Significance of obstetric factors in prognosis of low birthweight children.

Obstetric factors were studied in an unselected series of mothers of LBW-children and compared with those in a corresponding control series. Both groups consisted of 161 women with single pregnancies and 16 with twin pregnancies. Of the 188 LBW-children, 14% were twins. Of the single infants, 42% were appropriate for gestational age (AGA), i.e. within the 10th to 90th percentile according to Swedish curves for intrauterine growth, and 58% small for gestational age (SGA). The commonest causes of low birthweight (LBW) in the AGA-group were bleeding (34%) and premature rupture of the membranes (28%). In the SGA-group toxaemia was found in 15%, but in 50% of the SGA-group no cause of LBW was demonstrable. In this latter group the average placental weight was low. The mortality was noted and 89% of the living children were examined neurologically at 5 years of age. The prognosis of the child depended on the duration of pregnancy. Bleeding during pregnancy was a prognostically unfavourable sign, but even serious bleeding complications did not exclude a normal development of the child. The prognosis was best for those infants in whom no cause of LBW was demonstrable.