Spontaneous abortion and aging of human ova and spermatozoa

Abstract

To test the hypothesis that aging of human gametes within the genital tract increases the chance of abortion, we measured the probabilities of abortion after insemination on a given day of the menstrual cycle in relation to the day of the shift in the basal body temperature in 965 patients. Cases came from family-planning and sterility clinics where basal body temperature and coital records are kept routinely. The probability of abortion diminished significantly (P less than 0.001) as the shift in temperature was approached and the increased to its highest point (24 per cent) three days later. Animal experiments have shown that aging of both spermatozoa and ova before fertilization is accompanied by higher probabilities of abortion. Present evidence indicates that this higher prevalence is also true for human beings.

PIP: The basal body temperature in 965 patients were subject to analysis with coital records in order to determine the probability of abortion after insemination on a given day of the menstrual cycle in relation to the shift in basal body temperature. Coital records were examined to assign a responsible insemination, and basal body temperature charts examined to determine a thermal shift. There were 890 term deliveries and 75 spontaneous abortions. The overall probability of abortion was 7 .8%. The lowest corresponded to Day -2 (3.2%) and the highest to Day +3 (24%). The probability of abortion diminished significantly (P less than .001) as the shift in temperature was approached and then increased to its highest point 3 days later. These results strongly suggest that aging of human spermatozoa in the female genital tract is associated with an increased frequency of spontaneous abortions.