While you release simply a single egg each calendar month, your partner releases millions of sperm in a single ejaculation — all with an middle on that single prize. Only simply i of those sperm will be crowned the victor, and the odds are stacked confronting fertilization.

Luckily, egg and sperm have developed some pretty cool tricks to requite themselves a fighting chance. Read on to notice out how fertilization actually works.

What is fertilization?

fertilization and implantation medical illustration

Fertilization is when a man's sperm combines with a woman'southward egg to grade a single cell. It's ane of the first steps toward pregnancy, but there are more than hurdles to cross.

Where does fertilization occur?

Some people think fertilization happens in the uterus, since that's where the baby develops. Notwithstanding, fertilization actually occurs in the fallopian tubes.

Each sperm has a unmarried goal: to meet up with the egg. To reach the target, though, a sperm cell has to continue a lengthy and strenuous journeying.

First, it must brand its way from the vagina to the cervix, and then it has to swim through the uterus to the fallopian tubes. Once there, if the sperm is the lucky one, it will penetrate the egg and fertilize it. The newly fertilized egg (now chosen a zygote) will brand its way from the fallopian tubes to the uterus. There, it volition hopefully implant in the uterine wall and grow into a baby.

Most of the time, implantation occurs in the uterus as information technology should. However, sometimes the fertilized egg implants and grows somewhere outside of the uterus. This is called an ectopic pregnancy.

Usually, an ectopic pregnancy occurs in a fallopian tube (which is why y'all may accept heard of information technology being called a tubal pregnancy), just it may also happen in an ovary, the cervix or even the abdomen.

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Since none of those areas has the right tissue or the infinite to arrange a growing pregnancy, an ectopic pregnancy is not a feasible pregnancy.

When does fertilization occur?

For fertilization to happen, the timing and weather must be just right. The fertilization process can only occur during a fairly small window within just a few days of ovulation (a few days before upward until a 24-hour interval after you lot ovulate).

Even if a sperm does make its way to the fallopian tube, that doesn't mean it will definitely be able to fertilize the egg. Aside from various fertility-related bug that can hamper the process, the timing may be off, meaning the sperm arrived as well early or too late to encounter up with the egg. Or the sperm may have entered the wrong fallopian tube (an egg is normally nowadays in only 1 of the fallopian tubes in any given calendar month).

How long does it have for a sperm to fertilize an egg?

Opposite to what many people believe, fertilization doesn't occur immediately later sex. The fastest sperm can reach the egg in every bit lilliputian as an hour after, but the entire fertilization process can accept several hours. Later ejaculation, the sperm are gearing up for that long journey.

For near a half an hour after sex activity, the semen coagulates in a adult female'southward vagina, forming a physical bulwark that prevents the sperm from wandering very far in the wrong direction. This protection disappears within 30 minutes, when the semen reliquefies.

Whatever sperm that haven't fabricated information technology up through the cervix past so are eliminated from the running. The vagina is very acidic and speedily destroys any errant cells, including sperm.

The sperm that make information technology to the next pace — the cervical culvert — spend time going through biochemical changes, picking up the tail-thrashing speed that's required for them to swim their mode through the uterus and fallopian tubes to find their target.

The cervical canal is a much more welcoming environment, where the mucus is particularly designed to send sperm efficiently when you lot're most fertile.

As you approach ovulation, your suddenly copious mucus becomes stretchy, clear and thin (that's one of the reasons why observing it is such an effective method of determining your ovulation time). The changes happen on a microscopic level likewise, as strings of molecules line upwards like railroad train tracks and then that sperm can hop on and ride to their destination.

The sperm that exercise achieve the egg nonetheless have their work cutting out for them. The race is on to exist the first one to plow through the difficult outer layer of the egg.

And there's plenty of competition. Hundreds of sperm will surround the egg during the frantic battle to the finish, all trying to penetrate the egg's membrane to reach the cytoplasm, where the sperm will then release its own genetic contribution.

Every bit soon as one lucky sperm jail cell succeeds in penetrating the egg, the egg immediately undergoes a chemical reaction that prevents other sperm cells from following suit. Then the chromosomes carried by the sperm and egg come up together, and the egg is officially fertilized.

Tin can you lot feel when an egg gets fertilized?

You won't feel when an egg gets fertilized. You lot also won't feel pregnant afterward two or three days. But some women tin can experience implantation, the procedure in which the fertilized egg travels downwards the fallopian tube and buries itself deep within the wall of the uterus.

This happens almost viii to nine days later fertilization, though information technology tin happen earlier or afterward, depending. Symptoms of implantation may include intestinal cramps and light haemorrhage. Whether you lot feel anything or not, implantation is the moment that fertilization gives way to pregnancy!

How long can sperm live within you to get pregnant?

Sperm tin can survive inside the female reproductive tract for nigh 72 hours. And, in some cases, the sperm tin can live for up to 5 days. But the lifespan of an egg is much shorter. The egg lives for merely 12 to 24 hours afterwards ovulation.

If sperm aren't hanging around past time the egg makes it to the fallopian tube (or if they don't reach the destination shortly after the egg arrives), the body reabsorbs the egg, and the window of opportunity for conception that month closes.

Every bit you've no doubt learned by now, the road to fertilization is a bumpy 1, with plenty of twists and turns. Information technology takes a lot of piece of work, the correct weather and perfect timing for the egg and sperm to see up and produce that baby y'all're hoping for. Simply once they do, you've embarked on your own amazing journey: the journey of parenthood.