J KAU: Med. s«. vol. 6, pp. 11-19 (1418 A.H. /1998 A.D.) Macrosomia in Newborns of Diabetic Mothers Still a Valid End -Point ...or Is It? HASSAN A. NASRAT, FRCOG, FRCS Department of Obstetrics & Gynecology, Faculty of Medicine & Allied Sciences, King Abdulazi; University, Jeddah, Saudi Arabia ABSTRACT. Hyperglycaemia is one factor among several other maternal and fetal determinants of neonatal size at birth. The objectives of the present study is to assess the potential role of maternal hyperglycaemia "defined by 3rd trimester mean blood glucose level" together with some other maternal variables as a determinant of fetal weight at birth and the risk of macrosomia "birth weight < 4000 g", Data from 178 diabetic and 219 non-diabetic pregnant women were analyzed using multiple and logistic regression analysis. The results showed that 3rd trimester blood glucose level and duration of gestation, each had a significant positive relation to fetal weight at birth. However, the incidence of delivering < 4000 g baby was primarily related to maternal age in both the diabetic and non-diabetic groups, as well as to maternal body weight and duration of gestation in the non-diabetic group. It is concluded that. macrosomic newborns of diabetic mothers include two varieties of neonatal population: those with true "pathological macrosomia" together with constitutionally large newborns who do not exhibit the stigma of diabetic macrosmia. If macrosomia is to be used as an end-point in evaluating the outcome of management of diabetic pregnancies, a differentiation should be made between these two varieties of neonatal populations. Keywords: Gestational diabetes, Macrosomia, Hyperglycaemia, Risk factors. Introduction With recent developments in antenatal and neonatal care the mortality among infants of diabetic mothers have been reduced to a rate which is almost similar to that of nonmortality is a more appropriate end-point in evaluating the outcome of diabetic pregnancies. In this respect, fetal macrosomia is probably the most commonly reported morCorrespondence & reprint requests to: Dr. H. A. Nasrat, PO Box 6615, Jeddah 21452, Saudi Arabia. Accepted for publication after revision I, June 1997. Received 27th March 1997. 11