The rising rate of preterm birth in Scotland is as much a result of an increase in spontaneous preterm birth as it is of preterm birth that is medically-induced to avoid risking the lives of the mother and child, according to research published this week in the open access journal PLoS Medicine.
The results emphasize that preterm birth, which remains the single biggest cause of infant death in many developed countries, continues to be a major obstetric and neonatal problem despite the reductions that there have been in stillbirths and perinatal deaths as a result of improved maternal medical care.
Jane Norman, of the University of Edinburgh, and colleagues from NHS National Services in Scotland, researched a population-wide database of linked maternity records, infant health and death records in Scotland. They identified 1.49 million singleton births between 1980 and 2004, of which 90,000 were preterm births - babies born before they reach 37 weeks of gestation. Both spontaneous preterm births and medically-induced preterm births increased between 1980 and 2004; in absolute terms the rates of increase in each type of preterm birth were similar. Examining the database, the researchers found that maternal complications including pre-eclampsia (a condition causing high blood pressure) and placenta previa (the covering of the opening of the cervix by the placenta) played a decreasing role in preterm births over the period, whilst gestational and pre-existing diabetes played an increasing role. The researchers also found that there was an overall decline in stillbirth and in neonatal and perinatal deaths amongst preterm babies in the period covered - although at 28 weeks gestation and beyond, stillbirths and perinatal deaths reduced amongst medically-induced preterm babies, but were not reduced in babies who were spontaneously preterm.