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

Luckily, egg and sperm accept adult some pretty absurd tricks to give themselves a fighting chance. Read on to discover out how fertilization actually works.

What is fertilization?

fertilization and implantation medical illustration

Fertilization is when a human being's sperm combines with a woman's egg to form a single cell. It's one of the first steps toward pregnancy, simply there are more hurdles to cross.

Where does fertilization occur?

Some people retrieve fertilization happens in the uterus, since that'due south where the baby develops. However, fertilization actually occurs in the fallopian tubes.

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

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

Most of the time, implantation occurs in the uterus as it should. Yet, 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 you may have heard of it being called a tubal pregnancy), but it may also happen in an ovary, the cervix or fifty-fifty the abdomen.

Go on Reading Below

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

When does fertilization occur?

For fertilization to happen, the timing and conditions must be only right. The fertilization procedure can only occur during a fairly small window within just a few days of ovulation (a few days before up until a day subsequently you 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 issues that can hamper the process, the timing may be off, meaning the sperm arrived too early or too late to meet up with the egg. Or the sperm may take entered the wrong fallopian tube (an egg is unremarkably present in only one of the fallopian tubes in any given month).

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

Opposite to what many people believe, fertilization doesn't occur immediately afterward sex. The fastest sperm can achieve the egg in every bit lilliputian every bit an hr afterwards, but the entire fertilization procedure can have several hours. Later ejaculation, the sperm are gearing up for that long journeying.

For about a half an hr afterwards sex, the semen coagulates in a woman'southward vagina, forming a physical barrier that prevents the sperm from wandering very far in the wrong management. This protection disappears within thirty minutes, when the semen reliquefies.

Whatsoever sperm that oasis't made information technology upwards through the cervix by so are eliminated from the running. The vagina is very acidic and quickly destroys any errant cells, including sperm.

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

The cervical canal is a much more welcoming surroundings, where the mucus is peculiarly designed to transport sperm efficiently when you're most fertile.

Equally you arroyo ovulation, your suddenly copious fungus 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 also, as strings of molecules line upward like railroad train tracks so that sperm tin hop on and ride to their destination.

The sperm that do reach the egg still have their work cutting out for them. The race is on to be the first one to plow through the hard outer layer of the egg.

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

As soon every bit one lucky sperm cell succeeds in penetrating the egg, the egg immediately undergoes a chemical reaction that prevents other sperm cells from following suit. And then the chromosomes carried by the sperm and egg come together, and the egg is officially fertilized.

Can you experience when an egg gets fertilized?

You won't feel when an egg gets fertilized. You also won't feel pregnant after two or iii days. Merely some women tin feel implantation, the process in which the fertilized egg travels down the fallopian tube and buries itself deep within the wall of the uterus.

This happens about eight to 9 days after fertilization, though information technology can happen earlier or later, depending. Symptoms of implantation may include intestinal cramps and low-cal haemorrhage. Whether yous feel anything or non, implantation is the moment that fertilization gives way to pregnancy!

How long tin can sperm live within y'all to become significant?

Sperm can survive inside the female reproductive tract for nigh 72 hours. And, in some cases, the sperm can live for upwardly to v days. Just the lifespan of an egg is much shorter. The egg lives for only 12 to 24 hours later ovulation.

If sperm aren't hanging around by time the egg makes information technology to the fallopian tube (or if they don't achieve the destination soon afterward the egg arrives), the body reabsorbs the egg, and the window of opportunity for conception that calendar month closes.

As y'all've no doubt learned by at present, the route to fertilization is a bumpy ane, with enough of twists and turns. Information technology takes a lot of work, the right atmospheric condition and perfect timing for the egg and sperm to run into upwards and produce that baby y'all're hoping for. Simply once they do, you've embarked on your own astonishing journey: the journey of parenthood.