Evaluation of blood type as a potential risk factor for early postpartum hemorrhage

Evaluation of blood type as a potential risk factor for hemorrhage during vaginal hysterectomy

OBJECTIVE

To examine the association between the O blood type and bleeding tendency in patient undergoing vaginal hysterectomy.

METHODS

This was a retrospective cohort study including all women who had undergone vaginal hysterectomy at our institution between January 2015 and September 2020. All women underwent blood type and complete blood count testing pre- and post-operatively. The estimated intraoperative blood loss, the need for blood transfusion, pre- and postoperative hemoglobin and hematocrit measurements and surgical data were recorded for all patients. Patients with known coagulopathies or those taking antithrombotic medications were excluded from the study. Statistical analysis was performed using student t, χ2, Fischer exact, and ANOVA tests as well as a stepwise logistic regression model.

RESULTS

The study included 106 patients (35.2 %) with O and 195 patients (64.8 %) with non-O (i.e., A, B or AB) blood types. The O blood type was significantly associated with a higher risk for moderate blood loss (defined as a pre- to postoperative Hb or HCT drop >2gr or >6 %, respectively) (p = 0.012), but not with severe (defined as a Hb or HCT drop of >3gr or >9 %, respectively) perioperative bleeding, nor with the need for blood transfusion.

CONCLUSION

The O blood type was found to be significantly associated with moderate but not with severe intraoperative bleeding during and following vaginal hysterectomy.

Hemostatic biomarkers associated with postpartum hemorrhage: a systematic review and meta-analysis

Postpartum hemorrhage (PPH) is a leading cause of maternal morbi-mortality. Although obstetric risk factors are well described, the impact of predelivery hematologic and hemostatic biomarkers remains incompletely understood. In this systematic review, we aimed to summarize the available literature on the association between predelivery hemostatic biomarkers and PPH/severe PPH. Searching MEDLINE, EMBASE, and CENTRAL databases from inception to October 2022, we included observational studies on unselected pregnant women without bleeding disorder reporting on PPH and on predelivery hemostatic biomarkers. Two review authors independently performed title, abstract and full-text screening, upon which quantitative syntheses of studies reporting on the same hemostatic biomarker were conducted, calculating the mean difference (MD) between women with PPH/severe PPH and controls. A search on 18 October 2022 yielded 81 articles fitting our inclusion criteria. The heterogeneity between studies was considerable. With regard to PPH, the estimated average MD in the investigated biomarkers (platelets, fibrinogen, hemoglobin, Ddimer, activated partial thromboplastin time, and prothrombin time) were not statistically significant. Women who developed severe PPH had lower predelivery platelets than controls (MD = -26.0 109/L; 95% confidence interval, -35.8 to -16.1), whereas differences in predelivery fibrinogen concentration (MD = -0.31 g/L; 95% confidence interval, -0.75 to 0.13) and levels of factor XIII or hemoglobin were not statistically significant in women with and without severe PPH. Predelivery platelet counts were, on average, lower in women with severe PPH compared with controls, suggesting the potential usefulness of this biomarker for predicting severe PPH. This trial was registered at the International Prospective Register of Systematic Reviews as CRD42022368075.

Distribution of ABO and Rh blood groups among pregnant women attending the obstetrics and gynecology clinic at the Jordan University Hospital

The ABO and D antigen status of red blood cells (Rh blood grouping systems) are important hematological classification systems that categorize blood groups according to the presence or absence of certain erythrocytic antigens. These antigens affect the outcomes of blood transfusions as well as various hematological and immunological diseases. We aimed to study ABO and Rh blood group distribution among pregnant women visiting the antenatal care clinic at Jordan University Hospital (JUH) in Amman, Jordan. A retrospective analysis of all pregnant women delivering at the Jordan University Hospital (JUH) between October 1, 2016, and September 31, 2021. ABO and D antigen status of red blood cells (Rh blood groups) were summarized and documented. 20,136 pregnant women data were analyzed, the O blood group was the most prevalent (n = 7840, 38.9%), followed by A (n = 7506, 37.3%). For the D antigen status, the Rh-positive (Rh+) category was the most common (n = 18,159, 90.2%). For the (O) blood group; O-Rh+ type was the most prevalent (90.1%). Determining the blood group type accurately helps eliminate the critical consequences of both ABO and Rh incompatibility and offers clinicians an opportunity to take timely prophylactic measures. In our analyses O and Rh+ blood groups were the most prevalent.

Blood Type and Outcomes in Pregnant Women with Placenta Previa

Background

Placenta previa increases the risks of obstetrical complications. Many studies have reported a link between various ABO blood types and pregnancy complications. This study is aimed at describing and comparing the characteristics and outcomes of women with placenta previa by ABO blood type.

