Getting pregnant requires healthy sperm to survive in the female vagina, travel to the uterus and fallopian tubes and fertilize an egg. A normal semen sample contains millions of sperm, but only one can successfully fertilise an egg.
The structure (morphology) of sperm is also important; normal sperm have oval heads and long tails that work together to propel them.
During sex
Despite popular misconception, it doesn’t take millions of healthy sperm to fertilize an egg. In fact, a fertile man releases about 15 million sperm per milliliter of semen, which is plenty to get pregnant. Nonetheless, some men have lower sperm counts and need more than others to get pregnant.
The number of sperm is important, but so is their movement and structure (morphology). Sperm must move to reach the egg located in the woman’s fallopian tubes. They also need to be shaped to fit through the narrow opening of the female cervix. If they aren’t able to do this, pregnancy won’t occur. Typically, sperm are shaped with oval heads and long tails to compete against other sperm for the egg.
If you want to increase your chances of conceiving, have sex every two to three days. Doing this throughout your partner’s menstrual cycle, and especially on the day you ovulate, increases your chances of getting pregnant even more. Having sex in the morning, when your partner wakes up and is most active, may also help. But don’t overdo it. Too much sex or masturbation can cause a lowering of your partner’s sperm count. It can also interfere with conception by causing vaginal infections, which reduces your chances of getting pregnant. In addition to sex, there are many other ways to improve fertility. These include avoiding smoking, alcohol and other toxins; using lubricants during sex; not having unprotected sex; and lying on your back for 20 minutes after sex to ensure the last sperm survives.
After sex
It takes just one sperm to impregnate an egg, but each time men ejaculate, they release millions of sperm cells. Of those, only the healthiest have the best chance of swimming to and fertilizing an egg. That’s why the quality of sperm counts and motility is so important for getting pregnant.
When sperm is discharged, it travels up the cervical mucus toward the fallopian tubes in search of an egg to fertilize. Fertility is improved if the semen contains at least 15 million sperm cells per milliliter. The number of sperm cells that are motile, or have the ability to swim, also improves pregnancy chances. This is determined by a sperm cell’s structure (morphology) and how well it moves.
Men can increase their sperm count and motility by eating a healthy diet, exercising regularly and taking multi-vitamins. Maintaining a healthy weight and avoiding smoking can also help. Some doctors advise abstaining from sex for a few days before ovulation, which increases the concentration of sperm cells in the semen and improves the chances of an immaculate egg.
A common belief is that lying on the back with your hips elevated after sex will enhance pregnancy rates by giving the sperm a better opportunity to swim to an egg. However, this is unfounded. Studies have found that sperm reaches the cervical canal within seconds of ejaculation, regardless of body position.
During the menstrual cycle
A few sperm are enough to get pregnant if they reach an egg and are fertilized. That’s why it’s important to have regular sex throughout your menstrual cycle: to increase the chances of that one lucky sperm making it to where it needs to go. But just how much sperm is needed to conceive?
The amount of sperm needed for pregnancy depends on several factors, including quantity and movement. To reach an egg, sperm must travel through the female cervix, uterus, and fallopian tubes. This requires a lot of wriggling and swimming, which is known as motility. The structure (morphology) of the sperm also plays a role. Typical sperm have oval heads and long tails that work together to propel them. More sperm with this shape are more likely to fertilize an egg.
As you approach ovulation, the lining of your womb starts to thicken in preparation for a fertilised egg. Your cervical mucus also changes, becoming slippery and stretchy to help any sperm swim through it. This happens around the day you start your period – known as ovulation.
If a sperm meets an egg and is fertilised, the fertilised egg attaches to the uterine lining and starts dividing. This process is called implantation and forms the basis for your baby’s DNA. Usually, only one fertilised egg makes it to the uterus – any other eggs are passed out of the body.
During pregnancy
It takes a single healthy sperm to fertilize an egg to cause pregnancy, but there are other factors that can also impact the chances of getting pregnant. These include a man’s semen count, the shape of the sperm (or morphology) and their ability to swim. The health of the cervix and fallopian tubes is another important factor, as well as the number of eggs in the woman’s ovaries.
The odds of becoming pregnant are higher if the amount of semen discharged in a single ejaculate is above the minimum level of 15 million sperm per milliliter. A higher sperm count means that more healthy sperm are available to reach an egg and fertilize it, and the sperm have a better chance of being fertilized by a healthy egg.
There are many reasons why sperm can’t reach an egg and fertilize it, such as poor motility or morphology or being lost along the way. However, the ‘finalists’ that make it to an egg may not need many of them to succeed as only one sperm is required to fertilise the egg [10].
It can be difficult to get a clear picture of the fertility process, especially for men. If you have questions about your sperm count, talk to a maternal child health nurse on 1800 882 436 or book a video call.
