Ethnic differences in congenital malformations in the Netherlands: analyses of a 5-year birth cohort

A Comparative Prevalence of Birth Defects between Newborns of Immigrant and Native-Born Mothers in Taiwan: Ten Years of Population-Based Data

In recent years, newborns born to immigrant mothers have accounted for about 10% of the total births in Taiwan. However, little is known about whether there are differences between newborns of immigrant and native-born mothers regarding the prevalence and the possible causes of birth defects. By combining four nationwide databases and assessing all newborns between 2005 and 2014 in Taiwan as research subjects, this study determined the prevalence of birth defects stratified into nine categories (neuronal, facial, cleft, circulatory, respiratory, digestive, urogenital, musculoskeletal and chromosomal abnormalities) in the newborns of immigrant mothers and native-born mothers. We found that the prevalence of any birth defects in newborns of immigrant mothers (ranging from 0.98 to 1.24%) was lower than that of native-born mothers (2.86%). Skeletomuscular system defects are the most common among newborns of women from the main immigrant countries (0.24–0.42%), while circulatory system defects were the most common among newborns of Taiwanese women (0.92%). The risks of all defects remained lower for newborns of immigrant mothers (AORs ranged from 0.37 to 0.47) after controlling for possible confounding variables. The higher rates of birth defects among newborns of native-born mothers may be attributed to an older maternal age at childbirth and a higher prevalence of diabetes than that of immigrant mothers. The findings from this study imply that the prevalence of birth defects between newborns of immigrant and native-born mothers is not similar, as evidenced by a decade of population-based data.

Value and Diagnostic Efficacy of Fetal Morphology Assessment Using Ultrasound in A Poor-Resource Setting

BACKGROUND

Ultrasound is operator-dependent, and its value and efficacy in fetal morphology assessment in a low-resource setting is poorly understood. We assessed the value and efficacy of fetal morphology ultrasound assessment in a Nigerian setting.

MATERIALS AND METHODS

We surveyed fetal morphology ultrasound performed across five facilities and followed-up each fetus to ascertain the outcome. Fetuses were surveyed in the second trimester (18th-22nd weeks) using the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) guideline. Clinical and surgical reports were used as references to assess the diagnostic efficacy of ultrasound in livebirths, and autopsy reports to confirm anomalies in terminated pregnancies, spontaneous abortions, intrauterine fetal deaths, and still births. We calculated sensitivity, specificity, positive and negative predictive values, Area under the curve (AUC), Youden index, likelihood ratios, and post-test probabilities.

RESULTS

In total, 6520 fetuses of women aged 15-46 years (mean = 31.7 years) were surveyed. The overall sensitivity, specificity, and AUC were 77.1 (95% CI: 68-84.6), 99.5 (95% CI: 99.3-99.7), and 88.3 (95% CI: 83.7-92.2), respectively. Other performance metrics were: positive predictive value, 72.4 (95% CI: 64.7-79.0), negative predictive value, 99.6 (95% CI: 99.5-99.7), and Youden index (77.1%). Abnormality prevalence was 1.67% (95% CI: 1.37-2.01), and the positive and negative likelihood ratios were 254 (95% CI: 107.7-221.4) and 0.23 (95% CI: 0.16-0.33), respectively. The post-test probability for positive test was 72% (95% CI: 65-79).

CONCLUSION

Fetal morphology assessment is valuable in a poor economics setting, however, the variation in the diagnostic efficacy across facilities and the limitations associated with the detection of circulatory system anomalies need to be addressed.

TESTING THE EFFECT OF THE EPIDEMIOLOGIC PARADOX: BIRTH WEIGHT OF NEWBORNS OF IMMIGRANT AND NON-IMMIGRANT MOTHERS IN THE REGION OF VALENCIA, SPAIN

