Population-based Birth Registry Research Articles

The prevalence of anemia during pregnancy and its correlates vary by trimester and hemoglobin assessment method in Eastern Maharashtra, India.

Approximately half of pregnant women in India are anemic, representing over 7.5 million women. Few studies have assessed the relationship between multiple micronutrient deficiencies and anemia during pregnancy or the trajectory of hemoglobin (Hb) during pregnancy in low-resource settings. We enrolled 200 pregnant women from the Maternal and Newborn Health (MNH) registry, a population-based pregnancy and birth registry in Eastern Maharashtra, India to address these gaps. The women provided capillary (finger-prick) and venous blood specimens at enrollment (<15 weeks), and a second capillary specimen in the 3rd trimester (>27 weeks). Capillary specimens were analyzed at the time of collection with a HemoCue Hb 201+; venous specimens were shipped on dry ice to a laboratory for cyanmethemoglobin assessment. In the 1st trimester, mean Hb concentration and anemia (Hb<11.0 g/dL) prevalence using capillary specimens were 10.9 ± 1.5 g/dL and 51.1%; mean Hb concentration using venous blood specimens was estimated to be 11.3 ± 1.3 g/dL and anemia prevalence was 37.5%. The prevalence of iron, vitamin B12 and folate deficiencies were 40%, 30% and 0%, respectively. Among women with anemia in the 1st trimester (venous blood), 56% had concurrent iron deficiency (inflammation-adjusted serum ferritin <15 µg/L) indicating that their anemia may be amenable to iron supplementation. In total, 21% of women had ID and anemia, 19% ID in the absence of anemia, 16.5% anemia in the absence of ID and 43.5% had neither. By the 3rd trimester, mean Hb from capillary specimens had declined to 10.1 ± 1.35 g/dL and anemia prevalence increased to 70.7%, despite 99.4% mothers reporting receipt of iron-folic acid (IFA) supplements during her current pregnancy, and 83.9% reporting IFA consumption the previous day. Significant predictors of anemia in the 1st trimester (both venous and capillary) included the number of weeks gestation at the time of Hb assessment and inflammation-adjusted serum ferritin. For 3rd trimester anemia, significant predictors included 1st trimester height, BMI and IFA consumption during the 3rd trimester (but not 1st trimester micronutrient biomarkers), indicating that IFA supplementation over the course of pregnancy may have influenced micronutrient status and anemia risk. Our findings highlight the severity of the burden of anemia and micronutrient deficiencies in Eastern Maharashtra, but also highlight that in many cases, ID and anemia affect different individuals. Preventing and managing anemia in pregnancy in India will require strengthening both clinical and community-based strategies targeting iron deficiency, as well as other causes of anemia.

Antenatal corticosteroids and newborn respiratory outcomes in twins: A regression discontinuity study.

To estimate the effect of antenatal corticosteroids on newborn respiratory morbidity in twins. Regression discontinuity applied to population-based birth registry data. British Columbia, Canada, 2008-2018. Twin pregnancies admitted for birth between 31+0 and 36+6 weeks of gestation. During our study period, Canadian clinical practice guidelines recommended antenatal corticosteroid administration for imminent preterm birth up to 33+6 weeks. We used a logistic model to compare the predicted risks of our outcomes among pregnancies admitted for birth immediately before this clinical cut-point (higher probability of exposure to antenatal corticosteroids) versus immediately after it (lower probability). Our primary outcome was a composite of newborn respiratory distress or in-hospital death. Our secondary outcome was a composite of newborn respiratory intervention or in-hospital death. Among 2524 pregnancies (5035 liveborn twins), 47% of admissions before 34+0 weeks of gestation were exposed to antenatal corticosteroids but only 4.2% of admissions after this cut-point were exposed. The risk of newborn respiratory distress or in-hospital mortality increased abruptly at 34+0 weeks, corresponding to a protective effect of treatment (risk ratio [RR] 0.69, 95% CI 0.53-0.90; risk difference [RD]-12 cases per 100 births, 95% CI -20 to -4.1). There was no clear evidence for or against an effect on newborn respiratory intervention or in-hospital death (RR 0.89, 95% CI 0.70-1.13; RD -4.2 per 100, 95% CI -13 to +4.2). Our findings provide evidence for the effectiveness of antenatal corticosteroids in preventing adverse newborn respiratory outcomes in twins.

