Retrospective study to determine the prevalence of MCMA twin and all triplet pregnancies

A retrospective study to determine the prevalence of MCMA twin and all triplet pregnancies using population-based NorSTAMP and STORK data for 2000-2013, to compare birth outcomes and clinical management of these pregnancies across the NE and with those from the STORK multiple pregnancy cohort, and also before and after the publication of the NICE guidelines.

This project consisted of two studies using pregnancy data from NorSTAMP and STORK between 2000 and 2013.

The first study was looking at how common monochorionic monoamniotic (MCMA) twin pregnancies are, which share a placenta and an amniotic sac. It also looked at how these pregnancies are managed and whether sharing a placenta and sac affected the health of the babies. This study found that in every 100,000 pregnancies, 8 are MCMA twin pregnancies. About one third of these pregnancies experienced a loss before 24 weeks, usually because of extremely premature spontaneous labour, but for the majority of pregnancies, there was a higher survival rate compared with in previous decades. This is probably because of early diagnosis, being monitored closely throughout pregnancy, and having a planned birth around 32–34 weeks of gestation.

The second study aimed to investigate babies’ health and growth patterns in monochorionic triplet pregnancies, where three babies share one placenta. Despite being monitored closely in pregnancy, monochorionic triplet pregnancies carried a significantly increased risk of stillbirth, mainly due to feto-fetal transfusion (TTTS) and selective fetal growth restriction. However, once the babies were born, they were as healthy as any other triplet babies.

This study was carried out by Dr Therese Hannon at Newcastle upon Tyne NHS Foundation Trust and was fully funded by Twins Trust. The other collaborators were SV Glinianaia (main researcher at Newcastle University Institute of Health & Society), J Rankin, A Khalil, SN Sturgiss, and B Thilaganathan. Read more about the studies we have funded here: https://twinstrust.org/who-we-are/what-we-do/research/research-bursaries.html