CRC Handbook of Chemistry and Physics, 76th edition

Book reviewswell as endogenous factors such as obesity or hormonal disorders.A conception closely associated in time with ovulation has been suggested to result in more boys.5A high frequency of sexual intercourse should, according to this hypothesis, lead to a predominance of boys and a decline in the sex ratio according to age or parity could reflect a decline in sexual activity by age or a change in endogenous hormones over time.A low frequency could