Background Studies using vital records-based maternal weight data have become more common, but the validity of these data is uncertain. Methods We evaluated the accuracy of prepregnancy body mass index (BMI) and gestational weight gain (GWG) reported on birth certificates using medical record data in 1204 births at a teaching hospital in Pennsylvania from 2003 to 2010. Deliveries at this hospital were representative of births statewide with respect to BMI, GWG, race/ethnicity, and preterm birth. Forty-eight strata were created by simultaneous stratification on prepregnancy BMI (underweight, normal weight/overweight, obese class 1, obese classes 2 and 3), GWG (<20th, 20–80th, >80th percentile), race/ethnicity (non-Hispanic white, non-Hispanic black), and gestational age (term, preterm). Results The agreement of birth certificate-derived prepregnancy BMI category with medical record BMI category was highest in the normal weight/overweight and obese class 2 and 3 groups. Agreement varied from 52% to 100% across racial/ethnic and gestational age strata. GWG category from the birth registry agreed with medical records for 41% to 83% of deliveries and agreement tended to be the poorest for very low and very high GWG. The misclassification of GWG was driven by errors in reported prepregnancy weight rather than maternal weight at delivery, and its magnitude depended on prepregnancy BMI category and gestational age at delivery. Conclusions Maternal weight data, particularly at the extremes, are poorly reported on birth certificates. Investigators should devote resources to well-designed validation studies, the results of which can be used to adjust for measurement errors by bias analysis.

Contraceptive counseling in primary care settings is associated with increased hormonal contraceptive use at last intercourse. Increasing provision of contraceptive counseling in primary care may reduce unintended pregnancy.

Sedentary behavior and sleep may be working in concert to increase the likelihood of a child becoming overweight, but in paradoxical ways. Reduction of sedentary behavior (that is, media screen time) has been extensively researched and touted as an intervention target. Inadequate sleep as a putative risk factor for obesity is only beginning to be explored. In this paper, we review the current state of research regarding these factors, and describe the existing evidence and mechanisms proposed to explain these relationships. Whereas the association between weight and sedentary behavior has been consistently shown in observational studies, effect sizes are small, and multiple mechanisms appear to be operating. Recent cross-sectional and longitudinal evidence suggests a link between short sleep duration and weight. Possible mechanisms here include direct metabolic effects as well as indirect behavioral pathways, including the presence of electronic media in children’s bedrooms. Measurement issues present a challenge to both areas of research. Prospective studies that include more accurate measures of both sedentary behavior and of sleep will be needed to clarify causal pathways.

The solid lines represent the point estimate and dashed lines represent its 95% confidence bands. Outcomes are preterm birth <32 weeks (orange lines), small-for-gestational-age birth (green lines), large-for-gestational-age birth (purple lines), and infant death (blue lines). Risks were set at the population average for maternal race/ethnicity, maternal education, maternal age, marital status, parity, insurance source, smoking during pregnancy, pre-existing diabetes or hypertension, height, prepregnancy weight, infertility treatment, infant sex, neonatal care level of birth facility, year of birth, urban residence, and racial composition of neighborhood.

Objective To assess the joint and independent relationships of gestational weight gain and prepregnancy body mass index (BMI) on risk of infant mortality. Methods We used Pennsylvania linked birth-infant death records (2003–2011) from infants without anomalies to underweight (n=58,973), normal weight (n=610,118), overweight (n=296,630), grade 1 obese (n=147,608), grade 2 obese (n=71,740), and grade 3 obese (n=47,277) mothers. Multivariable logistic regression models stratified by BMI category were used to estimate dose-response associations between z-scores of gestational weight gain and infant death after confounder adjustment. Results Infant mortality risk was lowest among normal weight women and increased with rising BMI category. For all BMI groups except for grade 3 obesity, there were U-shaped associations between gestational weight gain and risk of infant death. Weight loss and very low weight gain among women with grade 1 and 2 obesity were associated with high risks of infant mortality. However, even when gestational weight gain in women with obesity was optimized, the predicted risk of infant death remained higher than that of normal weight women. Conclusions Interventions aimed at substantially reducing preconception weight among women with obesity and avoiding very low or very high gestational weight gain may reduce risk of infant death.

