Summary

Following in vitro fertilisation treatment, a 40-year-old woman was expecting trichorionic, triamniotic triplets. Her cervix shortened from 34 mm at 16⁺⁵ weeks to 16 mm at 20⁺⁵ weeks, a risk reported with 100% delivery before 28 weeks gestation. She was admitted to hospital and at 24⁺¹ weeks was given corticosteroids. From 21⁺⁵ weeks her cervical length remained below 16 mm. However, weekly fetal fibronectin (fFN) tests were negative from 22⁺⁵ weeks to delivery at 35⁺⁵ weeks. This, along with an absence of symptoms, gave her doctors confidence to manage her as an outpatient from 28 weeks. At 33⁺⁵ weeks she was diagnosed as having pre-eclampsia and three live births were delivered by prelabour caesarean section. Prior to delivery her cervical length was 10 mm and fFN test remained negative. There are no reports of outcome following a negative fFN with a short cervix in triplet pregnancies but fFN could be a useful tool, in conjunction with cervical length measurement, in the management of triplets.