Multifetal pregnancies: preterm admissions and outcomes.

OBJECTIVE To describe the rates of antenatal hospital admission during twin or higher order multifetal pregnancies, and the admission outcomes as discharge undelivered, transfer to higher care, or spontaneous or elective delivery. METHODS Cohort study using linked birth and hospital data. The cohort comprised women who gave birth to twins or higher order multiple infants of≥24 weeks gestation in 2001-2008 and who were admitted to hospital in weeks 20-36 of the pregnancy. RESULTS In 63.4% of 10 779 twin pregnancies and 99.5% of 197 triplet and quadruplet pregnancies, the woman was admitted to hospital at least once in weeks 20-36 of the pregnancy, for a total 10 985 admissions. Almost half the admissions (46.3%) ended in discharge without delivery, 10.7% in transfer to higher care, 21.1% in spontaneous labour and birth, and 21.8% in elective delivery (induction or prelabour Caesarean section). The reason for admission was preterm labour in 34.2% of admissions. CONCLUSIONS Hospital admission during pregnancy is common for women with multifetal pregnancies, with many of these admissions resulting in preterm birth. This is the first study to report the rate of pregnancy admissions for women with multifetal pregnancies, and provides a baseline for future studies of hospital use in this population.