LMWH was administered during an IVF cycle using either the GnRH - agonist or antagonist protocol in poor responders. Drug was started at the beginning of the cycle and stopped at the time of pregnancy test if negative, or continued if pregnancy occurred until the 32th weeks of gestation

IVF cycle using either the GnRH - agonist or antagonist protocol in poor responders.

Heparin from start till hcg test

>2 between groups

Presence of fetal heart at transvaginal ultrasound at 6+2 gestational weeks

>20 weeks of gestation