BREECH PRESENTATION IN SOUTH AUSTRALIA, 1987-1989

This study compares the maternal, obstetrical, labour and pregnancy ou tcome characteristics of 2,412 breech-presenting births with 17,946 ve rtex-presenting births. Mothers of babies presenting as breeches were significantly more likely to have had a previous miscarriage, an obste tric complication, a threatened miscarriage or threatened labour durin g the current pregnancy, or Caesarean section than mothers of babies w ith vertex presentation. The babies presenting as breeches had signifi cantly more neonatal morbidity and perinatal mortality. They showed hi gher rates of suspected intrauterine growth retardation, prematurity, low birth-weight, low Apgar scores and congenital anomalies. The overa ll perinatal mortality for breech presentations was almost 9 times hig her than for vertex presentations. Unconditional multiple logistic reg ression analysis showed that, even after adjusting for low birth-weigh t and the presence of congenital anomalies, breech presentation still showed a statistically significant association with perinatal death. T he study alludes to the possibility that breech presentation, in a sig nificant number of cases, may not be coincidental but a marker for som e preconceptional or prenatal disturbance. The study also shows an exc ess of breech presentations in females which is unexplained and may po int to a genetic or hormonal susceptibility of the fetus.