FETAL HEART-RATE PATTERNS IN PREGNANCIES COMPLICATED BY MATERNAL DIABETES

Objective: To compare the fetal heart rate (FHR) pattern between fetus es of well controlled diabetic and non diabetic mothers using a comput erized analysis of FHR. Study design: Weekly fetal surveillance was pe rformed in 99 fetuses of mothers with diabetes class A, 21 fetuses of mothers with diabetes class B-R, and 55 fetuses of non-diabetic women, starting at 30 weeks' gestation. All diabetic patients were well cont rolled. Fetal surveillance included a computerized analysis of the FHR , umbilical and uterine Doppler velocimetry, and a biophysical profile . Changes of FHR variation, frequency of FHR accelerations, and umbili cal and uterine Doppler velocimetry were calculated using a regression analysis for each patient. The average slopes and the intercept at 30 , 34, and 38 weeks' gestation of these variables were compared among t he three groups. Results: The slope of FHR variation and the frequency of accelerations had a lower rate of increase during the third trimes ter in fetuses of mothers with diabetes class A (0.84 +/- 0.25 ms/week and 0.06 +/- 0.02/20 min/week, respectively) compared with fetuses of non-diabetic mothers (1.34 +/- 0.55 ms/week and 0.5 +/- 0.1/20 min/we ek, respectively). In fetuses of mothers with diabetes class B-R, FHR variation did not change with gestation (-0.011 +/- 0.2 ms/week) with a small increase in the frequency of accelerations (0.02 +/- 0.004/20 min/week). While no differences were observed at 30 weeks) gestation, FHR variation and the frequency of accelerations were significantly re duced at 34 weeks' gestation in fetuses of mothers with diabetes class B-R compared with fetuses of non-diabetic mothers (P < 0.01). At 38 w eeks' gestation, fetuses of mothers with diabetes class B-R and diabet es class A had both significantly reduced FHR variation as well as fre quency of accelerations compared with fetuses of non-diabetic mothers (P < 0.01). The rate of decrease of the umbilical and uterine artery S /D ratios were similar among the three groups. Conclusions: The FHR pa ttern appears to be different in fetuses of well controlled diabetic m others when related to fetuses of non-diabetic mothers. Disease specif ic standards should be considered for interpretation of FHR patterns i n diabetic pregnancies. Copyright (C) 1996 Elsevier Science Ireland Lt d.