Methods

Data for this study was obtained from a retrospective cohort study between January 1, 2014, and June 30, 2019, of all clinically confirmed placenta previa in a university-based tertiary medical center. Both types of A, B, O, AB, and combining O and non-O blood types were compared to the characteristics and outcomes.

Results

1678 participants with placenta previa were included in this study. The highest participants were blood type O with 666 (39.7%), followed by type A with 508 (30.3%) and type B with 395 (23.5%), and the lowest participants were AB with 109 (6.5%). Blood type AB had a higher incidence of antepartum hemorrhage (p = 0.017), predelivery anemia (p = 0.036), and preterm birth (p = 0.015) in placenta previa women. Meanwhile, the incidence of rhesus D positive (97.9% vs. 95.8%, p = 0.012) and twins (5.0% vs. 2.7%, p = 0.011) was higher in the non-O group, and the incidence of neonatal asphyxia (5.9% vs. 9.2%, p = 0.016) was lower in the non-O group.

Conclusion

Type AB blood may be a potential risk factor for women with placenta previa. This finding may help provide any obstetrician to predict the risk of complication for placenta previa women by the ABO blood types.

Assessment of post-partum haemorrhage risk among women with moderate thrombocytopenia

It is unknown whether moderate thrombocytopenia represents a risk factor for post-partum haemorrhage (PPH). We assessed PPH risk among women with a platelet count of between 100 and 50 × 109 /l and stratified the risk for O/non-O blood group. We included consecutive women undergoing vaginal delivery or caesarean section with moderate thrombocytopenia. Women with >150 × 109 /l platelets at delivery were selected as controls and matched for age, type of birth and ethnicity. Odds ratios (ORs) with their 95% confidence intervals (95% CIs) were calculated as risk estimates. A total of 94 thrombocytopenic women and 94 controls were included in the study. The rate of PPH was significantly higher in thrombocytopenic women than in controls (37% vs. 10%, p < 0.001); there was a higher risk of PPH in the thrombocytopenic group when compared to the control group (adjusted OR 4.7, 95% CI 2.1-10.8, p < 0.01) and this association was stronger in blood group O carriers (adjusted OR 11.0, 95% CI 2.4-49.6, p < 0.01). In conclusion, our study shows that a moderate thrombocytopenia is a risk factor for PPH, especially in blood group O carriers.

Risk factors for stillbirth and early neonatal death: a case-control study in tertiary hospitals in Addis Ababa, Ethiopia

BACKGROUND

Ethiopia is a Sub-Saharan country that has made significant improvements in maternal mortality and under-five mortality over the past 15 years. However, the nation continues to have one of the highest rates of perinatal mortality in the entire world with current estimates at 33 deaths per 1000 live births.

METHODS

This case-control study was conducted between October 2016 and May 2017 at Tikur Anbessa Hospital and Gandhi Memorial Hospital. All women who had a stillbirth or early neonatal death (i.e. death within 7 days) during this period willing to participate were included as cases. A systematic random sample of women delivering at the hospital were approached for recruitment as controls to generate a 2:1 ratio of controls to cases. Data on risk factors were retrieved from medical records including delivery records, and treatment charts. Statistical differences in background and social characteristics of cases and controls were determined by t-test and chi-squared (or fisher's exact test) for quantitative and categorical variables respectively. Binary logistic regression analysis was completed to determine any associations between risk factors and stillbirth/early neonatal death.

RESULTS

During the study period, 366 women delivering at the hospitals were enrolled as cases and 711 women delivering at the hospitals were enrolled as controls. Records from both hospitals indicated that the estimated stillbirth and neonatal mortality rates were 30.7 per 1000. Neonatal causes (43.4%) were the most common, followed by antepartum (32.5%) and intrapartum (24.5%). Risk factors for stillbirths and early neonatal death were low maternal education (aOR 1.747, 95%CI 1.098-2.780), previous stillbirth (aOR 9.447, 95%CI 6.245-14.289), previous preterm birth (aOR 3.620, 95%CI 2.363-5.546), and previous child with congenital abnormality (aOR 2.190, 95% 1.228-3.905), and antepartum hemorrhage during pregnancy (aOR 3.273, 95% 1.523-7.031).

CONCLUSION

Antepartum hemorrhaging is the only risk factor in our study amenable for direct intervention. Efforts should be maximized to improve patient education and antenatal and obstetric services. Moreover, the most significant cause of mortality was asphyxia-related causes. It is imperative that obstetric capacity in rehabilitation services are strengthened and for further studies to investigate the high burden of asphyxia at these tertiary hospitals to better tailor interventions.

