ABSTRACT
Pre-gestational diabetes mellitus affects less than 1% of all pregnancies and is a significant cause of fetal morbidity and mortality. It is hypothesized that impaired placental function, in the form of abnormal placental weight and/or abnormal placental histology, may be responsible for this event in such pregnancies. Delayed villous maturation of placental villi, which is one of the findings associated with pre-gestational diabetes increases the rate of perinatal mortality. There is limited literature regarding the delayed maturation of placental villous. This review included trials [randomized and non-randomized], cohort and case-control studies registered in Medline/PubMed database, from January 2001 to September 2012 that evaluated the clinical significance of delayed villous maturation and its prevalence in pre-gestational diabetic cases compared to normal pregnancies. It emphasizes that further studies with focus on possible clinical or ultrasound markers of placental delayed villous maturation, especially in a high risk-group such as women with pre-gestational diabetes mellitus are highly recommended