The occurrence and incidence of early pregnancy wastage in an in vitro fertilization and embryo transfer (IVF-ET) program have been studied in 750 patients. In 297 (39.6%) a pregnancy was diagnosed; of these, 14.8% were biochemical and 24.8% clinical pregnancies. In the latter group 23.6% aborted, while 75.8% had clinical ongoing pregnancies. The mean embryo quality score of the biochemical pregnancy group was similar to that of the clinical ongoing pregnancy group but statistically different from that of the clinical abortion group (P less than 0.005). Furthermore, the clinical ongoing pregnancy rate in women with previous biochemical pregnancy was 24.7%, a significantly higher percentage compared to clinical ongoing pregnancies achieved in IVF-ET cycles (P less than 0.05). It is possible that biochemical pregnancy does not represent an index for infertility but rather an intact stage of reproduction leading toward implantation. The high clinical pregnancy rate in subsequent cycles may probably serve as an encouraging sign or a marker for future clinical pregnancy.