Does swallowing sperm really reduce the risk of recurring miscarriage?

Don't get too excited, there is a catch to the study.

Photo credit: Corey Motta on Unsplash
  • A new study finds a relationship between how often women gave their partners oral sex and the number of miscarriages they'd endured.
  • While it demonstrates correlation, the study does not prove causation.
  • The study will undoubtedly be the catalyst for further studies into this area.

A new study, published in Journal of Reproductive Immunology on March 27, suggests that woman who more frequently gave their partners oral sex, and swallowed the semen, were less likely to suffer recurring miscarriages.

Wait; what?

In the study, Dutch researchers compared the habits of 97 woman who have suffered recurrent miscarriage, defined as the loss of three or more consecutive pregnancies, to 137 women who did not. It was found that the woman who did not endure recurring miscarriages were performing markedly more oral sex on their partners than the members of the former group.

Of the women with recurring miscarriages, a little more than half reported giving oral sex. Nearly 75 percent of the other group reported doing so.

Now, this is all just correlation right now, and we all know that correlation does not prove causation. The scientists have yet to identify a mechanism that relates giving oral sex and having fewer miscarriages. It also relies entirely on self-reporting by a small number of test subjects.

At this point we don't know if the results aren't caused by other factors — suppose that woman who enjoy giving oral sex are just somehow inclined to have fewer miscarriages, for example. However, this study could be the basis for further investigation into the issue that does find something more tangible.

The authors of the study have speculated on what that mechanism might be. One idea is that exposure to the genetic material of their partners might be giving their immune system time to recognize it and reduce the chance it will see a fetus as foreign if it includes the same DNA. As they mentioned in their study, this notion isn't without precedent:

"A well-known route to induce immune tolerance is via oral exposure, possibly because the gut has the most adequate absorption in the absence of an inflammatory environment. In transplantation models of rats, oral administration of MHC molecules diminishes the occurrence of allograft rejection. In addition, Clark et al showed that direct seminal plasma antigen presentation to a mouse model of NK-cell mediated recurrent miscarriage may prevent the rejection of embryos. Koelman et al hypothesized that a potent way of inducing tolerance towards paternal HLA antigens of the fetus in pregnancy would be exposure of these antigens to oral mucosa. To support this theory, they showed that both oral sex and swallowing sperm reduced the incidence of preeclampsia."

The above excerpt references several other studies, including one that showed a connection between swallowing semen and a reduced rate of preeclampsia in expecting mothers.

The researchers conclude, "[Oral] exposure to seminal fluid seems to induce maternal tolerance to paternal antigens and therefore influence pregnancy outcome in a positive way."

The maternal immune system

Strange as it is to think, in a way a fetus is like a foreign object in the mother's body which the immune system would have an interest in. While the womb is supposed to be an immunologically privileged area, some studies have suggested that unexplainable miscarriages could be caused by an immune response to the fetus. RH disease and preeclampsia are examples of less severe reactions to an improper immune response.

While the idea of more oral sex as a practical solution to the problem of recurring miscarriage will undoubtedly interest quite a few people, the jury is still out.

A still from the film "We Became Fragments" by Luisa Conlon , Lacy Roberts and Hanna Miller, part of the Global Oneness Project library.

Photo: Luisa Conlon , Lacy Roberts and Hanna Miller / Global Oneness Project
Sponsored by Charles Koch Foundation
  • Stories are at the heart of learning, writes Cleary Vaughan-Lee, Executive Director for the Global Oneness Project. They have always challenged us to think beyond ourselves, expanding our experience and revealing deep truths.
  • Vaughan-Lee explains 6 ways that storytelling can foster empathy and deliver powerful learning experiences.
  • Global Oneness Project is a free library of stories—containing short documentaries, photo essays, and essays—that each contain a companion lesson plan and learning activities for students so they can expand their experience of the world.
Keep reading Show less

What the world will look like in the year 250,002,018

This is what the world will look like, 250 million years from now

On Pangaea Proxima, Lagos will be north of New York, and Cape Town close to Mexico City
Surprising Science

To us humans, the shape and location of oceans and continents seems fixed. But that's only because our lives are so short.

Keep reading Show less

Why we must teach students to solve big problems

The future of education and work will rely on teaching students deeper problem-solving skills.

Future of Learning
  • Asking kids 'What do you want to be when you grow up?' is a question that used to make sense, says Jaime Casap. But it not longer does; the nature of automation and artificial intelligence means future jobs are likely to shift and reform many times over.
  • Instead, educators should foster a culture of problem solving. Ask children: What problem do you want to solve? And what talents or passions do you have that can be the avenues by which you solve it?
  • "[T]he future of education starts on Monday and then Tuesday and then Wednesday and it's constant and consistent and it's always growing, always improving, and if we create that culture I think that would bring us a long way," Casap says.
Keep reading Show less

Allosaurus dabbled in cannibalism according to new fossil evidence

These Jurassic predators resorted to cannibalism when hit with hard times, according to a deliciously rare discovery.

Fig 3. Shed lateral tooth of Allosaurus sp. (MWC 5011) found at the Mygatt-Moore Quarry, white arrow indicates the distal denticles.

Stephanie K. Drumheller et.al
Surprising Science
  • Rare fossil evidence of dinosaur cannibalism among the Allosaurus has been discovered.
  • Scientists analyzed dinosaur bones found in the Mygatt-Moore Quarry in western Colorado, paying special attention to bite marks that were present on 2,368 of the bones.
  • It's likely that the predatory carnivore only ate their already-dead peers during times when resources were scarce.
Keep reading Show less
Scroll down to load more…