Role of Zinc (Zn) in Human Reproduction: A Journey from Initial Spermatogenesis to Childbirth.

Zinc (Zn), the second-most necessary trace element, is abundant in the human body. The human body lacks the capacity to store Zn; hence, the dietary intake of Zn is essential for various functions and metabolism. The uptake of Zn during its transport through the body is important for proper development of the three major accessory sex glands: the testis, epididymis, and prostate. It plays key roles in the initial stages of germ cell development and spermatogenesis, sperm cell development and maturation, ejaculation, liquefaction, the binding of spermatozoa and prostasomes, capacitation, and fertilization. The prostate releases more Zn into the seminal plasma during ejaculation, and it plays a significant role in sperm release and motility. During the maternal, labor, perinatal, and neonatal periods, the part of Zn is vital. The average dietary intake of Zn is in the range of 8-12 mg/day in developing countries during the maternal period. Globally, the dietary intake of Zn varies for pregnant and lactating mothers, but the average Zn intake is in the range of 9.6-11.2 mg/day. The absence of Zn and the consequences of this have been discussed using critical evidence. The events and functions of Zn related to successful fertilization have been summarized in detail. Briefly, our current review emphasizes the role of Zn at each stage of human reproduction, from the spermatogenesis process to childbirth. The role of Zn and its supplementation in in vitro fertilization (IVF) opens opportunities for future studies on reproductive biology.

Alleviation of Fertility Disorders Based on Probiotics Induced Immune System Improvement: A Review.

Infertility is a worldwide problem affecting a large percentage of the population. Several products and techniques have been adopted to alleviate infertility condition, but the most recent and promising result was obtained through supplementation of probiotics. Continuous research on probiotics opened up a previously unknown area of its role as a modern medicine in improving fertility. New research findings suggest a profertility effect of several probiotics strains through alleviation of various fertility based disorders and modulation of the immune system. The goal of this review is to cover all the major fertility based disorders, particularly highlighting the role of probiotics in improving fertility through alleviation of such fertility based disorders.

Comparing the effectiveness of infertility treatments by numbers needed to treat (NNT).

To compare the clinical efficiency of different modes of treatment of infertile couples and to estimate the possible benefit of nutraceutical food supplementation (NFS), the numbers needed to treat (NNT) was calculated in 4143 infertile couples based on controlled trials in recent literature and personal data. The NNT expresses the number of individuals who need to be treated to obtain one complementary pregnancy. In female infertility, the NNT of mild or moderate endometriosis was 8.4, and in anti-estrogens treatment of anovulation, it was 5.9. In tamoxifen treatment of idiopathic oligozoospermia, NNT was 3.9, and in antioxidant supplementation, it was 7.8. Treatment of varicocele yielded NNT of 6.3 and 6.8 after 1 year in multi- or single-centre trials, respectively, and NFS lowered the NNT after 3 months to 2.6. Adding NFS to the male partner increased the ongoing pregnancy rate by IVF with NNT of 8.3, and adding NFS to both partners reduced the NNT to 4.0. Although these results were obtained in heterogeneous trials and populations, it is suggested that the NNT should be useful for comparing the effectiveness of different modes of treatment of the infertile couple, and that complementary nutraceutical food supplementation may be beneficial.