Relationship Between Gestational Weight Gain and Health Service Utilization in Early Childhood: A Retrospective Cohort Study.

Gestational weight gain (GWG) outside recommended ranges can negatively impact both the woman and child. The long-term effects of below-recommended or above-recommended GWG on the child are unclear. This retrospective cohort study used a population-based birth registry of 258,005 live births to evaluate the relationship between maternal GWG and paediatric health service use. The results suggest below recommended GWG in underweight women in particular is associated with an increased rate of hospitalizations and specialist visits for the child in the first 24months. Findings indicate that GWG may impact paediatric outcomes in ways that depend on pre-pregnancy body mass index, as derived from maternal height and weight measures.

Seasonal trends and maternal characteristics as predictors of maternal undernutrition and low birthweight in Eastern Maharashtra, India.

Few studies have assessed whether women and infants in rural and peri‐urban communities in South Asia experience seasonal fluctuations in nutritional status; however, a handful of studies have documented seasonal variability in risk factors for undernutrition including food availability, physical activity and infections. We used data from the Maternal and Newborn Health (MNH) registry, a population‐based pregnancy and birth registry in Eastern Maharashtra, India, to analyse seasonal trends in birthweight and maternal nutritional status—body mass index (BMI) and haemoglobin—in the first trimester of pregnancy. We plotted monthly and seasonal trends in birthweight, and maternal BMI and haemoglobin, and used multivariable regression models to identify seasonal and maternal characteristics that predicted each outcome. Between October 2014 and January 2018, MNH included 29,253 livebirths with recorded birthweight. BMI was assessed in 15,252 women less than 12 weeks of gestation and haemoglobin in 18,278 women less than 13 weeks of gestation. Maternal characteristics (age, education, parity and height) were significantly associated with nutritional status; however, there were minimal seasonal fluctuations in birthweight or maternal nutrition. There were significant secular trends in maternal haemoglobin; between 2014 and 2018, the prevalence of maternal anaemia decreased from 91% to 79% and moderate or severe anaemia from 53% to 37%. The prevalence of maternal underweight (45.3%) and overweight (9.8%) and low birthweight (19.1%) remained relatively constant over the study period. Our findings highlight that in some rural and peri‐urban areas in South Asia, tackling systemic drivers of malnutrition may be more effective than targeted interventions based on season.

Social variations in pregnancy outcomes in Murmansk county-one of the Northernmost European provinces

Abstract Background Pregnancy outcomes are widely used indicators of population wellbeing varying both between and within countries. The aim of this study was to assess social variations in preterm births and term small-for-gestation-age (SGA) infants in the Northernmost provinces of Europe - the Murmansk region - using the data from the first Russian population-based birth registry. Methods A registry-based study of 52 806 births in the Murmansk region for a 5-year period was performed. We studied the prevalence and social determinants of moderate-to-late preterm births (MLPTB, 224-258 days of gestation), very preterm births (VPTB, 196-223 days) and extremely preterm births (EPTB, 154-195 days) and term SGA for both weight and length births (SGAWL). Associations between social factors and pregnancy outcomes were studied by multivariable logistic regression. Results The prevalence of PTB was 6.9 with EPTB, VPTB and MLPTB constituting 0.3%, 0.6% and 6.0%, respectively. A total of 4.1% of infants were SGAWL. Women with primary, secondary and vocational education were 1.59 (95%CI:1.22-1.85), 1.33 (95%CI:1.20-1.48), 1.19 (95%CI:1.22-1.85) times more likely to have MLPTB than women with higher education. Corresponding values for VPTB were 1.65 (95%CI:0.88-3.08), 1.41 (95%CI:1.02-1.95) and 1.27 (95%CI:0.92-1.75), respectively. Single and cohabiting women had significantly elevated risk for MLPTB (ORs=1.47 (95%CI:1.30-1.66) and 1.39 (95%CI:1.26-1.44)) and VLPTB (ORs=2.00, 95% CI: 1.42-2.81 and 1.32, 95% CI: 0.97-1.79) compared to married women. Unmarried mothers were more likely to have SGAWL boys (OR = 1.60, 95% CI: 1.38-1.86) and SGAWL girls (OR = 1.51, 95%CI:1.31-1.76) compared to married women. Conclusions We observed significant social variations in pregnancy outcomes by maternal education and marital status in the Murmansk region. Registry data can be used as an effective tool for monitoring inequalities in pregnancy outcomes as indicators of social inequalities. Key messages We found significant social variations in pregnancy outcomes in the Northernmost province of Europe - the Murmansk county (Russia). Birth registry data can be used for monitoring of health inequalities in Russia.

