Evidence against genetic factors causing major loss of embryos.

A report of a high incidence of genetic abnormality after in vitro fertilisation' led to a suggestion that the apparently low fecundity in man' may be partly explained by a high incidence of loss of embryos due to genetic factors. Data from induction of ovulation in patients with hypogonadotrophic hypogonadism, however, suggest that a high incidence of conception may be achieved.3 Advances in ultrasound monitoring of ovarian function during induction of ovulation now permit more accurate assessment of data on conception.