Motility Parameters and Fertility
Claude Gagnon in Controls of Sperm Motility, 2020
Cervical mucus represents one of the first and most profound barriers that a spermatozoon must transcend on its route towards the human ovum. Analysis of the relationship between the movement characteristics of human spermatozoa and their capacity for cervical mucus penetration has been facilitated by the development of in vitro tests to quantify this aspect of human sperm function.2 In general, these tests involve the use of capillary tubes loaded with cervical mucus, one end of which is inserted into a liquified semen sample. After a defined period of incubation at 37°C, the number of spermatozoa penetrating the mucus is assessed. There is, as yet, no universally agreed means of calculating the outcome of such cervical mucus penetration assays, although a number of authors3,4 have used the formula introduced by Katz et al.2 This calculation depends upon a knowledge of the concentration of motile spermatozoa in semen in units of 106/ml (Cs), the concentration of spermatozoa in the mucus as the 106/ml (Cm), the length of the capillary tube in micrometers (1), the time of the incubation in seconds (t), and the mean path velocity of the cells (Vs). Insertion of these values into the following equation:
Biomechanical Factors In Fetal And Maternal Changes In Pregnancy And Labor
Sujoy K. Guba in Bioengineering in Reproductive Medicine, 2020
Cervix and the cervical mucus figure in many aspects of human reproduction. Character of the cervical mucus gives an indication of the fertile period. Consistency of the cervical mucus is closely related to the ability of the spermatozoa to penetrate the cervical mucus and pass on to the uterus proper. In pregnancy the character of the cervix changes and clinical assessment of the character is one of the diagnostic tests for pregnancy. In the continuation of pregnancy the cervix plays a major role and an incompetent cervix may lead to habitual abortion. In labor too, the cervical dilation is an important indicator of the progress of labor. Earlier it was thought that during labor the cervix plays a purely passive role of dilation under the forces exerted by the fetal presenting part. Now, concepts have changed and cervical characteristics are thought to be an important factor in the development of dystocia. Furthermore several gynecological procedures require the dilation of the cervix. In the past attention was directed primarily to the morphological characters of the cervix. Progressively it is being appreciated that the biomechanical factors are equally important. This realization has triggered research in the biomechanical characterization of the human cervix and the development of instrumentation to help in obtaining data for characterization.
Natural family planning methods: fertility awareness
Suzanne Everett in Handbook of Contraception and Sexual Health, 2020
The cervical mucus method involves a woman observing her cervical mucus every day. The mucus varies throughout the cycle. Following menstruation there is little cervical mucus and this is often described as ‘dry’. The level of the hormones oestrogen and progesterone are low, and the mucus is known as infertile mucus. There may be an absence of cervical mucus or it may appear sticky, and, if stretched between two fingers, will break. As the ovum begins to ripen increasing amounts of oestrogen are produced, causing an increase in cervical mucus. This marks the beginning of the fertile phase. Oestrogen levels continue to rise prior to ovulation and the cervical mucus increases in amount, becoming clear and stretchy; if held between two fingers it can stretch easily without breaking.
The effect of a levonorgestrel-releasing intrauterine device on female sexual function
Published in Journal of Obstetrics and Gynaecology, 2021
Gokce Turan, Pinar Yalcin Bahat, Berna Aslan Cetin, Nurullah Peker
The levonorgestrel-releasing intrauterine system (LNG-IUS) was first introduced in 1990 (Gemzell-Danielsson et al. 2013). The main indications of LNG-IUSs include contraception, treatment of heavy menstrual bleeding (HMB), endometriosis and endometrial protection during oestrogen replacement (Hurskainen et al. 2004; Philip et al. 2019). Hysterectomy and LNG-IUSs are the most effective treatment methods (Hurskainen et al. 2004). LNG-IUSs secrete low serum concentrations of levonorgestrel (LNG) (340–380 pmol/l) and are well tolerated (Cim et al. 2018). LNG-IUS creates local effects by secreting daily in the uterine cavity. With this local effect, cervical mucus becomes thickened and inhibits the mobility and activity of sperms (Zalel et al. 2003). In addition, it also stimulates the production of glycodelin A, which is a glycoprotein, from the endometrium, and prevents oocytes and sperm binding, which acts as a contraception effect (Shulman et al. 2004; McCarthy 2006). As well as the contraceptive effect, LNG-IUS causes significant decreases in the volume and duration of the menstrual bleeding because it suppresses the endometrial glands in the endometrium and has a protective effect on the endometrium. For this reason, there is also an increasing use in the treatment of HMB (Phillips 2003). Again, with a similar effect, it also relieves the symptoms of dysmenorrhoea. As well as contraception and HMB treatment, LNG-IUS has been approved for endometrial protection as the part of hormone therapy for menopause symptoms with LNG it releases (Sitruk-Ware and Inki 2005).
Prediction of male infertility by the World Health Organization laboratory manual for assessment of semen analysis: A systematic review
Published in Arab Journal of Urology, 2018
Amir S. Patel, Joon Yau Leong, Ranjith Ramasamy
Another absolute predictor for male infertility is the detection of globozoospermia on semen analysis. It is a rare but severe form of teratozoospermia, characterised by the presence of round-headed spermatozoa lacking an acrosome [42]. The acrosome contains the digestive enzyme, acrosin, which is essential for binding and penetration of the zona pellucida of the ovum. It also facilitates cervical mucus penetration and intrauterine sperm migration. It also participates in chromatin decondensation in the oocyte [43]. Considering these factors, we can understand how globozoospermic cells have difficulties adhering and fusing with the oocyte membrane, ultimately causing infertility. A microscopic image of globozoospermic spermatozoa can be seen in Fig. 2 [44].
The prevalence of cervical insufficiency in Chinese women with polycystic ovary syndrome undergone ART treatment accompanied with negative prognosis: a retrospective study
Published in Journal of Obstetrics and Gynaecology, 2021
Yaoqiu Wu, Meihong Cai, Xiaoyan Liang, Xing Yang
Cervical insufficiency (CI) is a major cause of late miscarriage and premature birth that affects 0.1–1.0% of all pregnancies (El-Nashar et al. 2013; Wang et al. 2016). CI is sometimes considered as a structural ‘weakness’ biochemically and biomechanically due to acquired or inherent cervical tissue defects or an outcome of asymptomatic second trimester pregnancy loss or premature birth; however, CI usually involves a combination of both types of pathological conditions (Vink and Feltovich 2016; Wang et al. 2016). The pathophysiology of CI is still poorly understood. Some authors postulated that localised cervical defects such as decreased cervical collagen concentration, elastic fibre content or increased smooth muscle cells (the ‘muscular cervix’) promoted the process of softening, effacement and dilatation during the pregnancy cause (Volozonoka et al. 2020). Premature cervical ripening (CR) is now the generally accepted cause of CI (Vink and Mourad 2017).
Related Knowledge Centers
- Diaphragm
- Egg Cell
- Sperm
- Uterine Cavity
- Vagina
- Uterus
- Pregnancy
- Female Reproductive System
- Cervical Canal
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