Neighborhood Deprivation and Neural Tube Defects

BACKGROUND

Individual measures of socioeconomic status (SES) have been associated with an increased risk of neural tube defects (NTDs); however, the association between neighborhood SES and NTD risk is unknown. Using data from the National Birth Defects Prevention Study (NBDPS) from 1997 to 2011, we investigated the association between measures of census tract SES and NTD risk.

METHODS

The study population included 10,028 controls and 1829 NTD cases. We linked maternal addresses to census tract SES measures and used these measures to calculate the neighborhood deprivation index. We used generalized estimating equations to calculate adjusted odds ratios (aORs) and 95% confidence intervals (CIs) estimating the impact of quartiles of census tract deprivation on NTDs adjusting for maternal race-ethnicity, maternal education, and maternal age at delivery.

RESULTS

Quartiles of higher neighborhood deprivation were associated with NTDs when compared with the least deprived quartile (Q2: aOR = 1.2; 95% CI = 1.0, 1.4; Q3: aOR = 1.3, 95% CI = 1.1, 1.5; Q4 (highest): aOR = 1.2; 95% CI = 1.0, 1.4). Results for spina bifida were similar; however, estimates for anencephaly and encephalocele were attenuated. Associations differed by maternal race-ethnicity.

CONCLUSIONS

Our findings suggest that residing in a census tract with more socioeconomic deprivation is associated with an increased risk for NTDs, specifically spina bifida.

Association between maternal body mass index and congenital anomalies: A case-control study in Tuscany (Italy)

OBJECTIVE

To investigate the relationship between prepregnancy maternal body mass index (BMI) and congenital anomalies (CAs).

DESIGN

Case-control study on data collected by the registry of CAs of Tuscany (Italy) and birth certificates from 2005 to 2017.

MAIN EXPOSURE

Maternal prepregnancy BMI.

MAIN OUTCOME MEASURES

Any major CAs and groups of organ-specific anomalies. Odds ratios (ORs) were estimated using logistic regression models adjusted for maternal factors.

RESULTS

Maternal BMI ≥25 was significantly associated with all nervous system anomalies (OR = 1.61, 95% confidence interval [95% CI] 1.13-2.29) and with neural tube defects (OR = 2.03, 95% CI 1.00-4.12); maternal underweight was significantly associated with orofacial clefts (OR = 1.67, 95% CI 1.12-2.48). After stratification by education, in the low education group, mothers with BMI ≥25 had an increased risk of nervous system anomalies (OR = 2.19, 95% CI 1.01-4.76), whereas underweight mothers had an increased risk of nervous system anomalies (OR = 3.89, 95% CI 1.44-10.53), orofacial clefts (OR = 2.59, 95% CI 1.24-5.42), and urinary anomalies (OR = 1.74, 95% CI 1.07-2.82). In the medium/high education group, the only significantly increased risk was found in mothers with BMI ≥25 for nervous system anomalies (OR = 1.50, 95% CI 1.00-2.25).

CONCLUSION

Main results have shown a positive association of maternal BMI ≥25 with nervous system anomalies and maternal underweight with orofacial clefts. The study has also evidenced the impact of social status and provided clues to the role of maternal ethnic background.

Educational disparities in perinatal health in Denmark in the first decade of the 21st century: a register-based cohort study

OBJECTIVE

To investigate socioeconomic differences in six perinatal health outcomes in Denmark in the first decade of the 21st century.

DESIGN

A population-based cohort study.

SETTING

Danish national registries.

PARTICIPANTS

A total of 646 829 live born children and 3076 stillborn children (≥22+0 weeks of gestation) born in Denmark from 2000 to 2009. We excluded children with implausible relations between birth weight and gestational age (n=644), children without information on maternal country of origin (n=138) and implausible values of maternal year of birth (n=36).

MAIN OUTCOME MEASURES

We investigated the following perinatal health outcomes: stillbirth, neonatal and postneonatal mortality, small-for-gestational age, preterm birth grated into moderate preterm, very preterm and extremely preterm, and congenital anomalies registered in the first year of life.

