A case-control study of stillbirths at a teaching hospital in Zambia, 1979-80: antenatal factors.

A total of 266 mothers of stillborn babies (cases) and 266 mothers of live-born babies (controls), matched for parity, were studied in an attempt to define the causes of the stillbirths. Altogether, 16% of mothers in the former group were over 35 years old, compared with 9% in the latter; in addition, 16% of cases had a history of past perinatal death, compared with only 2.4% among the controls.Mothers of stillborn babies had fewer attendances at the antenatal clinic and a longer interval between the last visit and delivery, compared with the control group; 8% of the former group had no antenatal care. Only 47% of mothers had a Venereal Disease Research Laboratory (VDRL) test reported before delivery. The VDRL test was positive in 34% of the cases tested and in 7% of controls.Of the 266 stillborn infants, 56% were of low birth weight; 12% of the 170 macerated stillbirths were associated with intrapartum problems that may have contributed to death, compared with 46% of the 96 fresh stillbirths. Prolonged labour and prolapsed cord were the commonest intrapartum factors associated with death. The most common antepartum factors were a positive VDRL test, abruptio placentae, and a history of illness. A total of 5% of the stillborn infants had some congenital abnormality. No cause of death could be identified in 13.5% of these infants, the majority of whom were of low birth weight.