Mortality factors in infants with congenital diaphragmatic hernia: A systematic review

Congenital diaphragmatic hernia (CDH) is a malformation of the diaphragm accounting for 8% of all major congenital anomalies. Although many clinical factors of survival in children with CDH have been established, limited research exists on the role of sociodemographic and other factors. We aimed to systematically identify and summarize all available international literature, published from January 2000 to July 2017, evaluating specific mortality factors for children with prenatally diagnosed, isolated, left-sided CDH.

MEDLINE, PROSPERO, EMBASE, Scopus, The Cochrane Library databases, and the table of contents for the past 5 years for relevant journals were searched systematically. The risk factors of interest were as follows: birth weight, gestational age (GA) at diagnosis, GA at birth, infant sex, maternal age, ethnicity, socioeconomic status (SES), and plurality. The primary outcome measure was survival. Data were extracted on study design, study quality, participant data, and survival-related effect estimates.

Seven studies fulfilled the inclusion criteria. In total, 347 children were included in the review. Birth weight, GA at diagnosis, and GA at birth were evaluated in five studies each, infant sex in two, and maternal age in one. None of these factors were significantly associated with survival. No studies evaluated the influence of plurality, ethnicity or SES.

Although the factors of interest showed no significant association with survival, more evidence is required to confirm these findings. Understanding whether sociodemographic factors are associated with survival may help inform the development of public health interventions to improve survival rates for children with CDH.