Background: The purpose of the study was to describe number, type, time and place for all obstetric ultrasound examinations that pregnant women in Denmark had performed during their pregnancies. Further, to compare these results with results from a similar national survey performed five years previously.
Methods: During a two-week period in February 1990 and a two-week period in May 1995, all delivery departments in Denmark (1990: 57/1995: 49) participated in two identical designed studies with the aim as described above. For all women who delivered in these periods variables were recorded from the women's case records and after interview. After the exclusion of 108/145 women without complete registrations, the material consisted of 2268/2315 women; approximately 3.7%/3.4% of all deliveries in Denmark 1990/1995. The chi2 and t-test were used for statistical analyses with a statistical significance level of 5%.
Results: Of all obstetric ultrasound examinations 99%/96% took place in hospitals. Twenty/seven percent of the women had no examination during their pregnancies. The mean number of obstetric ultrasound examinations was 1.5/1.9 for all women and 1.9/2.1 for women who had at least one examination. In total 40%/54% of the women were offered a screening examination. Women with an offer of screening had a mean number of examinations: 1.8/2.0 and women without an offer: 1.3/1.9 (1990: p<0.05; 1995: non-significant).
Conclusion: The studies have shown an increasing number of women with an offer of ultrasound screening and in general an increased use of ultrasound examinations in obstetrics during the five year period 1990-1995 in Denmark.