Bio

Bio


Currently a Senior Epidemiologist/Biostatistician in the Division of Maternal-Fetal Medicine and Obstetrics. My work aims to improve health care, experiences, and outcomes for pregnant and postpartum individuals. I'm particularly interested in applying novel epidemiologic methods to perinatal health and health systems research, with a focus on maternal morbidities and mortality.

Honors & Awards


  • Ruth L. Kirschstein National Research Service Award Individual Postdoctoral Fellowship (F32HD091945), Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) (2017-2019)
  • Postdoctoral Fellowship, Stanford Child Health Research Institute (CHRI) (2018-2019)

Education & Certifications


  • PhD, University of California, Berkeley, Epidemiology (2017)
  • MS, University of California, Los Angeles, Epidemiology (2014)
  • BS, Cornell University, Human Biology, Health and Society (Minor in Global Health) (2010)

Publications

All Publications


  • Risk of severe maternal morbidity in relation to prepregnancy body mass index: Roles of maternal co-morbidities and caesarean birth. Paediatric and perinatal epidemiology Leonard, S. A., Carmichael, S. L., Main, E. K., Lyell, D. J., Abrams, B. 2019

    Abstract

    An association between prepregnancy body mass index (BMI) and severe maternal morbidity (SMM) has been reported, but evidence has been mixed and potential explanations have not been examined.To evaluate the association between prepregnancy BMI and SMM in a large, diverse birth cohort and assess potential mediation by obesity-related co-morbidities and caesarean birth.This cohort study used linked birth certificate and hospitalisation discharge records from Californian births during 2007-2012. We assessed associations between prepregnancy BMI and SMM, and used inverse probability weighting for multiple mediators to estimate relative and absolute natural direct and indirect effects accounting for mediation by co-morbidities (hypertensive conditions, diabetes, asthma) and caesarean birth.Among 2 650 182 births, the prevalence of SMM was 1.42%. Adjusted risk ratios for the total association between prepregnancy BMI category and SMM were 1.12 (95% confidence interval [CI] 1.07, 1.18) for underweight, 1.02 (95% CI 0.99, 1.04) for overweight, 1.04 (95% CI 1.00, 1.07) for obesity class 1, 1.14 (95% CI 1.09, 1.20) for obesity class 2, and 1.28 (95% CI 1.22, 1.36) for obesity class 3 compared to women with normal weight. After accounting for mediation by co-morbidity and caesarean birth, the risk ratios were 1.19 (95% CI 1.14, 1.26) for underweight, 0.91 (95% CI 0.89, 0.94) for overweight, 0.86 (95% CI 0.84, 0.89) for obesity class 1, 0.88 (95% CI 0.84, 0.92) for obesity class 2, and 0.89 (95% CI 0.83, 0.95) for obesity class 3.Co-morbidities and caesarean birth explained an association between high prepregnancy BMI and SMM. These findings suggest that promotion of healthy prepregnancy weight, along with management of co-morbidities and support of vaginal birth in pregnant women with high BMI, could reduce the risk of SMM. However, these mediators did not reduce the elevated risk of SMM observed in women with low BMI.

    View details for DOI 10.1111/ppe.12555

    View details for PubMedID 31106879

  • The contribution of maternal characteristics and cesarean delivery to an increasing trend of severe maternal morbidity. BMC pregnancy and childbirth Leonard, S. A., Main, E. K., Carmichael, S. L. 2019; 19 (1): 16

    Abstract

    Severe maternal morbidity - life-threatening childbirth complications - has more than doubled in the United States over the past 15?years, affecting more than 50,000 women (1.4% of deliveries) annually. During this time period, maternal age, obesity, comorbidities, and cesarean delivery also increased and may be related to the rise in severe maternal morbidity. We sought to evaluate: (1) the association of advanced maternal age, pre-pregnancy obesity, pre-pregnancy comorbidities, and cesarean delivery with severe maternal morbidity, and (2) whether changes in the prevalence of these risk factors affected the trend of severe maternal morbidity.This population-based cohort study used linked birth record and patient discharge data from live births in California during 2007-2014 (n?=?3,556,206). We used multivariable logistic regression models to assess the association of advanced maternal age (?35?years), pre-pregnancy obesity (body mass index ?30?kg/m2), pre-pregnancy comorbidity (index of 12 conditions), and cesarean delivery with severe maternal morbidity prevalence and trends. Severe maternal morbidity was identified by an index of 18 diagnosis and procedure indicators. We estimated odds ratios, predicted prevalence, and population attributable risk percentages.The prevalence of severe maternal morbidity increased by 65% during 2007-2014. Advanced maternal age, pre-pregnancy obesity, and pre-pregnancy comorbidity also increased during this period, but cesarean delivery did not. None of these risk factors affected the increasing trend of severe maternal morbidity. However, the pre-pregnancy risk factors together were estimated to contribute to 13% (95% confidence interval: 12, 14%) of severe maternal morbidity cases in the study population overall, and cesarean delivery was estimated to contribute to 37% (95% confidence interval: 36, 38%) of cases.Pre-pregnancy health and cesarean delivery are important risk factors for severe maternal morbidity but do not explain an increasing trend of severe maternal morbidity in California during 2007-2014. Investigation of other potential contributors is needed in order to identify ways to reverse the trend of severe maternal morbidity.

