The multifactorial etiology of cerebral intraventricular hemorrhage (IVH) m
ay involve coagulation disturbances and venous infarction. We tested whethe
r coagulation abnormalities associated with adult venous thrombosis would c
onstitute a risk factor for IVH in newborn infants. In 22 infants (gestatio
nal age 24.3-39.9 wk, median 28.0 wk) with neonatal IVH grade II to IV, the
frequencies of congenital resistance to activated protein C due to a point
mutation in the factor V gene (Gln506-FV) and a polymorphism in the prothr
ombin gene (G20210A-FII) were assessed and compared with those observed in
29 premature newborn infants without IVH and in 302 (Gln506-FV) or 526 (G20
210A-FII) healthy adults. In infants with IVH, four (18%) heterozygous carr
iers of Gln506-FV and one (5%) heterozygous carrier of G20210A-FII were fou
nd. One infant without IVH was heterozygous for Gln506-FV (3%). When compar
ed with the frequency of Gln506-FV in the general population, the odds rati
o for being a carrier of Gln506-FV for patients with IVH was 5.9 (95% confi
dence interval 1.7-20.3, p = 0.013) and for patients without IVH 0.9 (95% c
onfidence interval 0.1-7.6, p > 0.99). The absolute risk of IVH in a newbor
n infant with heterozygous Gln506-FV and born before 30 wk of gestation was
estimated at 80%, whereas the corresponding risk for all infants born befo
re 30 wk was 14%. Gln506-FV was more common in newborn infants with IVH tha
n in the general population, whereas there was no difference in the frequen
cies of Gln506-FV in infants without IVH and in the general population. Thu
s, Gln506-FV may be a risk factor of IVH. The risk of IVH in a premature in
fant with Gln506-FV or other established thrombophilic coagulation abnormal
ity may be considerable.