In-vitro fertilization pregnancies in Australia and New Zealand, 1979-1985. Australian In-Vitro Fertilization Collaborative Group.

We report here data on 1510 pregnancies that resulted from in-vitro fertilization in 12 in-vitro fertilization units in Australia and in one unit in New Zealand in the period 1979 to 1985. Live births occurred in 57.5% of all pregnancies (including preclinical abortions) and in 69.0% of clinical pregnancies. There was a high incidence of ectopic pregnancies (5.2% of clinical pregnancies) and spontaneous abortions (24.3% of intrauterine pregnancies). Of 902 viable pregnancies, 202 (22.4%) pregnancies resulted in multiple births. There were 700 infants who were born after singleton births and 438 infants who were born after multiple births. The over-all incidence of preterm delivery was 27.0%, with an incidence of 18.5% of singleton pregnancies. Low birth weight occurred in 34.8% of infants. The perinatal death rate was 47.5 deaths per 1000 births; still births accounted for three-quarters of these deaths. These findings can be used to counsel infertile couples about the risks of reproductive losses after treatment by in-vitro fertilization. National health surveys should include questions that relate to the prevalence of infertility to encourage studies of the prevention of infertility and to assess the requirements for clinical services.