THE USE OF A POPULAITON-BASED BIRTH REGISTRY TO STUDY INFANT MORTALITY IN AN ARCTIC RUSSIAN SETTING

The paper presents experience in probabilistic linkage of the records in the Arkhangelsk County Birth Registry with regional infant mortality data. Practical issues of the procedure of independent depersonalized datasets linkage are discussed. Two datasets have similar indirect identifiers that were used to match the records. The combined database contains information on maternal health and pregnancy outcome as well as infant health. Also, it includes data on infant's age at death and cause of death. Our experience can be useful for researchers dealing with registry-based studies in settings where personal identification numbers are not available. Linked data sets give an opportunity to explore risk factors of neonatal and infant death and to investigate survival in newborns having different health problems, including prematurity. Our experience can be used for development of large birth cohorts using the data from the population-based birth registries in the Russian North as baseline for studying long-term effects of factors during pregnancy on health later in life.

Caesarean Delivery in a German Population Based Birth Cohort with Special Focus on Maternal Request 1990-2013

Background: In the industrialized world, the proportion of caesarean sections (CS) is increasing over time. Estimating the incidence of caesarean delivery on maternal request (CDMR) to be 7–14% of all CS today. Previous studies described advanced maternal age, increasing maternal body mass index (BMI), multiple pregnancies, breech presentation, suspected low infant birthweight and private hospital status as reasons for the overall increase. The aim of this study was to evaluate the birth mode distribution in correlation to influencing factors over time. Methods: We analysed data on CDMR of the population-based Mainz birth registry from 1990-2013. The following known exposure were considered to be relevant: maternal age, BMI, diabetes, smoking and ethnicity, assisted reproductive technologies (ART), socioeconomic status of the family, infants birthweight, and year of data collection as a proxy for unknown risk factors. A logistic regression model quantifies the impact of these factors. Results: The overall proportion of CDMR was 4.1% of all births in the study period and 17.1% of all CS. The proportion of CDMR increased from 0.8% to 4.5% as well as CS from 16.4% to 29.5% from 1990 to 2013. The logistic regression model for CDMR showed significant results for maternal age, infants birthweight &gt;90%ile, ART, smoking mothers, BMI, and maternal diabetes. However, a large proportion of the yearly increase remains unexplained. Conclusion: Since the CDMR proportion rises over time independently from the other factors, there have to be other factors influencing the CDMR rate.

The association between sex and most childhood cancers is not mediated by birthweight

BackgroundMale sex is associated with an increased risk of childhood cancer as is high birthweight. Given that sex determination precedes birthweight we conducted a mediation analysis to estimate the direct effect of sex in association with childhood cancer tumor type with birthweight as the mediator. MethodsCases (n = 12,632) and controls (n = 64,439) (ages 0–14 years) were identified from population-based cancer and birth registries in Minnesota, New York, and Washington states (1970–2014). An inverse odds weighting (IOW) mediation analysis was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) as the measure of association between sex and cancer. ResultsA significant indirect effect was observed for sex and lymphoid leukemia, mediated by birthweight (indirectOR: 1.03; 95% CI: 1.02–1.04). We observed significant direct effects for male sex and lymphoid leukemia (directOR: 1.16; 95% CI: 1.08–1.25), Hodgkin lymphoma (directOR: 1.48; 95% CI: 1.22–1.81), Burkitt lymphoma (directOR: 5.02; 95% CI: 3.40–7.42), other non-Hodgkin lymphoma (directOR: 1.42; 95% CI: 1.18–1.70), intracranial embryonal tumors (directOR: 1.49; 95% CI: 1.26–1.76), hepatoblastoma (directOR: 1.90; 95% CI: 1.40–2.59), and rhabdomyosarcoma (directOR: 1.47; 95% CI: 1.19–1.81). There were also inverse associations for extracranial GCTs (directOR: 0.41; 95% CI: 0.26–0.63) and thyroid carcinoma (directOR: 0.35; 95% CI: 0.25–0.50). ConclusionSignificant direct effects for sex and numerous childhood cancer types suggests sex-specific factors such as differences in gene expression from the autosomes or the X chromosome, rather than birthweight, may underlie sex differences in tumor risk.

