The objective of this systematic review was to explore the association between gestational hypertensive disease (GHD) and birthweight discordance in twin pregnancies. PubMed, Embase, Web of Science and Cochrane Library were systematically searched for studies reporting the risk of birthweight discordance in twin pregnancies complicated compared with those not complicated by GHD from establishment until July 2021. Risk of bias was assessed with the Newcastle-Ottawa Scale. According to the classification of GHD, sub-group analyses reporting...