Predictors of post-partum weight retention in a prospective longitudinal study.

Post-partum weight retention (WR) occurs in 60-80% of women with some retaining ≥10 kg with contributing factors reported as pre-pregnancy body mass index (BMI), gestational weight gain (GWG) and breastfeeding. A longitudinal study of pregnancy, with 12-month post-partum follow-up was conducted to determine factors associated with WR. Pregnant women (n = 152) were recruited from the John Hunter Hospital antenatal clinic in New South Wales, Australia. Pre-pregnancy weight was self-reported; weight was measured four times during pregnancy (for GWG) and in the first 12 months post-partum. Infant feeding data were obtained via questionnaires. Breastfeeding was categorised as exclusive, predominant, complementary or not breastfeeding. Linear mixed models tested the predictors of WR, with and without adjustment for potential confounders. Compared with pre-pregnancy weight, 68% of women retained weight at 12 months, median (interquartile range) [4.5 kg (2.1-8.9)]. After adjustment, GWG was positively associated with WR (P < 0.01), but pre-pregnancy weight did not predict WR. For each additional week of any breastfeeding, 0.04 kg less weight was retained. Compared with women who retained weight, those women who did retain had higher rates of exclusive breastfeeding at three months (P < 0.05), but the number of weeks of exclusive breastfeeding failed to predict WR for all women. WR following childbirth is common and associated with GWG, while the number of weeks of 'any' breastfeeding contributed to post-partum weight loss. Whether these factors are modifiable strategies to optimise the weight status of women at this life stage requires further research.

Greater maternal weight gain during pregnancy predicts a large but lean fetal phenotype: a prospective cohort study.

The objective of this study is to describe the fetal phenotype in utero and its associations with maternal pre-pregnancy weight and gestational weight gain. This prospective longitudinal cohort included 179 Australian women with singleton pregnancies. Serial ultrasound measurements were performed at 19, 25, 30 and 36 (±1) weeks gestation and maternal anthropometry were collected concurrently. The ultrasound scans included the standard fetal biometry of head circumference, biparietal diameter, abdominal circumference, and femur length, and body composition at the abdomen and mid-thigh, including fat and lean mass cross-sectional areas. Maternal gestational weight gain was compared to current clinical guidelines. The participants had an average of 3.7 ± 0.8 scans and birth data were available for 165 neonates. Fifty four per cent of the cohort gained weight in excess of current recommendations, according to pre-pregnancy body mass index (BMI). Maternal gestational weight positively predicted fetal abdominal circumference (P 0.029) and lean abdominal mass area (P 0.046) in linear mixed model regression analysis, adjusted for known and potential confounders. At any pre-pregnancy BMI gaining weight above the current recommendations resulted in a larger fetus according to standard biometry, because of significantly larger lean muscle mass at the abdomen (P 0.024) and not due to an increase in fat mass (P 0.463). We have demonstrated the importance of maternal weight gain, independent of pre-pregnancy BMI, to support the growth of a large but lean fetus. Prenatal counselling should focus on achieving a healthy BMI prior to conception so that gestational weight gain restrictions can be minimised.