National population-based estimates for major birth defects, 2016-2020

BACKGROUND

We provide updated crude and adjusted prevalence estimates of major birth defects in the United States for the period 2016-2020.

METHODS

Data were collected from 13 US population-based surveillance programs that used active or a combination of active and passive case ascertainment methods to collect all birth outcomes. These data were used to calculate pooled prevalence estimates and national prevalence estimates adjusted for maternal race/ethnicity for all conditions, and maternal age for trisomies and gastroschisis. Prevalence was compared to previously published national estimates from 1999 to 2014.

RESULTS

Adjusted national prevalence estimates per 10,000 live births ranged from 0.63 for common truncus to 18.65 for clubfoot. Temporal changes were observed for several birth defects, including increases in the prevalence of atrioventricular septal defect, tetralogy of Fallot, omphalocele, trisomy 18, and trisomy 21 (Down syndrome) and decreases in the prevalence of anencephaly, common truncus, transposition of the great arteries, and cleft lip with and without cleft palate.

CONCLUSION

This study provides updated national estimates of selected major birth defects in the United States. These data can be used for continued temporal monitoring of birth defects prevalence. Increases and decreases in prevalence since 1999 observed in this study warrant further investigation.

Update from a cohort study for birth defects in Hunan Province, China, 2010-2020

To define the relationship between sex, residence, maternal age, and a broad range of birth defects by conducting a comprehensive cross-analysis based on up-to-date data. Data were obtained from the Birth Defects Surveillance System in Hunan Province, China, 2010-2020. Prevalences of birth defects (number of cases per 10,000 fetuses (births and deaths at 28 weeks of gestation and beyond)) with 95% confidence intervals (CI) were calculated by sex, residence, maternal age, year, and 23 specific defects. Cross-analysis of sex, residence, and maternal age was conducted, and crude odds ratios (ORs) were calculated to examine the association of each maternal characteristic with birth defects. A total of 1,619,376 fetuses and 30,596 birth defects were identified. The prevalence of birth defects was 188.94/10,000 (95% CI 186.82-191.05). Birth defects were more frequent in males than females (210.46 vs. 163.03/10,000, OR = 1.30, 95% CI 1.27-1.33), in urban areas than in rural areas (223.61 vs. 162.90/10,000, OR = 1.38, 95% CI 1.35-1.41), and in mothers ≥ 35 than mothers 25-29 (206.35 vs. 187.79/10,000, OR = 1.10, 95% CI 1.06-1.14). Cross-analysis showed that the prevalence of birth defects was higher in urban females than in rural males (194.53 vs. 182.25/10,000), the difference in prevalence between males and females was more significant for maternal age < 20 compared to other age groups (OR = 1.64, 95% CI 1.37-1.95), and the prevalence difference between urban and rural areas is more significant for maternal age 25-34 compared to other age groups (OR = 1.49, 95% CI 1.43-1.57). Cleft palates were more frequent in males, and nine specific defects were more frequent in females. Five specific defects were more frequent in rural areas, and eight were more frequent in urban areas. Compared to mothers 25-29, five specific defects were more frequent in mothers < 20, seven specific defects were more frequent in mothers 20-24, two specific defects were more frequent in mothers 30-34, and ten specific defects were more frequent in mothers ≥ 35. Our data indicate that sex, residence, and maternal age differences in the prevalences of birth defects and most specific defects are common. We have found some new epidemiological characteristics of birth defects using cross-analysis, such as residence is the determining factor for the prevalence of birth defects, the difference in prevalence between males and females was more significant for maternal age < 20 compared to other age groups, the prevalence difference between urban and rural areas is more significant for maternal age 25-34 compared to other age groups. And differences in the epidemiological characteristics of some specific defects from previous studies. Future studies should examine mechanisms. Our findings contributed to clinical counseling and advancing research on the risk factors for birth defects.

National population-based estimates for major birth defects, 2010-2014

BACKGROUND

Using the National Birth Defects Prevention Network (NBDPN) annual data report, U.S. national prevalence estimates for major birth defects are developed based on birth cohort 2010-2014.

METHODS

Data from 39 U.S. population-based birth defects surveillance programs (16 active case-finding, 10 passive case-finding with case confirmation, and 13 passive without case confirmation) were used to calculate pooled prevalence estimates for major defects by case-finding approach. Fourteen active case-finding programs including at least live birth and stillbirth pregnancy outcomes monitoring approximately one million births annually were used to develop national prevalence estimates, adjusted for maternal race/ethnicity (for all conditions examined) and maternal age (trisomies and gastroschisis). These calculations used a similar methodology to the previous estimates to examine changes over time.

