INVESTIGATION OF EFFECTS OF PRENATAL X-RAY EXPOSURE OF HUMAN OOGONIA AND OOCYTES AS MEASURED BY LATER REPRODUCTIVE PERFORMANCE

This epidemiologic study is designed to test the hypothesis that oocytes at a sensitive stage in fetal life might be damaged by the levels of x-ray exposure used in pelvimetry, and might exhibit this damage in some way that could be detected in the F2 child. Fifteen hundred Negro females born in Baltimore hospitals in 1947-1952, who were exposed to x-ray in utero, and 1,500 matched controls are now living in Baltimore. At the end of 1967,1,100 F2 births to these F2 mothers had been ascertained. Exposed mothers had higher birth rates man controls, and similar rates of neonatal deaths, fetal deaths, and ascertained abortions. Most comparisons of exposed vs. control F2 births failed to show a significant increase in the problems encountered by exposed mothers in pregnancy and labor, or in the condition and course of their babies. On the other hand, when F2 births were analyzed by the time during fetal life when the F2 exposure occurred, the following differences were observed. 1) F1 mothers exposed before 30 weeks of fetal life gave birth to significantly increased numbers of male babies and to fewer female babies compared with F1 mothers exposed later in fetal life, or compared with controls. These babies had longer gestations and lower Apgar scores. Placenta weights were lower, and more mothers in this group had precipitate labors. 2) Babies born to mothers exposed at 37 or more weeks of gestation had significantly more neonatal jaundice. © 1969 by The Johns Hopkins University.