Trends in singleton preterm birth in Victoria, 2007 to 2017: A consecutive cross-sectional study

Abstract

Introduction: Preterm birth is a major cause of perinatal morbidity and mortality worldwide. In many countries preterm birth rates are increasing, largely as a result of increases in iatrogenic preterm birth, whereas in other countries rates are stable or even declining. The objective of the study is to describe trends in singleton preterm births in Victoria from 2007 to 2017 in relation to trends in perinatal mortality to identify opportunities for improvements in clinical care. Material and methods: We conducted a consecutive cross-sectional study in all women with a singleton pregnancy giving birth at ≥20 weeks of pregnancy in Victoria, Australia, between 2007 and 2017, inclusive. Rates of preterm birth and perinatal mortality were calculated and trends were analyzed in all pregnancies, in pregnancies complicated by fetal growth problems, hypertension, (pre)eclampsia or prelabor rupture of membranes (PROM), and in (low-risk) pregnancies not complicated by any of these conditions. Results: There were 811 534 singleton births between 2007 and 2017. Preterm birth increased from 5.9% (4074 births) to 6.4% (4893 births; P