Simpson J L, Gray R H, Perez A, Mena P, Barbato M, Castilla E E, Kambic R T, Pardo F, Tagliabue G, Stephenson W S, Bitto A, Li C, Jennings V H, Spieler J M, Queenan J T
Baylor College of Medicine, Houston, TX, USA.
Adv Contracept. 1997 Jun-Sep;13(2-3):201-14. doi: 10.1023/a:1006556022127.
Conceptions involving aging gametes are of relevance to natural family planning (NFP) because women using NFP to avoid pregnancy abstain from intercourse during the fertile time of the cycle. To help verify the safety of pregnancies occurring among NFP practitioners, our group has, since 1986, conducted a large cohort study involving six experienced NFP centers. Timing of conception was determined from NFP charts, in which women recorded days on which intercourse occurred. The number of days from the most probable conception intercourse to probable day of ovulation was first determined, and used as an estimate of the time gametes remained in the genital tract before fertilization. Several studies have already been completed, cohort as well as case-control in nature.
涉及衰老配子的受孕情况与自然计划生育（NFP）相关，因为使用NFP来避免怀孕的女性在月经周期的排卵期会避免性交。为了帮助验证自然计划生育实践者怀孕的安全性，自1986年以来，我们的团队开展了一项大型队列研究，涉及六个经验丰富的自然计划生育中心。受孕时间根据自然计划生育图表确定，女性在图表中记录性交发生的日期。首先确定从最可能受孕性交到可能排卵日的天数，并将其用作配子在受精前留在生殖道内时间的估计值。已经完成了几项研究，包括队列研究和病例对照研究。
