Antepartum fetal surveillance tests during sickle cell crisis

A study was conducted to evaluate the characteristics of antepartum fetal assessment tests for women with sickle cell disease during crisis. A total of 24 women with 39 episodes of crisis after 34 weeks of pregnancy were studied. All subjects were evaluated with nonstress tests, biophysical profile score, and uterine and umbilical artery systolic/diastolic ratios during and after sickle cell crisis. Results revealed that the incidence of nonreactive nonstress tests was significantly higher during crisis compared with the period after crisis (58.9% vs 10.3%, p < 0.05). The frequency of biophysical profile score <8 was significantly higher during crisis compared with after crisis (33.3% vs 7.7%, p < 0.05). All subjects had an increase in uterine systolic/diastolic ratio during crisis. The average uterine systolic/diastolic ratio was 3.92 (range, 2.16 to 4.24) during crisis and 2.54 (range, 1.98 to 3.23) after crisis (p < 0.05). In contrast, there was no significant change in the mean umbilical systolic/diastolic ratios during and after crisis (2.58 and 2.62, respectively). We conclude that, although sickle cell disease crisis is associated with a higher incidence of abnormal biophysical test results, in most patients these results will revert to normal after crisis. The increase in uterine vascular resistance without a concordant increase in umbilical vascular resistance suggests that the transient effects of sickling during crisis may not compromise umbilical blood flow.