less than 18 weeks gestation were recruited for a postal questionnaire study via Australian pregnancy online forums, pregnancy and parenting magazines, and antenatal clinics. In early-mid pregnancy (Time 1; mean (M) = 16.81 weeks gestation, standard deviation (SD) = 1.18), participants reported demographics, pre-pregnancy weight, height, and body attitudes (salience of weight and shape, attractiveness, strength and fitness and feeling fat). In late pregnancy, body attitudes (Time 2; M = 32.65 weeks gestation, SD = 0.91) and weight (Time 3; M = 37.15 weeks gestation, SD = 1.55) were reported. Pre-pregnancy BMI and total GWG were calculated. Moderation analyses were conducted. Findings: in early-mid pregnancy, pre-pregnancy BMI moderated the relationship between feeling fat and GWG. Pre-pregnancy BMI did not moderate the relationship between body attitudes and GWG for salience of weight and shape, attractiveness or strength and fitness in early-mid pregnancy. In late pregnancy, prepregnancy BMI moderated the relationship between all four body attitude facets (salience of weight and shape, attractiveness, feeling fat and strength and fitness) and GWG. Conclusion/Implications for practice: the relationship between body attitudes and GWG was moderated by pre-pregnancy BMI, particularly in late pregnancy. It is recommended that antenatal health care providers monitor women's body attitudes throughout pregnancy to aid in the management of healthy GWG and promote positive maternal and infant health outcomes. This is particularly important for women entering pregnancy with an underweight/normal weight BMI.