The mean peak systolic to end-diastolic (S/D) umbilical artery ratio was measured in 291 Doppler studies performed during pregnancy in 35 insulin-dependent diabetic women. A normal decline was observed in the umbilical artery S/D ratio, from 4.2 ± 0.21 at 18 weeks to 2.18 ± 0.22 at 38 weeks. There was no significant correlation between mean third-trimester S/D and either glycosylated hemoglobin(r= 0.25) or mean blood glucose levels(r= 0.15). Fetuses of women with vascular disease (class F/R or chronic hypertension) had a mean third-trimester S/D of 3.0 or higher in five of ten cases, compared with three of 25 in patients with uncomplicated diabetes (P< .03). Mean second- and third-trimester S/D ratios differed significantly in patients with and without vascular disease: 4.34 ± 0.7 and 3.2 ± 0.65 versus 3.72 ± 0.42 and 2.55 ± 0.32, respectively (P< .03). Two of three women without vascular disease who demonstrated an elevated mean S/D ratio developed preeclampsia and delivered appropriate for gestational age infants. In women with vascular disease, four of five with an abnormal mean third-trimester umbilical artery S/D ratio were delivered of growth-retarded infants, whereas all five with normal umbilical artery S/D ratios had appropriate for gestational age infants. In three of the abnormal cases, elevated S/D ratios were present in the second trimester before ultrasound documentation of fetal growth retardation. These data suggest the following: 1) Normal fetal placental resistance can be expected in most pregnancies complicated by diabetes in the absence of maternal vasculopathy; 2) the umbilical artery S/D ratio is independent of glycemic control in a well-controlled diabetic population; and 3) patients with vasculopathy (class F/R or chronic hypertension) represent a high-risk group for fetal growth retardation, which may be detected by early umbilical artery Doppler studies.(Obstet Gynecol 73:961, 1989)
From the Departments of Obstetrics and Gynecology, Ohio State University School of Medicine, Columbus, Ohio; and the University of Pennsylvania, Philadelphia, Pennsylvania.
© 1989 The American College of Obstetricians and Gynecologists