An Australian analysis shows the risk of cardiovascular events and early death may even be lower for women who have IVF.
Women who have fertility treatment do not have a higher risk of death or heart attack or stroke, according to four decades of Australian IVF data.
The study analysed Monash IVF clinical registries data from 1975 – when assisted reproduction services first became available in Australia – to 2018.
A comparison of 33,500 women who had fertility treatment and 10,600 who did not, found no apparent increases in all-cause death or cardiovascular mortality.
“Fertility therapy did not increase the risks of all-cause or CVD death beyond those of other Australian women of the same age,” the authors wrote in the MJA.
In fact, they found that after accounting for age, both all-cause and cardiovascular disease mortality were lower over the study period among women who had fertility treatment.
“Among women who registered for fertility therapy, all-cause and CVD mortality was lower than for the general female population of the same age, which may reflect confounding by socio-economic status and other health determinants.”
That was consistent with the “healthy patient” phenomenon, they said.
“Healthy lifestyle behaviours, greater socio-economic advantage, and other factors may have led to women undergoing fertility treatment having lower CVD risk prior to therapy, so that any rise in risk linked with treatment may have been less apparent.
“Nevertheless, socio-economic status can serve as a proxy for CVD risk, and our adjusting for it may have partially accounted for prior CVD risk.”
They did find that socio-economic advantage was linked to lower mortality among women who had received fertility treatment.
“This conclusion is consistent with the association between social disadvantage and higher mortality in the general population and the negative association between the affordability and use of assisted reproduction technologies.
“Women who seek fertility therapy may be healthier than other women of the same age, having modified their behaviour to maximise the chance of conception. Socio-economic advantage is consequently a major determinant of the ‘healthy patient’ effect with respect to fertility treatment in Australia.”
But women who had more intensive fertility treatment also had no higher mortality rates, they said.
“The standardised mortality ratio was significantly lower for women who had undergone three or more stimulated cycles than for those who had undergone fewer cycles, and the number of oocytes produced was not associated with differences in all-cause mortality.”
The authors said the findings had important clinical implications for the 55,000 women who use assisted reproduction technologies in Australia each year.
“They are counselled about fertility treatment decisions with only limited understanding and discussion of its impact on their longer-term health.
“Our study provides information for discussions by women and their clinicians of the long-term safety of fertility therapy, and provides some reassurance for women who have previously undergone such treatment.”
The authors said cardiovascular mortality had not previously been investigated in Australian women who have undergone fertility treatment, and long-term cardiovascular disease data for women over 60 was also limited.
Previous studies had raised concerns about the long-term safety of fertility therapy and its effect on cardiovascular risk, they said.
“Fertility treatment could lead to adverse cardiovascular events by inducing background thrombosis, activating the renin–angiotensin system, or by vascular injury caused by ovarian hyperstimulation.
“Fertility treatment is associated with increased risks of pregnancy-related complications such as maternal metabolic syndromes (eg, gestational diabetes, hypertension), which are in turn associated with higher long term CVD risk for both mothers and their children.”
The authors said the findings were consistent with a smaller Canadian study of 7000 women that found a lower risk of cardiovascular disease mortality and morbidity among women who had successful fertility therapy.
