Neonatal death rates are higher after evening and late night deliveries than after daytime deliveries, according to a report by researcher in California.

"The problem most likely represents a mismatch between the clinical demands that Arise at night and a hospital's capacity to deal with these demands," Dr. Jeffrey B. Gould from Stanford University, Palo Alto, told Reuters Health.

Gould and his associates used data from linked birth-death certificates for more than 3 million infants in California to investigate the influence of time of birth and the risk of neonatal death.

Overall, neonatal mortality was 2.08 deaths per 1000 live births, the team reports in the medical journal Obstetrics & Gynecology. The death rate was lower for daytime births (1.88 per 1000 live births) than for early night (2.37 per 1000 births) and late night (2.31 per 1000 live births) births.

Even after adjusting for adequacy of prenatal care, complications of pregnancy, gender, and birth weight, neonatal mortality was 12 percent higher for infants born in the early night and 16 percent higher for infants born late at night, the report indicates.