Association between ABO and Rh Blood Groups and Risk of Preeclampsia: A Case-Control Study from Iran

[Relationship Between ABO Blood Group and Pregnancy Complications]

ABO blood group system is the most commonly used blood group classification system in clinic practice. The relevant antigens, A, B and H determinants, are complex carbohydrate molecules that are expressed in red blood cells and other cell lines and tissues. These antigens are determined by the ABO locus located on chromosome 9 (9q34.1-q34.2). ABO blood group is associated with the development of many human diseases, e.g., cardiovascular diseases, infectious diseases, and tumors. The relationship between the ABO blood group of pregnant women and various pregnancy complications, including preeclampsia (PE) and the related diseases, pregnancy associated venous thromboembolism (PA-VTE), gestational diabetes mellitus (GDM), and postpartum hemorrhage (PPH), have become the focus of obstetricians' recent research interest. Herein, we reviewed the relationship between ABO blood group and these pregnancy complications, and found that most of the reported findings supported the following views: 1) Blood type O is a protective factor for PE, while blood type AB increases the risk of PE; 2) blood types other than O are more prone to PA-VTE than blood type O; 3) blood type O or blood type AB may be related to the pathogenesis of GDM; 4) women of blood type O are at higher risks for PPH than those of other blood types. More in-depth epidemiological and genetic studies are needed to confirm these findings in the future. These findings can provide new ideas for researching into the pathogenesis of obstetric diseases and form the theoretical basis for obstetricians to prevent and treat related diseases.

The Association Between ABO Blood Group and Preeclampsia: A Systematic Review and Meta-Analysis

Objective: This meta-analysis comprehensively evaluated the association between ABO blood group and the risk of preeclampsia (PE).

Design: Systematic review and meta-analysis.

Data sources: PubMed, Web of Science, and ScienceDirect databases from their inception to September 23, 2020.

Methods: Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were obtained through random-effects and fixed-effects models according to heterogeneity. Meta-regression analysis was applied to explore the source of heterogeneity. We conducted a subgroup analysis by the publication year, study design, state, and Newcastle-Ottawa Scale (NOS) score. In addition, we calculated the rate of each ABO blood group in PE by total pooled effects.

Results: A total of 12 articles with 714,153 patients were included in our analysis. Compared with people without PE (control group), the O blood group presented a lower risk of PE (OR 0.95, 95% CI 0.93–0.97). The AB (OR 1.46, 95% CI 1.12–1.91) blood group presented a higher risk. However, the total pooled OR and 95% CI for the A (OR 1.02, 95% CI 0.90–1.16) and B (OR 1.02, 95% CI 0.98–1.05) blood groups were not significant. The funnel plot and linear regression equation showed that there was no publication bias for the O, A, or B blood groups (all P > 0.05). However, the funnel plot and linear regression equation for the AB blood group were obviously asymmetric (P < 0.05), and the publication bias persisted even after the trim-and-fill method was applied (P < 0.05). Multivariable meta-regression analysis did not find a specific source of heterogeneity. The A blood group showed an association with early-onset PE (OR 0.53, 95% CI 0.33–0.83), and the other blood groups showed no significant differences. In PE, the rates of the O, A, B, and AB blood groups decreased gradually (0.39, 0.33, 0.19, 0.07).

Conclusion: These findings suggest that pregnant women with AB blood group are more likely to develop PE, and more attention should be paid to AB blood group whose blood pressure is high but not sufficient to diagnose PE.

Systematic Review Registration: Prospero CRD42021227930.

Relationship between ABO blood groups and gestational hypertensive disorders: A protocol for systematic review and meta-analysis

BACKGROUND

The distribution of ABO blood group is related to the incidence of various diseases. Gestational hypertensive disorders (GHD) is one of the most important risk factors during pregnancy, which has certain heredity. It is reported that ABO blood type is associated with the risk of GHD. However, the results are still controversial. In this study, we conducted a systematic review and meta-analysis to clarify the relationship between ABO blood group and GHD.

METHODS

All eligible studies come from Embase, Cochrane Library, Pubmed, Chinese databases SinoMed, Chinese National Knowledge Infrastructure, Chinese Scientific Journals Database, and Wanfang Data. The retrieval time is from the establishment of the database to March 2021. The language will be limited to Chinese and English. The 2 reviewers will be responsible for the selection of the study, the extraction of data, and the evaluation of the quality of the research. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the corresponding associations. Sensitivity analysis, publication bias assessment, and heterogeneity test were performed using STATA 16.0.

RESULTS

The results of this meta-analysis will be published in peer-reviewed journals.

CONCLUSION

This study will provide evidence to support the relationship between ABO blood group and the risk of GHD.

ETHICS AND DISSEMINATION

The private information from individuals will not be published. This systematic review also will not impair endangering participants' rights. Ethical approval is not required. The results may be published in a peer-reviewed journal or disseminated in relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/3X9YZ.

Placental protein 13: An important biological protein in preeclampsia

Placental protein 13 (PP13), a glycan binding protein predominantly expressed in syncytiotrophoblast, dimeric in nature, lacks N-terminal signal peptide, bypasses the endoplasmic reticulum, and secretes into maternal circulation as exosomes or microvesicles. PP13 has jelly roll fold conformation with conserved carbohydrate recognition domain which specifically binds to β-galactosides of the glycan receptors during placentation. PP13 binds to glycosylated receptors on human erythrocytes and brings about hemagglutination by the property of lectin activity; other functions are immunoregulation and vasodilation during placentation and vascularization. The gene LGALS13 located on 19q13.2 comprising four exons expresses a 32-kDa protein with 139 amino acid residues, PP13. Impaired expression due to mutation in the gene leads to a nonfunctional truncated PP13. The low serum levels predict high risk for the onset of preeclampsia or obstetric complications. Hence, PP13 turned to be an early marker for risk assessment of preeclampsia. The recombinant PP13 and monoclonal antibodies availability help for replenishing PP13 in conditions with low serum levels and for detection and prevention of preeclampsia, respectively.