Recurrent stillbirths: a matched case-control study of unexplained stillbirths at term

The aim of this study was to assess the recurrent risk of an unexplained stillbirth at term. A total of 75 women who delivered stillbirths were matched for maternal age and parity with 75 controls. After excluding explained stillbirths, matched cases and controls were compared for maternal age, length of gestation, birth weight and 'interval to next birth'. The main outcome measure was the frequency of recurrence of a stillbirth. Both groups were similar for maternal age and length of gestation. Birth weight was marginally different (odds ratio (OR) = 0.997, 95% confidence interval (CI) 0.996, 0.999) and 'interval to next birth' was longer (OR = 1.08, 95% CI 1.00, 1.17). There were no stillbirths in cases and controls at follow-up. We conclude that a woman who has had an unexplained stillbirth at term has no greater risk of recurrence than a matched control. However, the 'interval to next birth' was significantly longer.