Heart Valve Prostheses in Pregnancy: Outcomes for Women and Their Infants

Abstract

BackgroundAs the prognosis of women with prosthetic heart valves improves, and increasing number are contemplating and undertaking pregnancy. Accurate knowledge of perinatal outcomes is essential, assisting counseling and guiding care. The aims of this study were to assess outcomes in a contemporary population of women with heart valve prostheses undertaking pregnancy and to compare outcomes for women with mechanical and bioprosthetic prostheses.Methods and ResultsLongitudinally linked population health data sets containing birth and hospital admissions data were obtained for all women giving birth in New South Wales, Australia, 2000–2011. This included information identifying presence of maternal prosthetic heart valve. Cardiovascular and birth outcomes were evaluated. Among 1 144 156 pregnancies, 136 involved women with a heart valve prosthesis (1 per 10 000). No maternal mortality was seen among these women, although the relative risk for an adverse event was higher than the general population, including severe maternal morbidity (139 versus 14 per 1000 births, rate ratio [RR]=9.96, 95% CI 6.32 to 15.7), major maternal cardiovascular event (44 versus 1 per 1000, RR 34.6, 95% CI 14.6 to 81.6), preterm birth (183 versus 66 per 1000, RR=2.77, 95% CI 1.88 to 4.07), and small‐for‐gestational‐age infants (193 versus 95 per 1000, RR=2.03, 95% CI 1.40 to 2.96). There was a trend toward increased maternal and perinatal morbidity in women with a mechanical valve compared with those with a bioprosthetic valve.ConclusionsPregnancies in women with a prosthetic heart valve demonstrate an increased risk of an adverse outcome, for both mothers and infants, compared with pregnancies in the absence of heart valve prostheses. In this contemporary population, the risk was lower than previously reported.

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

“…27 There were seven retrospective studies, two population-based cohort studies, 20,21 two multicentre unselected case series 28,32,33 and three single-centre unselected case series 28,30,31 (Table 1). Ten studies captured a total of 305 women undertaking 392 pregnancies.…”

“…All included studies reported information on maternal mortality and any pregnancy loss. Eight of the 11 studies allowed identification of perinatal mortality 20,21,[27][28][29]31,32,34 and three studies had insufficient details to differentiate early pregnancy loss from fetal death at >22 weeks. 30,33,35 No studies reported the incidence of infective endocarditis or neonatal admissions to the intensive care unit.…”

“…21 Of the remaining studies without control groups, one study 32 was awarded the maximum six stars, seven were awarded five stars [27][28][29]31,[33][34][35] and one was awarded three stars. 30 All included studies were assessed as including an adequate representation of cases, with appropriate follow up (Table 1).…”

“…6 In this systematic review the two largest studies reported vastly different rates of pregnancy loss, 23/136 (17%) and 67/107 (63%). 20,21 Both were retrospective, population-based studies and scored favourably when assessed for risk of bias (Table 1). However, methods and study populations varied; Sillesen et al 20 attempted to contact women to identify spontaneous first trimester abortions.…”

“…Recent individual studies report lower rates of adverse outcomes than presented in two systematic reviews, published in 2000 and 2008, which focused only on mechanical valves and influence of anticoagulant type and included pregnancies from the previous four decades. 6,12,20,21 Given the advances in prosthetic heart valve design, obstetric and medical care and improved outcomes of women receiving heart valve prostheses, further investigation of the outcomes of pregnancies in the setting of maternal heart valve prosthesis is necessitated in this contemporary setting, defined as the last 20 years.…”