Placental pulsatility index: a new, more sensitive parameter for predicting adverse outcome in pregnancies suspected of fetal growth restriction.

INTRODUCTION: The pulsatility indices of the umbilical and uterine arteries are used as the surrogate measures of utero-placental perfusion. Combining the two might simplify the evaluation of total placental vascular impedance, possibly improve prediction of adverse outcomes, and help identify pregnancies with suspected fetal growth restriction that need more intense surveillance. MATERIAL AND METHODS: Umbilical and uterine blood flow velocities were recorded using pulsed-wave Doppler in a longitudinal study of 53 low-risk pregnancies (248 observations) during 20-40 weeks of gestation. Pulsatility indices was calculated for each of these vessels. A new placental pulsatility index was constructed as: (umbilical artery pulsatility index + mean of the left and right uterine artery pulsatility indices)/2, and mean +2 SD defined as abnormal. Gestational age-specific reference percentiles were calculated for the second half of pregnancy and related to values obtained from 340 pregnancies with suspected intra-uterine growth restriction to test its ability to predict adverse pregnancy outcome. RESULTS: The placental pulsatility index was closely associated with gestational age and decreased with advancing gestation in normal pregnancy. The placental pulsatility index had a higher sensitivity and comparable specificity in predicting adverse outcome in pregnancies suspected of intra-uterine fetal growth restriction when compared with conventional umbilical and uterine artery pulsatility indices. CONCLUSIONS: The new placental pulsatility index, reflecting placental vascular impedance on both the fetal and maternal side of placenta, improves prediction of adverse outcome in pregnancies suspected of intra-uterine fetal growth restriction.

Uterine artery Doppler in high-risk pregnancies at 23-24 gestational weeks is of value in predicting adverse outcome of pregnancy and selecting cases for more intense surveillance.

OBJECTIVE: To assess the role of the placental arterial Doppler examination at 23-24 gestational weeks for predicting adverse perinatal outcome in high-risk pregnancies. DESIGN: Retrospective register study. SETTING: Skåne University Hospital in Malmö. POPULATION: Six hundred and forty-five women with high-risk pregnancies, without fetal malformations or chromosomal abnormalities. METHODS: Placental (uterine and umbilical artery) Doppler ultrasound examination at 23-24 gestational weeks. MAIN OUTCOME MEASURES: Adverse perinatal outcomes including preeclampsia, small-for-gestational age newborns (smaller than 3rd percentile or smaller than the 10th percentile), preterm delivery (<34 weeks or <37 weeks of gestation at delivery), cesarean section, admission to the neonatal intensive care unit and intra-uterine fetal death. RESULTS: Abnormal uterine artery Doppler values were detected in 45% of this high-risk group but abnormal umbilical artery Doppler indices were only seen in 3.7%. Adverse perinatal outcome increased significantly with increasing placental vascular impedance (p < 0.0001). There were seven cases of intrauterine fetal death and in five the uterine artery Doppler values at 23-24 weeks were abnormal. A strong correlation between abnormal uterine artery Doppler and preeclampsia was present, but not with other forms of hypertensive disorder. CONCLUSION: Placental Doppler screening at 23-24 weeks can be used in detecting pregnancies at risk of adverse outcome and in selecting cases for more intense surveillance. A surveillance plan is proposed based on Doppler screening at 23-24 weeks of gestation.

Nuchal cord in post-term pregnancy - relationship to suspected intrapartum fetal distress indicating operative intervention.

Color Doppler Ultrasound was performed on 202 post-term pregnancies to detect the presence of a nuchal cord. A nuchal cord was diagnosed if the umbilical cord could be followed 360 degrees around the fetal neck. The results were not disclosed to the managing obstetrician, midwife, and patient. The perinatal outcome was analyzed according to Apgar score, umbilical cord artery and vein pH and base excess (BE), perinatal death, cesarean section, operative delivery for fetal distress (ODFD) and admission to neonatal intensive care unit (NICU). A nuchal cord was detected in 69 patients (34.2%). The incidence was not affected by parity or reduced amniotic fluid volume. There was no statistically significant increased risk for 1- and 5-min Apgar scores <7, umbilical artery pH <7.1, umbilical vein pH <7.20, umbilical artery base excess <-11, umbilical vein base excess <-11, perinatal death, cesarean section, ODFD or admission to NICU. Nuchal cord in post-term pregnancies is not associated with an increased risk for signs of fetal distress and operative intervention during labor and delivery.

Amniotic fluid index in low-risk pregnancy as an admission test to the labor ward.

BACKGROUND: Oligohydramnios has been shown to be a predictor of intrapartal fetal distress. In a selected group of low-risk pregnancies, however, it has not yet been established that oligohydramnios contributes to intrapartal fetal distress. METHODS: Ultrasonically estimated four-quadrant amniotic fluid index as a test for admission to the labor ward was evaluated as a predictive factor for fetal distress during labor in a prospective "blind" study comprising 600 low-risk pregnancies. Oligohydramnios was defined as an amniotic fluid index < or = 50 mm. The parturients were divided into two groups according to the status of the fetal membranes. The amniotic fluid index results were correlated to fetal outcome: Apgar score at 1 and 5 min, pH of blood in umbilical artery and vein, operative delivery because of fetal distress, cesarean delivery because of fetal distress, and number of babies referred to the neonatal intensive care unit. RESULTS: Two-hundred and sixty-seven women had ruptured membranes. Among these a significant increase in operative delivery because of fetal distress was seen in cases of oligohydramnios compared with the normal amount of amniotic fluid (odds ratio 3.86, confidence interval = 1.25-11.9). No significant differences were seen regarding other variables of perinatal outcome. The group with intact membranes comprised 333 parturients. Among these, no significant differences in perinatal outcome could be seen in relationship to the amniotic fluid index, although a 50% increase in emergency operations for fetal distress was seen in women with oligohydramnios. A significant correlation might have been evident even in that group if a larger sample had been studied. CONCLUSION: The results indicate that measurement of the amniotic fluid index in low-risk pregnant women admitted for labor might identify parturients with an increased risk of intrapartal fetal distress.