Antenatal ultrasonography in Dunedin: one year's data.

Two thousand and forty-five pregnancies were registered during one calendar year, at the two hospitals in Dunedin. One thousand five hundred and ninety-four liveborn infants and 15 stillborn infants resulted from 1585 pregnancies. Of this group of pregnant women, 74% had one or more ultrasonographic studies (mean number of scans = 1.5). Of the 1609 infants delivered, 0.4% had a major anomaly of the central nervous system, and 0.7% had hydroenphrosis. Four hundred and sixty pregnancies resulted in spontaneous or therapeutic abortion. Ten point nine percent of those women undergoing therapeutic abortion had ultrasonographic studies. It is apparent from this retrospective audit, that antenatal ultrasonography has become almost routine in those women carrying an infant to term. The relative rarity of fetal anomalies is similar to other, larger, series.