RESULTS

Maternal educational level was inversely associated with all adverse perinatal outcomes. For all examined outcomes, the risk association displayed a clear gradient across the educational levels. The associations remained after adjustment for maternal age, maternal country of origin and maternal year of birth. Compared with mothers with vocational education, mothers with more than 15 years of education had an adjusted risk ratio for stillbirth of 0.64(95% CI 0.56 to 0.72). The corresponding adjusted risk ratios for neonatal mortality, postneonatal mortality, congenital anomalies, moderate preterm birth and small-for-gestational age were, respectively, 0.79(95% CI 0.67 to 0.93), 0.57(95% CI 0.42 to 0.78), 0.87(95% CI 0.83 to 0.91), 0.80(95% CI 0.77 to 0.83) and 0.83(95% CI 0.81 to 0.85).

CONCLUSION

Substantial educational inequalities in perinatal health were still present in Denmark in the first decade of the 21st century.

A Prospective Study of Spectrum, Risk Factors and Immediate Outcome of Congenital Anomalies in Bida, North Central Nigeria

Background:

Congenital disorders are structural, metabolic, behavioral and functional disorders that are present at birth. Their manifestations are protean ranging from mild anomalies to life-threatening conditions.

Aim:

The objectives of this study were to describe the congenital anomalies in children seen at Federal Medical Center, Bida over a 12 month period, determine possible factors associated with these anomalies; and their short term outcome.

Subjects and Methods:

Children with clinically recognized congenital malformations were recruited consecutively over a 12 month period and socio-demographic, etiologic and other relevant clinical data were obtained. A detailed examination was also performed and abnormalities documented. The data was analyzed using Epi-info version 6 (Atlanta, USA). The Chi-square was used to identify significant differences for categorical variables. Mid-P and Fisher's exact tests were utilized as appropriate. A P < 0.05 was considered to be significant.

Results:

A total of 46 children with congenital anomalies were seen during the study period, all which were recruited into the study. The hospital based prevalence amongst neonates was 111/1000 neonates. The most common system affected was the digestive system(50.0%) followed by the central nervous system and head and neck anomalies. There was no significant difference in distribution of anomalies amongst the various ethnic groups. About 22% of families were consanguineous, all being first cousins and 8.7% of mothers were greater than 35 years of age. The case fatality rate for congenital malformations was 2.2%, while 60.9% were referred to other hospitals for further care.

Conclusion:

The study has demonstrated a wide variety of congenital anomalies in Bida, North-Central Nigeria with the digestive system anomalies being the most frequent. The findings of this study strengthen the need for empowerment of the institution in appropriate management of these disorders.

Towards reducing variations in infant mortality and morbidity: a population-based approach

Background

Our aims were (1) to improve understanding of regional variation in early-life mortality rates and the UK’s poor performance in international comparisons; and (2) to identify the extent to which late and moderately preterm (LMPT) birth contributes to early childhood mortality and morbidity.

Objective

To undertake a programme of linked population-based research studies to work towards reducing variations in infant mortality and morbidity rates.

Design

Two interlinked streams: (1) a detailed analysis of national and regional data sets and (2) establishment of cohorts of LMPT babies and term-born control babies.

Setting

Cohorts were drawn from the geographically defined areas of Leicestershire and Nottinghamshire, and analyses were carried out at the University of Leicester.

Data sources

For stream 1, national data were obtained from four sources: the Office for National Statistics, NHS Numbers for Babies, Centre for Maternal and Child Enquiries and East Midlands and South Yorkshire Congenital Anomalies Register. For stream 2, prospective data were collected for 1130 LMPT babies and 1255 term-born control babies.

Main outcome measures

Detailed analysis of stillbirth and early childhood mortality rates with a particular focus on factors leading to biased or unfair comparison; review of clinical, health economic and developmental outcomes over the first 2 years of life for LMPT and term-born babies.

Results

The deprivation gap in neonatal mortality has widened over time, despite government efforts to reduce it. Stillbirth rates are twice as high in the most deprived as in the least deprived decile. Approximately 70% of all infant deaths are the result of either preterm birth or a major congenital abnormality, and these are heavily influenced by mothers’ exposure to deprivation. Births at < 24 weeks’ gestation constitute only 1% of all births, but account for 20% of infant mortality. Classification of birth status for these babies varies widely across England. Risk of LMPT birth is greatest in the most deprived groups within society. Compared with term-born peers, LMPT babies are at an increased risk of neonatal morbidity, neonatal unit admission and poorer long-term health and developmental outcomes. Cognitive and socioemotional development problems confer the greatest long-term burden, with the risk being amplified by socioeconomic factors. During the first 24 months of life each child born LMPT generates approximately £3500 of additional health and societal costs.

