Clinical aspects of pregnancies established with cleaving embryos grown in vitro.

Details are given of four pregnancies established by fetilization in vitro and planting cleaving embryos into the mother. The pregnancies were monitored by hormone assays in early pregnancy and by ultrasound scans. Amniocentesis was used to assess the levels of alpha-fetoprotein and the karyotype of the fetuses at 15 weeks. Placental function tests and X-rays were used to monitor late pregnancy in one patient. Three of the pregnancies began uneventfully and the fetuses were normal in all respects. Two were delivered at or near term, the third being aborted spontaneously at 21 weeks while the parents were on holiday. The fourth pregnancy did not develop normally and a triploid fetus was aborted 12 weeks after the last menstrual period. The clinical difficulties inherent in selecting patients and preparing them for treatment are described. Some possible improvements in techniques are also described.