A randomised placebo-controlled trial of antenatal corticosteroids for planned birth in twins. STOPPIT-3 was a trial that aimed to find out if medicines called antenatal corticosteroids (ACS) given to women with a twin pregnancy prior to a planned birth of twins after 35 weeks of pregnancy reduced breathing difficulties in the twin babies. STOPPIT-3 planned to recruit 1,552 women from 50+ centres across the UK. Researchers invited women and pregnant people to consent to participate in the study who were expecting twins. They asked the women to have a single course of dexamethasone 6.6mg/2ml (an antenatal corticosteroid) given in two divided doses by intramuscular (IM) injection 24 hours apart. They followed the women and their babies for two years after delivery.Women were eligible for inclusion in the study if they were:>16 years old;with a viable twin pregnancy;and a planned caesarean birth or induction of labour scheduled between 35+0 -38+6 weeks gestation.See the funding award.***STOPPIT-M was a mechanistic study that tried to understand why ACS (antenatal corticosteroids) work for some babies and not for others. In STOPPIT-M, researchers collected a maternal blood sample as well as cord blood samples from each twin, amniotic fluid and placenta from each twin and used these to explore whether infant hypothalamic-pituitary-adrenal axis activity underpins side effects like low blood sugar and breathing difficulties in some babies.Main study website Get involved with pregnancy research Dr Sarah Stock introduces STOPPIT-3 and STOPPIT-M. Dr Sarah Murray and Dr Rosie Townsend discuss the benefits and risks of steroids in pregnancy. Dr Sarah Murray and Dr Rosie Townsend talk about steroids and neurodevelopment. This article was published on 2023-11-27