Unquestionable risks of twin pregnancies

It is recognised that multiple pregnancies increase the risk of obstetric and perinatal problems. In order to assess this risk, two groups of women undergoing in-vitro fertilisation (IVF) were compared: one in which a single embryo was transferred, and another in which two were transferred. As expected, the number of twin pregnancies in the first group was zero, but in the second group was 47%. The authors therefore recommend transferring a single embryo to prevent the unquestionable risks of twin pregnancies (Reprod Biomed Online, 31; 154-161,2015). It is certainly ethically difficult to accept subjecting a woman to a risk of twin pregnancy if this can be avoided.