Conclusions

Health professionals should be cautious in reviewing unadjusted early-life mortality rates, particularly when these relate to individual trusts. When more sophisticated analysis is not possible, babies of < 24 weeks’ gestation should be excluded. Neonatal services should review the care they offer to babies born LMPT to ensure that it is appropriate to their needs. The risk of adverse outcome is low in LMPT children. However, the risk appears higher for some types of antenatal problems and when the mother is from a deprived background.

Future work

Future work could include studies to improve our understanding of how deprivation increases the risk of mortality and morbidity in early life and investigation of longer-term outcomes and interventions in at-risk LMPT infants to improve future attainment.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Linking databases on perinatal health: a review of the literature and current practices in Europe

Background: International comparisons of perinatal health indicators are complicated by the heterogeneity of data sources on pregnancy, maternal and neonatal outcomes. Record linkage can extend the range of data items available and thus can improve the validity and quality of routine data. We sought to assess the extent to which data are linked routinely for perinatal health research and reporting. Methods: We conducted a systematic review of the literature by searching PubMed for perinatal health studies from 2001 to 2011 based on linkage of routine data (data collected continuously at various time intervals). We also surveyed European health monitoring professionals about use of linkage for national perinatal health surveillance. Results: 516 studies fit our inclusion criteria. Denmark, Finland, Norway and Sweden, the US and the UK contributed 76% of the publications; a further 29 countries contributed at least one publication. Most studies linked vital statistics, hospital records, medical birth registries and cohort data. Other sources were specific registers for: cancer (70), congenital anomalies (56), ART (19), census (19), health professionals (37), insurance (22) prescription (31), and level of education (18). Eighteen of 29 countries (62%) reported linking data for routine perinatal health monitoring. Conclusion: Research using linkage is concentrated in a few countries and is not widely practiced in Europe. Broader adoption of data linkage could yield substantial gains for perinatal health research and surveillance.

Is drug insurance status an effect modifier in epidemiologic database studies? The case of maternal asthma and major congenital malformations

BACKGROUND

Our previous work on the association between maternal asthma and congenital malformations was based on cohorts formed by women with public drug insurance, i.e., over-represented by women with lower socioeconomic status, questioning the generalizability of our findings. This study aimed to evaluate whether or not drug insurance status, as a proxy of socioeconomic status, is an effect modifier for the association between maternal asthma and major congenital malformations.

METHODS

A cohort of 36,587 pregnancies from asthmatic women and 198,935 pregnancies from nonasthmatic women selected independently of their drug insurance status was reconstructed with Québec administrative databases (1998-2009). Asthmatic women were identified using a validated case definition of asthma. Cases of major congenital malformations were identified using diagnostic codes recorded in the hospitalization database. Drug insurance status at the beginning of pregnancy was classified into three groups: publicly insured with social welfare, publicly insured without social welfare, and privately insured. Adjusted odds ratios were estimated with generalized estimation equations, including an interaction term between maternal asthma and drug insurance status.

RESULTS

The prevalence of congenital malformations was 6.8% among asthmatic women and 5.8% among nonasthmatics. The impact of asthma on the prevalence of congenital malformations was significantly greater in women publicly insured with social welfare (odds ratio = 1.42; 95% confidence interval, 1.25-1.61) than in the other two groups ([odds ratio = 1.10; 1.00-1.21] in the publicly insured without social welfare and [odds ratio = 1.13; 1.07-1.20] in the privately insured group).

CONCLUSION

The increased risk of major congenital malformation associated with asthma was significantly higher among pregnant women publicly insured with social welfare than among those privately insured. As a result of this effect modification by drug insurance status, findings from Québec observational studies using databases mainly formed of patients publicly insured with social welfare may not be generalized to the entire population.