Trends and determinants of stillbirth in developing countries: results from the Global Network\u2019s Population-Based Birth Registry

BackgroundStillbirth rates remain high, especially in low and middle-income countries, where rates are 25 per 1000, ten-fold higher than in high-income countries. The United Nations’ Every Newborn Action Plan has set a goal of 12 stillbirths per 1000 births by 2030 for all countries.MethodsFrom a population-based pregnancy outcome registry, including data from 2010 to 2016 from two sites each in Africa (Zambia and Kenya) and India (Nagpur and Belagavi), as well as sites in Pakistan and Guatemala, we evaluated the stillbirth rates and rates of annual decline as well as risk factors for 427,111 births of which 12,181 were stillbirths.ResultsThe mean stillbirth rates for the sites were 21.3 per 1000 births for Africa, 25.3 per 1000 births for India, 56.9 per 1000 births for Pakistan and 19.9 per 1000 births for Guatemala. From 2010 to 2016, across all sites, the mean stillbirth rate declined from 31.7 per 1000 births to 26.4 per 1000 births for an average annual decline of 3.0%. Risk factors for stillbirth were similar across the sites and included maternal age < 20 years and age > 35 years. Compared to parity 1–2, zero parity and parity > 3 were both associated with increased stillbirth risk and compared to women with any prenatal care, women with no prenatal care had significantly increased risk of stillbirth in all sites.ConclusionsAt the current rates of decline, stillbirth rates in these sites will not reach the Every Newborn Action Plan goal of 12 per 1000 births by 2030. More attention to the risk factors and treating the causes of stillbirths will be required to reach the Every Newborn Action Plan goal of stillbirth reduction.Trial registrationNCT01073475.

Late preterm birth and previous cesarean section: a population-based cohort study

Background: Late preterm birth (LPB) is increasingly common and associated with higher morbidity and mortality than term birth. Yet, little is known about the influence of previous cesarean section (PCS) and the occurrence of LPB in subsequent pregnancies. We aim to evaluate this association along with the potential mediation by cesarean sections in the current pregnancy.Methods: We use population-based birth registry data (2005–2012) to establish a cohort of live born singleton infants born between 34 and 41 gestational weeks to multiparous mothers. PCS was the primary exposure, LPB (34–36 weeks) was the primary outcome, and an unplanned or emergency cesarean section in the current pregnancy was the potential mediator. Associations were quantified using propensity weighted multivariable Poisson regression, and mediating associations were explored using the Baron-Kenny approach.Results: The cohort included 481,531 births, 21,893 (4.5%) were LPB, and 119,983 (24.9%) were predated by at least one PCS. Among mothers with at least one PCS, 6307 (5.26%) were LPB. There was increased risk of LPB among women with at least one PCS (adjusted Relative Risk (aRR): 1.20 (95%CI [1.16, 1.23]). Unplanned or emergency cesarean section in the current pregnancy was identified as a strong mediator to this relationship (mediation ratio = 97%).Conclusions: PCS was associated with higher risk of LPB in subsequent pregnancies. This may be due to an increased risk of subsequent unplanned or emergency preterm cesarean sections. Efforts to minimize index cesarean sections may reduce the risk of LPB in subsequent pregnancies.

GESTATION-SPECIFIC LIVE-BORN SINGLETON NEWBORNS BIRTH WEIGHT, LENGTH AND HEAD CIRCUMFERENCE PERCENTILES AND CURVES (ARKHANGELSK COUNTY BIRTH REGISTRY DATA)

Birth weight, length and head assessment are important for postnatal confirmation of fetal growth retardation. In Russia, there has so far not been sex-specific, population-based birth weight, length and head circumference percentiles and curves for singleton newborns. The aim of this study was to develop percentiles and curves for live-born newborns born at 28-42 weeks of gestation and compare these to other available data from the literature. Data of the Arkhangelsk County Birth Registry (2012-2014), Russia, were used. In total, we included 42116 live-born newborns by both sex without congenital malformation that could potentially influence on the results of anthropometry at birth. Sex-specific birth weight, length and head circumference percentiles and curves were created between 28 and 42 weeks of gestation. Data on mean and standard deviation for each week of gestation both for male and female newborns are also presented. As we used data from a comprehensive, population-based birth registry, percentiles and curves in our study are representative also for other regions of Russia.

A prospective observational description of frequency and timing of antenatal care attendance and coverage of selected interventions from sites in Argentina, Guatemala, India, Kenya, Pakistan and Zambia.

