Minor anomalies: can they predict specific major defects? A study based on 23 major and 14 minor anomalies in over 25,000 newborns with birth defects.

BACKGROUND

Minor anomalies (mAs) are morphological features with little clinical relevance that have been mentioned as possible predictors of major defects (MDs).

OBJECTIVES

To identify the preferential associations between selected MDs and mAs and to establish if mAs can serve as predictors for specific MDs.

STUDY

DESIGN

Information of newborns with birth defects was obtained from the ECLAMC (Latin American Collaborative Study of Congenital Malformations) database. The sample consisted of 27,247 live- and stillborn newborns with multiple malformations that included at least one of the selected MDs or mAs. The odds ratio and predictive values were calculated for significant associations, and concurrence rates in first degree relatives.

RESULTS

A total of 33 significant minor-major associations were identified. Single umbilical artery (SUA) and preauricular tags were the most frequent mAs; the former was associated with 10 MDs, the latter only with microtia. The highest positive predictive value was shown by SUA for anal atresia. Newborns with preauricular tags had significantly more relatives with microtia than expected.

CONCLUSIONS

No new relevant associations between MDs and mAs were identified and few mAs seem to serve as predictors for specific MDs in the same newborn. However, preauricular tags can predict the occurrence of microtia in other family members.