[Effects of maternal anemia on computerized cardiotocography and fetal biophysical profile]

Abstract

Purposes: To evaluate the influence of maternal hemoglobin (Hb) levels in the patterns of fetal heart rate (FHR) and in the fetal biophysical profile (FBP) in term gestations.

Methods: Pregnant women with anemia (Hb<11.0 g/dL) were prospectively evaluated between the 36(th) and the 40(th) week of gestation, from January 2008 to March 2009. The Control Group was composed of term and healthy pregnant women, with normal values of hemoglobin (Hb>11,0 g/dL). Cases of anomalies or fetal growing restrictions were excluded. The FHR evaluation was performed by computerized cardiotocography (8002 System-Sonicaid), and by record analysis during 30 minutes of exam. The FBP was done in all the patients. Student's, chi2 and Fisher's exact tests were used, with 0.05 significance level.

Results: The average of maternal Hb in the group with anemia (n=18) was 9.4 g/dL (DP=1.4 g/dL), and in the control group, 12.4 g/dL (DP=1.3 g/dL). There has been no significant mean differences between groups concerning the cardiotocography parameters, respectively: basal FHR(131.3 versus 133.7 bpm, p=0.5), FHR accelerations > 10b pm (7.9 versus 8.2, p=0.866), FHR accelerations > 15 bpm (5.2 versus. 5.4, p=0.9), episodes of high variation of the FHR (17.1 versus 15.5 min, p=0.5), episodes of variation of the FHR (4.4 versus 3.6 min, p=06), and short term variation (10.5 versus 10.9 ms, p=0.5). In both groups, all patients presented normal FBP.

Conclusions: This study suggests that light or moderate maternal anemia, without other maternal or fetal comorbidity, is not associated with abnormalities in the parameters of fetal biophysical profile and of the FHR analyzed by computerized cardiotocography.