BackgroundThe Global Network for Women’s and Children’s Health Research is one of the largest international networks for testing and generating evidence-based recommendations for improvement of maternal-child health in resource-limited settings. Since 2009, Global Network sites in six low and middle-income countries have collected information on antenatal care practices, which are important as indicators of care and have implications for programs to improve maternal and child health. We sought to: (1) describe the quantity of antenatal care attendance over a four-year period; and (2) explore the quality of coverage for selected preventative, screening, and birth preparedness components.MethodsThe Maternal Newborn Health Registry (MNHR) is a prospective, population-based birth and pregnancy outcomes registry in Global Network sites, including: Argentina, Guatemala, India (Belgaum and Nagpur), Kenya, Pakistan, and Zambia. MNHR data from these sites were prospectively collected from January 1, 2010 – December 31, 2013 and analyzed for indicators related to quantity and patterns of ANC and coverage of key elements of recommended focused antenatal care. Descriptive statistics were generated overall by global region (Africa, Asia, and Latin America), and for each individual site.ResultsOverall, 96% of women reported at least one antenatal care visit. Indian sites demonstrated the highest percentage of women who initiated antenatal care during the first trimester. Women from the Latin American and Indian sites reported the highest number of at least 4 visits. Overall, 88% of women received tetanus toxoid. Only about half of all women reported having been screened for syphilis (49%) or anemia (50%). Rates of HIV testing were above 95% in the Argentina, African, and Indian sites. The Pakistan site demonstrated relatively high rates for birth preparation, but for most other preventative and screening interventions, posted lower coverage rates as compared to other Global Network sites.ConclusionsResults from our large, prospective, population-based observational study contribute important insight into regional and site-specific patterns for antenatal care access and coverage. Our findings indicate a quality and coverage gap in antenatal care services, particularly in regards to syphilis and hemoglobin screening. We have identified site-specific gaps in access to, and delivery of, antenatal care services that can be targeted for improvement in future research and implementation efforts.Trial registrationRegistration at Clinicaltrials.gov (ID# NCT01073475)

Hyperemesis gravidarum and maternal cancer risk, a scandinavian nested case‐control study

Reproductive factors have been shown to influence cancer risk. Several pathological conditions during pregnancy have also been associated with subsequent altered cancer risk in the mother. Hyperemesis gravidarum (hyperemesis) is an early pregnancy condition characterized by severe nausea and vomiting resulting in weight loss and metabolic disturbances. Studies have reported associations between hyperemesis and cancer, but results are inconsistent. In this nested case-control study we linked the population-based medical birth registries and cancer registries in Norway, Sweden and Denmark in order to examine overall cancer risk and risk of specific cancer types in women with a history of hyperemesis, using conditional logistic regression. In total, 168,501 cases of cancer in addition to up to 10 cancer-free controls per case were randomly sampled, matched on year of birth and birth registry (n = 1,721,626). Hyperemesis was defined through the International Classification of Diseases. Analyses were adjusted for potential confounders. Hyperemesis was inversely associated with overall cancer risk with adjusted relative risk (aRR) of 0.93 (95% CI: 0.88-0.99), with cancer in the lungs (aRR: 0.60, 95% CI: 0.44-0.81), cervix (aRR: 0.66, 95% CI: 0.49-0.91) and rectum (aRR: 0.48, 95% CI: 0.29-0.78). Thyroid cancer was positively associated with hyperemesis (aRR 1.45, 95% CI: 1.06-1.99) and risk increased with more than one hyperemetic pregnancy (aRR 1.80, 95% CI: 1.23-2.63). Hormonal factors, in particular human chorionic gonadotropin, are likely to be involved in mediating these effects. This study is the first to systematically address these associations and provides valuable knowledge on potential long-term consequences of hyperemesis.

Caesarean section by immigrants' length of residence in Norway: a population-based study.