Increased risk of severe congenital heart defects in offspring exposed to selective serotonin-reuptake inhibitors in early pregnancy--an epidemiological study using validated EUROCAT data

BACKGROUND

Previous studies suggest a possible association between maternal use of selective serotonin-reuptake inhibitors (SSRIs) during early pregnancy and congenital heart defects (CHD). The purpose of this study was to verify this association by using validated data from the Danish EUROCAT Register, and secondary, to investigate whether the risk differs between various socioeconomic groups.

METHODS

We conducted a cohort study based on Danish administrative register data linked with the Danish EUROCAT Register, which includes all CHD diagnosed in live births, fetal deaths and in pregnancies terminated due to congenital anomalies. The study population consisted of all registered pregnancies (n = 72,280) in Funen, Denmark in the period 1995-2008. SSRI-use was assessed using The Danish National Prescription Registry, information on marital status, maternal educational level, income, and country of origin from Statistics Denmark was used as indicators of socioeconomic situation, and the CHD were studied in subgroups defined by EUROCAT. Logistic Regression was used to investigate the association between redeemed prescriptions for SSRIs and CHD.

RESULTS

The risk of severe CHD in the offspring of the 845 pregnant women who used SSRIs during first trimester increased four times (AOR 4.03 (95% CI 1.75-9.26)). We found no increased risk of septal defects. Socioeconomic position did not modify the association between maternal SSRI-use during pregnancy and severe CHD.

CONCLUSION

This study, which is based on data with high case ascertainment, suggests that maternal use of SSRIs during first trimester increases the risk of severe CHD, but does not support findings from previous studies, based on administrative register data, regarding an increased risk of septal defects. The study was unable to document an interaction between socioeconomic status and maternal SSRI-use on the risk of severe CHD.

Food fortification and decline in the prevalence of neural tube defects: does public intervention reduce the socioeconomic gap in prevalence?

OBJECTIVE

A significant decline in the prevalence of neural tube defects (NTD) through food fortification has been reported. Questions remain, however, about the effectiveness of this intervention in reducing the gap in prevalence across socioeconomic status (SES).

STUDY DESIGN

Using health number and through record linkage, children born in Ontario hospitals between 1994 and 2009 were followed for the diagnosis of congenital anomalies. SES quintiles were assigned to each child using census information at the time of birth. Adjusted rates and multivariate models were used to compare trends among children born in different SES groups.

RESULTS

Children born in low SES areas had significantly higher rates of NTDs (RR = 1.25, CI: 1.14-1.37). Prevalence of NTDs among children born in low and high SES areas declined since food fortification began in 1999 although has started rising again since 2006. While the crude decline was greater in low SES areas, after adjustment for maternal age, the slope of decline and SES gap in prevalence rates remained unchanged overtime.

CONCLUSIONS

While food fortification is successful in reducing the prevalence of NTDs, it was not associated with removing the gap between high and low SES groups.

Socioeconomic position and the risk of spontaneous abortion: a study within the Danish National Birth Cohort

OBJECTIVES

To investigate the relationship between different indicators of socioeconomic position and the risk of spontaneous abortion.

DESIGN

Cohort study.

SETTING

1996-2002, Denmark.

PARTICIPANTS

All first time participants, a total of 89 829 pregnant women, enrolled in the Danish National Birth Cohort were included in the present study. Overall, 4062 pregnancies ended in spontaneous abortion. Information on education, income and labour market attachment in the year before pregnancy was drawn from national registers.

MAIN OUTCOME MEASURE

Spontaneous abortion, that is, fetal death within the first 22 weeks of pregnancy, was the outcome of interest. The authors estimated HRs of spontaneous abortion using Cox regression analysis with gestational age as the underlying time scale.

RESULTS

Women with <10 years of education had an elevated risk of spontaneous abortion when compared with women with >12 years of education (HR 1.19 (95% CI 1.05 to 1.34)). The HR estimates for the four lowest income quintiles were all increased (HRs between 1.09 and 1.15) as compared with the upper quintile but did not differ considerably from each other. In general, no statistically significant association was found between labour market attachment and the risk of spontaneous abortion; however, the group of women on disability pension had an increased HR of spontaneous abortion when compared with women who were employed (HR 1.32 (95% CI 0.82 to 2.13)).

