Risk of Hypertensive Disorders in Pregnancy After Fresh and Frozen Embryo Transfer in Assisted Reproduction: A Population-Based Cohort Study With Within-Sibship Analysis

Sindre H Petersen^*, Kjersti Westvik-Johari, Anne Lærke Spangmose, Anja Pinborg, Liv Bente Romundstad, Christina Bergh, Bjørn Olav Åsvold, Mika Gissler, Aila Tiitinen, Ulla-Britt Wennerholm, Signe Opdahl

^*Corresponding author for this work