Background Conventional measures of gestational weight gain (GWG) are correlated with pregnancy duration, and may induce bias to studies of GWG and perinatal outcomes. A maternal weight-gain-for-gestational-age z-score chart is a new tool that allows total GWG to be classified as a standardized z-score that is independent of gestational duration. Our objective was to compare associations with perinatal outcomes when GWG was assessed using gestational age-standardized z-scores and conventional GWG measures. Methods We studied normal-weight (n=522,120) and overweight (n=237,923) women who delivered live-born, singleton infants in Pennsylvania, 2003-2011. GWG was expressed using gestational age-standardized z-scores and three traditional measures: total GWG (kg), rate of GWG (kg per week of gestation) and the GWG adequacy ratio (observed GWG/GWG recommended by the Institute of Medicine). Log-binomial regression models were used to assess associations between GWG and preterm birth and small- and large-for-gestational-age births while adjusting for race/ethnicity, education, smoking, and other confounders. Results The association between GWG z-score and preterm birth was approximately U-shaped. The risk of preterm birth associated with weight gain <10th percentile of each measure was substantially overestimated when GWG was classified using total kg and was moderately overestimated using rate of GWG or GWG adequacy ratio. All GWG measures had similar associations with small- or large-for-gestational-age birth. Conclusions Our findings suggest that studies of gestational age-dependent outcomes misspecify associations if total GWG, rate of GWG, or GWG adequacy ratio are used. The potential for gestational age-related bias can be eliminated by using z-score charts to classify total GWG.

Background Our objective was to estimate associations between gestational weight gain z-scores and preterm birth, neonatal intensive care unit admission, large- and small-for-gestational age birth (LGA, SGA), and cesarean delivery among grade 1, 2, and 3 obese women. Methods Singleton infants born in Pennsylvania (2003–2011) to grade 1 (body mass index (BMI) 30–34.9 kg/m2, n=148,335), grade 2 (35–39.9 kg/m2, n=72,032), or grade 3 (≥40 kg/m2, n=47,494) obese mothers were included. Total pregnancy weight gain (kg) was converted to gestational age-standardized z-scores. Multivariable Poisson regression models stratified by obesity grade were used to estimate associations between z-scores and outcomes. A probabilistic bias analysis, informed by an internal validation study, evaluated the impact of BMI and weight gain misclassification. Results Risks of adverse outcomes did not substantially vary within the range of z-scores equivalent to 40-week weight gains of −4.3 to 9 kg for grade 1 obese, −8.2 to 5.6 kg for grade 2 obese, and −12 to −2.3 kg for grade 3 obese women. As gestational weight gain increased beyond these z-score ranges, there were slight declines in risk of SGA but rapid rises in cesarean delivery and LGA. Risks of preterm birth and neonatal intensive care unit admission were weakly associated with weight gain. The bias analysis supported the validity of the conventional analysis. Conclusions Gestational weight gain below national recommendations for obese mothers (5–9 kg) may not adversely affect fetal growth, gestational age at delivery, or mode of delivery.

Background We evaluated whether computerized counseling about contraceptive options and screening for contraindications increased women’s subsequent knowledge and use of hormonal contraception. Methods For the study 814 women aged 18 to 45 years were recruited from the waiting rooms of three emergency departments and an urgent care clinic staffed by non-gynecologists and asked to use a randomly-selected computer module before seeing a clinician. Results Women in the intervention group were more likely to report receiving a contraceptive prescription when seeking acute care than women in the control group (16% vs 1%, p=0.001). Women who requested contraceptive refills were not less likely than women requesting new prescriptions to have potential contraindications to estrogen (75% of refills vs. 52% new, p=0.23). Three months after visiting the clinic, women in the intervention group tended to be more likely to have used contraception at last intercourse (71% vs 65%, p=0.91) and to correctly answer questions about contraceptive effectiveness, but these differences were not statistically significant. Conclusion Patient-facing computers appear to increase access to prescription contraception for women seeking acute care.