Key Takeaways
- Women are only fertile for a short period in the cycle.
- The extended fertility window results from the fact that sperm can survive for several days in the vagina and wait there for the egg.
- In order to determine when unprotected intercourse should occur if pregnancy is desired, the exact survival time of sperm must be known.
The maturation of sperm takes much longer than the maturation of an egg cell. The development of sperm cells takes about ten weeks and begins in the testes. From there, they move into the epididymis, where they mature and remain until they are expelled through the ejaculate (semen), passing through the vas deferens and then the urethra. Depending on the man’s age and health, an average ejaculate contains between 20 and 150 million sperm.
For sperm to survive as long as possible in the woman’s* body, her cycle phase is crucial. During the fertile days, the vaginal pH level is about 7.5, which is alkaline – the best condition for fast-swimming sperm. On the non-fertile days, however, the vaginal pH is acidic, between 3.5 and 5.5. This causes the sperm to die quickly.
Do female and male sperm differ?
The lifespan of sperm carrying a female X chromosome and those carrying a male Y chromosome is different. Male sperm live shorter but swim faster, while female sperm live longer but move more slowly. Some studies claim that sex immediately before or at the time of ovulation increases the likelihood of conceiving a boy, whereas sex a few days before ovulation increases the likelihood of conceiving a girl. However, this is not certain—other studies suggest that male sperm may also live longer.
How long do sperm survive in the vagina?
Outside the body, sperm do not survive long. Inside the female body, under optimal conditions, they can remain viable for up to five days. The female egg cell, by contrast, is fertile for 24 hours after ovulation. Studies show that 80% of women* who have unprotected sex during their fertile days become pregnant within six months at the latest.
How long is the fertile phase in the cycle?
The Ovy App accounts for sperm survival time in its “Getting Pregnant” mode by extending the fertile window to six days. Ovulation occurs within this fertile phase. While ovulation itself only lasts for 24 hours, sperm can survive for up to five days. Ideally, both partners should know when the fertile days fall within the cycle. With the Ovy Partner App, your partner can directly see when your fertile days occur.
Medically Reviewed
This text was created by medical editors on the basis of specialist medical literature and current studies. Our aim is to work scientifically, identify sources and regularly check that the content is up to date.
References & Literature
- Facharztmagazine, Redaktion. "Spermienfreundliches Vaginalmilieu erhöht Empfängnischance." gynäkologie+ geburtshilfe 26.2 (2021): 56-56.
- Maake, C. (2005). 3 Biologische Grundlagen der Sexualität. Sexualberatung: eine Einführung für Ärzte, Psychotherapeuten und Familienberater; 14 Tabellen.
- Kliesch, Sabine. "Genitale: Nebenhoden und Samenleiter." Komplikationen in der Urologie. Springer, Berlin, Heidelberg, 2021. 263-270.
