Intrapartum umbilical artery Doppler velocimetry as a predictor of adverse perinatal outcome: a systematic review.

OBJECTIVE: To evaluate the diagnostic prediction of intrapartum umbilical artery Doppler velocimetry for adverse perinatal outcomes using systematic quantitative overview of the available literature. DESIGN: Online searching of MEDLINE database (January 1966-September 1997), scanning of bibliography of known primary and review articles, review of recent journal issues and that from personal files. Study selection, assessment of study quality and data extraction were all performed in duplicate under masked conditions. PARTICIPANTS: 2700 women (unselected, low, high, and combined low and high obstetric risk populations) included in eight studies selected for meta-analyses. MAIN OUTCOME MEASURES: Likelihood ratios (LRs) for positive and negative test results were generated for the following outcome measures: Apgar scores < 7 at 1 and 5 minute following delivery, small for gestational age fetus; intrapartum fetal heart rate abnormality, umbilical arterial acidosis at delivery; and caesarean section for fetal distress. RESULTS: For Apgar score < 7 at 1 minute following delivery, the pooled LR was 2.5 (95% CI 1.7-3.7) for a positive test and 1.0 (95% CI 0.9-1.1) for a negative test result. A positive test predicted an Apgar score < 7 at 5 minute following delivery with a pooled LR of 1.3 (95% CI 0.4-4.1) while a negative test had a pooled LR of 1.0 (95% CI 0.8-1.2). For the prediction of a small for gestational age fetus, the pooled LR was 3.4 (95% CI 2.3-5.1) for a positive test and 0.9 (95% CI 0.8-1.0) for a negative test. The prediction for fetal heart rate abnormality during labour was similarly disappointing: the pooled LR for a positive test result was 1.4 (95% CI 0.9-1.2) whereas a negative test result generated a pooled LR of 0.9 (95% CI 0.9-1.0). With umbilical acidosis at delivery, the pooled LR was 1.6 (95% CI 1.1-2.5) for a positive test and 1.1 (95% CI 1.0-1.2) for a negative test. The LRs for the prediction of caesarean section for fetal distress were 4.1 (95% CI 2.7-6.2) for a positive test result and 0.9 (95% CI 0.8-1.0) for a negative test result. CONCLUSION: Intrapartum umbilical artery Doppler velocimetry is a poor predictor of adverse perinatal outcomes.     

Low amniotic fluid index as a predictor of adverse perinatal outcome.

OBJECTIVE: To determine whether an antepartum amniotic fluid index (AFI) of 5.0 cm or less is a predictor of adverse perinatal outcome. STUDY DESIGN: The antepartum testing records of 779 women seen over a 12-month period were reviewed. Data, including the reasons for testing, the testing results, and pregnancy outcome were abstracted from these records. Inclusion criteria included a nonanomalous fetus and delivery within 7 days of the last antepartum surveillance test (modified biophysical profile). Chi-square analysis, Fisher's exact test, t tests and receiver-operator curves (ROCs) were used for analysis. RESULTS: An AFI of 5.0 cm or less was significantly associated with an abnormal antepartum fetal heart rate (FHR) tracing but not with cesarean delivery, meconium-stained fluid, Apgars less than 7, or NICU admission. Subjects with an AFI of 5.0 cm or less had a higher rate of cesarean for fetal distress, but this did not reach statistical significance. ROCs produced no diagnostic cutoff values for AFI or largest pocket and prediction of any of the chosen parameters. CONCLUSIONS: Antepartum oligohydramnios is associated with an increased risk of fetal heart rate abnormalities. Although in our population it is not predictive of adverse perinatal outcome as measured by low Apgars and NICU admissions, this may be reflective of the aggressive antepartum and intrapartum management that these patients received.     

Amniotic fluid index as a predictor of adverse perinatal outcome in the HELLP syndrome

OBJECTIVE: To evaluate the prognostic value of an amniotic fluid index (AFI) < or = 5 cm for an adverse perinatal outcome in pregnancies with the syndrome of hemolysis, elevated liver enzymes and low platelets (HELLP syndrome). STUDY DESIGN: A prospective, observational study of patients with the HELLP syndrome. An ultrasound estimate of amniotic fluid volume was obtained on admission. Adverse intrapartum outcomes included amnioinfusion for variable decelerations and/or indicated abdominal/vaginal operative delivery for nonreassuring fetal heart rate changes. Maternal characteristics and perinatal outcome parameters were compared AFI < or = vs. > 5 cm. Statistical analysis was performed using chi2 analysis, Student's t test and receiver-operator characteristic curve (ROC) analysis. RESULTS: Between January 1996 and February 1999, 120 patients were enrolled. Twenty-six (22%) had an AFI < or = 5 cm. This group did not differ from that with AFI > 5 cm regarding the severity of the HELLP syndrome, admission-to-delivery interval (p = 0.354), variable decelerations in labor (p = 0.06), Apgar score of < 7 at 5 minutes (p = 0.361), cesarean delivery for nonreassuring fetal status (p = 1.0) or significant fetal acidosis (pH < 7.0 [p = 0.2101). ROC analysis revealed no AFI measurement between 0 and 16 cm that was useful for identifying the compromised fetus. CONCLUSION: Antepartum/intrapartum performance of AFI in patients with the HELLP syndrome is a poor prognostic test for subsequent fetal compromise.     

