Abstract:

Objective To compare the outcomes of direct singleton pregnancy and singleton pregnancy after reduction of multiple pregnancies with assisted reproductive techniques. Methods Retrospective analysis was done to the data of 300 patients who received assisted reproduction and achieved successful pregnancy in our hospital from January 2013 to December 2020. Among them，109 cases with singleton pregnancy were assigned as group A，91 cases with singleton pregnancy by reduction of multiple pregnancies as group B1 and another 100 with singleton pregnancy for natural fetal loss of multiple pregnancies as group B2. The three groups were compared in terms of complications and neonatal weight. Results The rate of pregnancy complications in group B1（97.8%） was higher than that in group B2（90%）and significantly higher than in group A（P < 0.05）. Pregnancy hyperten⁃ sion in group B1（28.6%）was significantly higher than that in group A（P < 0.05）. The incidences of premature rupture of membranes in the B1 and B2 groups（36.3% and 30%）were both significantly higher than that in group A（P < 0.05）. There were statistical differences in the incidence of anaemia among the three groups（P < 0.05）. The rate of preterm birth in group B was significantly higher than in group A（P < 0.05）. The rate of low weight （14.3%）in group B1 was significantly higher than that in group A and group B2（P < 0.05）. The rate of maternal and infant complications in B1 group at deduction of pregnancy < 8 weeks was significantly higher than in group B2 （P < 0.05）and the rate of preterm birth in B2 group was higher than in B1 group at reduction of pregnancy ≥ 8 weeks（P < 0.05）. Conclusion The rates of pregnancy complications，preterm birth and low neonatal weight among those with singleton pregnancy from reduction of multiple pregnancies are all higher than those among those with initial singleton pregnancy，and therefore prenatal examination should be emphasized after reduction. The rate of maternal and infant complications in those with reduction is higher than that in those for natural fetus loss，and therefore the reduction of multiple pregnancy is suggested between 8 and 12 weeks of gestation. Single embryo trans⁃ fer is recommended for older women undergoing initial assisted reproduction.

Key words:

assisted reproduction, multiple pregnancy, multiple fetal reduction, natural reduction, pregnancy outcome