Dataset Information

Outpatient calcium-channel blockers and the risk of postpartum haemorrhage: a cohort study.

ABSTRACT:

Objective

To determine whether outpatient exposure to calcium-channel blockers (CCBs) at the time of delivery is associated with an increased risk for postpartum haemorrhage (PPH).

Design

Cohort study.

Setting

United States of America.

Population or sample

Medicaid beneficiaries.

Methods

We identified a cohort of 9750 patients with outpatient prescriptions for CCBs, methyldopa, or labetalol for pre-existing or gestational hypertension whose days of supply overlapped with delivery; 1226 were exposed to CCBs. The risk of PPH was compared in those exposed to CCBs to those exposed to methyldopa or labetalol. Propensity score matching and stratification were used to address potential confounding.

Main outcome measures

The occurrence of PPH during the delivery hospitalisation.

Results

There were 27 patients exposed to CCBs (2.2%) and 232 patients exposed to methyldopa or labetalol (2.7%) who experienced PPH. After accounting for confounders, there was no meaningful association between CCB exposure and PPH in the propensity score matched (odds ratio 0.77, 95% CI 0.50-1.18) or stratified (odds ratio 0.79, 95% CI 0.53-1.19) analyses. Similar results were obtained across multiple sensitivity analyses.

Conclusions

The outpatient use of CCBs in late pregnancy for the treatment of hypertension does not increase the risk of PPH.

SUBMITTER: Bateman BT

PROVIDER: S-EPMC3866215 | biostudies-literature | 2013 Dec

REPOSITORIES: biostudies-literature

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Publications

Outpatient calcium-channel blockers and the risk of postpartum haemorrhage: a cohort study.

Bateman B T BT Hernandez-Diaz S S Huybrechts K F KF Palmsten K K Mogun H H Ecker J L JL Seely E W EW Fischer M A MA

BJOG : an international journal of obstetrics and gynaecology 20130911 13

<h4>Objective</h4>To determine whether outpatient exposure to calcium-channel blockers (CCBs) at the time of delivery is associated with an increased risk for postpartum haemorrhage (PPH).<h4>Design</h4>Cohort study.<h4>Setting</h4>United States of America.<h4>Population or sample</h4>Medicaid beneficiaries.<h4>Methods</h4>We identified a cohort of 9750 patients with outpatient prescriptions for CCBs, methyldopa, or labetalol for pre-existing or gestational hypertension whose days of supply over ...[more]

PMID: 24020971

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Project description:Objectives Postpartum haemorrhage (PPH) is a major cause of maternal mortality and morbidity worldwide. Experimental studies support the hypothesis that oxytocin administration during labour, a common although not evidence-based practice, may increase the risk of atonic PPH. The clinical studies, however, are inconclusive. The objectives of this study was to investigate the association between the level of oxytocin exposure during labour and the risk of severe PPH and to explore whether the prophylactic use of oxytocin after birth modifies this association. Design Population-based, cohort-nested case-control study. Setting 106 French hospitals from December 2004 through November 2006. Participants Women with term singleton vaginal deliveries, after an uncomplicated pregnancy. Cases were 1483 women with severe PPH, defined by peripartum change in haemoglobin of ?4 g/dl or need for blood transfusion. Controls were 1758 women from a random sample of parturients without PPH. Main outcome measures The independent association between the level of oxytocin during labour and the risk of severe PPH was tested and quantified with ORs through two-level multivariable logistic regression modelling. Results Oxytocin was administered during labour to 73% of cases and 61% of controls (crude OR: 1.7, 95% CI 1.5 to 2.0). After adjustment for all potential confounders, oxytocin during labour was associated with a significantly higher risk of severe PPH (adjusted OR: 1.8, 95% CI 1.3 to 2.6) in women who did not receive prophylactic oxytocin after delivery; the OR for haemorrhage increased from 1 to 5 according to the level of oxytocin exposure. In women who had prophylactic oxytocin after delivery, this association was significant only for the highest exposure categories. Conclusions Oxytocin during labour appears to be an independent risk factor for severe PPH. The results emphasise the need for guidelines clarifying the evidence-based indications for this procedure and the minimal useful regimens.

Project description:ObjectiveTo investigate the familial clustering of postpartum haemorrhage in the Swedish population, and to quantify the relative contributions of genetic and environmental effects.DesignRegister based cohort study.SettingSwedish population (multi-generation and medical birth registers).Main outcome measurePostpartum haemorrhage, defined as >1000 mL estimated blood loss.ParticipantsThe first two live births to individuals in Sweden in 1997-2009 contributed to clusters representing intact couples (n = 366,350 births), mothers with separate partners (n = 53,292), fathers with separate partners (n = 47,054), sister pairs (n = 97,228), brother pairs (n = 91,168), and mixed sibling pairs (n = 177,944).MethodsFamilial clustering was quantified through cluster specific tetrachoric correlation coefficients, and the influence of potential sharing of known risk factors was evaluated with alternating logistic regression. Relative contributions of genetic and environmental effects to the variation in liability for postpartum haemorrhage were quantified with generalised linear mixed models.ResultsThe overall prevalence of postpartum haemorrhage after vaginal deliveries in our sample was 4.6%. Among vaginal deliveries, 18% (95% confidence interval 9% to 26%) of the variation in postpartum haemorrhage liability was attributed to maternal genetic factors, 10% (1% to 19%) to unique maternal environment, and 11% (0% to 26%) to fetal genetic effects. Adjustment for known risk factors only partially explained estimates of familial clustering, suggesting that the observed shared genetic and environmental effects operate in part through pathways independent of known risk factors. There were similar patterns of familial clustering for both of the main subtypes examined (atony and retained placenta), though strongest for haemorrhage after retained placenta.ConclusionsThere is a maternal genetic predisposition to postpartum haemorrhage, but more than half of the total variation in liability is attributable to factors that are not shared in families.

Dataset Information

Outpatient calcium-channel blockers and the risk of postpartum haemorrhage: a cohort study.

Objective

Design

Setting

Population or sample

Methods

Main outcome measures

Results

Conclusions

Publications

Outpatient calcium-channel blockers and the risk of postpartum haemorrhage: a cohort study.

Similar Datasets

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