    View details for PubMedID 30626349

  • Racial and ethnic disparities in severe maternal morbidity prevalence and trends. Annals of epidemiology Leonard, S. A., Main, E. K., Scott, K. A., Profit, J., Carmichael, S. L. 2019

    Abstract

    Racial/ethnic disparities in severe maternal morbidity (SMM) are substantial, but little is known about whether these disparities are changing over time or the role of maternal and obstetric factors.We examined disparities in SMM prevalence and trends using linked birth certificate and delivery discharge records from Californian births during 1997-2014 (n = 8,252,025).The prevalence of SMM was highest in non-Hispanic (NH) Black women (1.63%), lowest in NH White women (0.84%), and increased from 1997 to 2014 by approximately 170% in each racial/ethnic group. The magnitude of SMM disparities remained consistent over time. Compared with NH White women, the adjusted risk of SMM was higher in women who identified as Hispanic (RR 1.14; 95% CI 1.12, 1.16), Asian/Pacific Islander (RR 1.23; 95% CI 1.20, 1.26), NH Black (RR 1.27; 95% CI 1.23, 1.31), and American Indian/Alaska Native (RR 1.29; 95% CI 1.15, 1.44), accounting for comorbidities, anemia, cesarean birth, and other maternal characteristics.The prevalence of SMM varied considerably by race/ethnicity but increased at similarly high rates among all racial/ethnic groups. Comorbidities, cesarean birth, and other factors did not fully explain the disparities in SMM, which remained persistent over time.

    View details for PubMedID 30928320

  • Maternal History of Child Abuse and Obesity Risk in Offspring: Mediation by Weight in Pregnancy. Childhood obesity Leonard, S. A., Petito, L. C., Rehkopf, D. H., Ritchie, L. D., Abrams, B. 2017

    Abstract

    Women's experience of childhood adversity may contribute to their children's risk of obesity. Possible causal pathways include higher maternal weight and gestational weight gain, which have been associated with both maternal childhood adversity and obesity in offspring.This study included 6718 mother-child pairs from the National Longitudinal Survey of Youth 1979 in the United States (1979-2012). We applied multiple log-binomial regression models to estimate associations between three markers of childhood adversity (physical abuse, household alcoholism, and household mental illness) and offspring obesity in childhood. We estimated natural direct effects to evaluate mediation by prepregnancy BMI and gestational weight gain.Among every 100 mothers who reported physical abuse in childhood, there were 3.7 (95% confidence interval: -0.1 to 7.5) excess cases of obesity in 2- to 5-year olds compared with mothers who did not report physical abuse. Differences in prepregnancy BMI, but not gestational weight gain, accounted for 25.7% of these excess cases. There was no evidence of a similar relationship for household alcoholism or mental illness or for obesity in older children.In this national, prospective cohort study, prepregnancy BMI partially explained an association between maternal physical abuse in childhood and obesity in preschool-age children. These findings underscore the importance of life-course exposures in the etiology of child obesity and the potential multi-generational consequences of child abuse. Research is needed to determine whether screening for childhood abuse and treatment of its sequelae could strengthen efforts to prevent obesity in mothers and their children.

    View details for DOI 10.1089/chi.2017.0019

    View details for PubMedID 28440693

  • Weight gain during pregnancy and the black-white disparity in preterm birth. Annals of epidemiology Leonard, S. A., Petito, L. C., Stephansson, O., Hutcheon, J. A., Bodnar, L. M., Mujahid, M. S., Cheng, Y., Abrams, B. 2017; 27 (5): 323?28.e1

