Gray R H
Department of Population Dynamics, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205.
Am J Obstet Gynecol. 1991 Dec;165(6 Pt 2):1982-4. doi: 10.1016/s0002-9378(11)90558-4.
Determining sex of offspring by timing of intercourse has been a subject of intense interest for the lay public and professional community. This metaaanalysis of couples practicing natural family planning provides an opportunity to evaluate sex ratios in relation to the timing of conception with several parameters, including basal body temperature shift and peak mucus as markers of ovulation. Data from six studies show a statistically significant lower proportion of male births among conceptions that occur during the most fertile time of the cycle.
通过性交时间来确定后代性别一直是普通大众和专业人士极为感兴趣的话题。这项针对采用自然计划生育的夫妇的荟萃分析，提供了一个机会，可利用包括基础体温变化和黏液峰值作为排卵标志等多个参数，来评估受孕时间与性别比例之间的关系。六项研究的数据显示，在月经周期最易受孕期间受孕的婴儿中，男婴出生比例在统计学上显著较低。