The epidemiological paradox and ‘healthy migrant effect’ refer to the favourable health outcomes in unprivileged groups under unfavourable socioeconomic conditions. Weight at birth is associated with the epidemiological paradox. However, differences in fertility structure (mainly mother's age and first maternity) might be the cause of the difference in weight at birth between children of immigrant and non-immigrant mothers. This paper aims to analyse the impact of the epidemiologic paradox by distinguishing between the factors related to fertility structure, in addition to other socio-cultural factors. The importance of fertility structure as the cause of weight-at-birth differences of the newborns of immigrant and non-immigrant women, and between those of subgroups of immigrant mothers, is tested. Based on data from birth registries for the period 1998–2009, a variance analysis was performed for Spanish mothers and for those of five major immigrant subgroups living in the region of Valencia, Spain, which experienced significant migrant inflows within a short period of time. A Scheffé test between pairs of nationalities was carried out. Finally, linear regression models were built. The results suggest that the most relevant factors are those related to fertility structure, and that consequently the epidemiological paradox does not apply for immigrant mothers as a whole, although Bolivian immigrant offspring may be an exception. This unexpected result requires further research to test to what extent this is due to the special adaptation of multigenerational high-altitude populations in pregnancy. The factors associated with fertility structure must be controlled when trying to relate birth weight differences between ethnic groups to socioeconomic factors.

A description of congenital anomalies among infants in Entebbe, Uganda

BACKGROUND: Data on congenital anomalies from developing countries of the sub-Saharan region are scarce. However, it is important to have comprehensive and reliable data on the description and prevalence of congenital anomalies to allow surveillance and the implementation of appropriate public health strategies for prevention and management. In this study, we describe the profile of congenital anomalies seen in a birth cohort in Entebbe, Uganda. METHODS: Congenital anomalies were defined as any structural defect present at birth. Pregnant women were recruited to the cohort between 2003 and 2005. Defects present at birth were recorded by the midwife at delivery and by physicians at the routine six-week postnatal visit and at illness-related visits until 1 year of life. The anomalies were classified by organ system according to the 10th version of the World Health Organization International Classification of Diseases (ICD-10). RESULTS: There were 180 infants with a congenital anomaly among 2365 births. The most commonly affected systems were the musculoskeletal (42.7 per 1000 births) and skin (16.1 per 1000 births). The prevalence of major anomalies was 20.3 per 1000 births; 1.7 per 1000 births for cardiac anomalies and 1.3 per 1000 births for neural system anomalies. Forty (22%) of the congenital anomalies were identified at birth, 131 (73%) at the 6-week postnatal visit, and nine (5%) at illness-related visits. CONCLUSION: Congenital anomalies are common in developing countries. Establishment of comprehensive databases for surveillance would be helpful for surveillance of effects of new exposures, for prevention, management, and health care planning. Birth Defects Research (Part A) 2011. © 2011 Wiley-Liss, Inc.

High perinatal mortality rate among immigrants in Brussels

BACKGROUND

The relation between immigration status and perinatal mortality is unclear. The objective of this study is to describe and measure inequalities in perinatal mortality and causes of perinatal deaths according to maternal nationality and socioeconomic status.

METHODS

A population-based cohort study related to all babies born during the period of 1998-2006 whose mothers were living in Brussels, irrespective of the place of delivery. Perinatal and post-perinatal mortality were analysed according to the nationality and sociodemographic characteristics of the mothers at birth. We used logistic regression to estimate the odds ratios (ORs) for the association between mortality and nationality.

RESULTS

The women of sub-Saharan Africa experience a 50% excess in perinatal mortality, which primarily reflects a high rate of preterm deliveries and low birth weight, as well as a low socioeconomic level. Paradoxically, despite their favourable rates of preterm and low-birth-weight births, Maghrebian and Turkish women experience a strong excess (50-70%) of perinatal mortality caused primarily by congenital anomalies. Differences in age, parity distributions and multiple births play no significant role, and the excess does not reflect low socioeconomic levels. This excess of perinatal mortality contrasts with the absence of an excess of post-perinatal mortality.

CONCLUSION

In Brussels, patterns of inequalities in perinatal mortality and causes of perinatal deaths vary according to nationality; perinatal mortality is increased in particular ethnic groups independently of socioeconomic status and maternal characteristics.

Maternal nickel exposure and congenital musculoskeletal defects

OBJECTIVE

To investigate whether women occupationally exposed to nickel in early pregnancy are at elevated risk of delivering a newborn with a malformation or deformation of the musculoskeletal system (ICD-10: Q65-Q79).

METHODS

Data about the newborn, maternal occupation and workplace were obtained using the Kola Birth Register (KBR). Each record in the KBR was assigned a categorical nickel (Ni) exposure rating according to the occupation the delivering woman had at the time of becoming pregnant. This was achieved by using as a guideline the water-soluble Ni subfraction of the inhalable aerosol fraction obtained by personal monitoring for nickel- and copper-refinery workers or/and measured urinary-Ni concentrations. The reference population was delivering women from the source population with background exposure level. In total, the study population consisted of 22,965 births.

