The Contribution of Fertility Treatments to Pregnancy Outcome in Patients with Recurrent Pregnancy Loss

Objective: To compare demographic characteristics, results of recurrent pregnancy loss (RPL) workup and pregnancy outcome of woman referred to the RPL clinic, with and without preceding fertility treatments.

Methods: a retrospective cohort study including patients treated at the RPL clinic, with two or more consecutive pregnancy losses, followed by a subsequent (index) pregnancy. Multiple logistic regression models were used to control for confounders to analyze weather infertility is a risk factor for RPL.

Results: A total of 675 patients were included in the study, of which 626 conceived spontaneously and 49 (7.26%). conceived following fertility treatments. There were more Jewish women at the fertility treatment pregnancies group (66% vs. 44%, p 0.002). The fertility treatment group had higher rates chronic diseases (39% vs. 26%, p 0.047) and a tendency towards more previous surgeries (41% vs. 28%, p 0.052). The mean gestational age of the previous pregnancy losses was lower in the fertility treatment group (8.36+4.3w vs. 10.77+3.3w, p 0.028). In the workup process – inherited thrombophilia was more commonly observed in the spontaneous pregnancies group (32% vs. 12%, p 0.016). Factor V leiden mutation homozygocity was more common at the fertility treatment group (7% vs. 0.9%, p 0.039). There was no significant difference in the rate of Clexane use between the two groups (36% vs. 25%, p 0.73). No significant difference was found regarding birth rate after 20w of gestational age (65% vs. 74%, p 0.162).

No significant difference was observed regarding the live- birth rate between the two groups who delivered (745 vs. 65%, p 0.138). The index pregnancies of the fertility treatment group (n=31) were characterized with higher rates of IUGR (14% vs. 2.5%, p<0.001) and cesarean sections (20% vs. 10%, p 0.019) with no significant difference in the preterm labor rates (14% vs. 9%, p 0.288). PET seems to be more common as well in the fertility treatment group (8% vs. 3%, p 0.057). Clexane use was significantly higher in the fertility treatment group (48% vs. 25%, p 0.005). In that group, clexane use was associated with higher delivery rates, compared to no clexane use (83% vs. 55%, p 0.043).

In a multiple logistic regression model for pregnancy loss (Table 1), controlling for confounders including maternal age, ethnicity, pregnancy losses previous to index- pregnancy and clexane use, ethnicity was found to be an independent risk factor for pregnancy loss, and clexane use had a protective effect.

Conclusions: RPL patients who conceive via fertility treatments do not have lower delivery rates but have higher rates of IUGR and CS.

In the fertility treatment group, ethnicity is found to be independent risk factors for pregnancy loss and the use of low molecular weight heparin has a protective effect.

Table 1: Multiple Logistic Regression of the Infertility Treatment Group