Maternal Risk of Cardiovascular Disease After Use of Assisted Reproductive Technologies

Best practice recommendations for medically assisted reproduction in patients with known cardiovascular disease or at high risk of cardiovascular disease

Increasing numbers of people are seeking assisted conception. In people with known cardiac disease or risk factors for cardiac disease, assisted conception may carry increased risks during treatment and any subsequent pregnancy. These risks should be assessed, considered and minimized prior to treatment.

Pregnancy, Reproductive Factors, and Female Heart Failure Risk and Outcomes

PURPOSE OF REVIEW

The purpose of this review is to provide an overview of recent evidence on female-specific risk factors related to reproductive status or pregnancy.

RECENT FINDINGS

Pregnancy-related factors, including hypertensive disorders and gestational diabetes, increase the risk of heart failure in women, while breastfeeding and hormone therapy may offer protection. Hypertensive disorders of pregnancy, gestational diabetes, polycystic ovarian syndrome, placental abruption, younger maternal age at first live birth, younger maternal age at last live birth, number of stillbirths, number of pregnancies, onset of menstruation before 12 years of age, shorter reproductive age, ovariectomy, and prolonged absence of ovarian hormones may increase the risk of heart failure in women. Conversely, breastfeeding status and hormone therapy (for menopause or contraception) may serve as protective factors, while fertility treatments have no discernible effect on the risk of heart failure.

Dyslipidemia management in women of reproductive potential: An expert clinical consensus from the national lipid association

Cardiovascular disease (CVD) is the leading cause of death among women and its incidence has been increasing recently, particularly among younger women. Across major professional society guidelines, dyslipidemia management remains a central tenet for atherosclerotic CVD prevention for both women and men. Despite this, women, particularly young women, who are candidates for statin therapy are less likely to be treated and less likely to achieve their recommended therapeutic objectives for low-density lipoprotein cholesterol (LDL-C) levels. Elevated LDL-C and triglycerides are the two most common dyslipidemias that should be addressed during pregnancy due to the increased risk for adverse pregnancy outcomes, such as preeclampsia, gestational diabetes mellitus, and pre-term delivery, as well as pancreatitis in the presence of severe hypertriglyceridemia. In this National Lipid Association Expert Clinical Consensus, we review the roles of nutrition, physical activity, and pharmacotherapy as strategies to address elevated levels of LDL-C and/or triglycerides among women of reproductive age. We include a special focus on points to consider during the shared decision-making discussion regarding pharmacotherapy for dyslipidemia during preconception planning, pregnancy, and lactation.

Estimating the impact of bias in causal epidemiological studies: the case of health outcomes following assisted reproduction

Researchers interested in causal questions must deal with two sources of error: random error (random deviation from the true mean value of a distribution), and bias (systematic deviance from the true mean value due to extraneous factors). For some causal questions, randomization is not feasible, and observational studies are necessary. Bias poses a substantial threat to the validity of observational research and can have important consequences for health policy developed from the findings. The current piece describes bias and its sources, outlines proposed methods to estimate its impacts in an observational study, and demonstrates how these methods may be used to inform debate on the causal relationship between medically assisted reproduction (MAR) and health outcomes, using cancer as an example. In doing so, we aim to enlighten researchers who work with observational data, especially regarding the health effects of MAR and infertility, on the pitfalls of bias, and how to address them. We hope that, in combination with the provided example, we can convince readers that estimating the impact of bias in causal epidemiologic research is not only important but necessary to inform the development of robust health policy and clinical practice recommendations.

Infertility treatment is associated with increased risk of postpartum hospitalization due to heart disease

BACKGROUND

Cardiovascular disease is a major cause of maternal mortality, but the extent to which infertility treatment is implicated in heart disease remains unclear.

OBJECTIVE

To evaluate the association between infertility treatment and postpartum heart disease.

METHODS

We designed a retrospective cohort study of patients who delivered in the United States between 2010 and 2018. The primary outcome was hospitalization within 12-month post-delivery due to heart disease (including ischemic heart disease, atherosclerotic heart disease, cardiomyopathy, hypertensive disease, heart failure, and cardiac dysrhythmias). We estimated the rate difference (RD) of hospitalizations among patients who conceived with infertility treatment and those who conceived spontaneously. Associations were expressed as hazard ratios (HRs) and 95% confidence intervals (CIs), derived from Cox proportional hazards regression after adjustment for potential confounders.

RESULTS

Infertility treatment was recorded in 0.9% (n = 287,813) of 31,339,991 deliveries. Rates of heart disease hospitalizations with infertility treatment and with spontaneous conception were 550 and 355 per 100,000, respectively (RD 195, 95% CI: 143-247; adjusted HR 1.99, 95% CI: 1.80-2.20). The most important increase in risk was observed for hypertensive disease (adjusted HR 2.16, 95% CI: 1.92-2.42). This increased risk was apparent as early as 30-day post-delivery (HR 1.61, 95% CI: 1.39-1.86), with progressively increasing risk up to a year.

