It is well known that cervical mucus restricts penetration of morphologically abnormal human sperm, both in vitro and in vivo. However, the mechanisms of such restriction are not well understood. Using videomicrography to simultaneously analyze the motions and morphology of individual human sperm, we analyzed differential penetration of normal and abnormal sperm into fresh human cervical mucus. Abnormal sperm swam slower in mucus than the normal sperm, but their flagellar beat parameters were not commensurately different. Multivariate statistical analysis of the relationship between individual sperm velocity and flagellar beat parameters indicated that the heads of the abnormal sperm experienced greater resistance from the mucus than did normal heads. Differential mucus resistance, more than altered motile vigor, appears to be responsible for the restriction of abnormal sperm during migration through mucus.
Katz, D. F., Morales, P., Samuels, S. J., & Overstreet, J. W. (1990). Mechanisms of filtration of morphologically abnormal human sperm by cervical mucus. Fertility and sterility, 54(3), 513-516.
Katz DF, Morales P, Samuels SJ, Overstreet JW. Mechanisms of filtration of morphologically abnormal human sperm by cervical mucus. Fertil Steril. 1990;54(3):513-516.
Katz, David F., et al. "Mechanisms of filtration of morphologically abnormal human sperm by cervical mucus." Fertility and sterility, vol. 54, no. 3, 1990, pp. 513-516.
Samples of semen and cervical mucus were provided by 18 couples. Cervical mucus was obtained for each day possible and stored at 4 degrees C until all the samples were collected. Flat capillary tubes were loaded with the mucous samples and spermatozoa from the husband's semen sample were allowed to migrate through the cervical mucus (3 cm column) into culture medium. The spermatozoa recovered after migration through cervical mucus were assayed in vitro with zona-free hamster oocytes. Control experiments were carried out using spermatozoa from the same semen sample but prepared by the swimming-up technique. Altogether, 557 eggs in the control group and 1236 eggs in the experimental group were analysed, and the results demonstrated that the % of sperm penetration, the mean number of sperm decondensations per penetrated egg and the mean number of spermatozoa adhering per egg all had higher values (P less than 0.05) for the control samples than for the experimental samples. We suggest that cervical mucus modifies human spermatozoa, as measured by their interaction with zona-free hamster oocytes.
The important role of cervical mucus from a reproduction standpoint is the transport and selection of spermatozoa. The study of the fertilizing ability of human spermatozoa by the use of zona-free hamster oocytes has shown that morphologically abnormal sperm can fuse with the zona-free hamster oocyte. The high proportion of morphologically abnormal spermatozoa present in human semen is significantly reduced after sperm migration through cervical mucus. The mucus, while a favorable environment for sperm survival, does not seem to contribute to the occurrence of sperm capacitation and acrosome reaction.
From January 1, 1968 to May 31, 1973, 100 patients received first kidney transplants from sibling donors. All recipients have been followed for at least two years and several as long as 7.5 years. One hundred per cent follow-up information is available. The absolute two-year patient survival is 85% and the absolute two-year kidney function survival is 76%. Patients with diabetes (especially males) have less success following transplantation than do patients without diabetes. When diabetic patients are excluded, older patients appear to do slightly less well than younger patients. Patients with phenotypically identical HL-A matches with the donor do better than patients without such matches. In the nondiabetic technically perfect transplant recepient, better than 90% long-term transplant function can be expectedwith no kidney losses after the first few months. In contrast, the less well-matched transplant demonstrated both an increased early rejection rate and a high rate of loss after the third to fifth year. Increasing doses of anti-lymphoblast globulin (ALG) had beneficial results in HL-A mismatched sibling transplants, but were slightly detrimental in phenotypically identical HL-A donor-recipient pairs because of an increased rate of infection. The results are compared with the results of transplants from other related donors and from cadavers performed during the same period.
Practice Committee of the American Society for Reproductive Medicine and Practice Committee of the Society for Reproductive Endocrinology and Infertility, 2026·Fertility and sterility
Luteal phase deficiency (LPD) is a clinical diagnosis associated with abnormal luteal phase length of ≤10 days. Potential etiologies of LPD include inadequate progesterone duration, inadequate progesterone levels, or endometrial progesterone resistance. Luteal phase deficiency has been described in association with medical conditions, but also in fertile, normally menstruating women. Although progesterone is important for the process of implantation and early embryonic development, LPD has not been proven to be an independent entity causing infertility or recurrent pregnancy loss. Controversy exists regarding the multiple proposed measures for diagnosing LPD, and assuming it can be diagnosed accurately, whether treatment improves outcomes. This document replaces the document of the same name, last published in 2021 (Fertil Steril 2021;115(6):1416-23).