RESULTS

Three hundred and four infants (13.3/1,000 births; 95% confidence interval (CI): 11.9-14.7) were diagnosed with isolated musculoskeletal defect(s) at birth. The adjusted odds ratio for the association between the maternal exposure to Ni and this outcome was 0.96 (95% CI: 0.76-1.21) per unit increase in exposure category.

CONCLUSION

The incidence of defects in the musculoskeletal system at birth was high, especially for feet deformities, but we found no effect of maternal exposure to water-soluble Ni on the risk of delivering a newborn with a defect. However, the incidence among women working in the copper refinery was higher than in the other employment groups.

Probabilistic record linkage is a valid and transparent tool to combine databases without a patient identification number

OBJECTIVE

To describe the technical approach and subsequent validation of the probabilistic linkage of the three anonymous, population-based Dutch Perinatal Registries (LVR1 of midwives, LVR2 of obstetricians, and LNR of pediatricians/neonatologists). These registries do not share a unique identification number.

STUDY DESIGN AND SETTING

A combination of probabilistic and deterministic record linkage techniques were applied using information about the mother, delivery, and child(ren) to link three known registries. Rewards for agreement and penalties for disagreement between corresponding variables were calculated based on the observed patterns of agreement and disagreements using maximum likelihood estimation. Special measures were developed to overcome linking difficulties in twins. A subsample of linked and nonlinked pairs was validated.

RESULTS

Independent validation confirmed that the procedure successfully linked the three Dutch perinatal registries despite nontrivial error rates in the linking variables.

CONCLUSIONS

Probabilistic linkage techniques allowed the creation of a high-quality linked database from crude registry data. The developed procedures are generally applicable in linkage of health data with partially identifying information. They provide useful source date even if cohorts are only partly overlapping and if within the cohort, multiple entities and twins exist.

Herbal medicines used during the first trimester and major congenital malformations: an analysis of data from a pregnancy cohort study

BACKGROUND

Major congenital malformations place a considerable burden on the affected child, the family and society. Any kind of medicine used during pregnancy might have a harmful impact; therefore, such practice has raised concerns. The objective of the current study was to explore the relationship between the use of herbal medicines by pregnant women during the first trimester of pregnancy and the risk of major congenital malformation in their live born infants.

METHODS

This was a cross-sectional analysis of data from a prospective pregnancy cohort, which was established between 1984 and 1987. To assemble the cohort, pregnant women of >or=26 weeks of gestation who came to the Taipei Municipal Maternal and Child Hospital in Taiwan for prenatal care were enrolled in the study and interviewed using a structured questionnaire. Detailed information, including herbal medicine use during different periods of pregnancy, was obtained during the interview. Past medical history, current obstetric data and details on conventional medicines used during pregnancy were abstracted from medical records. Data on birth weight, gestational duration and characteristics of live born infants were gathered from the Taiwan national birth register. Congenital malformation information was obtained from multiple sources: the newborn examination record (1984-7); the national death register (1984-2003); and Taiwan National Health Insurance data (1996-2000). Multiple logistic regression was used to estimate the odds ratio [OR] of major congenital malformation by herbal medicines used during the first trimester.

RESULTS

A total of 14,551 live births were analysed. After adjustment for confounding factors, taking huanglian during the first trimester of pregnancy was found to be associated with increased risk of congenital malformations of the nervous system (adjusted OR 8.62, 95% CI 2.54, 29.24). An-Tai-Yin was associated with an increased risk of congenital malformations of the musculoskeletal and connective tissues (adjusted OR 1.61, 95% CI 1.10, 2.36) and the eye (adjusted OR 7.30, 95% CI 1.47, 36.18).

CONCLUSION

We found evidence for a possible link between the use of specific herbal medicines during the first trimester of pregnancy and increased risks of specific groups of congenital malformations. We could not investigate whether the adverse effects were related to direct toxicity from the herbal medicines, or were from misuse, contamination or uncontrolled confounding. Nonetheless, we would advise caution regarding use of herbal medicines during pregnancy, and we suggest that further investigation of these findings is warranted.