The majority of premature births are not predictable nor are the causes known.
Women with a history of cervical incompetence or a previous premature birth or twins are at increased risk. Optimal maternal nutrition reduces the risk of prematurity. Infection in the mother vagina rnay predispose to prematurity and double the risk, though infection is usually not obvious. The organisms – most commonly GARDNERELLA – may exert their effect by infecting the cervix and the membranes leading to the production of prostaglandin and to uterine contractions. There are many women with Gardnerella who do not have premature labour and there is no way at present to predict who will benefit from antibiotic treatment during pregnancy, although women with a history of premature birth may benefit from prophylactic treatment.
Following premature rupture of the membranes there may be a benefit from antibiotics to delay the onset of labour while the baby’s lungs mature. Babies who have severe IUGR may need to be born early. The baby may then need neonatal intensive care.