    Abstract

    To quantify the relationship between pregnancy weight gain with early and late preterm birth and evaluate whether associations differed between non-Hispanic (NH) black and NH white women.We analyzed a retrospective cohort of all live births to NH black and NH white women in the United States 2011-2015 (n = 10,714,983). We used weight gain z-scores in multiple logistic regression models stratified by prepregnancy body mass index (BMI) and race to calculate population attributable risk (PAR) percentages for the contribution of high and low pregnancy weight gain to early and late preterm birth.Pregnancy weight gain was related to early and late preterm birth, but associations varied by BMI and race. For early preterm birth, the PAR percentage for high pregnancy weight gain ranged from 8 to 10% in NH black women and from 6 to 8% in NH white women. There was little evidence of racial differences in late preterm birth: PAR percentages ranged from 2 to 7% in NH black women and from 3 to 7% in NH white women.Moderate gestational weight gain is associated with lower rate of preterm birth, with greatest reductions for early preterm birth in NH black women.

    View details for DOI 10.1016/j.annepidem.2017.05.001

    View details for PubMedID 28595737

  • Trajectories of maternal weight from before pregnancy through postpartum and associations with childhood obesity. The American journal of clinical nutrition Leonard, S. A., Rasmussen, K. M., King, J. C., Abrams, B. 2017

    Abstract

    Background: Prepregnancy body mass index [BMI (in kg/m(2))], gestational weight gain, and postpartum weight retention may have distinct effects on the development of child obesity, but their combined effect is currently unknown.Objective: We described longitudinal trajectories of maternal weight from before pregnancy through the postpartum period and assessed the relations between maternal weight trajectories and offspring obesity in childhood.Design: We analyzed data from 4436 pairs of mothers and their children in the National Longitudinal Survey of Youth 1979 (1981-2014). We used latent-class growth modeling in addition to national recommendations for prepregnancy BMI, gestational weight gain, and postpartum weight retention to create maternal weight trajectory groups. We used modified Poisson regression models to assess the associations between maternal weight trajectory group and offspring obesity at 3 age periods (2-5, 6-11, and 12-19 y).Results: Our analysis using maternal weight trajectories based on either latent-class results or recommendations showed that the risk of child obesity was lowest in the lowest maternal weight trajectory group. The differences in obesity risk were largest after 5 y of age and persisted into adolescence. In the latent-class analysis, the highest-order maternal weight trajectory group consisted almost entirely of women who were obese before pregnancy and was associated with a >2-fold increase in the risk of offspring obesity at ages 6-11 y (adjusted RR: 2.39; 95% CI: 1.97, 2.89) and 12-19 y (adjusted RR: 2.74; 95% CI: 2.13, 3.52). In the analysis with maternal weight trajectory groups based on recommendations, the risk of child obesity was consistently highest for women who were overweight or obese at the beginning of pregnancy.Conclusion: These findings suggest that high maternal weight across the childbearing period increases the risk of obesity in offspring during childhood, but high prepregnancy BMI has a stronger influence than either gestational weight gain or postpartum weight retention.

    View details for DOI 10.3945/ajcn.117.158683

    View details for PubMedID 28877895

  • Gestational Weight Gain-for-Gestational Age Z-Score Charts Applied across U.S. Populations. Paediatric and perinatal epidemiology Leonard, S. A., Hutcheon, J. A., Bodnar, L. M., Petito, L. C., Abrams, B. 2017

    Abstract

    Gestational weight gain may be a modifiable contributor to infant health outcomes, but the effect of gestational duration on gestational weight gain has limited the identification of optimal weight gain ranges. Recently developed z-score and percentile charts can be used to classify gestational weight gain independent of gestational duration. However, racial/ethnic variation in gestational weight gain and the possibility that optimal weight gain differs among racial/ethnic groups could affect generalizability of the z-score charts. The objectives of this study were (1) to apply the weight gain z-score charts in two different U.S. populations as an assessment of generalisability and (2) to determine whether race/ethnicity modifies the weight gain range associated with minimal risk of preterm birth.The study sample included over 4 million live, singleton births in California (2007-2012) and Pennsylvania (2003-2013). We implemented a noninferiority margin approach in stratified subgroups to determine weight gain ranges for which the adjusted predicted marginal risk of preterm birth (gestation <37 weeks) was within 1 or 2 percentage points of the lowest observed risk.There were minimal differences in the optimal ranges of gestational weight gain between California and Pennsylvania births, and among several racial/ethnic groups in California. The optimal ranges decreased as severity of prepregnancy obesity increased in all groups.The findings support the use of weight gain z-score charts for studying gestational age-dependent outcomes in diverse U.S. populations and do not support weight gain recommendations tailored to race/ethnicity.

