The Grapevine

Women Who Swallow Sperm Have Lower Miscarriage Risk, Study Reveals

Women who perform more oral sex on their male partners may have lower risk of having recurrent miscarriage, according to a new study highlighting how oral exposure to sperm could "influence pregnancy outcome in a positive way."

The findings, published in the Journal of Reproductive Immunology, backs previous research that suggested there are some paternal factors, especially semen, that can affect the female immune system before and after conception. 

The researchers from the Leiden University Medical Center in the Netherlands found that oral exposure to seminal fluid could induce maternal tolerance to paternal antigens, ScienceAlert reported Wednesday. The findings come from the analysis of the data of 97 women who had at least three consecutive miscarriages before the study and 137 women who never lost pregnancies. 

The Dutch team provided questionnaires asking the participants about their sexual activities with their male partners. Results showed that 56.9 percent of the miscarriage group reported having oral sex with their partners, while 72.9 percent of the non-miscarriage group had more oral sex.

"This matched case control study suggests that women with recurrent miscarriage had less oral sex compared to women with uneventful pregnancy," the researchers said in the study. "This is in line with the hypothesis that the gut has the most adequate absorption in the absence of an inflammatory environment, and seminal fluid contains soluble HLA antigens which can already induce maternal immune tolerance towards inherited paternal antigens of the fetus before implantation."

An earlier research suggested that swallowing sperm could reduce the occurrence of the pregnancy disorder preeclampsia. 

The latest findings did not provide a direct link between oral sex and the reduction in miscarriages. However, the researchers said seminal fluid potentially has some immunoregulatory factors, which could play an important role in creating maternal tolerance to protect fetus during pregnancy.

Such factors, including cytokines, hormones and soluble HLA antigens have been proven effective through vaginal exposure. 

The researchers noted a larger study is needed to confirm their findings and to provide the direct link between sperm exposure and lower risk of recurrent msicarriages.