Objective To evaluate the efficacy and safety of anticoagulant agents, such as aspirin and heparin, in women with a history of at least two spontaneous miscarriages or one later intrauterine fetal death without apparent causes other than inherited thrombophilias. Methods We searched the Cochrane Pregnancy and Childbirth Group trials register (March 2004), the Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2004), MEDLINE (January 1966 to March 2004), and EMBASE (1980 to March 2004). We scanned bibliographies of all located articles for any unidentified articles. Randomised and quasi-randomised controlled trials that assessed the effect of anticoagulant treatment on the live-birth rate in women with a history of at least two spontaneous miscarriages or one later intrauterine fetal death without apparent causes other than inherited thrombophilias were eligible. Interventions included aspirin, unfractionated heparin, and low molecular weight heparin for the prevention of birth loss. One treatment could be compared with another or with placebo. Two authors assessed the trials for inclusion in the review and extracted the data. Data were entered into the Review Manager software and double checked. Results Two studies (242 participants) were included in the review and for both of them data were extracted for the subgroups of women fulfiling the inclusion criteria of the review. In one study, 54 pregnant women with recurrent spontaneous abortion without detectable anticardiolipin antibodies were randomised to low-dose aspirin or placebo. Similar live-birth rates were observed with aspirin and placebo [relative risk (RR) 1.00, 95% confidence interval (CI) 0.78 to 1.29]. In another study, a subgroup of 20 women who had had a previous fetal loss after the 20th week and had a thrombophilic defect were randomised to enoxaparin or aspirin. Enoxaparin treatment resulted in an increased live-birth rate, as compared to low-dose aspirin, RR 10.00, 95% CI 1.56 to 64.20). Conclusions The evidence on the efficacy and safety of thromboprophylaxis with aspirin and heparin in women with a history of at least two spontaneous miscarriages or one later intrauterine fetal death without apparent causes other than inherited thrombophilias is too limited to recommend the use of anticoagulants in this setting. Large, randomised, placebo-controlled trials are urgently needed.
ObjectiveTo systematically review the association between C677T and A1298C polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene and the risk of unexplained recurrent spontaneous abortion (URSA). MethodsWe searched PubMed, EMbase, CBM, CNKI, VIP and WanFang Data from inception to May 2015 to collect case-control studies about the association between the MTHFR gene C677T and A1298C polymorphisms and the risk of URSA. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, meta-analysis was performed using RevMan 5.0 and Stata 12.0 software. ResultsA total of 42 case-control studies involving 3 970 URSA patients and 5 297 controls were included. The results of meta-analysis showed that MTHFR C677T polymorphism was associated with the increased risk of URSA (T vs. C: OR=1.34, 95% CI 1.16 to1.54, P < 0.000 01; TT vs. TC+CC: OR=1.70, 95% CI 1.36 to 2.12, P < 0.000 01; TT+TC vs. CC: OR=1.34, 95% CI 1.11 to 1.62, P=0.002; TC vs. CC: OR=1.19, 95% CI 0.99 to 1.43, P=0.061; TT vs. CC: OR=1.95, 95% CI 1.48 to 2.56, P < 0.000 01). Subgroup analysis by ethnicity indicated that the MTHFR C677T polymorphism was associated with the increased risk of URSA in east Asians (T vs. C: OR=1.61, 95% CI 1.39 to 1.87, P < 0.000 01; TT vs. TC+CC: OR=2.05, 95% CI 1.54 to 2.71, P < 0.000 01; TT+TC vs. CC: OR=1.76, 95% CI 1.41 to 2.19, P < 0.000 01; TC vs. CC: OR=1.53, 95% CI 1.21 to 1.94, P < 0.000 01; TT vs. CC: OR=2.77, 95% CI 1.94 to 3.97, P < 0.000 01) but was not associated with the increased risk of URSA in Caucasians. The results of meta-analysis also showed that there was no significant association between the MTHFR A1298C polymorphism and the URSA in all population. ConclusionCurrent evidence indicates that significant association is found between MTHFR C677T mutation and URSA in east Asians but not in Caucasians. Further study indicates that women carrying TT or TC gene significantly increases the risk of URSA and TT mutant gene carriers have a higher URSA risk. There is no significant association between MTHFR A1298C mutation and URSA in all population. Due to the quantity and quality limitations of included studies, more high quality case-control or cohort studies are needed to verify the above conclusions.
ObjectivesTo systematically review the association between the level of blocking antibody and recurrent spontaneous abortions.MethodsPubMed, CNKI, CBM, WanFang Data and VIP databases were searched online to collect case-control studies on the association between the level of blocking antibody and recurrent spontaneous abortions from inception to May, 2017. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies, then meta-analysis was performed by using RevMan 5.3 software.ResultsA total of 12 case-control studies involving 3 413 patients were included. The results of meta-analysis showed that: there was a strong association between the blocking antibody negative and recurrent spontaneous abortions with statistical significance (OR=6.10, 95%CI 2.40 to 15.51, P=0.000 1).ConclusionsCurrent evidence shows that the blocking antibody negative is a risk factor for recurrent spontaneous abortions. Due to limited quality and quantity of the included studies, more high quality studies are required to verify above conclusions.