Mild ovarian stimulation for in vitro fertilization: are we ready to change? A meta-analysis

To compare the efficacy of mild ovarian stimulation versus conventional stimulation in in vitro fertilization (IVF).

Meta-analysis.

A systemic literature search was carried out for prospective randomised clinical trials. We electronically searched using PubMed, Medline and Embase for all the studies published from 1990 to December 2011.

Mild ovarian stimulation IVF that uses lower doses and/or shorter duration of gonadotrophins in GnRH antagonist co-treated cycle compared with conventional stimulation IVF.

Live birth rates per started cycle and ongoing pregnancy rates per started cycle of IVF.

On live birth rate, there was a significant difference in favour of the conventional stimulation [70/444 (15.7%) mild vs. 78/325 (24%) conventional] (OR 0.59, CI 0.41-0.85, p = 0.004). Similar findings were observed in the ongoing pregnancy data [140/696 (20%) mild vs. 144/547 (26%) in favour of conventional stimulation] (OR 0.72, CI 0.55-0.93, p = 0.01). The sub-analysis of two studies showed a statistically significant reduction of hyperstimulation syndrome in favour of the mild stimulation (OR 0.27, CI 0.11-0.66).

This analysis presents strong evidence in favour of conventional stimulation IVF, which therefore should currently be considered a treatment of choice for patients requiring IVF treatment.