predictions and shutting out skeptics. Reporting on the effects of PCE may have been affected by publication bias, a disproportionate publication of studies indicating more severe outcomes as the crack epidemic emerged. Scientific studies that reported PCE to have significant effects were more likely to be published than those that did not. Between 1980 and 1989, 57% of studies showing cocaine has effects on a fetus were accepted by the Society for Pediatric Research, compared with only 11% of studies showing no effects. Findings that other factors such as prematurity were behind symptoms that cocaine-exposed babies showed did not "fit within the narrative of what had become a national scare" and were given less attention. Ideas about severe effects of PCE may have been more readily embraced because they "fit in with cultural stereotypes". At the time, the proposed mechanism by which cocaine harmed fetuses was as a stimulant— cocaine was predicted to disrupt normal development of parts of the brain that dealt with stimulation, resulting in problems such as bipolar disorder and attention deficit disorder. Reports from the mid-1980s to early '90s raised concerns about links between PCE and slowed growth, deformed limbs, defects of the kidneys and genitourinary and gastrointestinal systems, neurological damage, small head size, atrophy or cysts in the cerebral cortex, bleeding into the brain's ventricles, and obstruction of blood supply in the central nervous system. After the early studies that reported that PCE children would be severely disabled came studies that purported to show that cocaine exposure in utero has no important effects. Almost every prenatal complication originally thought to be due directly to PCE was found to result from confounding factors such as poor maternal nutrition, use of other drugs, depression, and lack of prenatal care. More recently, the scientific community has begun to reach an understanding that PCE does have some important effects, but that they are not severe as was predicted in the early studies. The effects of PCE are subtle but they exist. Most people who were exposed to cocaine in utero are normal or close to it. Pathophysiology Cocaine, a small molecule, is able to cross the placenta into the bloodstream of the fetus. In fact, it may be present in a higher concentration in the amniotic fluid than it is in the mother's bloodstream. The skin of the fetus is able to absorb the chemical directly from the amniotic