RESULTS

The adjusted national birth prevalence estimates per 10,000 live births ranged from 0.62 for interrupted aortic arch to 16.87 for clubfoot, and 19.93 for the 12 critical congenital heart defects combined. While the birth prevalence of most birth defects studied remained relatively stable over 15 years, an increasing prevalence was observed for gastroschisis and Down syndrome. Additionally, the prevalence for atrioventricular septal defect, tetralogy of Fallot, omphalocele, and trisomy 18 increased in this period compared to the previous periods. Active case-finding programs generally had higher prevalence rates for most defects examined, most notably for anencephaly, anophthalmia/microphthalmia, trisomy 13, and trisomy 18.

CONCLUSION

National estimates of birth defects prevalence provide data for monitoring trends and understanding the impact of these conditions. Increasing prevalence rates observed for selected conditions warrant further examination.

Inherited genetic susceptibility to acute lymphoblastic leukemia in Down syndrome

Children with Down syndrome (DS) have a 20-fold increased risk of acute lymphoblastic leukemia (ALL) and distinct somatic features, including CRLF2 rearrangement in ∼50% of cases; however, the role of inherited genetic variation in DS-ALL susceptibility is unknown. We report the first genome-wide association study of DS-ALL, comprising a meta-analysis of 4 independent studies, with 542 DS-ALL cases and 1192 DS controls. We identified 4 susceptibility loci at genome-wide significance: rs58923657 near IKZF1 (odds ratio [OR], 2.02; Pmeta = 5.32 × 10-15), rs3731249 in CDKN2A (OR, 3.63; Pmeta = 3.91 × 10-10), rs7090445 in ARID5B (OR, 1.60; Pmeta = 8.44 × 10-9), and rs3781093 in GATA3 (OR, 1.73; Pmeta = 2.89 × 10-8). We performed DS-ALL vs non-DS ALL case-case analyses, comparing risk allele frequencies at these and other established susceptibility loci (BMI1, PIP4K2A, and CEBPE) and found significant association with DS status for CDKN2A (OR, 1.58; Pmeta = 4.1 × 10-4). This association was maintained in separate regression models, both adjusting for and stratifying on CRLF2 overexpression and other molecular subgroups, indicating an increased penetrance of CDKN2A risk alleles in children with DS. Finally, we investigated functional significance of the IKZF1 risk locus, and demonstrated mapping to a B-cell super-enhancer, and risk allele association with decreased enhancer activity and differential protein binding. IKZF1 knockdown resulted in significantly higher proliferation in DS than non-DS lymphoblastoid cell lines. Our findings demonstrate a higher penetrance of the CDKN2A risk locus in DS and serve as a basis for further biological insights into DS-ALL etiology.

Temporal trends in diagnoses of congenital microcephaly, Texas Hospital Discharge Diagnoses, 2000-2015

OBJECTIVE

Assess temporal trends in congenital microcephaly.

METHODS

We used Texas inpatient discharge diagnoses between 2000 and 2015, restricting to newborns. Between 2000 and 2003, the maximum number of fields for recording diagnostic codes was eight, and between 2004 and 2015 it was 24. Microcephaly was classified into four subgroups based on co-occurring diagnoses: A (Known Causes), B (Other Birth Defects), C (Preterm Birth or Fetal Growth Restriction) and D (Isolated Cases).

RESULTS

We identified 2,301 cases of microcephaly or 4.0 cases per 10,000 live births. There was an increase in the prevalence of microcephaly in 2012-2015 compared with 2000-2003, odds ratio = 1.85 (95% CI 1.64-2.10) Significant temporal increases in microcephaly were observed within each of the four microcephaly subgroups and significant temporal increases were also observed for eight other neonatal diagnoses during the same time period. When we restricted our analysis to cases with microcephaly identified using only the eight diagnostic codes available throughout the entire study period, the temporal trend for microcephaly was diminished or absent.

CONCLUSIONS

It remains uncertain whether the observed increases in microcephaly and other neonatal diagnoses are real or an artifact of the change in the number of fields. However, since it is unlikely that there would be a simultaneous increase in microcephaly and eight other neonatal diagnoses, it is likely that some or all of the temporal increases in neonatal diagnoses are artifactual.

Infectious outcomes of gastroschisis patients with intraoperative hypothermia

BACKGROUND

Perioperative hypothermia decreases nutrient and oxygen delivery to tissues and, in adult studies, increases the risk of infectious complications (ICs). Gastroschisis (GS) places newborns at risk for hypothermia by nature of exposed viscera and excessive heat loss. Although hypothermia is a known cause of mortality in GS, the rate of ICs in this at-risk cohort has not yet been delineated.

