Factor V Leiden, prothrombin G20210A and antibodies against phospholipids in recurrent spontaneous abortion

Recurrent miscarriage is not associated with a higher prevalence of inherited and acquired thrombophilia

PROBLEM

Although not being recommended in guidelines, many physicians perform routine screening for thrombophilia in RM patients suspecting a higher prevalence in these patients. The aim of this study was to analyze the prevalence of inherited and acquired thrombophilia in a large cohort of RM patients.

METHOD OF STUDY

Within a multicenter case-control study, n = 820 RM patients and n = 141 controls were included. The prevalence of inherited and acquired thrombophilia including deficiency of protein C/S and antithrombin, elevation of factor VIII activity, APC resistance including mutation in the factor V Leiden gene, mutation in the prothrombin gene and antiphospholipid antibodies were assessed. Further, we performed a meta-analysis of the prevalence of thrombophilia in RM patients including studies between 01/2000 and 01/2020.

RESULTS

An antiphospholipid syndrome (APLS) was only present in RM patients. Increased factor VIII concentration was significantly more prevalent in controls (RM vs controls: 5.8% vs 11.0%). None of the other thrombophilia did differ significantly between RM patients and controls. The meta-analysis revealed no significant difference in the occurrence of these thrombophilia between RM patients and controls.

CONCLUSION

The prevalence of inherited thrombophilia does not differ between RM patients and controls. When analyzing rare events like thrombophilia, a high number of patients are needed to obtain reliable results, which might explain contradictory findings in previous studies analyzing small cohorts of RM patients. Despite being less prevalent than previously described, we still recommend screening for APLS as it is associated with severe pregnancy complications.

Circulating levels of matrix proteases and their inhibitors in pregnant women with and without a history of recurrent pregnancy loss

BACKGROUND

We have recently shown that serum relaxin-2 levels are attenuated in women with a history of recurrent pregnancy loss (RPL). We sought to determine whether a history of RPL is also associated with changes in serum matrix metalloproteases (MMPs) and tissue inhibitors of matrix metalloproteases (TIMP) -1 and -2.

METHODS

We obtained serum from 20 pregnant women with a history of RPL and 20 age-matched pregnant women with no history of RPL (NRPL) at 6-8, 10-12, 20, and 34 weeks gestation, and from cord blood. We quantified total serum concentrations of MMP-1, MMP-3, MMP-9 and TIMP-1 and TIMP-2 by ELISA. We determined whether these serum marker levels were associated with a history of RPL and delivery before 37 weeks gestation.

RESULTS

There was no difference in the rates of miscarriage, preterm birth or prelabour rupture of fetal membranes between RPL and NRPL. However babies born to RPL were lighter than those born to NRPL. Serum MMP-1, 9, and TIMP-1 did not differ between RPL and NRPL but MMP-3 was higher in RPL vs. NRPL at 6-8 weeks (P < 0.05). Serum TIMP-2 levels were higher in RPL women at all gestations (P < 0.01). The ratio of RLX-2 (reported previously) to TIMP-2 at 10-12 weeks gestation was more strongly associated with a history of RPL than either peptide separately - area under the ROC curves for RLX-2 0.79 (95% CI 0.57 to 0.92), TIMP-2 0.83 (95% CI 0.63 to 0.95), and for RLX-2:TIMP-2 ratio 0.92 (95% CI 0.74 to 0.99).

CONCLUSIONS

Women with a history of RPL demonstrate increased serum TIMP-2 and reduced RLX-2 during a subsequent viable pregnancy. Determination of both markers in early pregnancy enhances the discrimination of women with a history of RPL. These observations suggest roles for these two peptides in early implantation and placental development. Whether these may prove to be reliable early predictive markers for subsequent pregnancy loss in the index pregnancy is unknown and will require further studies.

Inherited Thrombophilia is Associated With Pregnancy Losses That Occur After 12th Gestational Week in Serbian Population

Recurrent fetal loss (RFL) is a significant clinical problem, occurring in 1% to 5% of reproductive females. Inherited or acquired thrombophilia has been diagnosed in 50% to 65% of women with history of unexplained fetal loss. The objective of our study was to determine the prevalence of thrombophilia in women with unexplained RFL in Serbian population and to find out whether the presence of thrombophilia is associated with pregnancy losses that occur later than 12th gestational week. We have examined 147 women with unexplained RFL or intrauterine fetal death and 128 healthy women with at least 1 uncomplicated pregnancy. The antithrombin (AT), protein C (PC), protein S (PS), activated protein C (APC) resistance, factor V (FV) G1691A, factor II (FII) G20210A, and MTHFR C677T were determined. At least 1 inherited thrombophilic defect was found in 54 (36.7%) of 147 women with repeated fetal losses and in 11 (8.59%) of 128 controls (P < .001, OR 6.17, 95% CI 3.06-12.48). The most common thrombophilic abnormalities were homozygosity for MTHFR 677TT, FV Leiden, and FII G20210A. Deficiency of natural anticoagulants occurred in 10 patients, with protein S deficiency being the most frequent one. Thrombophilia was found in 46 of 94 women with RFL that occurred later than the 12th gestational week and in only 8 of 53 with RPL earlier than 12th week (P = .001). Our study has shown the association between the hereditary thrombophilia and RFL that occurred after the 12th gestational week in Serbian population.

Association between adverse pregnancy outcomes and maternal factor V G1691A (Leiden) and prothrombin G20210A genotypes in women with a history of recurrent idiopathic miscarriages

Thrombophilia was implicated in the development of pregnancy complications, including recurrent idiopathic pregnancy loss, and is aggravated in women who are carriers of factor V G1691A (FV Leiden) and prothrombin (PRT) G20210A single-nucleotide polymorphisms (SNPs). Previous studies examined the role of FV-Leiden and PRT G20210A in recurrent pregnancy loss with conflicting results. Here we examined the prevalence of FV Leiden and PRT G20210A SNPs, in 200 women with 3 or more consecutive early (n = 87), late (n = 41), or early-late (n = 72) recurrent pregnancy losses, and 200 age-matched fertile parous control women. APC resistance (APCR) was detected functionally (measuring the activated clotting time triggered by activated factor X in presence of a fixed amount of purified APC), and FV-Leiden and PRT G20210A genotypes were assessed by PCR. The frequency of the mutant FV (0.1400 vs. 0.0276; P < 0.001) but not PRT 20210 (0.0100 vs. 0.0225; P = 0.159) allele was higher in patients than controls, respectively. APC resistance with factor V Leiden was seen in 27% of patients compared to 11.5% of controls, while APC resistance without factor V Leiden was seen in 12.5% of patients compared to 9.5% of controls. Regression analysis demonstrated that the significant predictors for early abortion was FV Leiden; those for late abortion were oral contraceptive, APCR, and FV Leiden; and predictors for early-late abortions were oral contraceptives, obesity, FV Leiden, and smoking. APC resistance and FV Leiden, as well as combination of both, are common thrombotic defects seen in women with idiopathic recurrent pregnancy loss, thus testing for these is recommended in women who have experienced recurrent miscarriages.