| 27 Juin 2012
 Pediatric and Developmental Pathology – A Japanese study has  found that maternal rather than fetal factors are associated with fetal  growth restriction. A comparison of maternal and fetal  angiotensin-converting enzyme genotypes with the size of babies at birth  found evidence of this connection. This finding lends support to the  hypothesis that reduced placental blood flow leads to fetal growth  restriction. The current issue of the journal Pediatric and Developmental Pathology reports results of a study of 470 pairs of mothers and babies in Japan.  Mothers and babies were genotyped using maternal and cord blood, and  the weight, length, head circumference, and incidence of  small-for-gestational age status were recorded for full-term newborn  infants.  The  renin-angiotensin system is a hormone system that regulates blood  pressure and fluid balance in the body. The maternal renin-angiotensin  system affects the regulation of uteroplacental blood flow. A disorder  in the maternal system may contribute to reduced placental blood flow,  preeclampsia, and intrauterine growth restriction. This  study focused on both maternal and fetal insertion or deletion  polymorphism of the angiotensin-converting enzyme gene. Pairing of  either insertion/insertion, insertion/deletion, or deletion/deletion  gene alleles was identified. In adults, this insertion or deletion  polymorphism is considered a marker of renin-angiotensin system  function, and has been associated with cardiovascular disorders. Its  role in incidents related to pregnancy has not been as clearly defined.  In  this study, researchers found that the incidence of  small-for-gestational age in babies whose mothers had one or two  deletion alleles was greater than that in babies whose mothers had two  insertion alleles. No significant differences between these groups were  found when analyzing the infants’ alleles.  This  investigation provides evidence that the maternal renin-angiotensin  system, rather than the fetal system, has a greater effect on fetal  growth. Fetal growth may be restricted by reduced blood flow for a fetus  whose mother has a D allele. Full text of the article, “Maternal Deletion Allele of Angiotensin-Converting Enzyme Gene Is Associated with Fetal Growth Restriction,” Pediatric and Developmental Pathology, Vol. 15, No. 2, 2012, is available at http://www.pedpath.org/toc/pdpa/15/2.  About Pediatric and Developmental Pathology Pediatric and Developmental Pathology is the premier journal dealing with the pathology of disease from  conception through adolescence. It covers the spectrum of disorders  developing in-utero (including embryology, placentology, and  teratology), gestational and perinatal diseases, and all diseases of  childhood. For more information about the journal or society, please  visit: http://www.pedpath.org.