Background Twin births represent 1.8% of all births in Ireland. These pregnancies are at a greater risk for adverse perinatal outcomes compared to their singleton counterparts. Early diagnosis of amnionicity and chorionicity is essential as monochorionic pregnancies have a 3–5-fold increased risk of fetal morbidity and mortality compared to dichorionic pregnancies.

Aim To establish the intrauterine death (IUD) rate, beyond 12 weeks gestation, amongst twin pregnancies in Cork University Maternity Hospital (CUMH) between 2009 and 2012.

Methods Using the CUMH Twin Pregnancy and Perinatal Mortality Registers, we identified all cases of single or double fetal loss beyond 12 weeks gestation. Individual charts were then reviewed.

Findings During this four-year period, 692 twin pregnancies (572 DCDA, 117 MCDA, 2 MCMA, 1 conjoined) were managed in CUMH. Of these pregnancies, there were 10 single and 10 double IUDs. Overall, 8 DCDA, 10 MCDA and 2 MCMA pregnancies were affected. 2 pregnancies were excluded from study.

Conclusion From 2009 to 2012, in 3.17% of twin pregnancies there was loss of one or both twins after 12 weeks gestation. This represents a loss rate of 1.39%, 8.54% and 100% in DCDA, MCDA and MCMA twin pairs respectively.