OBJECTIVE: To compare the effectiveness of uterine artery Doppler and maternal serum screening in the prediction of pregnancy complications. MATERIALS AND METHODS: Prospective study with 49 primigravidae at their 18th gestational week, when a blood sample was collected for serum dosage by chemiluminescence (alpha-fetoprotein, human chorionic gonadotropin and nitric oxide) and radioimmunoassay (atrial natriuretic peptide). Uterine artery Doppler was performed between the 24th and 26th gestational weeks, for determining the presence or absence of notch in the flow velocity waveform. The non-parametric Mann-Whitney test was utilized for statistical analysis, and the Fisher exact test for analysis of qualitative parameters. RESULTS: Sensitivity, specificity, positive and negative predictive values were, respectively, 8.3%, 97.0%, 50.0% and 74.4% for alpha-fetoprotein; 8.3%, 87.9%, 20.0% and 72.5% for human chorionic gonadotropin; 16.7%, 97.0%, 33.3% and 76.2% for atrial natriuretic peptide; and 16.7%, 93.9%, 50.0% and 75.6% for nitric oxide. The uterine artery Doppler sensitivity was 75.0%, specificity 63.6%, positive predictive value 57.1%, and negative predictive value 87.5%. CONCLUSION: Uterine artery Doppler is an effective method for prediction of pregnancy complications as compared with maternal serum screening in low risk populations.

Keywords: Doppler, Serum screening, Preeclampsia, Complications, Pregnancy

OBJECTIVE: To estimate which is the best period to realize uterine artery Doppler for the prediction of pregnancy complications. MATERIALS AND METHODS: A prospective study was conducted with 45 women without a history of chronic diseases and in their first pregnancy. The uterine artery Doppler was performed between the pregnancy weeks 18-20, 24-26, 28-30 and 34-36, with determination of the resistance index, the pulsatility index, the A/B ratio and presence or absence of notch on the flow velocity waveform, as well as the result of the pregnancy. RESULTS: The Doppler index showed decrease in the course of the pregnancy, more pronounced in the normal pregnancies in comparison with the complicated pregnancies. This was most noticed in the examinations performed between the weeks 24-26. The best sensitivity/specificity relation for detecting pregnancy complications was achieved in the examination performed in this same period. CONCLUSION: The best period to perform uterine artery Doppler for prediction of pregnancy complications is between weeks 24-26 of gestation.

Keywords: Doppler, Uterine artery, Preeclampsia, Intrauterine growth restriction

OBJECTIVE: To prospectively analyze the amniotic fluid index of low-risk pregnant women who presented or not complications during pregnancy and perinatal period. MATERIALS AND METHODS: The amniotic fluid index was prospectively studied in 45 first pregnancy women with no diseases at study entry. The amniotic fluid index was determined at four time points during pregnancy - 18-20, 24-26, 28-30 and 34-36 weeks - and the values were correlated with the appearance of pregnancy and perinatal complications, uterine artery Doppler findings, gestational age at delivery, route of delivery, and newborn weight. RESULTS: Amniotic fluid index was not significantly different among patients with normal and high risk pregnancies at any of the four time points studied. Likewise, there was no association with gestational age at delivery, route of delivery or newborn weight. The mean amniotic fluid index at 28-30 weeks was higher (p = 0.004) in patients with bilateral incisure than in patients with normal Doppler. CONCLUSION: Prospective evaluation of amniotic fluid index in low-risk pregnancies does not seem to be a good predictor of complications during pregnancy or perinatal period.

Keywords: Amniotic fluid index, Complications of pregnancy, Doppler, Ultrasound