Counseling in medical genetics / Sheldon C. Reed.

  • Sheldon Clark Reed
Date:
1963
Catalogue details

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Counseling in medical genetics / Sheldon C. Reed. Source: Wellcome Collection.

    235/296 (page 221)
    The Environment 221 riage. This virus produces a long immunity, and it should be iso¬ lated and cultured very soon. Another environmental factor for which fears and fancies have far outrun the facts is anoxia. Anoxia is a natural hazard of childbirth, and in most cases the infant makes a normal adjust¬ ment to it. When infants suffer from delayed respiration or asphyxia during birth, it is widely accepted that this is responsi¬ ble for later difficulties such as convulsions, mental retardation and perhaps other neurologic abnormalities. The early studies were badly biased and were not adequate to prove their conten¬ tions. Prospective studies, as with rubella, are necessary to pro¬ vide useful data. Schachter and Apgar ( 1959 ) did a study of 104 newborn infants with follow-up and psychologic testing in 1956. They found that the group with perinatal complications was impaired on four psychologic tests and five diagnostic signs. They stated: The positive findings would appear to support previous results showing a significant effect of early asphyxia. However, the clinical significance of the data on the special tests appears to be ambiguous. In addition, the small though statistically significant impairment of 4.9 points in I.Q. for the complicated subjects is of questionable clinical significance. Even such slight differences as these were not apparent in the extensive study of Keith and Gage (1960). This was a sec¬ ond follow-up on Mayo Clinic children, of whom 80 per cent were between 8 and 14 years of age at the time of follow-up. Their sample started with 402 infants born after prolonged labor, 236 with asphyxia or delayed respiration at birth, 110 survivors whose mothers had toxemia and 633 controls. Other infants had died soon after birth, but this work was concerned only with survivors. If the infants survived, there were no significant differences in neurologic lesions or convulsions between the groups. The I.Q. differences for a 10 per cent sample gave a