Expanding diagnostic testing beyond cytogenetics: implications for birth defects research and surveillance

Impact of prenatal screening on congenital heart defects in neonates with Down syndrome in the US

BACKGROUND

Non-invasive prenatal screening (NIPS) has fundamentally changed the screening process for Down syndrome (DS). Rates of complex congenital heart defects (CHD) have decreased in international studies but whether these shifts exist in the US is unknown.

METHODS

Encounters for neonates with DS from 2007 to 2018 were obtained from the Pediatric Health Information System database. CHD were categorized as complex CHD, atrioventricular septal defects (AVSD), ventricular septal defects (VSD), and tetralogy of Fallot (TOF). Comparisons were made between pre-NIPS era (2007-2010) vs. post-NIPS era (2014-2018) and between states with low vs. high access to pregnancy termination as described by the Guttmacher Institute.

RESULTS

Among 9122 patients, 6% had complex CHD, 22% had an AVSD, 22% had a VSD, and 4% had TOF. No difference in proportions of CHD was seen between eras. A small difference was observed in the proportion of AVSD between states with low vs. high access to pregnancy termination (23 vs. 17%, p < 0.001).

CONCLUSIONS

The proportion of CHD in patients with DS appears to be stable despite widespread adoption of NIPS in the US. Variations were observed between states with low vs. high access to pregnancy termination. Population based studies are needed to fully evaluate the current epidemiology of CHD in DS.

IMPACT

Through investigation of the Pediatric Health Information System database, this study assesses contemporary epidemiology of congenital heart disease among patients with Down syndrome. It has been suggested that improved prenatal screening for Down syndrome has altered the cardiac phenotype in international populations. Whether a similar shift also exists in the United States is unknown. In a contemporary United States cohort, a shift in the proportion or type of heart defects over the past decade was not observed. Regional differences in the proportion of heart defects were seen and may be due to differential access to prenatal care.

Incidence, spectrum and outcome of congenital anomalies seen in a neonatal intensive care unit in Southern Nigeria

BACKGROUND

Congenital anomalies (CAs) refer to defects that are present in a newborn but occurred during intrauterine life. They can be due to genetic, modifiable environmental or multifactorial causes. There was no prior report of their burden in our state.

AIMS

This study aims to describe the incidence, spectrum, predisposing factors and outcome of CAs in our setting.

METHODS

It was a total population study of all neonates with major birth defects admitted into the unit during the study period. Their clinical-demographic features, diagnoses and outcome were entered into an excel sheet. Clinical detection of birth defects was based on standard diagnostic criteria. The data were analysed using IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp. Patterns and outcome of birth defects were presented as proportions. Selected characteristics were tested for possible association with birth defect using Fisher's exact test. The level of significance was set at P < 0.05.

RESULTS

The incidence of major CAs was 4.3/1000 live births. Female neonates were more affected (59.0%). Participants' mean gestational age was 37.7 ± 3.3 weeks. Central nervous system anomalies were the most common (38.5%) birth defects. These were followed by musculoskeletal, body wall and digestive system anomalies: 28.2%, 23.1% and 10.3%, respectively. One-third (33.3%) of the infants had multiple anomalies. Nearly three quarters of them (74.0%) were referred, 18.0% died while 5.0% were discharged alive.

CONCLUSION

A wide range of CAs occur in our setting with dire consequences. Provision of relevant specialised multidisciplinary care is desirable. Furthermore, pubic enlightenment on its modifiable possible causes can reduce the burden.