Survival times for sperm and the ovum have been estimated to be 1.4 days and 0.7 days, respectively. Sperm would have a 5% probability of surviving more than 4.4 days and a 1% probability of surviving more than 6.8 days.
Ejaculated sperm remain viable for several days within the female reproductive tract. Fertilization is possible as long as the sperm remain alive — up to five days. Sperm can also be preserved for decades when semen is frozen.
Once the sperm have entered the uterus, contractions propel the sperm upward into the fallopian tubes. The first sperm enter the tubes minutes after ejaculation. The first sperm, however, are likely not the fertilizing sperm. Motile sperm can survive in the female reproductive tract for up to five days.
Lifespan depends on where sperm land after ejaculation. Sperm that make it into the vagina after ejaculation can live up to five days. This is due to the protective effects of cervical mucus and cervical crypts. But if sperm have a chance to dry out, they basically die.
Pregnancy is technically only possible if you have sex during the five days before ovulation or on the day of ovulation. But the most fertile days are the three days leading up to and including ovulation.
Survival times for sperm and the ovum have been estimated to be 1.4 days and 0.7 days, respectively. Sperm would have a 5% probability of surviving more than 4.4 days and a 1% probability of surviving more than 6.8 days.
In a cycle where ovulation occurs, recent estimates suggest the chances of conception are between 3% seven days before ovulation and 42% the day before ovulation. Estimates from other studies suggest peak chances of conception are a bit lower — closer to 38% according to some, or 20% according to others.
For fertilization to occur, sperm must reach the egg within a specific timeframe. Sperm can survive for up to 72 hours after ejaculation, but the egg can survive for no more than 24 hours after ovulation. If sperm reach the fallopian tube too early, they risk dying before the egg shows up.
The 5 days before ovulation, together with the day you ovulate, are the days when you are most likely to conceive. Sperm can live up to 5 days inside your body, so if you have sex up to 5 days before your egg is released, you can get pregnant.
Usually, the sperm reaches the egg within 15 to 45 minutes of ejaculation. However, the process could be much longer than that if you haven't ovulated yet by the time you have sex, because sperm can live inside a reproductive tract and wait for an egg for up to five days.
And since about 20 percent of patients will have embryos that reach the blastocyst stage only on day 7 instead of 5 or 6, this is important to know.
Sperm, on the other hand, can live for 3 to 5 days inside your body. There is a window of time known as the “fertile window” where pregnancy is possible during each month. An egg can be fertilized if you have sex anywhere from approximately five days before ovulation until the day of ovulation.
It's important to remember that sperm can sometimes survive in the body for up to 7 days after you have sex. This means it may be possible to get pregnant soon after your period finishes if you ovulate early, especially if you have a naturally short menstrual cycle.
Amount and concentration
When males ejaculate, they release on average around 100 million sperm. It only takes one sperm fertilizing an egg to conceive a child. Millions of sperm die on the journey to reach the egg.
Sperm that's been ejaculated into a woman can live inside the uterus for 5 days.
Since sperm can only live for a maximum of 5 days in the female reproductive tract, only a small number of sperm will even survive the long journey through the female reproductive tract. Therefore, couples trying to conceive should plan to have intercourse a number of times in the days just prior to ovulation.
Only 6 percent of the conceptions could be firmly attributed to fertilization by sperm three or more days old.
Sperm can live up to five days inside a woman's body. This is why even if intercourse happens five days before a woman ovulates, she has a chance to get pregnant because the sperm can remain alive all that time and fertilize the egg.
This is because sperm can live for around 5 days inside a woman's body, so if you've had sex in the days before ovulation, the sperm can 'wait' for the egg to be released. These days before and just after the egg is released is often called the 'fertile window'.
Only 1 in 14 million of the ejaculated sperm will reach the Fallopian tube, but once there the sperm should pick up chemical signals from the egg to help them find their way forward. The sperm finally near the egg and push towards its shell (called the zona pellucida).
You ovulate about 12 to 14 days before the start of a new menstrual cycle. Your fertile window is the five days leading up to ovulation, plus the day of ovulation and the day after ovulation — so about seven days in total.
Females are most fertile within a day or two of ovulation, which is when the ovaries release an egg. But, it is possible to get pregnant in the days leading up to ovulation, as sperm can survive for several days inside the female body.
If your menstrual cycle lasts 28 days and your period arrives like clockwork, it's likely that you'll ovulate on day 14. That's halfway through your cycle. Your fertile window begins on day 10. You're more likely to get pregnant if you have sex at least every other day between days 10 and 14 of a 28-day cycle.
Super fertility has been classified as a monthly fecundity (the ability to get pregnant) rate of 60% or greater. A regular menstrual cycle and high antral follicle count are signs of high fertility. Perimenopause, fibroids, and endometriosis can make conceiving and sustaining pregnancy more difficult.