Adverse birth outcomes like preterm birth and infant mortality are unevenly distributed across socio-economic groups. Risks are usually lowest in groups with high socio-economic status and increase with decreasing status. The general aim of this thesis was to contribute to the understanding of the relation between socio-economic status and birth outcomes, focussing on maternal education and class, studying a range of birth outcomes. More specific aims were to investigate the relation between maternal education and infant health, to study the combined influence of maternal childhood and adult social class on inequalities in infant health and to explore the contribution of maternal working conditions to class inequalities in birth outcomes. The studies are population based, focussing on singletons births 1973-1990. During the period under study, educational differences in birth outcomes increased, especially between those with the lowest and highest education. The low birth weight paradox emerged, suggesting that the distribution of determinants for low birthweight infants differs for these groups. Further, an independent association was found between maternal childhood social class and low birthweight and neonatal mortality, but not for postneonatal mortality. Since this was found for the two outcomes closest to birth, this indicates that the association is mediated through the maternal body. Finally, there is a contribution of maternal working conditions to class inequalities in birth outcome. Lower job control, higher job hazards and higher physical demands were all to some degree related to increased risk of the following adverse birth outcomes: infant mortality, low birthweight, very low birthweight, foetal growth, preterm birth, very and extremely preterm birth. Working conditions demonstrated disparate associations with the birth outcomes, indicating a high complexity in these relationships.

Background: Some studies have suggested that the risk of preeclampsia in HIV positive pregnant women has increased since the use of HAART became routine. There is also a concern that HIV positive women on HAART have a higher risk of adverse fetal outcomes compared to HIV negative women. Methods: In this matched retrospective cohort study, the risk of preeclampsia and adverse fetal outcomes was examined in 91 HIV positive pregnant women receiving HAART and 273 HIV negative pregnant women. Multivariate logistic regression models were used to adjust for confounding factors. Results: The risk of preeclampsia and preterm birth did not differ significantly between HIV positive and HIV negative women. HIV treated with HAART was an independent predictor for giving birth to a low birthweight baby. Conclusions: HIV positive women on HAART do not have a higher risk of preeclampsia. They do however have a higher risk for lower birthweight infants.

Background: Some studies have suggested that the risk of preeclampsia in HIV positive pregnant women has increased since the use of HAART became routine. There is also a concern that HIV positive women on HAART have a higher risk of adverse fetal outcomes compared to HIV negative women. Methods: In this matched retrospective cohort study, the risk of preeclampsia and adverse fetal outcomes was examined in 91 HIV positive pregnant women receiving HAART and 273 HIV negative pregnant women. Multivariate logistic regression models were used to adjust for confounding factors. Results: The risk of preeclampsia and preterm birth did not differ significantly between HIV positive and HIV negative women. HIV treated with HAART was an independent predictor for giving birth to a low birthweight baby. Conclusions: HIV positive women on HAART do not have a higher risk of preeclampsia. They do however have a higher risk for lower birthweight infants.