    View details for DOI 10.1111/ppe.12435

    View details for PubMedID 29281119

  • Weight gain in pregnancy and child weight status from birth to adulthood in the United States. Pediatric obesity Leonard, S. A., Petito, L. C., Rehkopf, D. H., Ritchie, L. D., Abrams, B. 2016

    Abstract

    High weight gain in pregnancy has been associated with child adiposity, but few studies have assessed the relationship across childhood or in racially/ethnically diverse populations.The objectives of the study are to test if weight gain in pregnancy is associated with high birthweight and overweight/obesity in early, middle and late childhood and whether these associations differ by maternal race/ethnicity.Mother-child dyads (n = 7539) were included from the National Longitudinal Survey of Youth 1979, a nationally representative cohort study in the USA (1979-2012). Log-binomial regression models were used to analyse associations between weight gain and the outcomes: high birthweight (>4000?g) and overweight/obesity at ages 2-5, 6-11 and 12-19?years.Excessive weight gain was positively associated, and inadequate weight gain was negatively associated with high birthweight after confounder adjustment (P?

    View details for DOI 10.1111/ijpo.12163

    View details for PubMedID 27350375

    View details for PubMedCentralID PMC5404997

  • Prepregnancy Risk Factors for Preterm Birth and the Role of Maternal Nativity in a Low-Income, Hispanic Population MATERNAL AND CHILD HEALTH JOURNAL Leonard, S. A., Crespi, C. M., Gee, D. C., Zhu, Y., Whaley, S. E. 2015; 19 (10): 2295-2302

    Abstract

    The aim of this study was to assess potential prepregnancy risk factors for preterm birth in a low-income, Hispanic population in Southern California. Additionally, the study assessed whether the prevalence of preterm birth and any associations between risk factors and preterm birth differed between U.S.- and foreign-born mothers.The study sample included 1174 mothers participating in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) within 1 year postpartum, including an augment sample of mothers who delivered preterm. Maternal sociodemographic traits, prepregnancy health-related characteristics and behaviors, and birth outcomes were collected by telephone survey. Odds ratios for associations between risk factors and preterm birth were estimated by logistic regression with sampling weights. Effect measure modification of any association by maternal nativity was also assessed using interaction terms.After adjustment for confounding, significant prepregnancy risk factors for preterm birth included maternal age ?35 years (OR 2.00; 95 % CI 1.04, 3.84) compared to age 18-24 years, and experience of a financially stressful life event among U.S.-born, but not foreign-born, women (OR 2.61; 95 % CI 1.43, 4.77). The weighted prevalence of preterm birth was 15.1 % and did not significantly differ by maternal nativity (P = 0.19).Further investigation with large, prospective studies is needed to better understand the risk factors for and disparities in preterm birth among the growing Hispanic population in the U.S. so that women who are at risk prepregnancy can be identified and provided risk-specific services.

    View details for DOI 10.1007/s10995-015-1748-4

    View details for Web of Science ID 000361625100023

    View details for PubMedID 25994418

    View details for PubMedCentralID PMC4575879

  • Associations Between Preterm Birth, Low Birth Weight, and Postpartum Health in a Predominantly Hispanic WIC Population JOURNAL OF NUTRITION EDUCATION AND BEHAVIOR Leonard, S. A., Gee, D., Zhu, Y., Crespi, C. M., Whaley, S. E. 2014; 46 (6): 499-505

    Abstract

    To describe the postpartum health of predominantly Hispanic participants in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) and identify how health characteristics differ between mothers who delivered preterm or low birth weight infants and those who did not.Cross-sectional survey among postpartum WIC mothers.Los Angeles and Orange Counties, CA.WIC participants within 1 year of delivery (n = 1,420).Postpartum health behaviors, health characteristics, and birth spacing intentions and behaviors.Frequencies of health characteristics were estimated using analyses with sample weights. Differences were assessed with chi-square and Fisher exact tests with Bonferroni correction for pairs of tests.Many women exhibited postpartum risk factors for future adverse health events, including overweight or obesity (62.3%), depressive symptoms (27.5%), and no folic acid supplementation (65.5%). Most characteristics did not differ significantly (P > .025) between mothers of preterm infants and full-term infants or between mothers of low birth weight and normal birth weight infants.Despite few differences between postpartum characteristics of mothers who delivered preterm or low birth weight infants and those who did not, a high percentage of mothers had risk factors that need to be addressed. Current postpartum educational activities of WIC programs should be evaluated and shared.

