Northern Region Twin Survey, 1984

SummaryA survey of twin pregnancies occurring in the Northern Region of the United Kingdom in 1984 was carried out. Three hundred and fifty-one twin pregnancies were studied, representing 98 per cent of all the twin pregnancies in the region that year. Twins occurred once in every 110 pregnancies. The perinatal mortality rate in twin pregnancies was 42.7 per thousand total births and the extended perinatal mortality rate, including neonatal deaths up to 28 days, was 49.9 per thousand.The major cause of perinatal death was extreme immaturity; eight out of 35 perinatal deaths occurred before 26 weeks. Almost one-third of deaths (12 out of 35) were associated with delivery before 29 weeks.Nearly all (98.3 percent) twin pregnancies were identified by ultrasound before labour commenced. Intrauterine growth retardation was poorly identified by ultrasound. There was no apparent benefit from elective admission for rest.