The Atlanta Beltline is an urban redevelopment project that was designed to increase access to trails, parks, and greenspace in Atlanta, Georgia. Thirty-three miles of new trail will be developed, providing a place for the community to engage in purposeful physical activity and active transport around the city of Atlanta. Because physical activity is associated with improvements in birth outcomes and under the assumption that close proximity to the Atlanta Beltline encourages physical activity, I hypothesize that women residing within 0.5 mile of the Atlanta Beltline will show improvements in birth outcomes, as compared to women residing 1-1.5 miles away from the Beltline. Birth outcomes were measured as rates for low birth weight, premature live birth, and fetal mortality rates. Census tract data for birth outcomes for the time period “pre-Beltline,” 2002 - 2007, and “post-Beltline,” 2008 - 2012, was obtained from Georgia Department of Public Health. 18 census tracks in three areas along the Beltline (Northside, Eastside, West End) were identified as exposed and 17 in the same areas were unexposed. We found the following mean rates (SDs) of the outcomes in the exposed census tracks during the pre-Beltline period: 119.22 (48.39) low birth weight, 154.94 (55.80) premature birth, and 16.17(15.81) fetal death, all per 1,000 live birth. During the post-Beltline period in the exposed area, these measurements were: 107.55 (39.66) low births weight, 131.06 (48.92) premature birth, and 12.28 (13.51) fetal death, all per 1000 live birth. In the unexposed census tracks during the pre-Beltline period, mean rates (SDs) of the outcomes were 110.82 (42.81) low births weight, 144.88 (46.49) premature birth, and 19.94 (35.45) fetal death, all per 1000 live birth. During the post-Beltline period, these measurements in the unexposed area were: 100.88 (40.76) low births, 134.17 (47.85) premature birth, and 8.06 (6.89) fetal death, all per 1000 live birth. Overall in both the exposed and unexposed areas, the time trends for the examined measurements of birth outcomes were towards improvement; however, only a decrease in premature live birth in the exposed area (p=0.2) and fetal mortality in the unexposed area (p=0.1) were of statistically marginal significance. We conclude that currently no significant improvements in birth outcomes, associated with close proximity to the Atlanta Beltline have been detected.

Vitamin D status is assessed with circulating 25-hydroxyvitamin D [25(OH)D]. As some evidence suggests that low vitamin D status adversely affects neonatal health, this project aimed to determine the association between cord blood 25(OH)D levels and preterm birth (PTB; <37 weeks gestation), low birthweight (LBW; <2500 grams) and small for gestational age (SGA; <10th percentile) and to examine the relationship between maternal 25(OH)D levels during the first trimester of pregnancy and fetal 25(OH)D levels at birth in a Canadian population. This nested case-control study used serums, questionnaires and chart reviews collected in Quebec City. Compared to 25(OH)D concentrations ≥75 nmol/L, concentrations 37.5-<75, 50-<75, and <75 nmol/L were associated with lower odds of LBW, PTB and an adverse neonatal composite outcome, and PTB as well as LBW, respectively. Maternal and neonatal 25(OH)D were correlated (r=0.23, p<0.01; adjusted r=0.46, p<0.01). This study contributes to evidence for identifying further policy and research directions.

Introduction: The past decade has seen a significant shift in the demographics of childbearing in the United States. The average age of women at first birth has steadily increased over the last four decades, with the birth rate for women aged 40-44 more than doubling from 1990 to 2012. The aim of this study was to evaluate the risk of adverse pregnancy outcomes with increasing maternal age and paternal age using national health statistics data. Methods: The study population included 3 495 710 live births among women 15-54+ years of age from the 2012 Natality dataset. Outcomes were modeled for both maternal and paternal 5-year age groups using logistic regression analysis to calculate adjusted and unadjusted odds ratios (AORs, ORs) with 95% confidence intervals. Analysis was performed to examine the association between maternal and paternal age across seven different adverse outcomes, including low birthweight, low Apgar score, early term pregnancies, abnormal newborn conditions and presence of congenital anomalies. Results: The risks for most outcomes paralleled with advanced maternal age and paternal age. Logistic regression models demonstrated that maternal age groups 40-44, 45-49 and 50-54+ were at highest risk for an adverse pregnancy outcome compared to the 30-34 year old reference group. Abnormal newborn conditions including assisted ventilation, NICU admission and use of antibiotics were significant for all age groups 40 and older. Low Apgar score, low birthweight and early term pregnancies were significantly higher among mothers as well as fathers with advanced age. Conclusions: These findings suggest that advanced maternal age is a risk factor for a variety of adverse pregnancy outcomes. Women aged 35-39 have a similar risk of an adverse outcome as their younger counterparts. This suggests that perhaps we should begin assessing high-risk pregnancies as starting at an older age versus the de facto standard of 35.

