Induction with ovarian stimulators and especially HMG together with HCG are the principal causes of multiple pregnancies as has been revealed by the studies of 37 case histories of multiple pregnancies over and above twin pregnancies. It is important to be very careful and take strict precautions with these patients who often have psychological troubles that have to be treated first. It is useless to carry out cerclage (cervical stitching) after these triplet and quadruplet pregnancies have been diagnosed early by systematic echography, which should be used in every case where ovulation is induced. It is essential to supervise these patients in a special centre. The children tend to be small for datas and it is best to deliver them by cesarean section at 35 weeks onwards. It is important to avoid these very pathological pregnancies as far as possible. Echography of the ovary should be routine before induction of ovulation.