Objective: To review the utilization rate and pregnancy outcome of multifetal pregnancy reductions (MFR) in the Nordic countries during the period January 1986-June 1992.
Study design: All centers offering assisted conception in Denmark, Finland, Norway and Sweden were retrospectively surveyed by means of a questionnaire with regard to the number and methods used for MFR, pregnancy loss and the outcomes of the pregnancies. The response rate was 100%.
Results: During the period studied, 185 births of triplets or higher multiples occurred in Sweden, 120 in Finland and 102 in Denmark. MFR was performed in 42 women (Sweden 26, Finland 10, Denmark 6) but not in Norway at all. This gives an estimated average utilization rate of 1/7 multiple births of three or more in Sweden, 1/17 in Denmark and 1/12 in Finland. The most frequently used method was intracardiac or intrathoracic injection of a potassium chloride solution in gestational weeks 9-12. One pregnancy was reduced from seven to four fetuses, two from five to three, 10 from five to two, one from four to three, 17 from four to two, one from four to one, five from three to two, four from three to one and one from two to one. Nine (21%) pregnancies terminated in a spontaneous abortion within one week (n = 2) to several weeks (n = 7) after the procedure. Of the remaining 33 (79%) pregnancies which continued to delivery, two fetuses died in utero in the second trimester, three infants died perinatally and one child had transverse limb reduction defects. A successful pregnancy defined by the discharge home of at least one infant occurred in 79% of the cases.
Conclusion: This study gives national estimates on the utilization rate of MFR. Although MFR is performed more frequently in Sweden than in Denmark and Finland, the overall figures remain low in the Nordic countries. The incidence of pregnancy loss in this study is somewhat higher than in several larger reported series, probably reflecting the learning curve of the procedure. It seems reasonable that MFR should be performed in only a few centers in the Nordic countries.