Fertility after recurrent miscarriages: results of an observational cohort study.

Purpose: Recurrent pregnancy losses (RPL) are considered a pathological condition associated with heterogeneous laboratory and clinical findings, and are also linked to subfertility. We attempt to rank parameters derived from past history and diagnostic results with regard to the prognosis.

Methods: Observational trial on 719 consecutive couples who were referred to a tertiary immunological care centre (2006-2014) after three or more primary miscarriages. Information on past obstetric history and diagnostic procedures at baseline were correlated with cumulative pregnancy and delivery rates using Kaplan-Meier estimation, logistic regression and multivariate analysis.

Results: At baseline, median female age was 34.1 years, waiting time 3 years (1-17), number of preceding miscarriages 3 (3-9), 147 women (20.4%) had conceived at least once in ART or AIH cycles. After a median follow-up of 33.7 (1.7-123.0) months, 5-year pregnancy and delivery rates were 86.1 and 64.5%. Female age (< 35 years), waiting time (< 3 years) until baseline, tubal competence, and male factor fertility significantly correlated with favourable outcome (p < 0.001), while body mass index (> 29 kg/m), number of preceding miscarriages (> 4), late miscarriages, preclinical losses and smoking revealed non-significant negative trends. Mode of conception until baseline (spontaneously or ART/AIH) and classification into idiopathic and non-idiopathic RPL showed no prognostic relevance.

Conclusion: Although in general, chances to conceive a child are retained after three or more miscarriages, factors related to subfertility of both partners have an important impact on the outcome. Therefore, prolonged time to pregnancy (> 6-9 months) should result in preventive gynaecological care from the first miscarriage on, so that fertility can be preserved as best as possible.