Nuchal translucency as a predictor of adverse pregnancy outcome.

BACKGROUND: Thickened nuchal translucency (NT) has been related to fetal genetic syndromes, structural abnormalities, and other diseases. The aim of this research was to evaluate the association of NT with adverse pregnancy outcomes. STUDY DESIGN: In the period 2002-2004 in 2104 pregnant women between 10+6 and 13+5 weeks' gestation, NT was evaluated as a parameter for aneuploidy screening: out of these, 734 singleton pregnant women that underwent 2nd trimester amniocentesis and whose pregnancy outcome were known were selected. NT was statistically correlated to pregnancy and neonatal outcome. RESULTS: Median gestational age (GA) at NT evaluation was 11+2 weeks' gestation. NT median was 1.1 mm (0.9-1.4 mm, 25th-75th centile, range 0.5-4.0 mm). After multiple logistic regressions, the variables significantly associated to NT values were: threatened preterm labor (p<0.008) and preterm labor (p<0.02). The best diagnostic accuracy point was NT>95th centile and >1.5 MoM for the prediction of threatened preterm labor. CONCLUSION: In this series, increased NT values were associated to threatened preterm labor and preterm labor in euploid fetuses: this finding may have clinical consequences in the management of such pregnancies.     

Mid-trimester uterine artery Doppler ultrasound as a predictor of adverse obstetric outcome in high-risk pregnancy

ObjectiveThe aim of this study was to assess uterine artery Doppler ultrasonography efficiency in prediction of adverse pregnancy outcome in high-risk pregnancies.Materials and MethodsWe selected 70 pregnant women who were high risk for development of preeclampsia, abruption, low birth weight (LBW), and preterm delivery during their pregnancy, and Doppler ultrasonography was performed for them in 18–24 gestational weeks for evaluation of uterine artery notching. Absence of diastolic flow in uterine artery waves was defined as notching. The women were divided into two groups: with notching (Group A) and without notching (Group B), then they were compared for complications such as preeclampsia, abruption, LBW, and preterm delivery.ResultsIn 70 high-risk pregnant women, 27 women (39.2%) were in Group A and the others were in Group B. The birth weight in Groups A and B was 2,897.5 ± 757.15 and 3,248.39 ± 374.27, respectively. In our study, 15 patients were delivered before 37 gestational weeks (preterm labor). Preeclampsia, abruption, and LBW were significantly higher in the group with positive notching, but preterm delivery did not show any statistical difference between the two groups.ConclusionAccording to the results, uterine artery Doppler ultrasonography had high negative predictive value for prediction of preeclampsia, abruption, and LBW. Therefore, absence of uterine artery notching in mid-trimester evaluation of high-risk pregnant women may predict better pregnancy outcome. We recommend Doppler ultrasonography for all high-risk pregnant women in second trimester for prediction of pregnancy outcome.     

Quad screen as a predictor of adverse pregnancy outcome

OBJECTIVE: To estimate the effect of second-trimester levels of maternal serum alpha-fetoprotein (AFP), human chorionic gonadotrophin (hCG), unconjugated estriol (uE3), and inhibin A (the quad screen) on obstetric complications by using a large, prospectively collected database (the FASTER database). METHODS: The FASTER trial was a multicenter study that evaluated first- and second-trimester screening programs for aneuploidy in women with singleton pregnancies. As part of this trial, patients had a quad screen drawn at 15-18 6/7 weeks. We analyzed the data to identify associations between the quad screen markers and preterm birth, intrauterine growth restriction, preeclampsia, and fetal loss. Our analysis was performed by evaluating the performance characteristics of quad screen markers individually and in combination. Crude and adjusted effects were estimated by multivariable logistic regression analysis. Patients with fetal anomalies were excluded from the analysis. RESULTS: We analyzed data from 33,145 pregnancies. We identified numerous associations between the markers and the adverse outcomes. There was a relatively low, but often significant, risk of having an adverse pregnancy complication if a patient had a single abnormal marker. However, the risk of having an adverse outcome increased significantly if a patient had 2 or more abnormal markers. The sensitivity and positive predictive values using combinations of markers is relatively low, although superior to using individual markers. CONCLUSION: These data suggest that components of the quad screen may prove useful in predicting adverse obstetric outcomes. We also showed that the total number and specific combinations of abnormal markers are most useful in predicting the risk of adverse perinatal outcome.     

