How Long After Sex Does Conception Occur?

From Sex to Conception
Conception can occur while a couple is still curled up in bed after sex. Biggie Productions/Getty Images

There are close to equal numbers of sperm that contain either a male chromosome or a female chromosome. This determines the gender of the baby at the very point of egg fertilization. It will also play a role in the race to reach the egg. While male sperm aren't as hardy, they have a speed advantage. Though slower than their male counterparts, the advantage in longevity goes to female sperm.

But if they survive long enough to reach the fallopian tube, sperm cells can relax and enjoy a safe environment that's conducive to their continued survival. Some actually bind to the fallopian tube itself, as a means of receiving direct nourishment [source:].

When an egg enters the fallopian tube from the other end, it produces a scent that drives the sperm cells crazy. They become very excited and begin a process called capacitation, during which they shed certain proteins and become very excited. Both the shedding of proteins and the boost in mobility aid the sperm cell in its quest to penetrate the egg.

When a sperm cell finally makes contact with the egg, the head of the sperm releases enzymes that help it penetrate the egg's exterior. Once a sperm cell does, the two cells — the sperm and the egg — form a single-celled unit called a zygote, and the change prevents any other sperm cells from getting through [sources:, Suarez].

How long all of this takes can vary. The fastest sperm can get to a fallopian tube is about 30 minutes [source: WebMD.] But capacitation takes an estimated seven hours, so the sperm has to wait at least that long before it can penetrate an egg and begin the process of conception [sources: Reinisch and Beasley, Cleveland Clinic]. Once that happens, it takes about 24 hours for the sperm to finish fertilizing the egg [source: WebMD.]

Last editorial update on Mar 26, 2018 03:41:44 pm.

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More Great Links


  • Campbell, Denis. "'Wild, energetic sex is key to conception'." The Observer. March 22, 2009. (Feb. 7, 2018)
  • "The Great Sperm Race." (Feb. 7, 2018)
  • Cleveland Clinic. "Pregnancy: Ovulation, Conception & Getting Pregnant." (Feb. 7, 2018)
  • Dell'Amore, Christine. "How a Man Produces 1,500 Sperm a Second." National Geographic. Marcy 19, 2010. (Feb. 7, 2018)
  • Lindemann, Charles B., Ph.D. "Dr. Lindemann's Sperm Facts." Oakland University. (Feb. 7, 2018))
  • Mayo Clinic Staff. "How To Get Pregnant." (Feb. 7, 2018)
  • Mayo Foundation for Medical Education and Research. "Female fertility: Why lifestyle choices count." March 9, 2010. (Feb. 7, 2018)
  • Mayo Foundation for Medical Education and Research. "Getting Pregnant: Fertility." March 19, 2011. (Feb. 7, 2018)
  • Mayo Foundation for Medical Education and Research. "Healthy sperm: Improving your fertility." Dec. 16, 2010. (Feb. 7, 2018)
  • Mayo Foundation for Medical Education and Research. "Low Sperm Count: Diagnosis and Treatment." Dec. 7, 2017. (Feb. 7, 2018, )
  • Reinisch, June M. and Beasley, Ruth. "The Kinsey Institute New Report on Sex." St. Martin's Press. 1990. (Feb. 7, 2018)
  • Suarez, S.S. "Regulation of sperm storage and movement in the mammalian oviduct." International Journal of Developmental Biology. 2008. (Feb. 7, 2018)
  • Trost, Landon, M.D. "Abnormal Sperm Morphology: What Does It Mean?" Mayo Clinic. (Feb. 7, 2018)
  • Trost, Landon, M.D. "How Long Do Sperm Live After Ejaculation?" (Feb. 7, 2018)
  • University of Maryland Medical Center. "Fetal Development: Overview." Nov. 1, 2009. (Feb. 7, 2018) )
  • Von Radowitz, John. "'Daily sex for week boosts conception chance'." The Independent. June 30, 2009. (Feb. 7, 2018)
  • WebMD. "Conception Slideshow: From Egg to Embryo." March 30, 2010. (Feb. 7, 2018)
  • WebMD. "Pregnancy and Conception." 2010. (Feb. 7, 2018)