Chromosome studies on early human embryos fertilized in vitro.

The majority of early spontaneous abortions carry a lethal chromosomal anomaly. While it is recognized that several factors would be responsible for some IVF failures, it is important to determine the contribution of chromosomal aberrations to the preimplantation loss of embryos produced in vitro. Chromosome analysis of embryos not destined for replacement in the uterus could help to elucidate this phenomenon of early embryonic loss. Fifty-five out of 239 embryos fertilized in vitro were successfully karyotyped and amongst these the overall rate of diploidy was 25.5% in this study, which mainly comprised rejected embryos. Embryos without cleavage had mostly a chromosomal defect (20/38) and only a minority (9/38) were unfertilized. Numerical abnormalities were found in a total of 33/46 (71.7%) morphologically normal embryos. In contrast a diploid chromosomal complement was found in only 11.1% (1/9) of morphologically abnormal embryos.

In vitro fertilization and embryo transfer in Pretoria.

Details of the in vitro fertilization and embryo transfer programme at the Department of Obstetrics and Gynaecology of the H. F. Verwoerd Hospital and the University of Pretoria are presented. From 1 March 1982 to 30 November 1983, 67 cycles in 47 patients were induced using clomiphene citrate and human chorionic gonadotrophin (hCG) (46 patients) and human postmenopausal gonadotrophin/hCG (1 patient). In 5 patients ovum recovery was unsuccessful owing to severe adhesions. In the remaining 42 patients 59 oocyte recoveries out of a total of 62 attempts were successful, a 95% recovery rate. One hundred and seventy-nine ova were recovered (2,9 per laparoscopy), of which 143 (80%) were viable. Forty-six per cent of fertilized ova cleaved actively. Forty-one transfers of 66 embryos (average 1,6 embryos per transfer) resulted in 5 pregnancies (12% pregnancy rate per transfer). Three preclinical pregnancies aborted spontaneously. Two pregnancies are ongoing at 30 and 32 weeks' gestation. Thus, the programme has so far led to 2 third-trimester pregnancies. Consolidation and refinement of techniques should lead to a steady increase in success at this centre.