As is the case elsewhere in Australia, Victoria has seen a trend over the last ten years to more babies being born before 40 weeks. Between 2007 and 2017, the overall preterm birth rate (births before 37 weeks) in singleton pregnancies rose slightly, from 5.9% to 6.4%.
This increase occurred only in those babies born between 34 and 37 weeks (4.4% rising to 4.9%), with the rate of births prior to 34 weeks remaining stable at 1.5%. The spontaneous preterm birth rate over this same time period actually decreased, from 3.4% to 2.8%, and so it was the increase in iatrogenic (medically-initiated) early births from 2.5% to 3.6% that was responsible for the overall rise in the preterm birth rate.
Many of these preterm births will have been medically indicated, as the best way of managing complications of pregnancy affecting the mother, baby, or both. However, the overall incidence of two pregnancy complications that are common indications for early delivery – small for gestational age babies and maternal high blood pressure – has decreased over this decade, while the proportion of preterm birth in these conditions has increased. These data suggest that some babies are being born earlier than necessary.