Low Fertility Cohorts Study: The Low Fertility Cohorts Study, 1978: A Survey of White, Ever-Married Women Belonging to the 1901-1910 United States Birth Cohorts,Data Sharing For Demographic Research consists of personal interviews of white, ever-married women born between July 1, 1900, and June 30, 1910. In 1978, a national survey of 1,049 married women between the ages of 68 and 78 were interviewed between the months of March and July in order to investigate low fertility during the 1920s and 1930s and the women of childbearing age during those decades.Unexplained infertility: Unexplained infertility is infertility that is idiopathic in the sense that its cause remains unknown even after an infertility work-up, usually including semen analysis in the man and assessment of ovulation and fallopian tubes in the woman.merckmanuals > Unexplained Infertility Last full review/revision November 2008 by Robert W.Male infertilityReproductive toxicity: Reproductive toxicity is a hazard associated with some chemical substances, that they will interfere in some way with normal reproduction; such substances are called reprotoxic. It includes adverse effects on sexual function and fertility in adult males and females, as well as developmental toxicity in the offspring.Spermiogenesis: Spermiogenesis is the final stage of spermatogenesis, which sees the maturation of spermatids into mature, motile spermatozoa. The spermatid is more or less circular cell containing a nucleus, Golgi apparatus, centriole and mitochondria.Prenatal nutrition: Nutrition and weight management before and during :pregnancy has a profound effect on the development of infants. This is a rather critical time for healthy fetal development as infants rely heavily on maternal stores and nutrient for optimal growth and health outcome later in life.Isodemis: Isodemis is a genus of moths belonging to the subfamily Tortricinae of the family Tortricidae.Hyperactivation: Hyperactivation is a type of sperm motility. Hyperactivated sperm motility is characterised by a high amplitude, asymmetrical beating pattern of the sperm tail (flagellum).Sperm: Sperm is the male reproductive cell and is derived from the Greek word (σπέρμα) sperma (meaning "seed"). In the types of sexual reproduction known as anisogamy and its subtype oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell.Sexual motivation and hormones: Sexual motivation is influenced by hormones such as testosterone, estrogen, progesterone, oxytocin, and vasopressin. In most mammalian species, sex hormones control the ability to engage in sexual behaviours.Blood–testis barrier: The blood–testis barrier is a physical barrier between the blood vessels and the seminiferous tubules of the animal testes. The name "blood-testis barrier" is misleading in that it is not a blood-organ barrier in a strict sense, but is formed between Sertoli cells of the seminiferous tubule and as such isolates the further developed stages of germ cells from the blood.Semen quality: Semen quality is a measure of the ability of semen to accomplish fertilization. Thus, it is a measure of fertility in a man.Ovarian tissue cryopreservation: Ovarian tissue cryopreservation is cryopreservation of tissue of the ovary of a female.