Factors associated with spontaneous pre-term birth

Abstract

Factors associated with spontaneous pre-term birth in 283 singleton pregnancies were compared with those present in a total population of 16 994 women at risk studied in the First British Perinatal Mortality Survey. It was shown that the risk of spontaneous pre-term birth was related to low maternal age, low maternal weight, maternal smoking, low social class, illegitimacy, threatened abortion, and a previous history of antepartum haemorrhage, perinatal loss, or low birth weight livebirths.

PIP: Factors associated with spontaneous pre-term birth in 283 singleton pregnancies were compared with those present in a total population of 16,994 women at risk who were studied in the First British Perinatal Mortality Survey. There was considerable variation between the incidence of spontaneous pre-term births in different areas of Great Britain, but the number of total births in each region was too small for significance. There were 82 perinatal deaths (29%). This rate appeared fairly constant: in areas of low overall mortality, 43 of the 141 pre-term infants died (30%) compared with 39 of the 142 delivered in the areas of high overall mortality (27%). Risk of spontaneous pre-term birth was found to be related to low maternal age, low maternal smoking, low social class, illegitimacy, threatened abortion, and a previous history of antepartum hemorrhage, perinatal loss, or low birth weight livebirths. Prevention of spontaneous pre-term is of great importance, for the associated perinatal mortality (29% in the present series) and the subsequent infant death rate (25/1000) are high.