On the other side of the worldwide advance in assisted reproductive technology (ART), there is increasing concern about the maternal, fetal and post-natal risks of ART. To avoid multiple pregnancies, use of elective single embryo transfer (eSET) has been suggested in north European countries. In this review, we attempted to present an evidence-based discussion of the risks/benefits of ART and eSET. While many perinatal risks might be worse in ART than with natural conception in singleton pregnancies, the case is different in twin pregnancies and mainly depends on their monochorionic nature. Especially for early detection of intrauterine growth restriction, it is important to pay special attention to the location of umbilical cord insertion in the placenta. To evaluate the effectiveness of eSET, more studies are necessary with randomized controls.