Contexte : La corpulence de la femme est fortement associée à la croissance foetale. C’est pourquoi l’augmentation du poids des femmes en France devrait s’accompagner d’une augmentation parallèle du poids de naissance. Des modèles animaux ont récemment suggéré qu’en dehors de l’IMC avant grossesse, les variations du poids maternel dans la période périconceptionnelle peuvent être des indicateurs de son statut nutritionnel pendant cette période et influencer la croissance foetale et le déroulement de la grossesse.Objectif : 1) Evaluer les évolutions de la corpulence des femmes et du poids de naissance. 2) Analyser le rôle de la nutrition périconceptionnelle maternelle sur la croissance foetale et le déroulement de la grossesse.Populations : Les données utilisées pour cette thèse sont celles des enquêtes ObEpi, des enquêtes nationales périnatales françaises et de l’étude EDEN. 1) Pour chaque année d’enquête ObEpi (1997, 2000, 2003, 2006), des données sur le poids et la taille ont été obtenues par des questionnaires envoyés à 20000 ménages représentatifs de la population nationale. 2) Les paires mère-enfant parmi les naissances uniques vivantes des enquêtes périnatales de 1972, 1981, 1995, 1998 et 2003 ont été sélectionnées (n=8664, 4494, 11445, 12006, 12692, respectivement). Lors des enquêtes périnatales, les mères ont répondu à des questionnaires quelques jours après l’accouchement et des données sur le nouveau-né et l’accouchement ont été obtenues à partir du dossier médical. 3) Dans l’étude EDEN qui a inclu 2002 femmes recrutées dans les centres de Nancy et de Poitiers, les poids des femmes à l’âge de 20 ans et juste avant la grossesse, l’anthropométrie du foetus aux 2nd et 3`eme trimestres, le poids de naissance et les complications de la grossesse ont été recueillis. Des mesures de poids des femmes au cours de la grossesse ont été disponibles et ont permis d’estimer le poids des femmes à chaque semaine de la grossesse avec un modèle mixte.Résultats : L’analyse d’un effet cohorte de naissance avec les données des enquêtes ObEpi a montré une accélération de l’augmentation de la prévalence de l’obésité pour les générations nées après les années 1960 en particulier chez les femmes. L’augmentation de l’IMC avant grossesse en France s’est accompagnée d’une augmentation du poids de naissance de 1972 à 1995, avec une tendance à la baisse du poids de naissance par la suite. Par ailleurs, nous avons mis en évidence qu’une perte de poids depuis l’âge de 20 ans chez les femmes qui avaient un IMC <25kg/m2 était associée à un risque augmenté d’avoir un bébé petit pour son âge gestationnel après ajustement sur l’IMC avant grossesse. Une prise de poids avant la grossesse était associée à des risques augmentés de diabète et d’hypertension gestationnels après ajustement sur l’IMC avant grossesse. La variation du poids de la femme au premier trimestre de la grossesse était spécifiquement associée à la croissance fœtale et à la corpulence du nouveau-né indépendamment des variations au 2nd et au 3ème trimestres.Conclusion : Les hommes et les femmes nés après les années 1960 ont été exposés à un environnement qui a augmenté leur susceptibilité à l’obésité tout au long de la vie. Par ailleurs, des recherches supplémentaires sont nécessaires pour comprendre les facteurs associés à la non augmentation du poids de naissance depuis les années 1995 malgré une augmentation du poids des femmes. Nos résultats font penser que les variations de poids pré-conceptionnelles pourraient être prises en compte dans l’évaluation du risque obstétrical. / Birthweight is strongly and positively related to maternal preconceptional weight as well as with weight gain during pregnancy. Therefore, it would be expected that the increase in maternal weight before pregnancy, and weight gain during pregnancy, would be associated with an increase in birthweight in France. Animal models suggested that maternal weight changes in the periconceptional period can be considered as indicators of maternal energy balance and nutritional status, and may be involved in fetal growth and pregnancy outcomes.Obejective : 1) To evaluate time trends in maternal body size and birthweight. 2) To investigate the association of maternal weight changes in the periconceptional period with fetal growth and adverse pregnancy outcomes.Background : Birthweight is strongly and positively related to maternal preconceptional weight as well as with weight gain during preg Populations : Data were from ObEpi surveys ; French nationally representative perinatal surveys and the EDEN study. 1) For every ObEpi survey (1997, 2000, 2003 and 2006), data on weight and height were obtained for 20000 households representative of the French population.2) Mother-child pairs among singleton live births were included in the national perinatal surveys in 1972, 1981, 1995, 1998 and 2003 (n=8664, 4494, 11445, 12692 respectively). Mothers were interviewed a few days after delivery and data on delivery and the newborn were extracted from hospital records. 3) In the EDEN mother-child cohort, 1756 mother–child pairs had information on mother’s weight at 20 years, weight just before pregnancy, fetal anthropometry at second and third trimesters, infant’s birthweight and pregnancy complications. Also in the EDEN study 1744 women had prepregnancy weight available and at least 5 measures of weight in pregnancy. We extrapolated women’s weight at each week of gestation with a three-degrees polynomial model and estimated weight change during each trimester of gestation.Results : 1) Analyses based on data from ObEPI surveys showed that more recent cohorts (those born after the 1960’s) experienced an accelerated increase in the prevalence of obesity in relation to age during 1997-2006 particularly for women when compared with older birth cohorts. 2) Body mass index and weight gain during pregnancy increased between 1972 and 2003 ; paradoxically birth weight did not show a parallel increase. In fact, after adjusting for several potential confounders birthweight showed a decrease between 1995 and 2003.This corresponded with an increase in babies born small-for-gestational age (SGA) and a decrease in those born large-for-gestational age (LGA). 3) In women with BMI < 25 kg/m2, weight loss before pregnancy was associated with less fetal growth and increased risk of SGA.Factors including anemia and pathologies such as cancer were also considered but did not explain the findings. On the other hand, “large” weight gain between age 20 and pregnancy was associated with increased risk of gestational diabetes irrespective of overweight status of the woman. 4) Lastly, a significant association between the variation in maternal weightover the first trimester of pregnancy and fetal growth was noted even after accounting for the variation in weight over the last two trimesters. This association was independent of weight gain later in pregnancy and was partly explained by placental weight showing the importance of periconceptual nutritional status.Conclusion : Although the obesity epidemic became apparent in adults only in the 1990s in France, some of its origins can be found as early as the mid 1960s. The increasing trend in the prevalence of SGA in France, and in other countries such like the US, should prioritize research efforts towards a better understanding of the causes of this time trend. Our datasuggest that weight changes in periconceptional period could be taken into account when evaluating the obstetrical risk.

