Women with severe postpartum hemorrhage have a decreased endogenous thrombin potential before delivery

BACKGROUND

Severe postpartum hemorrhage (PPH), defined as a blood loss ≥1000 mL, is associated with maternal morbidity and mortality.

OBJECTIVES

We aimed at characterizing coagulation properties of predelivery plasmas from pregnant women with thrombin generation assay and hemostatic biomarkers (plasminogen activator inhibitor-1, tissue factor [TF], and thrombomodulin).

METHODS

A nested case-control study was conducted within the "Study of Biological Determinants of Bleeding Postpartum," a French prospective cohort study, in order to compare women with severe PPH (cases) and controls matched for age, body mass index, term, and mode of delivery. Plasma was collected at entry in the delivery room, and blood loss was measured objectively. The predelivery endogenous thrombin generation potential (ETP) was measured in plasma using calibrated automated thrombinography and low TF concentration. Hemostatic biomarkers were measured using ELISA kits.

RESULTS

A total of 142 women (71 cases and 71 controls) were investigated. There was no difference in the median lag phase, thrombin peak, and time to peak between cases and controls. However, median predelivery ETP was lower in cases than in controls (2170 vs 2408 nM.min, P < .0001), independently of mode of delivery and PPH etiology. Median plasminogen activator inhibitor-1 and TF levels were higher in cases compared with controls (107.4 vs 68.1 ng/mL, P = .0003; 34.4 vs 27.4 pg/mL, P = .007), whereas thrombomodulin levels did not differ between the 2 groups.

CONCLUSION

Among thrombin generation assay parameters, predelivery ETP levels may have a predictive value for severe PPH.

Family history of postpartum hemorrhage is a risk factor for postpartum hemorrhage after vaginal delivery: results from the French prospective multicenter Haemorrhages and Thromboembolic Venous Disease of the Postpartum cohort study

BACKGROUND

Postpartum hemorrhage is a major component of perinatal morbidity and mortality that affects young women worldwide and is still often unpredictable. Reducing the incidence of postpartum hemorrhage is a major health issue and identifying women at risk for postpartum hemorrhage is a key element in preventing this complication.

OBJECTIVE

This study aimed to estimate postpartum hemorrhage prevalence after vaginal delivery and to identify postpartum hemorrhage risk factors.

STUDY DESIGN

Unselected pregnant women ≥16 years of age admitted to 1 of 6 maternity wards in Brittany (France) for vaginal birth after 15 weeks of gestation were recruited in this prospective, multicenter cohort study between June 1, 2015, and January 31, 2019. Postpartum hemorrhage was defined as blood loss ≥500 mL in the 24 hours following delivery. Independent risk factors for postpartum hemorrhage were determined using logistic regression. Missing data were imputed using the Multivariate Imputation by Chained Equations method.

RESULTS

Among 16,382 included women, the postpartum hemorrhage prevalence was 5.37%. A first-degree family history of postpartum hemorrhage (adjusted odds ratio, 1.63; 95% confidence interval, 1.24-2.14) and a personal transfusion history (adjusted odds ratio, 1.90; 95% confidence interval, 1.23-2.92) were significantly associated with postpartum hemorrhage. The use of oxytocin during labor was also a risk factor for postpartum hemorrhage (adjusted odds ratio, 1.24; 95% confidence interval, 1.06-1.44). Inversely, smoking during pregnancy and intrauterine growth restriction were associated with a reduced risk for postpartum hemorrhage (adjusted odds ratio, 0.76; 95% confidence interval, 0.63-0.91, and 0.34; 95% confidence interval, 0.13-0.87, respectively).

CONCLUSION

In addition to classical risk factors, this study identified a family history of postpartum hemorrhage and personal transfusion history as new characteristics associated with postpartum hemorrhage after vaginal delivery. The association of postpartum hemorrhage with a family history of postpartum hemorrhage suggests a hereditary hemorrhagic phenotype and calls for genetic studies. Identifying women at risk for postpartum hemorrhage is a key element of being prepared for this complication.

Clinical risk factors for vasculo-placental disorders: results from a prospective case-control study nested in HEMOTHEPP French cohort study

OBJECTIVE

Determine clinical risk factors for vasculo-placental disorders in singleton pregnancies.

DESIGN

Prospective case-control study nested in HEMOTHEPP French cohort.

SETTING

Women delivered between June, 2015 and January, 2019 in any maternity ward of Finistère.

POPULATION

Cases were women with vasculo-placental disorders (pre-eclampsia, intrauterine growth restriction (IUGR), placental abruption or stillbirth). Controls were women matched for age at delivery and parity.

METHODS

Clinical data were collected by obstetricians or midwives during antenatal care visits and delivery, and recorded by trained research assistants.

MAIN OUTCOME MEASURES

Occurrence of a vasculo-placental disorder.

