Background: Preterm infants are at risk of periventricular haemorrhage. This can damage the brain and lead to neurodevelopmental abnormalities, including cerebral palsy. It has been suggested that vitamin K might improve coagulation in preterm infants.
Objectives: The objective of this review was to assess the effects of vitamin K administered to women at risk of imminent very preterm birth to prevent periventricular haemorrhage and associated neurological injury in the infant.
Search strategy: We searched the Cochrane Pregnancy and Childbirth Group trials register, Cochrane Controlled Trials Register, and bibliographies up to January 1999.
Selection criteria: Randomised or quasi-randomised trials of vitamin K administered parenterally or orally to women at risk of imminent preterm birth. The primary outcomes were neonatal mortality, neonatal neurological morbidity, as measured by the presence of periventricular haemorrhage (PVH) on ultrasound during the first week of life, and long term neurodevelopment. Secondary outcomes included other neonatal morbidity and any maternal side effects.
Data collection and analysis: Eligibility, trial quality assessment and data extraction were done independently by two reviewers.
Main results: Five trials were included, involving more than 420 women. The trials were of variable quality. Antenatal vitamin K was associated with a non-significant trend to a reduction in all grades of periventricular haemorrhage (relative risk (RR) 0.82, 95% confidence interval (CI) 0.67-1.00) and in severe PVH (grades 3 and 4) (RR 0.75, 95% CI 0.45-1.25) for babies receiving prenatal vitamin K compared with control babies. This trend disappeared when poorer quality trials were excluded. Information on neurodevelopment was given for a small sample of children in one trial and no differences were seen.
Reviewer's conclusions: Vitamin K administered to women prior to very preterm birth does not appear to be able to significantly prevent periventricular haemorrhages in preterm infants.