2006
Refers to the rate of childbearing in a population.
Remains stable through age 30 at 400 pregnancies per 1000 exposed women per year and then decreases significantly.
By age 45 years fertility rate about 100 per 1000 exposed women per year.
The likelihood of pregnancy resulting in a healthy live birth decreases as women age, and this is particularly true after age 35.
Fertility rates in the US declined 2 percent from 60.3 to 59.1 births for 1000 women between 2017 and 2018 (CDC).
The fertility rate in the US declined from 70.9 births per thousand women in 1990 to 56.1 per 1000 in 2022.
The age at first birth has risen from 27 years in 1990 to 30 years in 2019 as more women postpone first birth.
Recently birth rate declined across all three of the largest racial and ethnic groups in the US.
Reasons for trends in declining fertility may include lack of a partner, economic insecurity, career aspirations, long working hours, child bearing discrimination, lack of pregnancy and postpartum support, and child care challenges.
As women age the likelihood of spontaneous conception decreases, whereas the risk of miscarriage and late obstetrical and perinatal complications increase.
Female fertility is very low for approximately a decade before menopause and is declining during the during the 30s.
Primary infertility is generally used to refer to a couple that hasn’t conceived a child after at least one year of trying.
Secondary infertility describes couples that have conceived at least once but aren’t able to again.
The measurement of circulating sex steroids and pituitary gonadotrophins allows assessment of ovulatory function and diagnosis of the main relevant disorders of the ovary.
Ovarian and pituitary hormones do not reflect the activity of the great majority of follicles within the ovary, whose growth is necessary to support ovulation and fertility.
Smaller follicles present in the ovary are determinants of reproductive lifespan and age at menopause.
Females have a fixed number of non-growing follicles in the ovary, with up to 7,000,000 at 20 weeks in utero, up to 2 million at birth, and several hundred thousand at menarche.
Only 12% of pre-birth ovarian non-growing follicles remain by age 30 and oocyte depletion accelerates in the late 20s and 30s, with the mean of 65,000 at 25 years, 16,000 by 35 years and approximately 1000 by menopause.
Decreased by female cigarette smoking, alcohol consumption of > 4 drinks per week and caffeine intake of > 250 mg daily.
Decreased with female body mass index of >27 kg/m2 or <17 kg/m2.
Men are fertile from puberty to at least the 9th decade, with some fertile into the 10th decade.
Spermatogenesis is active through the years of male fertility.
Male fertility declines with age.
Significant association between advancing paternal age and the risk of autism spectrum disorder in their children, with a 5.75 times higher likelihood for men over the age of 40 year or older compared to the offspring of men less than 30 years.
Risk of autism spectrum disease not associated with maternal age.
Older men more likely to father a child with schizophrenia so that men over the age of 40 years are more than twice as likely to have such a child than men in their 20’s.
Increasing paternal age associated with risk of having a Down syndrome child and paternal age is a factor in half the cases of Down syndrome when the maternal age exceeds age 35.
Rate of miscarriages increases with advancing paternal age when maternal age is older than 35 years.
Advancing paternal age alone as well as the combination effect of advancing paternal and maternal age increases risk of genetic abnormalities leading to diseases in their children and an increased miscarriage rate.
Men older than 35 years twice as likely the be infertile as men younger than 25 years.
Among couples treated with intrauterine insemination the amount of time necessary to achieve pregnancy increases significantly with the age of the male partner.
After controlling for maternal age, couples in which men are older than 35 years of age have a 50% lower pregnancy rate compared with couples in which men are 30 years old or younger.
Women are fertile during the 12 hours after the monthly discharge of an ovarian dominant follicle.
To treat vas deferens causes of male infertility, sperm can be harvested by testicular sperm extraction (TESE), microsurgical epididymal sperm aspiration (MESA), or other methods of collecting sperm cells directly from the testicle or epididymis.