Intervention or expectant management for early onset selective fetal growth restriction in monochorionic twin pregnancy. FERN is a UK study taking place in multiple hospitals which looks at selective fetal growth restriction (where one baby grows smaller than the other baby), also known as sFGR or sIUGR, in monochorionic twin pregnancies (where both babies share one placenta). The study is looking at outcomes depending on whether they had an intervention or were monitored without any other treatment. The study wants to find out what care options are offered in sFGR pregnancies and the outcome for the babies. Twin pregnancies that share a placenta which develop sFGR can lead to poor outcomes for the babies. There is currently a lack of evidence to guide doctors as to how they should treat this condition, especially for sFGR which begins before 24 weeks of pregnancy. The FERN study has three working packages and RIE is a participating site for working package 1 – we are one of several UK Fetal Medicine Units aiming to recruit a total of 120 women (across all the sites) with a monochorionic twin pregnancy affected by early onset sFGR (<24 weeks). FERN will assess management strategies and clinical outcomes from routine practice. This will determine the natural history of sFGR, distribution of interventions and pregnancy outcomes. In other working packages, FERN has assessed parents’ preferences, doctors’ preferences, ethical dilemmas, current UK practice, the number of cases per year, what we already know about sFGR; and also what would be needed to design a new trial in the future comparing different treatments with monitoring the pregnancy without treatment in monochorionic twins who are diagnosed with sFGR. FERN study website I want to take part General information about pregnancy research More about the FERN study These twin pregnancies that share a placenta which develop sFGR can lead to poor outcomes for the babies. There is currently a lack of evidence to guide doctors as to how they should treat this condition, especially for sFGR which begins before 24 weeks of pregnancy. The FERN study wants to see if it’s possible to conduct a trial comparing different treatments with monitoring the pregnancy without treatment in monochorionic twins who are diagnosed with sFGR. It will also take into account parents’ preferences, doctors’ preferences, ethical dilemmas, current UK practice, the number of cases per year, what we already know about sFGR and what would be needed to design a new trial. The aim of the FERN study is for fifteen UK Fetal Medicine Units to recruit 120 women with a monochorionic twin pregnancy affected by early onset sFGR (<24 weeks). We will assess management strategies and clinical outcomes from routine practice. This will determine the natural history of sFGR, distribution of interventions and pregnancy outcomes. This article was published on 2024-02-01