Immigrants to Europe account for a significant proportion of births in a context of rising caesarean rates. We examined the risk of planned and emergency caesarean section (CS) by immigrants' length of residence in Norway, and compared the results with those of non-immigrants. We linked population-based birth registry data to immigration data for first deliveries among 23 147 immigrants from 10 countries and 385 306 non-immigrants between 1990-2009. Countries were grouped as having low CS levels (<16%; Iraq, Pakistan, Poland, Turkey, Yugoslavia, Vietnam) or high CS levels (>22%; the Philippines, Somalia, Sri Lanka, Thailand). Associations between length of residence and planned/emergency CS were estimated as relative risks (RR) with 95% confidence intervals (CI) in multivariable models. In the immigrant group with low CS levels, planned, but not emergency, CS was independently associated with longer length of residence. Compared with recent immigrants (<1 year), the risk of planned CS was 70% greater among immigrants with residency of 2-5 years (RR 1.70, CI: 1.19-2.42), and twice as high in those with residency of ≥ 6 years. (RR 2.01, CI: 1.28-3.17). Compared with non-immigrants, immigrants in the low group with residency <2 years had lower risk of planned CS, while those with residency >2 years had greater risk of emergency CS. In the high group, the risk of planned CS was similar to non-immigrants, while emergency CS was 51-75% higher irrespective of length of residency. Efforts to improve immigrants' labour outcomes should target subgroups with sustained high emergency caesarean risk.

Congenital bladder exstrophy associated with Duogynon hormonal pregnancy tests—Signal for teratogenicity or consumer report bias?

A combination of ethinylestradiol and 10mg norethisterone under the brand names of Duogynon (Germany) or Primodos (UK) was used as a pregnancy test until the 1970s. Until very recently there was continuing public concern about the safety of these drugs and legal proceedings were instituted against the medicinal authorization holder. Given the lack of epidemiological studies focusing on Duogynon/Primodos, the present study evaluates 296 consumer reports of the German Duogynon database and compares the reported birth defects with data from a population based birth registry. The most striking result is an increase of bladder exstrophy (OR=37.27; 95%-CI 14.56–95.28). Neural tube defects (OR=2.99; 95%-CI 1.85–4.84) and renal agenesis (OR=2.53; 95%-CI 1.17–5.45) were also significantly increased. Bladder exstrophy may be a yet undetected teratogenic effect of Duogynon, but may also represent a reporting bias. The present study highlights the difficulties of evaluating consumer reports which may be influenced by public media.

565: The association between maternal weight gain and neonatal mortality

weight gain and neonatal mortality Joel Larma Ohio State University, Division of Maternal Fetal Medicine, Department of Obstetrics & Gynecology, Columbus, OH OBJECTIVE: To determine the association between maternal weight gain in pregnancy and neonatal mortality using a large population based birth registry. STUDY DESIGN: This is a population based retrospective cohort study of all births between 37 and 42 weeks gestation using the National Health Center for Vital Statistics 2005 Linked Birth/Infant Death Cohort Data Set. The primary outcome was neonatal mortality and the primary predictor was maternal weight gain. Maternal weight gain was categorized as less than 10 pounds, 10-24 pounds, 25-35 pounds and greater than 35 pounds. The referent group for the regression analysis were individuals with 25-35 pounds of weight gain during pregnancy. Initial univariate analysis was performed using Chi-square or Fishers exact tests for categorical variables and the t-test or MannWhitney U test for continuous variables. A multiple logistic regression model was performed using predictor variables that were found to alter the primary OR by 10-15%. Goodness of fit was assessed using the Hosmer-Lemeshow test. All analyses were performed using STATA 11.0. RESULTS: There were 4,145,887 births included in the final analysis with 27,968 cases of infant mortality which corresponds to a neonatal mortality rate of 6.69 cases per 1000 births. The following variables were found to be confounding variables and were included as covariates in the final analysis: maternal race, paternal race, number of prenatal visits and marital status. The adjusted odds ratio (aOR) for neonatal mortality for those who gained 10-24 pounds (relative to those who gained 25-35 pounds) was 1.87 (95% CI 1.11, 1.27). The aOR for neonatal mortality for those who gained 10 pounds was 1.5 (1.23, 1.47) and the aOR for those who gained greater than 35 pounds was 0.99 (0.93, 1.05. The Hosmer-Lemeshow test was nonsignificant indicating goodness of fit. CONCLUSION: There is a significantly increased odds of neonatal mortality among mothers with poor maternal weight gain who delivered a term infant, even after controlling for potential confounding variables. 566 Battle of the sexes: does gender exert a protective effect on neonatal mortality? Joel Larma Ohio State University, Division of Maternal Fetal Medicine, Department of Obstetrics & Gynecology, Columbus, OH OBJECTIVE: To determine the relationship between male gender and neonatal mortality using a large population based birth registry. STUDY DESIGN: This is a population based retrospective cohort study of all births between 23 and 42 weeks gestation using the National Health Center for Vital Statistics 2005 Linked Birth/Infant Death Cohort Data Set. The primary outcome was neonatal mortality and the primary predictor was male gender. The referent group for the regression analysis was female gender. Initial univariate analysis was performed using Chi-square or Fishers exact tests for categorical variables and the t-test or Mann-Whitney U test when appropriate. A multiple logistic regression model was performed using predictor variables that were either chosen a priori or were found to alter the primary OR by 10-15%. Goodness of fit was assessed using the Hosmer-Lemeshow test. All analyses were performed using STATA 11.0. RESULTS: There were 4,145,887 births included in the final analysis with 27,968 cases of infant mortality (6.69 cases per 1000 births). Among these, there were 2,122,872 males (51.20%) and 2,023,015 females born (48.80%) with 10,918 (57.07%) neonatal deaths among males and 8,212 (42.93%) neonatal deaths among females. The neonatal mortality rate for males was 6.00 per 1000 births and was 4.73 per 1000 births for females. The following variables were found to be significant confounders and were included in the final model: maternal age, marital status, tobacco use, congenital anomalies, birthweight, maternal weight gain, number of prenatal visits, low 5 minute Apgar and gestational age. The adjusted odds ratio (aOR) for neonatal death among males relative to females was 1.30 (1.25, 1.36) after controlling for potential confounding variables. The Hosmer-Lemeshow test was nonsignificant indicating goodness of fit. CONCLUSION: There is a significantly increased odds of neonatal mortality among male infants relative to female infants even after controlling for potential confounding variables. www.AJOG.org Epidemiology, Infectious Disease, Intrapartum Fetal Assessment, Operative Obstetrics, Obstetric Quality & Safety, Public Health-Global Health PosterSessionIV

