Changes in the modes of twin birth in Victoria, 1983-2015

Objectives: To examine changes in the modes of delivery of twins in Victoria over 33 years.

Design: Retrospective population-based study.

Setting, participants: All twin births in Victoria, 1 January 1983 - 31 December 2015.

Major outcomes: Mode of birth (vaginal, planned or unplanned caesarean delivery); indications for caesarean delivery.

Results: During 1983-2015, 32 187 twin pregnancies ended in live or stillbirths in Victoria. The proportion of twins born by caesarean delivery increased from 24% (156 twin deliveries) in 1983 to 71% (782 deliveries) in 2015. The proportion of twin births by planned caesarean delivery with twin pregnancy as the sole indication for caesarean delivery increased across this period from 1.8% (12 twin deliveries) to 21% (231 deliveries). The proportion of twin births by caesarean delivery and the proportion of caesarean twin deliveries with twin pregnancy as the principal indication each differed between Victorian regions.

Conclusion: During 1983-2015, the proportion of twins born in Victoria by caesarean delivery increased almost threefold, mostly because caesarean delivery has become the preferred mode of birth for twin pregnancies. Regional differences in the delivery of twins suggest that the number of caesarean deliveries can be reduced with appropriate system and training support.