Infection and Infertility
Infection is a multifactorial process, which can be induced by a virus, bacterium, or parasite. It may cause many diseases, including obesity, cancer, and infertility. In this chapter, we focus our attention on the association of infection and fertility alteration. Numerous studies have suggested that genetic polymorphisms influencing infection are associated with infertility. So we also review the genetic influence on infection and risk of infertility.
Part of the book: Genital Infections and Infertility
Environmental Factors and Male Infertility
A significant decrease in human fertility has been observed in the last 50 years. Approximately 15% of couples of reproductive age have fertility problems and about half of these cases are because of male factors. A growing body of evidence suggests that environmental factors play an important role in the causes of male infertility. Our environment is contaminated by natural and synthetic chemicals, which could interact with the endocrine system, resulting in the reduction of human fertility. Studies carried out in recent years have proven that endocrine-disrupting chemicals may disturb fertility of men. Improper lifestyle factors such as smoking, alcohol consumption, high temperature, radiation also have negative impact on male fertility. This chapter is an overview of recent developments about the importance of endocrine-disrupting chemicals and lifestyle factors’ effects on sperm counts and male fertility in human.
Part of the book: Spermatozoa
Oxytocin and Pregnancy
Oxytocin, an important neuropeptide, exerts a wide influence on the central nervous system and the peripheral tissues. In the central nervous system, the oxytocin gene expression is mainly shown to be present in neurons in the hypothalamic paraventricular and supraoptic nuclei. Oxytocin gene also transcribes in the peripheral tissues such as uterus, placenta, and amnion. Oxytocin receptors can be founded in many tissues in humans, like the uterine, ovary, testis, kidney, and so on. And just in the same tissue, due to the variation of physiology factors, the amount of oxytocin changes a lot. Oxytocin secretion is closely linked with pregnancy advancing. During labor, the contractions of uterine smooth muscles and oxytocin secretion are inseparable. Moreover, oxytocin is also responsible for stimulating milk ejection after parturition. Oxytocin is associated with many diseases. Poor regulation of oxytocin may cause postpartum depression and infantile autism. In terms of physiology, fatal heart failure and gestational hypertension are concerned with oxytocin level. In this chapter, we will discuss the oxytocin in pregnancy as well as its clinical applications.
Part of the book: Oxytocin and Health
Prenatal Diagnosis: The Main Advances in the Application of Identification of Biomarkers Based on Multi-Omics
Prenatal diagnosis is to make the diagnosis of fetal structural abnormalities, genetic diseases, and pregnancy-related diseases before birth thus could offer evidence for intrauterine treatment or selectively termination of pregnancy. Up to now, researchers have applied multi-omics, including genomics, transcriptomics, and proteomics, in the discovery of prenatal diagnostic biomarkers. They have found some candidate biomarkers for aneuploids, preeclampsia, intrauterine growth retardation, and congenital structural abnormalities. With the momentous progress of biomarkers’ identification based on multi-omics for prenatal diagnosis, noninvasive prenatal testing (NIPT) has experienced tremendous progress and is revolutionizing prenatal screening and diagnosis over the past few decades. Extensive studies have also demonstrated the value of biomarkers. In particular, cell-free DNA (cfDNA), allows for a definitive diagnosis in early pregnancy for fetal diseases, including Down syndrome and other common aneuploidies. The cfDNA can be extracted from maternal plasma, posing no risk of miscarriage compared to the traditional invasive diagnosis directly analyzing fetal cells from amniocentesis or chorionic villus sampling. In this review, we would discuss the main advances, strengths, and limitations in the application of biomarkers for prenatal diagnosis along with the analysis of several representative fetal diseases.
Part of the book: Ectopic Pregnancy and Prenatal Diagnosis
Advances in Epigenetic Mechanisms and Transgenerational Inheritance of Male Infertility Induced by Exposure to Endocrine-Disrupting Chemicals View all chapters
Male fertility has declined over the last few decades. Therefore, the increasing concern about the link between the environment and male reproductive health has been raised. Studies have found that the exposure to environmental toxicants during fetal development or the mother’s perinatal period promotes the occurrence of infertility in adult male offspring. Environmental toxicants, especially endocrine disrupting chemicals (EDCs), such as phthalic acid ester (PAEs), can induce changes in epigenetic information related to paternal infertility, threatening the reproductive, and developmental health of offspring. Transgenerational epigenetic inheritance refers to a genetic phenomenon that does not involve DNA sequences and affects the phenotypic characteristics of offspring by altering gene expression through DNA or RNA methylation, histone modification, noncoding RNAs, etc. This review describes the concept and phenotype of intergenerational and transgenerational inheritance induced by EDCs, summarizes the recent achievements of important epigenetic molecular mechanisms, and provides a relevant theoretical basis for the protection of male fertility.
Part of the book: Recent Advances in Male Reproductive System