Background: Neonatal Abstinence Syndrome (NAS), a manifestation of the widespread opioid epidemic, has plagued our country, and particularly the region of Northeast Tennessee, for quite some time now. One question among many that seems to baffle almost everyone involved in research on the topic at hand is that why do only 35-40% of opioid exposed pregnancies result in NAS requiring medication while sparing the rest. Is there some discriminatory factor other than in utero opioid exposure involved? Thus, in light of this knowledge, we wanted to investigate whether birth weight at the time of delivery can influence the development of NAS; that is, are neonates of a low birth weight or high birth weight (with respect to gestational age thresholds) more likely to develop NAS. Methods: Therefore, we conducted a retrospective chart analysis of all deliveries within the Mountain States Health Alliance System over a 5 years period between July 1, 2011- June 30, 2016 at all 5 delivery sites in Northeast Tennessee and Southwest Virginia (N=18,728). Out of this sample size, we identified 2,392 at-term newborns as positive for prenatal opioid exposure, and then we stratified them into 2 categories: birth weight ≤3.5kg (proxy for low or average birth weight with respect to gestational age thresholds) and birth weight ≥3.5kg (proxy for high birth weight with respect to gestational age thresholds). Thereafter, we ran SPSS statistical analyses involving chi square, t tests, and logistic regression to assess whether one birth weight group was more likely to have a higher incidence rate of NAS compared to the other birth weight group. Results: We found that even after controlling for significant confounders such as marital status, race, and pregnancy smoking, benzodiazepine, and marijuana use, infants who were in the low to average birth weight group (≤3.5kg in this study) were almost twice as likely (statistically significant adjusted odds ratio of 1.95) to develop NAS compared to infants who were in the high birth weight group (≥3.5kg in this study). Our study helps shed some important light on the discriminatory factors for NAS development, with birth weight being a significantly associated clinical factor as we now know. Discussion & Implications: Unfortunately, the mechanism for the transport of opioids across the placenta is complicated, and poorly understood. There may be more ‘unbound or free opioids’ available in infants of low to average birth weight (with respect to gestational age thresholds) compared to infants of high birth weight (with respect to gestational age thresholds) resulting in a higher incidence of NAS in the former population. It is more of a speculation rather than a conclusion to explain the results of our study. However, being equipped with this knowledge that opioid exposed neonates of low to average birth weight (with respect to gestational age thresholds) have a higher risk of developing NAS will allow physicians to identify infants with a higher risk for NAS early, and this will subsequently lead to better outcomes and reduced severity in cases of NAS.