MATERIALS AND METHODS

A retrospective cohort study was performed at our single tertiary-referral hospital, evaluating patient and operative characteristics of all GS infants who underwent operative closure. Intraoperative temperatures were recorded, defining hypothermia as mild (35.5°C-35.9°C), moderate (35.0°C-35.4°C), or severe (<35°C). Temperature nadirs, procedural and anesthesia duration were observed. The primary outcome was 30-d surgical site infections. Secondary measures included other ICs.

RESULTS

Among 43 GS neonates, 21 (48.8%) had intraoperative hypothermia, classified as mild in 2 (4.7%), moderate in 8 (18.6%), and severe in 11 (25.6%). Nineteen ICs occurred in 35.9% of patients, including 10 (23.3%) surgical site infections. There was no association between hypothermia and ICs. Patient and operative characteristics were similar between normothermic and hypothermic groups, except that normothermic infants were more likely to have silos placed with delayed closure than hypothermic patients (63.6% versus 23.8%, P = 0.01).

CONCLUSIONS

Infants with GS are at high risk for hypothermia and ICs, though newborns with silos were less subject to temperature lability. A multiinstitutional study with greater power is needed to further investigate the relationship between perioperative hypothermia and surgical ICs.

Risk factors for congenital diaphragmatic hernia in the Bogota birth defects surveillance and follow-up program, Colombia

PURPOSE

The mortality rate for congenital diaphragmatic hernia (CDH) remains high and prevention efforts are limited by the lack of known risk factors. The aim of this study was to determine prevalence, risk factors, and neonatal results associated with CDH on a surveillance system hospital-based in Bogotá, Colombia.

METHODS

The data used in this study were obtained from The Bogota Birth Defects Surveillance and Follow-up Program (BBDSFP), between January 2001 and December 2013. With 386,419 births, there were 81 cases of CDH. A case-control methodology was conducted with 48 of the total cases of CDH and 192 controls for association analysis.

RESULTS

The prevalence of CDH was 2.1 per 10,000 births. In the case-control analysis, risk factors found were maternal age ≥35 years (OR, 33.53; 95 % CI, 7.02-160.11), infants with CDH were more likely to be born before 37 weeks of gestation (OR, 5.57; 95 % CI, 2.05-15.14), to weigh less than 2500 g at birth (OR, 9.05; 95 % CI, 3.51-23.32), and be small for gestational age (OR, 5.72; 95 % CI, 2.18-14.99) with a high rate of death before hospital discharge in the CDH population (CDH: 38 % vs BBDSFP: <1 %; p < 0.001).

CONCLUSIONS

The prevalence of CDH calculated was similar to the one reported in the literature. CDH is strongly associated with a high rate of death before hospital discharge and the risk factors found were maternal age ≥35 years, preterm birth, be small for gestational age, and have low weight at birth. These neonatal characteristics in developing countries would help to identify early CDH. Prevention efforts have been limited by the lack of known risk factors and established epidemiological profiles, especially in developing countries.

Stability of Orofacial Clefting Rate in Alberta, 1980–2011

Objective

To determine the prevalence and trends of orofacial clefts in Alberta (Canada) over a 33-year period (1980 through 2011) and to determine whether the trends differ for subcategories of orofacial clefts for the period from 1997 through 2011.

Design

A prevalence study based on the Alberta Congenital Anomalies Surveillance System, which has multiple sources of ascertainment, capability of verification, and an upper age limit of 1 year.

Inclusion

All live born and stillborn babies and fetal deaths less than 20 weeks' gestation (including terminations of pregnancy) born in Alberta of mothers who reside in Alberta.

Results and Conclusions

Rates for cleft lip with or without cleft palate and cleft palate only have been very stable over the 33-year period (1980 through 2011). These rates include all clefts (isolated, syndromes, recognizable conditions, chromosomal and multiple congenital anomalies). Ascertainment of fetal deaths less than 20 weeks' gestation began in 1997. There are trends for the 1997 through 2011 cohort with a marginally significant increase for cleft lip with or without cleft palate in the isolated category and a significant decrease for cleft palate, mainly in the associated groups. The impact of folic acid fortification and/or multivitamins/folic acid supplementation reports in the literature have shown no consensus with respect to a change in the prevalence of orofacial clefts. It is unclear whether folic acid fortification has had any impact in Alberta.

Anomalies associated with gastroschisis and omphalocele: analysis of 2825 cases from the Texas Birth Defects Registry

BACKGROUND/PURPOSE

The increasing prevalence of abdominal wall defects prompted analysis of anomalies associated with gastroschisis and omphalocele in the Texas Birth Defects Registry (TDBR).

