The state of health care isreflected by perinatal and neonatal morbidity and mortality as weIl as by the frequencies of long-term neurological and developmental disorders. Many factors, some without immediately recognizable significance to childbearing and many still unknown, undoubtedly contribute beneficially or adversely to the outcome of pregnancy. Knowledge concerning the impact of such factors on the fetus and survivinginfant iscritical. Confounding...