preterm birth

(premature birth)

birth of a baby before 37 weeks (259 days) of gestation (calculated from the first day of the mother's last menstrual period); a birth at less than 23 weeks is at present incompatible with life. Such factors as pre-eclampsia, multiple pregnancies (e.g. twins), maternal infection, and cervical incompetence may all result in preterm births, but in the majority of cases the cause is unknown. Conditions affecting preterm babies may include respiratory distress syndrome, feeding difficulties, inability to maintain normal body temperature, apnoea, infection, necrotizing enterocolitis, and brain haemorrhages. Supportive treatment is provided in an incubator in a neonatal unit; many infants survive with no residual handicap but the shorter the gestation period, the more serious are the problems to be overcome.