In most cases, yes, giving and receiving oral sex is safe during pregnancy. However, pregnant women should be careful if they decide to have oral sex, as there are some risks.

Air Embolism

Women who receive oral sex should warn their partners against blowing air into their vagina. Doing so can cause an air embolism – an air bubble – that can block a vein or artery, raising the woman’s risk for a heart attack or stroke. Air bubbles may also form in the placenta, which is dangerous for the fetus, who depends on the placenta for nourishment and oxygen.

Blowing into the vagina may also change air pressure, which can cause blood vessels to rupture.

Sexually-Transmitted Infections

Pregnant women should also be careful about contracting sexually-transmitted infections (STIs) during pregnancy. STIs – including HIV, HPV, herpes, gonorrhea, and chlamydia – can be transmitted during any type of sexual activity, including oral sex.

In some cases, STIs can be transmitted to the fetus, either through the placenta or through the birth canal during delivery. This can cause serious complications and health issues for the baby, including neurological problems, blindness, and blood infections. Stillbirth is another possibility.

Pregnant women can lower their risk for STIs by taking the following steps:

• Knowing their partner’s STI status. Partners should be tested. If a partner does have an STI, sex should be avoided.
• Using dental dams – pieces of latex or polyurethane that can act as a barrier. Dental dams are important while both giving and receiving oral sex. 
• Not receiving oral sex from someone with a cold sore. Cold sores are caused by the herpes virus.

Women who have questions about oral sex and pregnancy should speak to their doctor.

Resources

• American Pregnancy Association - “Oral Sex and Anal Sex During Pregnancy”
  (Updated: November 11, 2019)
  https://americanpregnancy.org/is-it-safe/oral-sex-anal-sex/
  
  
• Healthline.com - “Air Embolism”
  Kivi, Rose
  (Reviewed: August 15, 2017)
  https://www.healthline.com/health/air-embolism
  
  
• International Society for Sexual Medicine - “Can sexually-transmitted infections (STIs) pass to a fetus?”
  https://www.issm.info/sexual-health-qa/can-sexually-transmitted-infections-stis-pass-to-a-fetus/?ref_condition=sti-std
  
  
• “What is a dental dam? How is one used?”
  https://www.issm.info/sexual-health-qa/what-is-a-dental-dam-how-is-one-used/?ref_condition=female-sexual-health
  
  
• Mayo Clinic - “Placenta: How it works, what’s normal”
  (April 26, 2018)
  https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/placenta/art-20044425
  
  
• “Sex during pregnancy: What’s OK, what’s not”
  (July 10, 2018)
  https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/sex-during-pregnancy/art-20045318
  
  
• Parents.com - “Is Oral Sex Safe During Pregnancy?”
  Harris, Nicole
  https://www.parents.com/pregnancy/my-life/sex-relationship/is-oral-sex-safe-during-pregnancy/