    View details for DOI 10.1016/j.jneb.2014.06.008

    View details for Web of Science ID 000345000500010

    View details for PubMedID 25092236

    View details for PubMedCentralID PMC4252510

  • Larger Infant Size at Birth Reduces the Negative Association between Maternal Prepregnancy Body Mass Index and Breastfeeding Duration JOURNAL OF NUTRITION Leonard, S. A., Rasmussen, K. M. 2011; 141 (4): 645-653

    Abstract

    Women who are overweight or obese prepregnancy have shorter durations of producing milk (PM) and feeding breast milk exclusively (FBM-ex) than normal-weight women. We proposed that infant size at birth may reduce the negative associations between prepregnancy BMI and the durations of PM and FBM-ex. We used data from 2798 participants in the Infant Feeding Practices Study II and characterized infant size at birth as weight-for-gestational age (WGA). To assess possible mediation of the associations between maternal BMI and the durations of PM and FBM-ex by infant size at birth, Baron and Kenny's methods, the Sobel test, and bootstrapping were used. As expected, prepregnancy BMI was negatively associated (P < 0.0001) with the durations of PM and FBM-ex; it also was positively associated (P < 0.0001) with infant size at birth. However, infant WGA was positively associated (P < 0.0003) with the durations of PM and FBM-ex after adjustment for BMI. Thus, the negative associations between BMI and the durations of PM and FBM-ex were reduced by infant WGA; i.e. the statistical removal of infant size at birth increased the magnitude of the negative associations between BMI and the durations of PM and FBM-ex. Thus, the tendency of heavier mothers to deliver heavier infants reduces the true magnitude of the association between maternal prepregnancy BMI and shortened breastfeeding duration.

    View details for DOI 10.3945/jn.110.129874

    View details for Web of Science ID 000288876800016

    View details for PubMedID 21346096

  • Associations between high prepregnancy body mass index, breast-milk expression, and breast-milk production and feeding AMERICAN JOURNAL OF CLINICAL NUTRITION Leonard, S. A., Labiner-Wolfe, J., Geraghty, S. R., Rasmussen, K. M. 2011; 93 (3): 556-563

    Abstract

    Breast-milk expression is widely practiced by American mothers, but little is known about who expresses milk, how expression affects breastfeeding, or whether overweight or obese women, who have less breastfeeding success than do normal-weight women, express milk differently.We investigated 1) whether breast-milk expression behavior differed by body mass index (BMI; in kg/m(2)) category and 2) whether the different breastfeeding behaviors of overweight (BMI: ?25 and <30) and obese (BMI: ?30) women resulted in different breastfeeding outcomes.The subjects (n = 2288) provided information on BMI and breast-milk production, feeding, and expression in mail-in questionnaires as part of the Infant Feeding Practices Study II. Longitudinal and cross-sectional data were analyzed by using regression procedures adjusted for confounding.Women of different BMI categories overall did not differ in whether, when, or why they expressed breast milk. Before 2 mo postpartum, however, obese women were more likely (P = 0.04, unadjusted) to try milk expression and were less likely (P = 0.01, unadjusted) to express milk successfully. In addition, overweight or obesity was associated (P < 0.03, unadjusted) with a shorter duration of breast-milk production only in women who never expressed milk. In overweight or obese women, those who ever expressed milk had longer durations of breastfeeding (P < 0.003, unadjusted) than did those who never expressed milk.Breast-milk expression behaviors may differ by maternal BMI category only in the early postpartum period. In addition, breast-milk expression may reduce differences between BMI categories in the duration of breastfeeding and support longer durations of breastfeeding.

    View details for DOI 10.3945/ajcn.110.002352

    View details for Web of Science ID 000287475000014

    View details for PubMedID 21209224

  • Prenatal and postnatal inflammation-related risk factors for retinopathy of prematurity JOURNAL OF PERINATOLOGY Goldstein, G. P., Leonard, S. A., Kan, P., Koo, E. B., Lee, H. C., Carmichael, S. L. 2019; 39 (7): 964?73
  • Morbidly Adherent Placenta Among Women With Twin Gestation Miller, H., Fox, K., Carusi, D. A., Leonard, S., Lyell, D. LIPPINCOTT WILLIAMS & WILKINS. 2019: 68S
  • Racial and ethnic disparities in severe maternal morbidity prevalence and trends ANNALS OF EPIDEMIOLOGY Leonard, S. A., Main, E. K., Scott, K. A., Profit, J., Carmichael, S. L. 2019; 33: 30?36
  • Invited Commentary: The Causal Association Between Obesity and Stillbirth-Strengths and Limitations of the Consecutive-Pregnancies Approach. American journal of epidemiology Snowden, J. M., Leonard, S. A. 2019

