MENOPAUSE is a common stage in life. But it doesn’t have to be the end of a woman’s fertility.
Women’s fertility peaks between 20 and 24 years old. Then, a woman’s chance of pregnancy steadily declines through a process called perimenopause. It reaches its lowest point around the age of 51.
Ovulation
Ovulation is a monthly process that happens around halfway through the average 28-day menstrual cycle. During this time, one of your ovaries releases a mature egg that travels down the fallopian tube to be fertilized by sperm. If sperm fertilizes the egg, it will implant in the uterus, resulting in pregnancy. If the egg does not fertilize, it will eventually disintegrate and be reabsorbed by your body.
The 6 days leading up to and including ovulation are called the fertile window because it’s during this period that sexual activity can result in pregnancy. This is why it’s important to use condoms during this time.
Once an egg is released, sperm can fertilize it within 12 to 24 hours. After this, the egg can no longer be fertilized, so if you’re trying to get pregnant, it’s best to have sex in the day or two before ovulation.
The ovaries produce estrogen, which makes the environment in the vagina suitable for sperm survival. It’s also why women tend to ovulate in the middle of their menstrual cycles. This can change, however, during perimenopause and menopause. Decreased estrogen levels can make it harder for the ovaries to ovulate and produce an egg, while also making the vagina more acidic. This can reduce lubrication, which can lead to a lower sperm count and motility.
Testes
Each day, a man produces millions of sperm, the tiny cells that fertilize an egg during sexual intercourse. A few sperm might find and join with a woman’s egg released during ovulation, resulting in pregnancy. Men’s fertility declines gradually as they age, a process known as andropause. Testicular tissue mass decreases, and levels of the male sex hormone testosterone decrease as well. These changes are not necessarily permanent, though, and sperm production may increase again later in life.
The testicles are two egg-shaped organs contained in a pouch of skin called the scrotum that hangs behind the penis. Inside the testicles are Leydig cells that produce testosterone and tubes that form sperm. The scrotum maintains a lower temperature than the rest of the body to enable sperm production. The testes and scrotum are connected by a tube called the vas deferens, which transports and propels sperm during ejaculation. The vas deferens stretches about 18 inches from the testicles to the bladder, where semen is stored.
The shape of sperm can be affected by a variety of factors, including hormones and environmental conditions. Sperm is most likely to be shaped correctly when it is produced by a testicle that is a few degrees cooler than normal. When the testes are warm, they produce sperm with a different shape that is less likely to be able to fertilize an egg.
Uterus
The uterus, also called the womb, is a large organ that sits in your pelvic bones. It’s about the size of a fist and looks like an upside-down pear with two horn-like structures at the top (the fallopian tubes). The body of the uterus connects to the cervix, which opens into the vagina during pregnancy.
A moist mucous membrane lines the uterus. It becomes thicker during the menstrual cycle, reaching its highest thickness during ovulation. If an egg is fertilized, it attaches to the endometrium and receives nourishment from blood vessels that develop for this purpose. If the egg is unfertilized, the endometrium sheds and is expelled during menstrual bleeding.
The function of the uterus is to nurture the fertilized egg until it becomes a fetus and develops through birth. The uterus also helps maintain the structural integrity of the bladder, bowel and pelvic bones.
In men, the aging process that includes perimenopause and menopause causes changes in the testes, sperm production and the ability to get an erection. As a man gets older, his testicular tissue shrinks and the levels of the male sex hormone testosterone decline. These changes, however, are gradual and not as dramatic as they are in women. This is why men are still able to have children after they reach the age of 50, though it’s usually not recommended.
Sperm
Men are fertile nearly every day from the start of puberty, thanks to a surge in testosterone that triggers sperm production. A process called spermatogenesis produces sperm cell precursors, called spermatogonia, which undergo meiosis to reduce their number of chromosomes and then transform into spermatids. The spermatids then construct tails, or flagellums, to help them swim and fertilize eggs. This entire process, which is ongoing, takes a little over 72 days from start to finish. You can help speed the process up by keeping a healthy weight and getting plenty of exercise, which also helps your body produce antioxidants that are known to keep sperm cells healthy.
The tadpole-shaped sperm are found in a fluid called semen, which is made by glands in the penis and other male sex organs. Semen contains mature sperm and other fluids from the prostate, seminal vesicles and bulbourethral glands. This cocktail is a little like a sperm smoothie and provides the energy that sperm need to swim toward an egg and fertilize it.
Mature sperm, also called spermatozoa, have three parts: the head, middle and tail. The head contains a nucleus that is dense with DNA from 23 chromosomes. The neck and middle portion contain mitochondria, which supply the sperm with energy. The tail is a whiplike bundle of protein fibers that gives the sperm movement as it travels through the female reproductive tract to the egg for fertilization.