METHODS

Cases of gastroschisis (ICD9 code 756.71), omphalocele (756.70), and/or unspecified anomalies of the abdominal wall (756.79) were obtained from the TDBR after IRB approval and analyzed using Microsoft Access© and Excel© databases.

RESULTS

Analysis began with 2825 cases including 1831 of gastroschisis, 814 of omphalocele, and 180 of unspecified abdominal wall defects plus 9680 associated anomalies that were classified according to system. The overall prevalence of abdominal wall defects among 3,806,299 Texas births from 1999 to 2008 was 7.4 per 10,000 with 4.8 per 10,000 for gastroschisis and 2.1 for omphalocele. After excluding ambiguous cases (8.5% possibly misclassified), anomaly spectra were similar for the two AWD with musculoskeletal (limb contractures or defects), cardiovascular, gastrointestinal, urogenital, and central nervous system defects being most common. Of 1831 cases with gastroschisis, 594 (32%) had associated anomalies compared to 654 (80%) of 814 omphalocele cases.

CONCLUSIONS

Gastroschisis as well as omphalocele has significant associated anomalies that are important to appreciate during pre- and postnatal management.

Folic acid fortification and the birth prevalence of congenital heart defect cases in Alberta, Canada

BACKGROUND

Congenital heart defects (CHDs) are the most common type of congenital anomaly. The precise etiology is unknown and the development of successful primary prevention strategies is challenging. Folic acid may have a protective role; however published results have been inconsistent. This study examines the impact of mandatory folic acid fortification (FAF) on the prevalence of CHDs.

METHODS

CHD cases were ascertained using the Alberta Congenital Anomalies Surveillance System, Pediatric Cardiology Clinics, Pathology, and hospital records. The birth prevalence and odds ratios (OR) of isolated CHD cases (i.e., without noncardiac anomalies) were calculated comparing pre-FAF (1995-1997) with post-FAF (1999-2002).

RESULTS

The prevalence of isolated CHD cases remained relatively unchanged when pre-FAF (9.34, 95% confidence interval [CI] 8.79-9.92) was compared with post-FAF (9.41, 95% CI, 8.93-9.91). Left ventricular outflow tract obstruction (LVOTO) decreased post-FAF (OR, 0.76; 95% CI, 0.61-0.94). Coarctation of the aorta contributed to this decline (OR, 0.55; 95% CI, 0.32-0.92). Atrial septal defect (ASD) (OR, 1.42; 95% CI, 1.13-1.80) and ASD with ventricular septal defect (OR, 1.52; 95% CI, 1.10-2.10) increased post-FAF. The remaining types of CHDs were unchanged.

CONCLUSION

FAF alone does not have an impact on the prevalence of CHDs as a group and the majority of selected types of CHDs in Alberta. The decrease in LVOTO, particularly coarctation of the aorta, may be due to FAF or other environmental factors. The increase in ASD and ASD with ventricular septal defect may reflect an increase in diagnosis and ascertainment.

Congenital malformations associated with assisted reproductive technology: a California statewide analysis

BACKGROUND

Management of congenital malformations comprises a large part of pediatric surgical care. Despite increasing utilization of assisted reproductive technology (ART) and fertility-related services (FRS), associations with birth defects are poorly understood.

METHODS

Infants born after ART or FRS were identified from the California Linked Birth Cohort Dataset from 2006 to 2007 and compared to propensity matched infants conceived naturally. Factors associated with major congenital malformations were evaluated using Firth logistic regression.

RESULTS

With a cohort of 4,795 infants born after ART and 46,025 naturally conceived matched controls, major congenital malformations were identified in 3,463 infants. Malformations were increased for ART infants (9.0% vs. 6.6%, p<0.001). After adjusting for infant and maternal factors, ART infants exhibited increased odds of major malformations overall (OR 1.25, 95% CI 1.12-1.39), specifically defects of the eye (OR 1.81, 95% CI 1.04-3.16), head and neck (OR 1.37, 95% CI 1.00-1.86), heart (OR 1.41, 95% CI 1.22-1.64), and genitourinary system (OR 1.40, 95% CI 1.09-1.82). The likelihood of birth defects was increased for multiples (OR 1.35, 95% CI 1.18-1.54) and not singletons. Odds of congenital malformation after FRS alone (n=1,749) were non-significant.

CONCLUSION

ART contributes a significant risk of congenital malformation and may be more pronounced for multiples. Accurate counseling for parents considering ART and multidisciplinary coordination of care prior to delivery are warranted.