Analysis of birth weight percentile as a predictor of perinatal outcome

Birth weight-gestational age tables are convenient methods for the neonatal evaluation of intrauterine growth, however, the limits of acceptable birth weight for gestational age are controversial. The purpose of this study was to identify the birth weight percentiles that accurately predicted poor perinatal outcome from 28 through 41 weeks' gestational age. In a homogeneous population of 44,811 patients, the birth weight percentile that predicted poor perinatal outcome varied with gestational age. The birth weight percentile that predicted normal outcome in 80% of normal patients declined from the 55th percentile at 28 to 29 weeks to the 24th percentile at 34 to 35 weeks. From 28 through 35 weeks' gestational age, possibly owing to the confounding effects of prematurity, patients classified as normal by birth weight criteria still had a significant risk of poor outcome. After 36 weeks' gestational age, poor perinatal outcome occurred in 3.9% of patients and tended to occur at the extremes of birth weight. Classification by birth weights approximating the tenth and 90th percentiles identified a population in which the majority of the poor perinatal outcome occurred. However, poor outcome occurred in only 10% of patients with birth weights below the tenth or above the 90th percentiles. Among those with birth weights between the tenth and 90th percentiles, outcome was normal in 98%. Therefore, from 36 through 41 weeks' gestational age, the prevalence of poor perinatal outcome was low, and birth weight percentile was a weak predictor of outcome in the individual patient.     

Second trimester placental location as a predictor of an adverse pregnancy outcome.

OBJECTIVE: To determine if the second trimester placental location is associated with perinatal outcomes. MATERIALS AND METHODS: Observational study of placental location and the subsequent risk of an adverse pregnancy outcome. Placental location was divided into three categories, low, high lateral and high fundal. RESULTS: There were 3336 pregnancies analyzed in this study. Low implantation sites had a greater risk of preterm labor (odds ratio (OR) 1.70, 95% confidence interval (CI) 1.38 to 2.90, P<0.001), preterm delivery (OR 1.86, 95% CI 1.36 to 2.54, P<0.001), fewer fetuses with macrosomia (OR 0.56, 95% CI 0.38 to 0.83, P=0.010) and reduced risk of postpartum hemorrhage (OR 0.56, 95% CI 0.46 to 0.95, P=0.026). High lateral implantations had a greater risk of low 1-min (OR 1.80, 95% CI 1.11 to 2.93, P=0.017) and 5-min (OR 3.49, 95% CI 1.46 to 8.36, P=0.005) Apgar scores. CONCLUSIONS: Low placental implantation was associated with an increased risk of preterm labor, preterm delivery and a reduced risk of postpartum hemorrhage, and of a macrosomic fetus. High lateral implantation was associated with low Apgar scores.     

Role of sFlt-1/PlGF ratio and feto-maternal Doppler for the prediction of adverse perinatal outcome in late-onset pre-eclampsia

Archives of Gynecology and Obstetrics - The sFlt-1 (soluble fms-like tyrosine kinase-1)/PlGF (placental growth factor) ratio and uterine artery Doppler have shown to be helpful in the diagnosis of...     

Determining a threshold for amniotic fluid as a predictor of perinatal outcome at term

Objective: To determine a threshold level of amniotic fluid in low-risk term pregnancies predictive of adverse perinatal outcome. Methods: Prospective cohort study of low-risk patients at term undergoing amniotic fluid volume measurement. Amniotic fluid index (AFI) remained blinded unless ≤ 1?cm or ≥ 25?cm. Primary outcome was a positive fetal vulnerability index (FVI). The last AFI was evaluated as predictor of a +FVI. We estimated that we needed to perform ultrasounds on 620 women. Results: Patients were enrolled through 2004–2008. There were 24 (7.8%) patients delivering a neonate with +FVI. An AFI < 8?cm increased the risk of a +FVI (risk ratio 2.70 [95% CI 1.2, 6.0]; p?=?0.01); however, the area under the receiver operating characteristics curve was 0.60. Enrollment was stopped at 308 patients due to enrollment challenges. Conclusions: An AFI cutoff <8?cm was associated with an increase in FVI outcomes but had a low positive predictive value for a +FVI. Isolated incidentally found low fluid in uncomplicated pregnancies may not be an indication for immediate intervention.     

Human placental lactogen: a predictor of perinatal outcome?

Serial human placental lactogen (hPL) determinations were performed on 806 women with normal and abnormal pregnancies late in the pregnancy. These results were not reported to the clinicians involved. For the study population as a whole, low hPL levels did not effectively predict those adverse perinatal outcome variables evaluated. Further analysis revealed that this was true both for the normal and abnormal pregnancy groups. Our data do not support the routine use of antepartum hPL screening, as advocated by others, as a means of improving perinatal outcome. In certain at-risk patients, there was an association between low hPL values and the presence of 1 or more of the adverse outcome variables. However, these patients had been recognized clinically as having fetuses in jeopardy.