    Abstract

    There has been a resurgence in analyses of consecutive pregnancies (or similarly, sibling designs) in perinatal and pediatric epidemiology. These approaches have attractive qualities for estimating associations with complex multifactorial exposures like obesity. In an article appearing in this issue of the Journal, Yu et al. (Am J Epidemiol. 2019;000(00):000-000) apply a consecutive-pregnancies approach to characterize the risk of stillbirth among women who develop obesity between pregnancies ("incident obesity"). Working within a causal framework and using parametric and nonparametric estimation techniques, the authors find an increase in stillbirth risk associated with incident obesity. Risk differences varied between 0.4 per 1,000 births (95% confidence interval (CI): 0.1, 0.7) and 6.9 per 1,000 births (95% CI: 3.7, 10.0), and risk ratios ranged from 1.12 (95% CI: 1.02, 1.23) to 2.99 (95% CI: 2.19, 4.08). The strengths of this approach include starting from a clearly defined causal estimand and exploring the sensitivity of parameter estimates to model selection. In this commentary, we put these findings in the broader context of research on obesity and birth outcomes and highlight concerns regarding the generalizability of results derived from within-family designs. We conclude that while causal inference is an important goal, in some instances focusing on formulation of a causal question drives results away from broad applicability.

    View details for DOI 10.1093/aje/kwz079

    View details for PubMedID 31111943

  • Gestational Weight Gain and Severe Maternal Morbidity at Delivery Hospitalization. Obstetrics and gynecology Leonard, S. A., Carmichael, S. L., Abrams, B. 2019; 134 (2): 420

    View details for DOI 10.1097/AOG.0000000000003389

    View details for PubMedID 31348212

  • Prenatal and postnatal inflammation-related risk factors for retinopathy of prematurity. Journal of perinatology : official journal of the California Perinatal Association Goldstein, G. P., Leonard, S. A., Kan, P., Koo, E. B., Lee, H. C., Carmichael, S. L. 2019

    Abstract

    To evaluate the relationship between prenatal and postnatal inflammation-related risk factors and severe retinopathy of prematurity (ROP).The study included infants born <30 weeks in California from 2007 to 2011. Multivariable log-binomial regression was used to assess the association between prenatal and postnatal inflammation-related exposures and severe ROP, defined as stage 3-5 or surgery for ROP.Of 14,816 infants, 10.8% developed severe ROP. Though prenatal inflammation-related risk factors were initially associated with severe ROP, after accounting for the effect of these risk factors on gestational age at birth through mediation analysis, the association was non-significant (P?=?0.6). Postnatal factors associated with severe ROP included prolonged oxygen exposure, sepsis, intraventricular hemorrhage, and necrotizing enterocolitis.Postnatal inflammation-related factors were associated with severe ROP more strongly than prenatal factors. The association between prenatal inflammation-related factors and ROP was explained by earlier gestational age in infants exposed to prenatal inflammation.

    View details for PubMedID 30932029

  • Prepregnancy maternal body mass index and venous thromboembolism: A population based cohort study. BJOG : an international journal of obstetrics and gynaecology Butwick, A. J., Bentley, J., Leonard, S. A., Carmichael, S. L., El-Sayed, Y. Y., Stephansson, O., Guo, N. 2018

    Abstract

    OBJECTIVE: To assess the relationship between maternal body mass index (BMI) and pregnancy-related venous thromboembolism (VTE).DESIGN: Cross-sectional study.SETTING & POPULATION: 2,449,133 women with singleton pregnancies who underwent delivery hospitalization in California between 2008 and 2012.METHODS: Association of prepregnancy BMI and the risk of an antepartum and postpartum VTE was examined using logistic regression, with normal BMI as reference.MAIN OUTCOME MEASURES: Antepartum and postpartum VTE related hospitalization.RESULTS: The prevalences of antepartum and postpartum VTE increased with increasing BMI (antepartum: 2.3, 3.0, 3.8, 4.2, 4.7, and 10.6 per 10 000 women for underweight, normal BMI, overweight, obesity class I, II, and III, P<0.001. postpartum: 2.0, 3.1, 3.9, 5.6, 9.0, and 13.2 per 10 000 women, P<0.01). The adjusted odds of antepartum and postpartum VTE increased progressively with increasing BMI, and obese class III women being at highest risk of pregnancy-related VTE compared with normal BMI women: adjusted odds ratio (OR) for antepartum VTE: 2.9; 95% CI 2.2-3.8 and adjusted OR for postpartum VTE: 3.6; 95% CI 2.9-4.6.CONCLUSIONS: Our findings clearly demonstrate an increasing risk of pregnancy-related VTE with increasing BMI. This article is protected by copyright. All rights reserved.

