Weekly gestational weight gain in women with obesity and its association with risk of macrosomia / 中华围产医学杂志

ABSTRACT

Objective:To explore the characteristics of weekly gestational weight gain (GWG) in women with obesity and its correlation with the risk of macrosomia.Methods:Clinical data of women with singleton pregnancy and pre-pregnancy body mass index (PPBMI) ≥28 kg/m 2 were retrospectively analyzed, from January 2014 to December 2019, in Beijing Obstetrics and Gynecology Hospital, Capital Medical University (Beijing Maternal and Child Health Care Hospital). The participants were divided into three groups based on their PPBMI group A (28-<30 kg/m 2), group B (30-<32 kg/m 2), and group C (≥32 kg/m 2). The study compared the characteristics of GWG among the three groups, explored the correlation between the weekly weight gain during each gestational stage and the risk of macrosomia, and discussed the impacts of the GWG pattern in women with different PPBMI on the risk of macrosomia. Chi-square (or Fisher's exact), Kruskal-Wallis, and Mann-Whitney U tests were performed for statistical analysis. Multivariate logistic regression was used to analyze the impact of weekly weight gain in specific gestational stages on macrosomia. Results:(1) A total of 2 046 participants were included in the study, with 982 in group A, 588 in group B, and 476 in group C. For all of the 2 046 cases, the median PPBMI was 30.1 kg/m 2 (29.0-31.9 kg/m 2), GWG was 10.5 kg (7.3-14.0 kg), and neonatal birth weight was 3 520 g (3 215-3 816 g) with 60 (2.9%) ≥4 500 g, and the biggest baby weighed 5 580 g. Out of the births analyzed, macrosomia occurred in 318 cases (15.5%). (2) Among the three groups (A, B and C), the differences in maternal age [32.0 years (29.0-35.0 years), 32.0 years (29.0-35.0 years) and 32.0 years (29.0-34.0 years), H=6.58] and women with a history of type 2 diabetes mellitus [0.9% (9/982), 0.3% (2/588) and 1.9% (9/476), χ2=6.61] were statistically significant (all P<0.05). (3) The weekly weight gain in each group exhibited a gradual upward trend before 20-24 weeks, reached a plateau at 24-32 weeks, peaked at 32-36 weeks, and subsequently declined. The weekly weight gain of group A in the pre-pregnancy to 14 weeks [0.14 kg/week (0.00-0.25 kg/week)], 14 to 20 weeks [0.25 kg/week (0.17-0.42 kg/week)], and 20 to 24 weeks [0.38 kg/week (0.25-0.63 kg/week)] were higher than those of group B [0.07 kg/week (－0.03-0.21 kg/week), 0.25 kg/week (0.10-0.42 kg/week), and 0.38 kg/week (0.22-0.60 kg/week)], respectively ( Z value was－3.73,－2.16, and－2.01, all P<0.05). Likewise, the weekly weight gain of group B in the above three stages were all higher than those of group C [0.07 kg/week (－0.10-0.21 kg/week), 0.17 kg/week (0.05-0.33 kg/week), and 0.25 kg/week (0.08-0.50 kg/week)], respectively ( Z value was－2.55,－3.28, and－3.25, all P<0.05). (4) The risk of macrosomia increased with the weekly weight gain in specific gestational stages in different PPBMI groups. In group A, the stages correlated with increased risk were 14-20 weeks [adjusted odd ratio ( aOR)=2.669, 95% CI 1.378-5.169] and 20-24 weeks ( aOR=1.764, 95% CI 1.143-2.723), while the stages were 20-24 weeks ( aOR=2.149, 95% CI 1.156-3.996) and 36 weeks until delivery ( aOR=1.888, 95% CI 1.268-2.810) in group B, and pre-pregnancy to 14 weeks ( aOR=3.515, 95% CI 1.158-10.665) and 14-20 weeks ( aOR=3.021, 95% CI 1.058-8.628) in group C (all P<0.05). The risk of macrosomia increased when the weekly weight gain of both risk-related stages in group A ( aOR=2.255, 95% CI 1.029-4.940) ≥50th percentile, and group B ( aOR=4.399, 95% CI 1.017-19.023) ≥75th percentile, and for group C ( aOR=3.404, 95% CI 1.004-11.543) when the weekly weight gain above 25th percentile (all P<0.05). Conclusions:Weekly GWG demonstrates an observable gradual acceleration pattern in women with obesity. Therefore, clinical attention should be directed towards monitoring fluctuations in the weekly weight gain in this population, as excessive weekly weight gain before 24 gestational weeks is associated with an elevated risk of macrosomia.