Treatment-related and treatment-independent deliveries among infertile couples, a long-term follow-up.

Background: The aim of this hospital based long-term follow-up study was to further elucidate resolved and unresolved infertility in relation to risk factors and perinatal outcome considering treatment-related and treatment independent pregnancies.

Methods: The study included all couples attending the out-patient clinic of the Department of Gynecology in Umeå due to failure to initiate a pregnancy after at least 12 months during the period 1.1.1980-31.12.1989. Data from the Swedish Medical Birth Registry consisting of all registered births during 1.1.1980-31.12.1992 was linked to establish the number of children born.

Results: Six hundred and ninety-one couples were analyzed, out of which 42% had a delivery outcome. Of these women, 53% conceived in relation to given treatment whereas 47% conceived treatment-independently. Women with ovulatory disorder had a cumulative delivery rate of 82%, whereas those with unexplained infertility and tubo-peritoneal pathology displayed delivery rates of 57% and 31% respectively. Duration of infertility > 3 years was the major negative prognostic factor among patients with unexplained infertility. The frequency of premature deliveries, low birth weight and perinatal mortality was increased among patients with treatment related pregnancies.

Conclusion: For ovulatory disorders the prognosis for a resolved infertility is good. The results among patients with tubo-peritoneal pathology emphasizes the need of in vitro fertilization in modern treatment of infertility. Unexplained infertility is accompanied with a high rate of spontaneous pregnancies but prolonged duration is a negative prognostic factor for these patients. Irrespective of diagnosis, the perinatal outcome is worse in patients with treatment-related pregnancies.