It is very unlikely that a woman will get pregnant from oral sex. Pregnancy can only occur if semen comes into contact with an egg. Swallowing semen will, therefore, not result in pregnancy under normal circumstances.
The digestive system does not connect to the reproductive system. Therefore, swallowed semen cannot enter the vagina, uterus, or any other reproductive organ that would allow sperm to fertilize an egg.
However, combining oral sex with other sexual activities that bring the semen into contact with the vagina may result in pregnancy.
In this article, we look at why oral sex cannot directly lead to pregnancy, what other sexual acts are unlikely to lead to pregnancy, and those that can. We also explain how to practice safer sex and debunk other common sex myths.
When a person swallows semen, it follows the same path through the digestive system as anything else that a person eats or drinks. This route does not offer a way to the reproductive organs and will not result in pregnancy.
Swallowed semen does not come into contact with the vagina, and by the time women urinate or have a bowel movement containing the remnants of the semen, it is impossible for it to get them pregnant.
Women can only get pregnant from penile-vaginal contact when semen enters the vagina or another reproductive organ.
Therefore, women who swallow semen and then have intercourse can get pregnant. If they do not swallow the semen, they should dispose of it in an appropriate manner. Any accidental contact between semen and the vagina may result in pregnancy.
As with many other biological facts, there are unusual exceptions to this rule involving people who suffer significant trauma or have atypical anatomy. However, these examples are extremely rare.
A 1988 case study details the story of a 15-year-old girl who did not have a functioning vagina and was unable to have intercourse. She performed oral sex on a man, and a resulting fight with an ex-partner led to her receiving a stab wound in the abdomen.
After complaints of pain in the lower abdomen, she gave birth to a baby via cesarean delivery 9 months later.
The study’s author suspects that the knife wound damaged the gastrointestinal tract and allowed swallowed semen to fertilize an egg, enabling the girl to become pregnant. However, for women who do not experience such trauma, semen cannot fertilize an egg solely from oral sex.
Healthy semen contains millions of sperm, which are tiny reproductive cells that can swim to an egg. If a sperm fertilizes the egg, the egg then travels to the uterus to attempt to embed itself in the uterine lining. This process, called implantation, begins a pregnancy.
Not all implantation attempts are successful. To successfully produce a pregnancy, sperm must fertilize an egg, and the egg must implant in the uterus.
Sexual contact must take place around the time of ovulation if it is to result in pregnancy. While women can ovulate at any point during their cycle, ovulation typically occurs around the midpoint. Women with regular cycles can usually pinpoint ovulation by taking ovulation tests, using counting methods, and looking for signs of fertility.
For pregnancy to occur, the sperm must have a viable path to the egg, which requires contact with the vagina. The overwhelming majority of women who get pregnant do so from unprotected sexual intercourse. However, it is possible to get pregnant from other forms of contact, such as:
- sexual intercourse where birth control fails
- manual sexual contact (fingering), if a person touches the vagina after touching semen
- anal sex, when semen gets near the vagina
- oral sex, if a partner has semen in their mouth and then makes contact with the vagina
While the withdrawal method — pulling out before ejaculation — decreases the risk of pregnancy, it is not very effective and may result in pregnancy.
Any type of sexual contact can result in pregnancy if semen comes into contact with the vagina. However, some sex acts that are much less likely to cause pregnancy include:
- oral sex, if neither partner has semen in or on their mouth or hands when making contact with the vagina
- anal sex, especially with a condom or other barrier method
- manual sex with clean hands that have not touched semen
- vaginal sex when using appropriate birth control methods
No sex is completely safe. Barrier methods fail, and contraceptives such as oral birth control cannot prevent sexually transmitted infections (STIs).
People can reduce the chances of pregnancy and infection by using a barrier method, such as a condom, along with a backup method, such as an intrauterine device (IUD) or hormonal birth control. People who wish to reduce their risk further can:
- Consider abstinence or outercourse, which is sex that does not involve vaginal penetration. People may try oral sex, manual stimulation, mutual masturbation, or phone sex.
- Use a barrier method, such as a condom or dental dam, when engaging in oral sex.
- Ask a doctor about frequent testing for STIs.
- Have as few partners as possible.
Any contact between the penis and vagina can cause a pregnancy, but certain strategies can reduce the risk. These include:
- Monitoring fertility signs: These can help people pinpoint the time of likely ovulation and avoid sex at fertile times. Women may be fertile when they have thick, watery cervical fluid, get a positive ovulation test result, and are near the middle of their cycle. People can use apps to track fertility.
- Tracking menstrual periods: If periods are regular, a woman is not typically fertile during, right before, and right after her period. Apps are available to help track periods.
- Using birth control methods: Condoms, birth control pills, and IUDs can prevent pregnancy with correct use. For the best results, people should use a backup method. For example, they can use a condom that contains spermicide.
Some other common misconceptions regarding sexual health may include:
Can you clean the vagina after sex to prevent pregnancy?
No. There is no scientifically proven way to remove semen once it has entered the vagina.
Does standing during or after sex prevent pregnancy?
No. There is no proven way to remove semen once it has entered the vagina, and gravity does not prevent sperm from fertilizing an egg. Scientists have also not proven that any specific position during sex increases the likelihood of pregnancy.
Is it better to use two condoms at once, instead of one?
No. Using two condoms at once offers less protection because they can cause friction that weakens the material. As a result, the condoms may be more likely to break, which could result in an unplanned pregnancy or an STI.
Can masturbating before sex prevent pregnancy?
No. According to Planned Parenthood, masturbating does not lower sperm count. Therefore, it is not an effective way to prevent pregnancy.
Does the birth control pill start working immediately?
No. It can take up to 7 days after a woman starts taking birth control pills for them to be effective. People should still use backup birth control methods, such as condoms, as this not only further prevents pregnancy but also protects against STIs.
Performing oral sex and swallowing semen may increase the risk of certain infections, such as STIs. In normal circumstances, however, it will not cause a pregnancy.
No form of sex is without risk. People can practice safer sex by using birth control methods, such as condoms.
Anyone who is concerned about the risks of oral sex or needs help avoiding pregnancy should consult a doctor, midwife, or family planning clinic.