Ecochard R, Cottinet D, Mathieu C, Rabilloud M, Czyba J C
Département d'Information Médicale, Hospices Civils de Lyon, France.
Int J Androl. 1999 Jun;22(3):163-72. doi: 10.1046/j.1365-2605.1999.00164.x.
We analysed 12,100 consecutive cycles of artificial insemination by donor spermatozoa in 1901 infertile couples. In our analysis, particular attention was given to finding an appropriate way of taking into account the respective effects of female and male factors on the pregnancy success rate and the level at which these factors act (cycle vs. woman and donation vs. donor). A total of 1213 pregnancies occurred. The pregnancy rate per cycle was lower as the age of the woman increased (p < 0.0001) and varied with the type of infertility: fecundity was higher (p = 0.03) in the case of azoospermia than of severe oligozoospermia. After taking into account these factors, significant unexplained variation in likelihood to conceive remained. A part of this heterogeneity was shown to be due to variation in fecundability between semen donors. In order to explain this heterogeneity between donors, compositional covariates were used, particularly the mean of results of the semen analysis performed for donations from the same donor. For each semen characteristic, the overall mean of the different donations of a donor was an important predictive factor of successful insemination: after taking into account all of the other factors, the odds ratios for an increase of 50 x 10(6)/mL spermatozoa, of a 20% increase in sperm motility and of a 2 point increase in the post-thaw quality index, were, respectively, 1.13, 1.37 and 1.56. After adjustment for these factors, the specific characteristics of each semen donation were no longer significantly predictive of successful insemination. This observation has a biological interpretation: sperm with low parameters but produced by a normally fertile man can have a satisfactory success rate.
我们分析了1901对不育夫妇连续12100个供精人工授精周期。在分析过程中，我们特别关注如何找到一种合适的方法，来综合考虑女性和男性因素对妊娠成功率的各自影响，以及这些因素发挥作用的层面（周期与女性、捐赠与供体）。总共发生了1213次妊娠。随着女性年龄的增加，每个周期的妊娠率降低（p<0.0001），并且因不育类型而异：无精子症患者的受孕能力高于严重少精子症患者（p=0.03）。在考虑这些因素之后，受孕可能性仍存在显著的无法解释的差异。结果表明，这种异质性部分归因于精液供体之间生育力的差异。为了解释供体之间的这种异质性，我们使用了构成协变量，特别是对来自同一供体的捐赠精液分析结果的均值。对于每个精液特征，供体不同捐赠的总体均值是人工授精成功的一个重要预测因素：在考虑所有其他因素后，精子浓度每增加50×10⁶/mL、精子活力增加20%、解冻后质量指数增加2个点的优势比分别为1.13、1.37和1.56。在对这些因素进行调整后，每次精液捐赠的具体特征不再是人工授精成功的显著预测因素。这一观察结果具有生物学解释：参数较低但由正常生育男性产生的精子也可具有令人满意的成功率。