    View details for PubMedID 30500109

  • Maternal body mass index and risk of intraventricular hemorrhage in preterm infants. Pediatric research Pai, V. V., Carmichael, S. L., Kan, P., Leonard, S. A., Lee, H. C. 2018

    Abstract

    BACKGROUND: Intraventricular hemorrhage (IVH) and pre-pregnancy obesity and underweight have been linked to inflammatory states. We hypothesize that IVH in preterm infants is associated with pre-pregnancy obesity and underweight due to an inflammatory intrauterine environment.METHODS: Population-based study of infants born between 22 and 32 weeks' gestation from 2007 to 2011. Data were extracted from vital statistics and the California Perinatal Quality Care Collaborative. Results were examined for all cases (any IVH) and for severe IVH.RESULTS: Among 20,927 infants, 4,818 (23%) had IVH and 1,514 (7%) had severe IVH. After adjustment for confounders, there was an increased risk of IVH associated with pre-pregnancy obesity, relative risk 1.14 (95% CI 1.06, 1.32) for any IVH, and 1.25 (85% CI 1.10, 1.42) for severe IVH. The direct effect of pre-pregnancy obesity on any IVH was significant (P<0.001) after controlling for antenatal inflammation-related conditions, but was not significant after controlling for gestational age (P=0.56).CONCLUSION: Pre-pregnancy obesity was found to be a risk factor for IVH in preterm infants; however, this relationship appeared to be largely mediated through the effect of BMI on gestational age at delivery. The etiology of IVH is complex and it is important to understand contributing maternal factors.Pediatric Research accepted article preview online, 06 April 2018. doi:10.1038/pr.2018.47.

    View details for PubMedID 29624572

  • Healthier vending machines in a university setting: Effective and financially sustainable. Appetite Viana, J., Leonard, S. A., Kitay, B., Ansel, D., Angelis, P., Slusser, W. 2018; 121: 263?67

    View details for DOI 10.1016/j.appet.2017.11.094

    View details for PubMedID 29137969

  • Do the health benefits of education vary by sociodemographic subgroup? Differential returns to education and implications for health inequities. Annals of epidemiology Vable, A. M., Cohen, A. K., Leonard, S. A., Glymour, M. M., Duarte, C. D., Yen, I. H. 2018; 28 (11): 759?66.e5

    Abstract

    Evidence suggests education is an important life course determinant of health, but few studies examine differential returns to education by sociodemographic subgroup.Using National Longitudinal Survey of Youth 1979 (n = 6158) cohort data, we evaluate education attained by age 25 years and physical health (PCS) and mental health component summary scores (MCS) at age 50 years. Race / ethnicity, sex, geography, immigration status, and childhood socioeconomic status (cSES) were evaluated as effect modifiers in birth year adjusted linear regression models.The association between education and PCS was large among high cSES respondents (? = 0.81 per year of education, 95% CI: 0.67, 0.94), and larger among low cSES respondents (interaction ? = 0.39, 95% CI: 0.06, 0.72). The association between education and MCS was imprecisely estimated among White men (? = 0.44; 95% CI: -0.03, 0.90), while, Black women benefited more from each year of education (interaction ? = 0.91; 95% CI: 0.19, 1.64). Similarly, compared to socially advantaged groups, low cSES Blacks, and low and high cSES women benefited more from each year of education, while immigrants benefited less from each year of education.If causal, increases in educational attainment may reduce some social inequities in health.

    View details for PubMedID 30309690

    View details for PubMedCentralID PMC6215723

  • Breastfeeding Is Associated With Reduced Obesity in Hispanic 2- to 5-Year-Olds Served by WIC. Journal of nutrition education and behavior Whaley, S. E., Koleilat, M., Leonard, S., Whaley, M. ; 49 (7S2): S144?S150.e1

    Abstract

    To examine the relationship between breastfeeding (BF) and odds of childhood obesity in a large, primarily Hispanic Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) population.A large urban WIC program in California.Infants enrolled in WIC born between 2004 and 2007 and observed to age 5 years (N = 39,801; 88.6% Hispanic).Level of BF: fully BF, fully formula feeding, or combination feeding.Obesity at age 2-5 years, measured by body mass index (BMI) ? 95th percentile.Logistic regression analyses to evaluate the association between initiation, duration, and exclusivity of BF and odds of obesity at age 2-5 years, controlling for ethnicity, preferred language, family size, poverty level, and maternal BMI.Infants exclusively formula fed at birth were significantly more likely than fully breastfed infants to be obese at age 2-5 years (?(2) [2, N = 39,801] = 123.31; P < .001). For every additional month of any BF, obesity risk at age 2-5 years decreased by 1%. Every additional month of full BF conferred a 3% decrease in obesity risk. Ethnicity, preferred language, family size, poverty level, and maternal BMI were also significantly related to obesity risk.Breastfeeding may have a role in the attenuation of obesity in early childhood among Hispanic children. The BF promotion and support offered at WIC may have a significant role in reducing rates of early childhood obesity.

