Frozen embryo transfer following IVF has been linked to an increased risk of high blood pressure in resulting pregnancy, following a study of over 4.5 million pregnancies.
Using data from the Medical Birth Registries of Denmark, Norway, and Sweden researchers showed that there was a 74 percent increase in risk of hypertensive disorders during pregnancy following frozen embryo transfer compared to natural conception. There was no increase in risk with fresh embryo transfer. This was demonstrated both at a population level and in mothers who had children conceived both ways, in a paper published in the journal Hypertension.
These results had previously been announced at the annual meeting of the European Society of Human Reproduction and Embryology in July 2022 (see BioNews 1054).
'Our sibling comparisons indicate that the higher risk is not caused by factors related to the parents,' said lead study author Dr Sindre Petersen, fellow at the Norwegian University of Science and Technology in Trondheim, Norway. 'Future research should investigate which parts of the frozen embryo transfer process may impact risk of hypertension during pregnancy.'
