Thrombophilic gene polymorphisms and recurrent pregnancy loss: a systematic review and meta-analysis

Impact of Thrombophilic Polymorphisms in Antenatal Women on Perinatal Health: A Single-Center Prospective Study

BACKGROUND

Despite pregnancy's hypercoagulable state, the correlation between inherited thrombophilia and thrombotic adverse pregnancy outcomes remains uncertain. The objective of this study was to determine the prevalence of inherited thrombophilic polymorphisms among asymptomatic pregnant individuals and to examine their potential correlation with adverse perinatal outcomes.

METHODS

in this single-center prospective study, 105 healthy pregnant women were included. Genotyping was conducted for factor V Leiden (FVL), prothrombin gene mutation, methylenetetrahydrofolate reductase enzyme (MTHFR) C677T, MTHFR A1298C, and plasminogen activator inhibitor-1 (PAI-1), alongside the assessment of protein C (PC), protein S (PS), and antithrombin (AT) levels. The study analyzed the association between inherited thrombophilic polymorphisms and pregnancy complications linked to placental insufficiency, such as gestational hypertension (GH), preeclampsia (PE), intrauterine death (IUD), fetal growth restriction (FGR), and placental abruption.

RESULTS

The prevalence of identifiable thrombophilic polymorphism mutations was 61.9% (95% confidence interval-CI 52.4-70.8%), with the most common single mutation being PAI-1 4G/5G (12/105, 11.4%, 95% CI 6.4-18.5). The most frequent combined mutation was heterozygosity for MTHFR C677T and PAI-1 (12/105, 11.4%, 95% CI 6.4-18.5). Notably, no FVL homozygous carriers or single homozygous and heterozygous carriers for prothrombin polymorphisms were found. Additionally, no deficiencies in PC and AT were detected among participants. Except for homozygosity for PAI-1, none of the studied polymorphisms demonstrated a significant association with pregnancy complications linked to placental insufficiency.

CONCLUSIONS

The asymptomatic carriers of inherited thrombophilic polymorphisms do not have an increased risk of adverse perinatal outcomes.

Platelet Glycoprotein Receptor Ia-C807T and IIIa-PlA1/PlA2 Genetic Polymorphisms Are Associated With Enhanced Platelet Function in Women With Recurrent Miscarriages

INTRODUCTION

Thrombophilic genetic polymorphisms of the platelet glycoproteins Ia (GpIa) and IIIa (GpIIIa) have been associated with an increased risk of recurrent miscarriages. The aim of this study was to investigate the association of genetic polymorphisms GpIa-C807T and GpIIIa-T1565C-PlA1/PlA2 with platelet function in women with unexplained spontaneous recurrent miscarriages.

METHODS

This cross-sectional study comprised 196 unrelated nulliparous Greek women with a history of unexplained recurrent miscarriages. Patients were genotyped for the presence of the GpIa-C807T (rs1126643) and GpIIIa-T1565C-PlA1/PlA2 (rs5918) genetic polymorphisms by pyrosequencing, and the collagen/epinephrine closure time (COL/EPI CT) of the subjects was assessed using the platelet function analyzer (PFA)-100.

RESULTS

 In the total population of women with recurrent miscarriages, the COL/EPI CT ranged from 70 to 160 seconds (median: 122 seconds, interquartile range (IQR): 102.3-138 seconds). In comparison with the double homozygotes CC/PlA1PlA1 that had the most prolonged CT (mean: 131.9 ± 17.5 seconds), the COL/EPI CT was statistically significantly shorter for the GpIa-807T single carriers (mean: 120.3 ± 20.9 seconds) (p=0.011) (absolute difference: 11.6 seconds, 95% confidence interval (CI): 21.2 to -2.0 seconds; relative difference: -9%, 95% CI: -16% to -2%), and the GpIIIa-PlA2 single carriers also displayed a trend for shorter COL/EPI CT (mean: 121.3 ± 23.7 seconds) (p=0.141) (absolute difference: -10.6 seconds, relative difference: -8%), whereas the combined carriers of the GpIa-807T and the GpIIIa-PlA2 alleles exhibited the shortest COL/EPI CT (mean: 104.1 ± 19.7 seconds) (absolute difference: -27.7 seconds, 95% CI: -39.1 to -16.3 seconds; relative difference: -21%, 95% CI: -30% to -12%) (p<0.001). In comparing genotype frequencies in the lower half with those in the upper half of the COL/EPI CT range, the GpIa-807T and the GpIIIa-PlA2 single carriers were associated with higher odds of COL/EPI CT < 122 seconds (odds ratio (OR)=3.4, 95% CI: 1.5 to 7.5, p=0.002, and OR=2.6, 95% CI: 1.0 to 7.2, p=0.053, respectively). The association was strongest for the combined carriers with OR of 15.0 (95% CI: 5.2 to 43.2, p<0.001) for COL/EPI CT below the median and OR of 35.5 (95% CI: 4.4 to 284.5, p<0.001) for COL/EPI CT < 100 seconds.

CONCLUSION

The GpIa-C807T and GpIIIa-PlA1/PlA2 polymorphisms and more pronouncedly the combined carriers of the risk variants are associated with enhanced platelet reactivity expressed via shorter COL/EPI CT. These findings provide further evidence for the role of platelet-associated genetic thrombophilia in the pathogenesis of recurrent miscarriages and promote the analysis of platelet function as a diagnostic tool in the evaluation of this disorder.

Genetic Architecture of Pregnancy Loss: Co-inheritance of Risk Factors in Bosnian Women

Pregnancy-related complications (PRC) re-present a serious public health and healthcare challenge. In European countries, infertility among couples varies from 5 to 24 %. The cause of PRC may include autoimmune and metabolic factors, correctness of the karyotype and variants of selected genes. The impact magnitude of genetic variants in one of PRC, pregnancy loss (PL), is still unexplored. Therefore, in this study, raw data on 12 single-nucleotide polymorphisms (SNPs) that were published separately in 2017-2019 were re-examined. We analysed the co-inheritance of 12 SNPs: rs6025 FV, rs429358 and rs7412 ApoE, rs1799752 ACE, rs1799889 PAI-1, rs1799963 PT, rs1801133 MTHFR, rs9468 and rs1800547 INV 17q21.31, rs731236 and rs1544410 VDR, and rs10421768 HAMP. Each time, the same study group of 154 women with PL, mean age 33 (± 5.4) years, and 154 mothers without PL, mean age 31.4 (± 6.7) years, with at least one live-born child, a control group, was investigated. In Bosnian women, no relationship of the co-inheritance pattern of any of the studied variants with PL was confirmed: P was in the range 0.248-1.0. In conclusion, the role of co-inheritance of heterozygotes and homozygotes or homozygotes of selected genes in PL has not been fully confirmed.