    View details for DOI 10.1016/j.jneb.2017.03.007

    View details for PubMedID 28689551

  • Living in Violent Neighbourhoods is Associated with Gestational Weight Gain Outside the Recommended Range PAEDIATRIC AND PERINATAL EPIDEMIOLOGY Galin, J., Abrams, B., Leonard, S. A., Matthay, E. C., Goin, D. E., Ahern, J. 2017; 31 (1): 37-46

    Abstract

    During pregnancy, most women do not meet gestational weight gain (GWG) guidelines, potentially resulting in adverse maternal and infant health consequences. Social environment determinants of GWG have been identified, but evidence on the relationship between neighbourhood violence and GWG is scant. Our study aims to examine the relationship between neighbourhood violence and GWG outside the recommended range.We used statewide vital statistics and health care utilization data from California for 2006-12 (n = 2 364 793) to examine the relationship of neighbourhood violence (quarters of zip-code rates of homicide and assault) in the first 37 weeks of pregnancy with GWG (categorized using the Institute of Medicine's pregnancy weight gain guidelines). We estimated risk ratios (RR) and marginal risk differences, and analyses were stratified by maternal race/ethnicity and prepregnancy body mass index.Residence in neighbourhoods with the highest quartile of violence was associated with more excessive GWG (adjusted RR 1.04, 95% confidence interval CI 1.03, 1.05), compared to the lowest quartile of violence; violence was not associated with inadequate GWG. On the difference scale, this association translates to 2.3% more women gaining weight excessively rather than adequately if all women were exposed to high violence compared to if all women were exposed to low violence. Additionally, associations between neighbourhood violence and excessive GWG were larger in non-white women than in white women.These findings support the hypothesis that violence can affect weight gain during pregnancy, emphasizing the importance of neighbourhood violence as a public health issue.

    View details for DOI 10.1111/ppe.12331

    View details for Web of Science ID 000392509800007

    View details for PubMedID 27921300

    View details for PubMedCentralID PMC5195875

  • Associations of maternal obesity and psychosocial factors with breastfeeding intention, initiation, and duration(1-4) AMERICAN JOURNAL OF CLINICAL NUTRITION Hauff, L. E., Leonard, S. A., Rasmussen, K. M. 2014; 99 (3): 524-534

    Abstract

    Psychosocial factors influence breastfeeding outcomes, but little is known about these characteristics and how they influence breastfeeding behavior of obese women, who are a group that experiences poor breastfeeding outcomes.Our objectives were to determine whether 1) maternal prepregnancy body mass index (BMI) is associated with social knowledge of, social influence toward, maternal confidence in, and behavioral beliefs about breastfeeding; 2) BMI and these psychosocial factors predict outcomes of intention to breastfeed, ever breastfed, and the duration of breastfeeding; and 3) BMI and psychosocial factors are associated with these breastfeeding outcomes independent of each other.Participants (n = 2824) in the Infant Feeding Practices Study II provided data on psychosocial characteristics and breastfeeding outcomes. In this prospective cohort study, data were analyzed by using logistic and proportional hazards regression models.Prepregnancy BMI was associated with confidence in (P < 0.0001), social influence toward (P = 0.02), and social knowledge of (P < 0.0001) breastfeeding but not with behavioral beliefs about breastfeeding (P = 0.45). Obese women did not differ from under- and normal-weight women in the intention to breastfeed (P = 0.07) but had lower odds of ever breastfeeding (P = 0.04) and were at greater risk of an earlier cessation of exclusive (P = 0.0009) and any (P = 0.03) breastfeeding. Only the association with exclusive breastfeeding remained significant after controlling for psychosocial factors (P = 0.01). All psychosocial factors were positively associated with each breastfeeding outcome.Despite their intentions to breastfeed, women with high prepregnancy BMI had psychosocial characteristics associated with poor breastfeeding outcomes. However, these characteristics did not fully explain the association between maternal obesity and breastfeeding outcomes.

    View details for DOI 10.3945/ajcn.113.071191

    View details for Web of Science ID 000332143900015

    View details for PubMedID 24401717

    View details for PubMedCentralID PMC3927688

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