Gestational weight gain and the association with offspring growth and obesity

Pediatric obesity is a key public health concern in the United States. We studied the association between gestational weight gain (GWG) and offspring growth and obesity risk across three developmental periods thought to be associated with obesity in later life. Mother-child pairs from the Maternal Health Practices and Child Development pregnancy cohort and were followed from <26 weeks gestation to 16 years postpartum. GWG was calculated as a ratio of observed to expected gain based on the 2009 Institute of Medicine GWG guidelines and women were classified as gaining below, within, or above the guidelines as inadequate, adequate, and excessive, respectively. We also studied GWG z-scores which account for prepregnancy BMI and are uncorrelated with gestational length. At birth, 8, 18, and 36 months, offspring weight-for-age z-scores (WAZ) were calculated, as well as body-mass-index-for-age z-scores (BMIZ) at these ages and 10 and 16 years. In accordance with current recommendations, z-scores were calculated based on the 2006 WHO growth standards for children <24 months and the 2000 CDC growth references for children ≥24 months. Child obesity was defined as a BMI ≥95th percentile at 36 months, 10 and 16 years. Compared to adequate, excessive GWG was associated with heavier weight at birth, slower infant growth, and greater risk for obesity at 36 months. At 10 and 16 years, higher GWG was associated with a greater risk of adolescent obesity. Inadequate GWG was associated with lower weight at birth and rapid weight gain from birth to 18 months, but not obesity risk. Children with rapid infant weight gain were more likely to be obese at 10 and 16, but not 3 years. GWG may exert a lasting influence on child growth and may lead to persistent obesity in this low-income sample of black and white mothers and their children. Limiting excessive GWG may impact the intergenerational cycle of obesity, making the findings of this dissertation relevant to public health

The impact of exposure misclassification on associations between prepregnancy body mass index and adverse pregnancy outcomes

Prepregnancy body mass index (BMI) is a widely used marker of maternal nutritional status that relies on maternal self-report of prepregnancy weight and height. Pregravid BMI has been associated with adverse health outcomes for the mother and infant, but the impact of BMI misclassification on measures of effect has not been quantified. The authors applied published probabilistic bias analysis methods to quantify the impact of exposure misclassification bias on well-established associations between self-reported prepregnancy BMI category and five pregnancy outcomes (small- and large-for gestational age birth (SGA; LGA), spontaneous preterm birth (sPTB), gestational diabetes (GDM), and preeclampsia) derived from a hospital-based delivery database in Pittsburgh, PA (2003-2005; n=18 362). The bias analysis method recreates the data that would have been observed had BMI been correctly classified, assuming given classification parameters. The point estimates derived from the bias analysis account for random error as well as systematic error caused by exposure misclassification bias and additional uncertainty contributed by classification errors. In conventional multivariable logistic regression models, underweight women were at increased risk of SGA and sPTB, and reduced risk of LGA, while overweight, obese, and severely obese women had elevated risks of LGA, GDM, and preeclampsia compared with normal-weight women. After applying the probabilistic bias analysis method, adjusted point estimates were attenuated, indicating the conventional estimates were biased away from the null. However, the majority of relations remained readily apparent. This analysis suggests that in this population, associations between self-reported prepregnancy BMI and pregnancy outcomes are slightly overestimated

Unnamed Partners From Syphilis Partner Services Interviews, 7 Jurisdictions.

BackgroundReducing transmission depends on the percentage of infected partners treated; if many are missed, impact on transmission will be low. Traditional partner services metrics evaluate the number of partners found and treated. We estimated the proportion of partners of syphilis patients not locatable for intervention.MethodsWe reviewed records of early syphilis cases (primary, secondary, early latent) reported in 2015 to 2017 in 7 jurisdictions (Florida, Louisiana, Michigan, North Carolina, Virginia, New York City, and San Francisco). Among interviewed syphilis patients, we determined the proportion who reported named partners (with locating information), reported unnamed partners (no locating information), and did not report partners. For patients with no reported partners, we estimated their range of unreported partners to be between one and the average number of partners for patients who reported partners.ResultsAmong 29,719 syphilis patients, 23,613 (80%) were interviewed and 18,581 (63%) reported 84,224 sex partners (average, 4.5; 20,853 [25%] named and 63,371 [75%] unnamed). An estimated 11,138 to 54,521 partners were unreported. Thus, 74,509 to 117,892 (of 95,362-138,745) partners were not reached by partner services (78%-85%). Among interviewed patients, 71% reported ≥1 unnamed partner or reported no partners; this proportion was higher for men who reported sex with men (75%) compared with men who reported sex with women only (65%) and women (44%).ConclusionsApproximately 80% of sex partners were either unnamed or unreported. Partner services may be less successful at interrupting transmission in networks for men who reported sex with men where a higher proportion of partners are unnamed or unreported