Silverman E M, Silverman A G
JAMA. 1978 Oct 20;240(17):1875-7. doi: 10.103/00006450-09000-00010.
Cervicovaginal scrapings from 675 women who had volunteered information about the time of their last coitus and their contraceptive and douching practices were stained with Papanicoalaou stain and screened for spermatozoa. Generally, as the interval between coitus and preparation of the smears (postcoital interval) increased, the percentage of smears with spermatozoa and the mean number of spermatozoa per smear decreased, but the percentage of spermatozoa with tails did not change significantly. Spermatozoa were found irregularly after the seventh and rarely after the tenth postcoital day. Vaginal douching, pregnancy, use of oral contraceptives, coitus interruptus, condoms, and vasectomy were associated with reduced prevalence of spermatozoa in smears.
从675名自愿提供上次性交时间、避孕措施及阴道灌洗情况等信息的女性身上获取宫颈阴道刮片，用巴氏染色法染色并筛查精子。一般来说，随着性交与涂片制备之间的间隔时间（性交后间隔）增加，含有精子的涂片百分比以及每张涂片的精子平均数会下降，但有尾精子的百分比没有显著变化。在性交后第7天之后，精子出现情况不规则，在第10天之后则很少发现。阴道灌洗、怀孕、使用口服避孕药、体外射精、使用避孕套以及输精管切除术与涂片中精子出现率降低有关。