Birth characteristics and Wilms tumors in children in the Nordic countries: A register‐based case–control study

Little is known about causes of Wilms tumor. Because of the young age at diagnosis, several studies have looked at various birth characteristics. We conducted a registry-based case-control study involving 690 cases of Wilms tumor aged 0-14 years, occurring in Denmark, Finland, Norway or Sweden during 1985-2006, individually matched to five controls drawn randomly from the Nordic childhood population. Information on birth characteristics was obtained from the population-based medical birth registries. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using conditional logistic regression analysis. We observed a distinct association between Wilms tumor and high birth weight (≥4 kg) for girls (OR 1.97, CI 1.50-2.59) but not for boys (1.04, 0.78-1.38); overall, the OR was 1.43 (1.17-1.74). Among girls, risk increased by 28% (15-42%) per 500 g increase in birth weight. Large-for-gestational age girls also had a higher risk (2.48, 1.51-4.05), whereas no effect was seen for boys (1.12, 0.60-2.07). An association was seen with Apgar score at 5 min < 7 for both sexes combined (5.13, 2.55-10.3). ORs close to unity were seen for parental age and birth order. In our large-scale, registry-based study, we confirmed earlier observations of an association between high birth weight and risk of Wilms tumor, but we found an effect only in girls. The higher risk of infants with low Apgar score might reflect hypoxia causing cell damage, adverse side effects of neonatal treatment or reverse causation as low Apgar score might indicate the presence of a tumor.

Epidemiology of Congenital Anomalies in a Population-based Birth Registry in Taiwan, 2002

Congenital anomalies are important medical and public health conditions. However, the occurrence rates of congenital anomalies and their risk factors are unknown in Taiwan. We used the medical-practitioner-reported birth registry in 2002 to determine the occurrence of individual congenital anomalies and their associated risk factors, such as maternal age, fetal sex, and plurality. The birth registry was started in 2001 in Taiwan. We obtained the data for 2002 from the Department of Health, and translated the coding of congenital anomalies to International Classification of Diseases 9th revision-clinical modification (ICD-9-CM). The occurrence rates of individual congenital anomalies were calculated. The effects of maternal age, fetal sex, and plurality were calculated as odds ratios (ORs) by logistic regression analysis. A total of 1775 infants were diagnosed as having congenital anomalies among 242,140 live and deceased newborn infants delivered in Taiwan in 2002.The occurrence rates of congenital anomalies of the nervous system, eyes and face, cardiovascular, digestive, urogenital, musculoskeletal and respiratory systems, and chromosomes were 0.67 per thousand, 1.86 per thousand, 1.47 per thousand, 0.62 per thousand, 0.71 per thousand, 2.05 per thousand, 0.07 per thousand and 0.79 per thousand, respectively. Sex chromosomal anomalies, Down syndrome, and trisomy 18 were associated with maternal age of > or = 35 years (OR, 15.9, 4.6, and 2.3, respectively). Such elevation was even more prominent for maternal age > or = 40 years (OR, 35.5, 22.2, and 11.62, respectively). A milder and borderline significant maternal age (> or = 40 years) effect was seen with cleft lip, with or without cleft palate (OR, 2.1). Female births had more cleft palates (OR, 1.6). There was no relationship between plurality and anomalies. The occurrence rates for individual congenital anomalies in Taiwan were reported. Older maternal age was a risk factor for the occurrence of chromosomal and orofacial anomalies. More active prenatal screening and further investigation of causal factors of congenital anomalies are of major importance.

