[Clinical trends in 520 twin pregnancies in 22 years]

In the last 22 years 520 twin pregnancies were seen at the Department of Obstetrics and Gynecology, University of Ulm. The material was analyzed retrospectively according to the 4 time periods 1965-1974, 1975-1980, 1981-1983, and 1984-1987. An equal-size group of singleton pregnancies was used as control. 1. By the 20th week the diagnosis had been established in 67% between 1984 and 1987 and 29% between 1975 and 1980. 2. A cervical cerclage was most commonly done between 1981 and 1983 (75%). The frequency decreased afterwards and a cerclage was only done in 18% in 1987. 3. Tocolytic agents were used in 7% between 1965 and 1974 and in two thirds of cases in the last years. 4. Hospital admission before delivery was most common between 1975 and 1980 (33%). In the last 7 years it was only half as common (15%). 5. There was no difference in the frequency of preeclampsia and eclampsia between singleton and twin pregnancies in the last years. 6. Maternal hemoglobin levels below 10% were more common in twin pregnancies than in the control group: Before delivery 11%, after delivery 22% in the twin pregnancies, compared with 6% and 4% in the singleton pregnancies. 7. There was no increase in the duration of pregnancy in the last 22 years. The difference between actual birth date and estimated date of delivery remained about the same in the 4 examined time periods: 21 days, 20 days, 21 days, 27 days. There was a slight increase in the frequency of delivery before the 37th week in twin pregnancies: 38%, 41%, 43%, 47%.