biostudies-literatureRosenberg EALFSwedish Association of Local Authorities and RegionsAssar Gabrielssons Foundationhoz039https://www.ebi.ac.uk/biostudies/studies/S-EPMC6920108biostudies-literatureUnknown2019(4)<h4>Study question</h4>Is childbirth after IVF associated with a risk of relapse in breast cancer?<h4>Summary answer</h4>Women who had been diagnosed with breast cancer and completed treatment had no increased risk of relapse if they gave birth after conceiving with IVF.<h4>What is known already</h4>Pregnancy and childbirth have not been shown to increase the risk of relapse in breast cancer. Ovarian stimulation during IVF increases the oestrogen levels and could theoretically increase the risk of relapse in breast cancer.<h4>Study design size duration</h4>This is a retrospective register study, using national Swedish register data from the National Patient Register, the Medical Birth Register, the Swedish National Cancer Register, the National Breast Cancer Register, the National Quality Human reproduction openNo increased risk of relapse of breast cancer for women who give birth after assisted conception.PMC6920108FB 15-20ALFGBG-720291Rosenberg EFredriksson ABergh CEinbeigi ZStrandell AfalseNo increased risk of relapse of breast cancer for women who give birth after assisted conception.<h4>Study question</h4>Is childbirth after IVF associated with a risk of relapse in breast cancer?<h4>Summary answer</h4>Women who had been diagnosed with breast cancer and completed treatment had no increased risk of relapse if they gave birth after conceiving with IVF.<h4>What is known already</h4>Pregnancy and childbirth have not been shown to increase the risk of relapse in breast cancer. Ovarian stimulation during IVF increases the oestrogen levels and could theoretically increase the risk of relapse in breast cancer.<h4>Study design size duration</h4>This is a retrospective register study, using national Swedish register data from the National Patient Register, the Medical Birth Register, the Swedish National Cancer Register, the National Breast Cancer Register, the National Quality 2019-01-01T00:00:00Z20192025-04-26T15:46:43.178Z2020-05-22T00:49:00ZS-EPMC69201083187207010.1093/hropen/hoz039