RESULTS

505 women with vasculo-placental disorder (299 pre-eclampsia, 253 IUGR, 44 placental abruptions, 11 stillbirths) and 1515 matched controls were selected out of 20,075 participants. In multivariable analysis, four clinical parameters were associated with pre-eclampsia: obesity (Odd ratio (OR) = 3.11, 95%CI 2.11-4.58), French overseas origin (OR = 4.41, 95%CI 1.87-10.42), previous vasculo-placental disorder (OR = 5.14, 95%CI 2.72-9.70), aspirin during pregnancy (OR = 10.10, 95%CI 1.99-51.08). Three clinical parameters were associated with IUGR: auto-immune/inflammatory disorder (OR = 3.75, 95%CI 1.83-7.68), previous vasculo-placental disorder (OR = 3.63, 95%CI 2.06-6.41), smoking during pregnancy (OR = 2.66, 95%CI 1.91- 3.71). A previous venous thromboembolism (VTE) was associated with IUGR in univariable but not in multivariable analysis (OR = 3.72, 95%CI 0.82-17.00, p = 0.09).

CONCLUSIONS

Clinical risk factors differ between IUGR and pre-eclampsia, the later, but not the former, being associated with cardiovascular risk factors.

Risk factors for recurrence during a pregnancy following a first venous thromboembolism: A French observational study

BACKGROUND

Women with a previous venous thromboembolism (VTE) are at risk of recurrence during pregnancy.

OBJECTIVES

We aimed to assess the incidence rate of recurrent VTE during pregnancy, according to the period of pregnancy, and the clinical parameters associated with recurrence, in a prospective cohort of women of childbearing age after a first VTE.

PATIENTS/METHODS

A total of 189 women aged 15-49 years with a first documented VTE were followed until a subsequent pregnancy of at least 20 weeks' gestation between 2000 and 2020. VTE recurrences during pregnancy were recorded, as were potential clinical risk factors for recurrence.

RESULTS

Recurrent VTE occurred in six women during antepartum: five during the first trimester (incidence rate 106.4 per 1000 women-years) (95% confidence interval [CI] 46.3-226.0); none during the second trimester; and one during the third trimester (incidence rate 27.0 per 1000 women-years [95% CI 4.8-138.2]). During postpartum, recurrences occurred in 11 women (incidence rate 212.8 per 1000 women-years [95% CI 119.9-349.1]). These 17 recurrent VTEs presented as pulmonary embolism ± deep vein thrombosis (DVT) in five patients and isolated DVT in 12. Failure of thromboprophylaxis occurred in two cases (33.3%) antepartum and in 10 cases (90.9%) postpartum. In multivariable analysis, only obesity (defined on prepregnancy body mass index) was associated with recurrent VTE (odds ratio 3.34 [95% CI 1.11-10.05, p = .03]).

CONCLUSIONS

This study confirms a high risk of recurrent VTE postpartum, despite thromboprophylaxis, in women with a previous VTE. Only obesity was associated with VTE recurrence during pregnancy, suggesting that low-dose anticoagulation might not be appropriate in obese pregnant women.

Haematological parameters associated with postpartum haemorrhage after vaginal delivery: Results from a French cohort study

BACKGROUND

Immediate postpartum haemorrhage (PPH) is a major, feared and often unpredictable issue. Besides many clinical risk factors, some biological parameters could also be predictive of PPH.

OBJECTIVE

To study simple and easily accessible haematological parameters as potential risk factors for PPH after vaginal delivery.

METHODS

All women who had a vaginal delivery between April 1, 2013 and May 29, 2015 in the maternity ward of Brest University Hospital (France) were included, after oral informed consent obtained. Clinical data were collected by obstetricians or midwives during antenatal care visits, labour and delivery, and recorded by trained research assistants. Haematological variables, including immature platelet fraction, were measured from a blood sample systematically collected at the entrance in the delivery room. PPH, measured with a graduated collector bag, was defined as blood loss of at least 500 ml.

RESULTS

2742 women were included. PPH occurred in 141 (5%) women. Seven clinical factors were independently associated with PPH: pre-eclampsia (OR 5.85, 95%CI 2.02, 16.90), multiple pregnancy (OR 3.28, 95%CI 1.21, 8.91), assisted reproduction (OR 2.75, 95%CI 1.45, 5.20), antepartum bleeding (OR 2.15, 95%CI 1.24,3.73), post-term delivery (OR 1.93, 95%CI 1.17, 3.17), obesity (OR 2.95, 95%CI 1.76, 4.93) and episiotomy (OR 2.51, 95%CI 1.63, 3.74). Three haematological factors were additionally identified as independent risk factors for PPH: platelets < 150 Giga/L (OR 2.98, 95%CI 1.63, 5.46), fibrinogen < 4.5 g/l (OR 1.86, 95%CI 1.21, 2.87) and APTT ratio ≥ 1.1 (OR 2.16, 95%CI 1.31, 3.57). Immature platelet fraction was not associated with PPH.

CONCLUSION

Besides classical clinical risk factors, this study identifies simple haematological parameters as risk factors for PPH.