Cytogenetic aspects of recurrent pregnancy loss

Major advances in examination of the gamete, preembryo, and early aborted fetus have given us more information on the incidence of chromosome abnormalities. Most of the gamete information has come from analysis of human sperm, samples of which are easily collected. Retrieval of oocytes has been difficult and has replied on voluntary donation by laparoscopy. New follicle harvesting methods using ultrasound-guided vaginal retrievals could make these cells more accessible for analysis in families with recurrent trisomy and suspected germ cell mosaicism. At present, most couples with recurrent loss have chromosomally normal abortuses. Aside from specific maternal endocrine or structural complications, most of these abortions remain unexplained. Molecular approaches and immunologic investigations (as outlined in other contributions to this publication), in concert with well-defined epidemiologic studies, should contribute a great deal to our understanding of the factors involved in recurrent spontaneous abortion.