CONCLUSIONS

Although the absolute risk of postpartum heart disease hospitalization is low, infertility treatment is associated with an increased risk, especially for hypertensive disease. These findings highlight the importance of timely postpartum follow-ups in patients who received infertility treatment.

Risk of stroke the year following a delivery after using assisted reproductive technologies

BACKGROUND

Studies indicate that individuals who deliver after assisted reproductive technologies (ART) may have an increased risk of cardiovascular disease (CVD). A recent large study from the U.S. showed a higher risk of stroke during the first year after delivery.

OBJECTIVES

To compare the risk of stroke during the first year after delivery according to the use of ART in the Nordic countries.

METHODS

Registry-based cohort study using nationwide data from Denmark (1994-2014), Finland (1990-2014), Norway (1984-2015) and Sweden (1985-2015). Data on ART conception were available from ART quality registries and/or Medical Birth Registries (MBRs). National data on stroke were available from hospital and cause-of-death registries. The risk of stroke during the first year after delivery was estimated with Cox proportional hazard regression, adjusting for age, calendar year of delivery, multiple births, and country.

RESULTS

A total of 2,659,272 primiparous individuals had a registered delivery in the MBRs during the study period, and 91,466 (4%) of these gave birth after ART. We observed no overall increased risk of stroke during the first year after delivery among individuals conceiving after ART (adjusted hazard ratio [HR] 1.10, 95% CI 0.77, 1.57). Similarly, there was no convincing evidence that the short-term risk of stroke was higher within 1, 2, 3, or 6 months after delivery, with adjusted HRs ranging between 1.23 and 1.33 and confidence intervals including the null value for all time periods. A secondary analysis also including multiparous individuals (n = 3,335,478) at the start of follow-up yielded similar findings.

CONCLUSIONS

We found no evidence of an increased short-term risk of stroke among individuals who delivered after using ART.

The risk of perinatal and cardiometabolic complications in pregnancies conceived by medically assisted reproduction

PURPOSE

To examine the impact of medically assisted fertility treatments on the risk of developing perinatal and cardiometabolic complications during pregnancy and in-hospital deliveries.

METHODS

We conducted a retrospective cohort study using medical health records of deliveries occurring in 2016-2022 at a women's specialty hospital in a southern state of the Unites States (US). Pregnancies achieved using medically assisted reproductive (MAR) techniques were compared with unassisted pregnancies using propensity score matching (PSM), based on demographic, preexisting health, and reproductive factors. Study outcomes included cesarean delivery, gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy (HDP), delivery complications, and postpartum readmission. We used Poisson regression with robust standard errors to generate risk ratios (RRs) and 95% confidence intervals (CIs) for all study outcomes.

RESULTS

Among 57,354 deliveries, 586 (1.02%) pregnancies were achieved using MAR and 56,768 (98.98%) were unassisted ("non-MAR"). Compared to the non-MAR group, MAR pregnancies had significantly higher prevalence of all study outcomes, including GDM (15.9% vs. 11.2%, p < 0.001), HDP (28.2% vs. 21.1%, p < 0.001), cesarean delivery (56.1% vs. 34.6%, p < 0.001), delivery complications (10.9% vs. 6.8%, p = 0.03), and postpartum readmission (4.3% vs. 2.7%, p = 0.02). In a PSM sample of 584 MAR and 1,727 unassisted pregnancies, MAR was associated with an increased risk of cesarean delivery (RR = 1.11, 95% CI = 1.01-1.22); whereas IVF was associated with an increased risk of cesarean delivery (RR = 1.15, 95% CI = 1.03-1.28) and delivery complications (RR = 1.44, 95% CI = 1.04-2.01).

CONCLUSIONS

Women who conceived with MAR were at increased risk of cesarean deliveries, and those who conceived with IVF were additionally at risk of delivery complications.

Assisted reproductive technology: what are the cardiovascular risks for women?

INTRODUCTION

Infertility affects 15% of women of reproductive age in the United States. The use of assisted reproductive technology (ART) has been rising globally, as well as a growing recognition of reproductive factors that increase risk for cardiovascular disease (CVD).

AREAS COVERED

Women with infertility who use ART are more likely to have established CVD risk factors, such as obesity, dyslipidemia, hypertension, and diabetes. They are also more likely to experience adverse pregnancy outcomes, which are associated with both peripartum and long-term cardiovascular complications. ART may lead to increased cardiometabolic demands due to ovarian stimulation, pregnancy itself, and higher rates of multifetal gestation. Preeclampsia risk appears greater with frozen rather than fresh embryo transfers.

EXPERT OPINION

The use of ART and its association with long term CVD has not been well-studied. Future prospective and mechanistic studies investigating the association of ART and CVD risk may help determine causality. Nevertheless, CVD risk screening is critical pre-pregnancy and during pregnancy to reduce pregnancy complications that elevate future CVD risk. This also offers a window of opportunity to connect patients to longitudinal care for early management of cardiometabolic risk profile and initiation of preventive lifestyle and pharmacotherapy interventions tailored toward patient-specific risk factors.