A randomized controlled trial of third-trimester routine ultrasound in a non-selected population.

OBJECTIVE: To compare detection rates of small-for-gestational-age fetuses, large-for-gestational-age fetuses, congenital anomalies and adverse perinatal outcomes in pregnancies randomized to third-trimester routine ultrasound or ultrasound on clinical indication. DESIGN: Randomized controlled trial. SETTING: National Center for Fetal Medicine in Norway between 1989 and 1992. POPULATION: A total of 6780 pregnancies from a non-selected population. METHODS: Two routine ultrasound examinations at 18 and 33 weeks were compared with routine ultrasound at 18 weeks and ultrasound on clinical indication. Suspected small-for-gestational-age fetuses were followed with serial scans and cardiotocography. Doppler ultrasound was not used. MAIN OUTCOME MEASURES: Detection rates of small-for-gestational-age and large-for-gestational-age fetuses, congenital anomalies and adverse perinatal outcomes. RESULTS: Third trimester routine ultrasound improved detection rates of small-for-gestational-age fetuses from 46 to 80%, but overall perinatal morbidity and mortality remained unchanged. Detection of large-for-gestational-age fetuses increased from 36 to 91%. There was a significant increase of induction of labor and elective cesarean sections due to suspected small-for-gestational-age and a significant decrease of induction of labor and elective cesarean sections due to suspected large-for-gestational-age in the study group; there were no other differences regarding intervention. The detection rate of congenital anomalies was 56%, with no significant difference between the groups. CONCLUSIONS: Routine use of third-trimester routine ultrasound increased detection rates of small-for-gestational-age and large-for-gestational-age fetuses. This did not alter perinatal outcomes. Third-trimester ultrasound screening should not be rejected before a policy of adding Doppler surveillance to the high-risk group identified has been investigated further.

Inter-observer variation in assessment of 845 labour admission tests: comparison between midwives and obstetricians in the clinical setting and two experts.

OBJECTIVE: To assess the inter-observer agreement in assessment of the labour admission test between midwives and obstetricians in the clinical setting and two experts in the non-clinical setting, the inter-observer agreement between two experts in the non-clinical setting and to what degree fetal distress in labour could be predicted by the two experts. DESIGN: Observational study. SETTING: The maternity unit of Hammerfest Hospital, Norway. POPULATION: Eight hundred and forty-five high and low risk women. METHOD: The labour admission test was first assessed by the midwife or obstetrician in the clinical setting, and was later assessed by two experts. The traces were assessed as normal, equivocal or ominous. Weighted kappa (kappaw), proportion of agreement (Pa) and predictive values were calculated. MAIN OUTCOME MEASURES: Weighted kappa, proportion of agreement, sensitivity, positive predictive value and likelihood ratios. RESULTS: Inter-observer agreement between Expert 1 and Expert 2: kappaw 0.38 (CI 0.31-0.46), Pa for reactive labour admission test 0.86 (CI 0.83-0.88) and Pa for equivocal/ominous test 0.33 (CI 0.26-0.40). Agreement between Expert 1 and midwives/obstetricians: kappaw 0.25 (CI 0.15-0.36), Pa for reactive labour admission test 0.89 (CI 0.87-0.91) and Pa for equivocal/ominous labour admission test 0.18 (CI 0.11-0.25). Agreement between Expert 2 and midwives/obstetricians: kappaw 0.28 (CI 0.20-0.37), Pa for reactive labour admission test 0.85 (CI 0.82-0.88) and Pa for equivocal/ominous test 0.20 (CI 0.14-0.26). Totally 5.9% of the newborns had fetal distress. At cutoff equivocal test, sensitivity was 0.22 and 0.31 in the two observers. Positive predictive values were 0.13 and 0.11. Likelihood ratio for a positive test was 2.30 and 1.92 and likelihood ratio for a negative test 0.86 and 0.83. CONCLUSION: A labour admission test is still routine practice in most obstetric units in the Western world when there is little evidence on its benefits. The results from this study may provide some reconsideration for such practice, and for more research.