Blood type association with bleeding outcomes at delivery in a large multi-center study

Postpartum hemorrhage is a leading cause of maternal death globally. Recent studies have associated Type-O group to increased risk of bleeding. We aimed to determine if women with Type-O blood are at higher risk of PPH. This is a retrospective cohort analysis of a multi-center database included women admitted to labor and delivery from January 2015 to June 2018. All deliveries resulting in live birth were included. Association between Type-O and non Type-O were examined using chi-square test and fishers exact test. Prevalence of postpartum hemorrhage, estimated blood loss, drop in hematocrit and red blood cell transfusion were compared. The matched sample included 40,964 Type-O and the same number of no Type-O. The overall prevalence of postpartum hemorrhage was 6.4%, and there was no difference in the prevalence of PPH among Type-O compared to non Type-O (6.38% vs. 6.37% respectively; p = 0.96). There was no difference in hematocrit drop and estimated blood loss between Type-O and non Type-O in all deliveries. However, in cesarean delivery there was a significant difference in blood loss among the two groups. Finally, Type-O had 1.09-fold increased risk for transfusion compared to non Type O (95% CI 0.9-1.34). There is an association between Type-O group and risk of bleeding in women undergoing cesarean delivery. More prospective studies, taking into account coagulation profile, platelet count and tissue factors, are needed to draw a conclusion on whether ABO system can be considered a heritable risk of postpartum hemorrhage.

ABO O gene frequency increase in the US might be causing increased maternal mortality

Maternal mortality rate has increased in the United States over the past 30 years from 16 deaths per 100,000 births to 28 deaths per 100,000 births while the rest of the world is experiencing declining rates. Increasing obesity and c-section rates in the US have been cited as contributing factors needing remediation, and because of the two to three fold difference in maternal mortality rates in non-Hispanic black women compared to white women, inequality and implicit racial bias has been targeted as well for remediation. Using an epidemiologic approach, a hypothesis here brought to bear is that US immigration policy changes over the past 50 years have brought changes in the gene pool that have caused increasing obstetric hemorrhage and other causes of maternal death. ABO gene frequencies have changed in the US during this time such that ABO O, a gene associated with hemorrhage and mortality in pregnancy, has increased in frequency in the US thus increasing population maternal mortality rate. Using mendelian randomization logic, noting the increase in ABO O gene in the US population over the past 30 years and the association of ABO O gene with both hemorrhage and lower longevity, the increase in frequency of the ABO O gene in the past 30 years in the US population might be causative of an increase in maternal mortality rate. Consequences of this hypothesis would include recognition of the role of ABO gene and thus ABO blood group in prediction of risk of obstetric hemorrhage. Thus those at risk on this basis would be under high surveillance and would have medications and treatment strategies readily available. While research on ABO gene and pregnancy has been done, much of the research is being done in countries other than the US, and given the increasing mortality in the US as well as the role that ABO gene may have in that, further research needs to be done in US populations to quantify risk for all adverse events in pregnancy related to ABO blood type including hemorrhage as well as inter-related causes including pre-eclampsia, cardiovascular disease, thromboembolic disease and infection.

Early experience with transfusing low titer group O whole blood in the pre-hospital setting in Israel

BACKGROUND

The Israeli Defense Force Medical Corps (IDF-MC) recently implemented the use of low titer group O whole blood (LTOWB) in the airborne combat search and rescue unit (CSAR) for both military and civilian patients during transport to definitive care. LTOWB is preferentially used by the CSAR instead of red blood cell units and freeze-dried plasma (FDP) for patients with signs of hemorrhagic shock. Ten percent of group O donors were eligible to donate LTOWB as they had anti-A and -B IgM titers of <50.

METHODS

All patients treated by CSAR providers with LTOWB between July 2018 and June 2019 were included.

RESULTS

Between July 2018 and June 2019, eight patients have received 10 units of LTOWB. All patients suffered blunt injuries, 6 out of 8 (75%) of whom were due to motor vehicle accidents. Four patients (4 out of 8, 50%) received a single LTOWB unit, two patients (2 out of 8, 25%) received two units. Two pediatric patients received fewer than one unit of LTOWB. Median (range) heart rate was 130 (30-150) bpm, median systolic blood pressure was 107 (80-124) mmHg, and median Glasgow coma scale was 8 (on a scale of 3-15). For four (4 out of 8, 50%) patients, LTOWB was the only blood product used for volume resuscitation. All six adult patients were treated with 1 g of tranexamic acid at the point of injury.

CONCLUSIONS

The CSAR has successfully implemented a LTOWB program for the pre-hospital treatment of bleeding patients, and as its experience grows this product will be made available to other units and in civilian hospitals.