Mechanical heart valve prosthesis in pregnancy - multicenter retrospective observational study

Mechanical Heart Valves, Pregnancy, and Bleeding: A Systematic Review and Meta-Analysis

Anticoagulant therapy is essential in pregnant women with mechanical heart valves to prevent valve thrombosis. The risk of bleeding complications in these patients has not gained much attention. This systematic review and meta-analysis investigate the prevalence of bleeding peri-partum and post-partum in women with mechanical heart valves and also investigate whether bleeding risk differed across anticoagulant regimens or according to delivery mode. The present study was conducted according to The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. Studies reporting bleeding prevalence in pregnant women with mechanical heart valves receiving anticoagulant therapy were identified through PubMed and Embase on December 08, 2021. Data on bleeding complications, delivery mode, and anticoagulation therapy were extracted. A total of 37 studies were included, reporting 423 bleeding complications in 2,508 pregnancies. A meta-analysis calculated a pooled prevalence of 0.13 (95% confidence interval [CI]: 0.09-0.18) bleeding episodes per pregnancy across anticoagulant regimens. The combination of unfractionated heparin (UFH) and vitamin K antagonist (VKA) and single VKA therapy showed the lowest risk of bleeding (8 and 12%). Unexpectedly, the highest risk of bleeding was found in women receiving a combination of low-molecular-weight-heparin (LMWH) and VKA (33%) or mono-therapy with LMWH (22%). However, this could be dose related. No difference in bleeding was found between caesarean section versus vaginal delivery (p = 0.08). In conclusion, bleeding episodes are common during pregnancy in women with mechanical heart valves receiving anticoagulant therapy. A combination of UFH and VKA or VKA monotherapy showed the lowest risk of bleeding.

Managing anticoagulation in pregnancy for the anaesthetist on the labour ward

Pregnancy is a hypercoaguable state. As part of the multidisciplinary team on labour ward, the anaesthetist plays a role particularly in advising the women and the obstetric team regarding the timing and even choice of regional analgesia given the potential risk of complications, as this may be affected by the anticoagulation treatment pregnant women may be on. It is important to understand the type of anticoagulation regimens parturients might be on and what sort of risk assessment they must undergo, as this has obstetric and anaesthetic implications. Although a rare presentation, management of women with mechanical prosthetic heart valves who are pregnant requires detailed and highly specialised care in tertiary care centres with a well-developed multidisciplinary team and pathway. Despite their rare presentation, it is important to understand the intricate and complex management that these women require as they have a high morbidity and mortality rate.

Prosthetic heart valves in pregnancy, outcomes for women and their babies: a systematic review and meta-analysis

BACKGROUND

Historically, pregnancies among women with prosthetic heart valves have been associated with an increased incidence of adverse outcomes.

OBJECTIVES

Systematic review to assess risk of adverse pregnancy outcomes among women with a prosthetic heart valve(s) over the last 20 years.

SEARCH STRATEGY

Electronic literature search of Medline, The Cochrane Library, Cumulative Index to Nursing and Allied Health Literature and Embase to find recent studies.

SELECTION CRITERIA

Studies of pregnant women with heart valve prostheses including trials, cohort studies and unselected case series.

DATA COLLECTION AND ANALYSIS

Primary analysis calculated absolute risks and 95% confidence intervals (CI) for pregnancy outcomes using a random effects model. The Freeman-Tukey transformation was utilised in secondary analysis due to the large number of individual study outcomes with zero events.

MAIN RESULTS

Eleven studies capturing 499 pregnancies among women with heart valve prostheses, including 256 mechanical and 59 bioprosthetic, were eligible for inclusion. Pooled estimate of maternal mortality was 1.2/100 pregnancies (95% CI 0.5-2.2), for mechanical valves subgroup 1.8/100 (95% CI 0.5-3.7) and bioprosthetic subgroup 0.7/100 (95% CI 0.1-4.5), overall pregnancy loss 20.8/100 pregnancies (95% CI 9.5-35.1), perinatal mortality 5.0/100 births (95%CI 1.8-9.8) and thromboembolism 9.3/100 pregnancies (95% CI 4.0-16.5).

CONCLUSIONS

Women with heart valve prostheses experienced higher rates of adverse outcomes than expected in a general obstetric population; however, lower than previously reported. Women with bioprostheses had significantly fewer thromboembolic events compared to women with mechanical valves. Women should be counselled pre-pregnancy about risk of maternal death and pregnancy loss. Vigilant surveillance by a multidisciplinary team throughout the perinatal period remains warranted for these women and their infants.

TWEETABLE ABSTRACT

Metaanalysis suggests improvement in #pregnancy outcomes among women with #heartvalveprostheses.