CONCLUSIONS

Educational level and income were inversely associated with the risk of spontaneous abortion. As these factors most likely are non-causally related to spontaneous abortion, the findings indicate that factors related to social position, probably of the environmental and behavioural type, may affect spontaneous abortion risk. The study highlights the need for studies addressing such exposures in order to prevent spontaneous abortions.

Socioeconomic status and prevalence of congenital heart defects: does universal access to health care system eliminate the gap?

BACKGROUND

A twofold increase in the prevalence of congenital heart defects (CHDs) has been reported since the early 1970s with higher rates among children from low socioeconomic status (SES). This increase and the observed SES gap are postulated to be reflective of higher ascertainment, especially increased use of ultrasound and echography. The purpose of this study was to examine if trends over time in the prevalence of CHD were the same for high and low SES groups.

METHODS

Using the child's health number as a unique identifier and through record linkage, children born in Ontario between 1994 and 2007 were followed for the diagnosis of CHD. Using postal codes and census information, SES quintiles were assigned to each child. We used adjusted rates and used multivariate models to compare trends in the prevalence rate among children born in different SES groups.

RESULTS

Children born in low SES areas (23% of all births) had significantly higher rates of CHDs (rate ratio = 1.20; 95% confidence interval [CI] = 1.15-1.24). While prevalence of nonsevere CHDs declined in all SES groups since 2000, severe CHDs, especially atrial septal defects were on the rise during the study period.

DISCUSSION

It is assumed that increased ascertainment is responsible for observed increase in the prevalence of CHD, especially minor defects. While the trend and pattern over time changed for severe and nonsevere CHDs, the SES gap remained consistent during the study period. Our results indicate that even free and universal access to a health care system does not eliminate the SES gap observed in the prevalence of CHD.

Socioeconomic inequalities in outcome of pregnancy and neonatal mortality associated with congenital anomalies: population based study

OBJECTIVES

To investigate socioeconomic inequalities in outcome of pregnancy and neonatal mortality associated with congenital anomalies.

DESIGN

Retrospective population based registry study.

SETTING

East Midlands and South Yorkshire regions of England (representing about 10% of births in England and Wales).

PARTICIPANTS

All registered cases of nine selected congenital anomalies with poor prognostic outcome audited as part of the United Kingdom's fetal anomaly screening programme with an end of pregnancy date between 1 January 1998 and 31 December 2007.

MAIN OUTCOME MEASURES

Socioeconomic variation in the risk of selected congenital anomalies; outcome of pregnancy; incidence of live birth and neonatal mortality over time. Deprivation measured with the index of multiple deprivation 2004 at super output area level.

RESULTS

There were 1579 fetuses registered with one of the nine selected congenital anomalies. There was no evidence of variation in the overall risk of these anomalies with deprivation (rate ratio for the most deprived 10th with the least deprived 10th: 1.05, 95% confidence interval 0.89 to 1.23). The rate ratio varied with type of anomaly and maternal age (deprivation rate ratio adjusted for maternal age: 1.43 (1.17 to 1.74) for non-chromosomal anomalies; 0.85 (0.63 to 1.15) for chromosomal anomalies). Of the nine anomalies, 86% were detected in the antenatal period, and there was no evidence that this varied with deprivation (rate ratio 0.99, 0.84 to 1.17). The rate of termination after antenatal diagnosis of a congenital anomaly was lower in the most deprived areas compared with the least deprived areas (63% v 79%; rate ratio 0.80, 0.65 to 0.97). Consequently there were significant socioeconomic inequalities in the rate of live birth and neonatal mortality associated with the presence of any of these nine anomalies. Compared with the least deprived areas, the most deprived areas had a 61% higher rate of live births (1.61, 1.21 to 2.15) and a 98% higher neonatal mortality rate (1.98, 1.20 to 3.27) associated with a congenital anomaly.

CONCLUSIONS

Antenatal screening for congenital anomalies has reduced neonatal mortality through termination of pregnancy. Socioeconomic variation in decisions regarding termination of pregnancy after antenatal detection, however, has resulted in wide socioeconomic inequalities in liveborn infants with a congenital anomaly and subsequent neonatal mortality.