Association of Parental Factors and Insulin-like Growth Factor 2 Polymorphism with Intrauterine Growth Restriction

Abstract

Polymorphism of insulin-like growth factor 2 (IGF2) is known to play a role in cell development. Only the paternal IGF2 copy is active, while the copy inherited from the mother is inactive. This study aimed to explore whether maternal and paternal factors influence IGF2 polymorphism in newborns with intrauterine growth restriction (IUGR) compared to appropriate for gestational age (AGA). A cross-sectional exploratory study was conducted from June 2014 to November 2015 at the Neonatology, Gynecology 1 Clinic, Cluj-Napoca, Romania. The ApaI IGF2 genotypes and allele frequencies were similar in the IUGR and AGA groups (p-value > 0.10). The IUGR babies with a protective IGF2 genetic profile had significantly younger parents (a difference in the median age of 8 years for mothers and 9 years for fathers; p-value < 0.009). The IUGR babies had parents with lower birth weights than AGA babies (mothers’ medians: 2800 g vs. 3100 g; fathers’ medians: 3000 g vs. 3400 g; p-value < 0.02). In univariable regression analysis, the mother’s and father’s birth weight proved to be associated with IUGR. The father’s birth weight proved to be the only factor significantly associated with IUGR, independent of the mother’s birth weight or the presence of a protective IGF2 genetic profile (odd ratio = 0.998 [0.996 to 1.000], p-value = 0.032).

Keywords: insulin-like growth factor 2 (IGF2) polymorphism; intrauterine growth restriction (IUGR); parental factors.