Characteristics of Recurrent Large-for-Gestational-Age Infants in Obese Women.

Objective The objective of this study was to identify characteristics associated with recurrent large-for-gestational-age (LGA) infants in obese women and to explore the relationship between interpregnancy weight change and gestational weight gain (GWG) on risk of recurrence. Study Design We conducted a population-based historical cohort study of 1,190 obese women in Missouri who delivered LGA infants in their first pregnancy with two consecutive pregnancies resulting in singleton live births during 1998 to 2005. Adjusted odds ratios (aORs) for recurrent LGA infants were calculated with multiple logistic regression. Population-attributable risk assessed the relative importance of specific characteristics. Results A second LGA infant was delivered by 501 women (42%). Recurrence of LGA infants was associated with GWG (aOR, 1.03 [per pound]; 95% confidence interval [CI], 1.02-1.04), maternal age (aOR, 1.05 [per year]; 95% CI, 1.02-1.08), birth weight of the first LGA infant (aOR, 1.001 [per gram]; 95% CI, 1.000-1.001), being married (aOR, 1.71; 95% CI, 1.02-2.49), diabetes (aOR, 1.79; 95% CI, 1.24-2.59), and pre-pregnancy body mass index (BMI) (aOR, 1.04 [per unit BMI]; 95% CI, 1.02-1.06). Excessive GWG contributed the most to LGA infant recurrence (13%). Interpregnancy weight change was not significantly associated with LGA infant recurrence. Conclusion Lower pre-pregnancy BMI and reduced GWG may mitigate the risk of recurrent LGA infants in obese women.

The impact of interpregnancy weight change on birthweight in obese women.

OBJECTIVE: The purpose of this study was to estimate the impact of interpregnancy weight change from first to second pregnancies in obese women on the risk of large-for-gestational-age (LGA) and small-for-gestational-age (SGA) infants. STUDY DESIGN: A population-based historical cohort analysis of 10,444 obese women in Missouri who delivered their first 2 singleton live infants from 1998-2005. Interpregnancy weight change was calculated as the difference between prepregnancy body mass index (BMI) of the first and second pregnancies. LGA and SGA births were compared among 3 interpregnancy weight change groups: (1) weight loss (≥2 BMI units), (2) weight gain (≥2 BMI units), and (3) reference group (BMI maintained within 2 units). Adjusted odds ratios (aOR) were calculated for LGA and SGA births with the use of multiple logistic regression. A dose-response relationship was assessed with a linear-by-linear χ(2) test. RESULTS: Compared with the reference group, interpregnancy weight loss was associated with lower risk of an LGA infant (aOR, 0.61; 95% confidence interval, 0.52-0.73), whereas interpregnancy weight gain was associated with increased risk of an LGA infant (aOR, 1.37; 95% confidence interval, 1.21-1.54). Interpregnancy BMI change was not related to SGA infant risk, except for weight loss of >8 BMI units. A significant dose-response relationship was observed for LGA infant risk (P < .001), but not SGA infant risk (P = .840). CONCLUSION: Mild-to-moderate interpregnancy weight loss in obese women reduced the risk of subsequent birth of LGA infants without increasing the risk of SGA infants. The interpregnancy interval may be a crucial period for targeting weight loss in obese women.