Infant mortality (IM) rates in the United States remains high. The higher rates of IM among specific groups in the United States is believed to be fueled by the high rates of adverse birth outcomes including low birthweight (LBW) and preterm births (PTB) among these groups. Adverse birth outcomes have also been linked to the presence of hypertensive disorders during pregnancy. The purpose of this cross-sectional study was to explore the association between hypertensive disorders during pregnancy and adverse birth outcomes and the impact of the residential neighborhood of expectant mothers on this association. The life course health development theory guided the framework for this study. Study data were obtained from the 2010 New York City birth records and the 2010 US Census. Descriptive statistics and logistic regression analysis were used to address the 3 research hypotheses of the study. The study found that prepregnancy hypertension (HTN) (AOR: 2.84 & 3.25), gestational HTN (AOR: 2.28 & 3.33) and eclampsia (AOR: 4.41 & 6.70) were significantly associated with PTB and LBW respectively. Neighborhood segregation was not significant for PTB (AOR: 1.01) or LBW (AOR: 1.03). Neighborhood poverty was significant for PTB (AOR: 0.86) but not for LBW (AOR: 1.05). Neighborhood segregation and poverty had significant moderating effects on the prepregnancy HTN (p = 0.00), gestational HTN (p = 0.00), eclampsia (p = 0.00) and PTB and LBW association. Results from this study can help to address disparities in birth outcomes among women of differing races and ethnicities and thereby contribute to positive social change.

Hypertension is a chronic disease with an estimated prevalence of nearly 50% in US adults. In addition to sociodemographic and lifestyle factors, evidence suggests that in utero and early life exposures may contribute to life-long risk of hypertension. This study aimed to investigate the potential associations between an individual’s birthweight and preterm birth status with their risk for hypertension in the Women’s Health Initiative (WHI) cohort. WHI is a large, multi-racial cohort of postmenopausal women. At study entry, birthweight and preterm birth status were self-reported by category (< 6 lbs., 6-7 lbs. 15 oz., 8-9 lbs. 15 oz., or ≥ 10 lbs.; ≥ 4 weeks premature or full term). Baseline and incident hypertension status were self-reported; mean systolic blood pressure, diastolic blood pressure, and 30-second pulse were also recorded at baseline by trained study staff. Linear, logistic, and Cox-proportional hazards regression models were used to generate crude and adjusted beta estimates, odds ratios, and hazards ratios, respectively. After adjusting for demographic and lifestyle factors, we found that participants born at a low birthweight had a higher mean systolic blood pressure than participants born at a normal birthweight and were at increased risk for both baseline and incident hypertension. Women born at a higher birthweight had a lower mean systolic blood pressure and were at lower risk for baseline and incident hypertension. When compared to participants born full term, participants born preterm were at increased risk for baseline and incident hypertension. These results support current research on early life exposures and health risks later in life. Long term follow-up or targeted counseling may be required for individuals born prematurely or at low birthweights to prevent and treat hypertension and associated cardiovascular outcomes.