Umbilical artery resistance index in diabetic pregnancies: the associations with fetal outcome and neonatal septal hypertrophic cardiomyopathy.

AIM

To determine the incidence of an abnormal umbilical artery resistance index (UARI) in diabetic pregnancies and the relation to fetal outcome and the development of neonatal septal hypertrophic cardiomyopathy.

METHODS

A case-control study with subjects comprising 50 randomly selected diabetic mothers and a matched control group of 50 non-diabetic pregnancies. Doppler studies of the UARI were carried out at least once per week, beginning from 36 weeks' gestation for both groups. Within 48 h post delivery, echocardiograms were carried out on the newborn infants to identify those with hypertrophic cardiomyopathy, particularly asymmetrical septal hypertrophy.

RESULTS

The numbers of patients with abnormal UARI were similar in both the diabetic and control groups. A higher proportion of operative deliveries for intrapartum fetal distress was seen in patients with an abnormal UARI in the diabetic group. However, the groups did not differ in the numbers of infants who were small for gestational age, who had low Apgar scores or umbilical artery acidosis, and who required admission to the special care nursery. Six infants of diabetic mothers (12%) had septal hypertrophy, but none of these were associated with abnormal antenatal UARI.

CONCLUSION

Diabetic pregnancy is not associated with a significantly higher incidence of abnormal UARI on Doppler study than non-diabetic pregnancy. UARI is not a useful single indicator by which to predict subsequent fetal outcome or the development of neonatal septal hypertrophic cardiomyopathy in diabetic pregnancies.