Objective To assess different anticoagulant regimens in pregnant women with mechanical heart valves: taking oral warfarin throughout the pregnancy, or heparin in the 1st trimester and oral warfarin for the other trimesters. The main outcome measures were major maternal complications and perinatal outcomes. Methods The MEDLINE, EMbase, CBM and CNKI were searched. The quality of the included studies was evaluated and data were extracted by two reviewers independently. Meta-analyses were performed on the results of homogeneous studies. Result Seven studies involving 629 pregnancies in 469 patients met the inclusion criteria for this review, all of which were retrospective surveys. The comparison between the administration of heparin in the 1st trimester plus oral warfarin for the other trimesters and warfarin throughout the pregnancy showed that, there are not significant different in the incidence of major maternal complications and the incidence of adverse perinatal outcomes. Conclusion Compared with the administration of warfarin throughout the pregnancy, the administration of heparin in the 1st trimester and oral warfarin for the other trimesters might increase the incidence of major maternal complications, but with a similar incidence of adverse perinatal outcomes.
