Low molecular weight heparin treatment and impact of inherited thrombophilia type in pregnancies with previous adverse outcome.

Objective: To assess the impact of low molecular weight heparin (LMWH) treatment in 50 pregnancies of women with inherited thrombophilia and adverse pregnancy outcome (APO) in previous untreated pregnancies. The impact of "Conventional" (FVL, PT, AT, PC, PS) and "Novel" (MTHFR, PAI-1, ACE) thrombophilias on APO was investigated.

Methods: The primary outcomes (PO) were: early and late pregnancy loss (EPL, LPL), preterm birth (PTB) or term birth (TB) compared to the last untreated pregnancies of the same women. Secondary outcomes (SO) were APO in LMWH treated and last untreated pregnancies ended with birth. PO and SO were compared in relation to the thrombophilia type.

Results: LMWH decreased EPL and LPL rate and improved TB rate compared with last untreated pregnancies (p < 0.001). There were less PTB (p = 0.019) and no cases of intrauterine fetal death (IUFD) (p = 0.0019) in LWMH-treated pregnancies. The division to Conventional and Novel thrombophilias showed: (a) difference between pregnancy losses and birth rate (p = 0.0069) and (b) no difference in the prevalence of APO in untreated pregnancies ended with birth.

Conclusions: LMWH treatment improves pregnancy outcome in women with inherited thrombophilia and APO in previous pregnancies. Novel thrombophilias have the equal impact on the pregnancy outcome compared to the Conventional thrombophilias.