Aim: The aim of the study was to evaluate changes in the course of twin deliveries over the years, with particular emphasis on the history of infertility duration of pregnancy mode of delivery indications for caesarean section (CS) and infant condition.
Material and methods: The study consisted of three groups of patients who delivered twins at the First Department of Obstetrics & Gynecology Medical University of Warsaw: 92 women in years 1987-1991 (G1), 62 in years 1997-2001 (G2) and 126 in years 2007-2010 (G3). The history of infertility treatment (especially in vitro fertilization), mode of delivery indications for cesarean section and newborn condition were taken into account. The results were afterwards compared among the groups and the differences were analyzed with the use of Statistica 10.0 software, with p value <0.05 considered as significant.
Results: The rate of twin deliveries in G1 was 1.03% of all deliveries, 1.09% in G2 and 1.77% in G3 (p=0.049 G3 vs. G1). An increase of twin deliveries among primiparas (from 44.5% in G1 through 48.3% in G2 to 66.7% in G3; p=0.0016) and primiparas after in vitro fertilization (from 9.76% in G1 through 26.67% in G2 to 58% in G3; p<0.001) was noted. The average age of patients and mean duration of pregnancies were similar in G1, G2 and G3. However there was a significant increase in preterm delivery rate in G2 and G3 in comparison to G1 (G1 - 38.4%; G2 - 63.3%; G3 - 64.3%; G1 vs G2 and G3 p<0.001). CS was performed in 47.8% vs. 58% vs. 90.5% of all cases (p<0.0001). In G1 CS was most often performed when the presentation of the 1st fetus was non-cephalic (53.3%). In G2 and G3 the non-cephalic presentation of the 1st or 2nd fetus was equally important as an indication for CS (30.5%, 30.5% and 19.3%, 21.9%, respectively). Manual maneuvers on the 2nd twins were applied in 25% vs. 6.5% vs. 0.79% of deliveries (p<0.01). Cesarean section on the second twin, after the first twin was delivered vaginally was performed in 1.07% of the cases in G1, 1.61% in G2 and in 0.79% in G3 (p=ns). There were no differences in the Apgar scores of the first twins in the 1st and 5th minute of life among the studied groups. However, second twins were delivered in significantly better condition in G2 and G3 than in G1 (5-minute Apgar of 8-10 points: 79.7% vs. 93.3% vs. 92.6%; p<0.05).
Conclusions: Twin pregnancy rate almost doubled over the years, mostly due to a growing popularity of the infertility treatment. Cesarean section is increasingly being chosen to deliver twins. The non-cephalic position of the 2nd fetus has become an important indication for cesarean section. Change in the mode of twin deliveries can be beneficial for the condition of the 2nd twin.