Area-level poverty and preterm birth risk: A population-based multilevel analysis

BackgroundPreterm birth is a complex disease with etiologic influences from a variety of social, environmental, hormonal, genetic, and other factors. The purpose of this study was to utilize a large population-based birth registry to estimate the independent effect of county-level poverty on preterm birth risk. To accomplish this, we used a multilevel logistic regression approach to account for multiple co-existent individual-level variables and county-level poverty rate.MethodsPopulation-based study utilizing Missouri's birth certificate database (1989–1997). We conducted a multilevel logistic regression analysis to estimate the effect of county-level poverty on PTB risk. Of 634,994 births nested within 115 counties in Missouri, two levels were considered. Individual-level variables included demographics factors, prenatal care, health-related behavioral risk factors, and medical risk factors. The area-level variable included the percentage of the population within each county living below the poverty line (US census data, 1990). Counties were divided into quartiles of poverty; the first quartile (lowest rate of poverty) was the reference group.ResultsPTB < 35 weeks occurred in 24,490 pregnancies (3.9%). The rate of PTB < 35 weeks was 2.8% in counties within the lowest quartile of poverty and increased through the 4th quartile (4.9%), p < 0.0001. High county-level poverty was significantly associated with PTB risk. PTB risk (< 35 weeks) was increased for women who resided in counties within the highest quartile of poverty, adjusted odds ratio (adjOR) 1.18 (95% CI 1.03, 1.35), with a similar effect at earlier gestational ages (< 32 weeks), adjOR 1.27 (95% CI 1.06, 1.52).ConclusionWomen residing in socioeconomically deprived areas are at increased risk of preterm birth, above other underlying risk factors. Although the risk increase is modest, it affects a large number of pregnancies.

Cancer Risk in Children with Birth Defects and in Their Families: A Population Based Cohort Study of 5.2 Million Children from Norway and Sweden

Cancer and birth defects may share factors that influence risk. A malformation may involve physiologic changes or changes in lifestyle that might affect cancer risks. In Norway and Sweden, the population-based medical birth and cancer registries were linked to identify subsequent cancer occurrence in children with birth defects and among their parents and siblings. Altogether, 5.2 million children and their families were included. The standardized incidence ratio (SIR) served as a measure of relative risk. There was an increased overall cancer risk in individuals with birth defects in the two countries [SIR, 1.7; 95% confidence interval (95% CI), 1.6-1.9], and the increased risk remained into early adulthood. Individuals with malformations in the nervous system were at increased risk of developing cancer in the brain/nervous system (Norway: SIR, 58; 95% CI, 41-80; Sweden: SIR, 8.3; 95% CI, 4.0-15), individuals with Down syndrome were at an increased risk of leukemia (Norway: SIR, 36; 95% CI, 26-48; Sweden: SIR, 36; 95% CI, 28-46), and there was an increased overall cancer risk for individuals with multiple birth defects (Norway: SIR, 5.5; 95% CI, 3.3-8.7; Sweden: SIR, 3.6; 95% CI, 2.2-5.4). There was no increased overall cancer risk among mothers (SIR, 1.0; 95% CI, 1.0-1.0), fathers (SIR, 1.0; 95% CI, 0.9-1.0), and siblings (SIR, 1.0; 95% CI, 0.9-1.1) of children with birth defects. We observed an increased overall cancer risk in individuals with birth defects. The highest risks were seen for individuals with malformations in the nervous system, Down syndrome, and multiple defects. No increased overall cancer risk was seen among their parents or siblings.