Fetal Surveillance In Pregnancies With Pregestational Diabetes Mellitus: A Longitudinal Study - Revista Brasileira de Ginecologia e Obstetrícia

Purpose: to study fetal surveillance examinations in pregnancies complicated by pregestational diabetes mellitus, and to correlate them with large for gestational age (LGA) newborns. Methods: Between March 1999 and June 2001, 46 singleton pregnancies with pregestational diabetes mellitus without fetal anomalies were followed prospectively. From the 28th gestational week on, the following examinations were performed weekly: fetal biophysical profile, amniotic fluid index (AFI), and dopplervelocimetry of umbilical and middle cerebral arteries. The newborns with birthweight above the 90th percentile according to local standard values were characterized as LGA infants. Fisher’s exact test and Student’s t test were used for statistical analysis. Results: The mean gestational age at delivery was 37.6 weeks and 15 (32.6%) newborns were LGA. LGA fetuses showed significant increase in the AFI mean performed in the 32nd (16.5 cm, p=0.02), 33rd (16.7 cm, p=0.03), 34th (17.0 cm, p=0.02), 35th (17.9 cm, p=0.000), 36th (15.8 cm, p=0.03) and 37th (17.5 cm, p=0.003) weeks. Non-LGA fetuses presented the following mean AFI values: 13.5cm (32nd week), 13.1cm (33th week), 13.4 (34th week), 12.8 (35th week), 12.5 (36th week) and 12.8cm (37th week). AFI values equal to or above 18.0 cm were associated with the occurrence of LGA infants, when detected at the following gestational ages: 34th (60%, p=0.03), 35th (71.4%, p=0.01), 36th (80%, p=0.02) and 37th (66.7%, p=0.04) week. Non-LGA infants presented the following proportion of AFI values equal to or above 18.0 cm: 40.0% (34th week), 28.6% (35th week), 20.0% (36th week), and 33.3% (37th week). Conclusions: abnormal increase in AFI, mainly with values equal to or above 18.0 cm, is related to LGA infants at delivery. The maternal treatment should be adjusted to achieve the best result for maternal-fetal control, according to the AFI values during pregnancy.