Effectiveness of antenatal care: a population based study.

OBJECTIVE

To analyse the effectiveness of antenatal care as a screening for nonsymptomatic disease and obstetrical risk conditions.

DESIGN

Programme evaluation of antenatal care in a geographically based cohort.

SETTING

Routine clinical practice in primary and specialist level of health care without intervention.

SUBJECTS

One thousand nine hundred and eight women residing in one Norwegian county giving birth during a 12 month period, 1988 to 1989.

OUTCOME MEASURES

The detection rates at the time of delivery, for women with five conditions: twin pregnancies, placenta praevia, breech presentation, small for gestational age (SGA) and pre-eclampsia.

RESULTS

Two hundred and ninety-two women had one or more of the actual conditions, 124 (42%) had been diagnosed at the time of the delivery. The detection rate for SGA was remarkably low (14%). The detection rates for pre-eclampsia (75%), breech presentation (69%), placenta praevia (57%) and twin pregnancies (94%) were in the same range as results reported in the literature. The number of false positive antenatal diagnosis was insignificant.

CONCLUSIONS

Assessing the effectiveness of antenatal diagnosis of growth retardation is connected with major unsolved methodological problems. Clinical management of such cases may be better than indicated by the results based on the ultimate SGA classification. For important obstetrical conditions this study describes an applicable method for practical evaluation of the effectiveness of antenatal care. Areas where care could be improved are demonstrated.