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Oral sex is associated with reduced incidence of recurrent miscarriage (sciencedirect.com)
27 points by bitadder 2639 days ago
10 comments

Isn’t that just a correlation that they discovered? Aren’t there thousands of hidden variables that could explain this correlation without a causal relationship?

Isn’t that a pretty weak p Value ?

I just read the abstract and might have mis-interpreted it. But on a first glance this looks like an April fools joke.

Well this idea has been around for a while. I always foundit a bit iffy... like, human sperm is one of the most innocent things people get in their mouths/digestive tracts... so if that can influence your immune system (and making it less effective at that), what will eating some wild viruses-containing meat or bacteria-covered fruit do?!
We typically try it to render it inert by cooking and cutting out glands.

See, sperm contains hormone-like peptides, evolved for humans to react to. You do not generally eat concentrated amounts thereof. (At least didn't...)

I wonder about the causal link/s. Speculating, maybe less stressed/anxious/depressed and healthier people have more fun, better genes or have more resources to have better healthcare? Also, less stressed mothers seem inherently more likely to bring a child to term than a stressed mom-to-be because IIRC stress induces both labor or spontaneous abortion. Maybe there's a MHC or other immune component that leads to stronger attraction and/or healthier babies? There was a dating startup in the late 90's that promised to match people on MHC, but I'm not sure how far they got on that.... maybe AI/deep learning trained on a big enough SNPs samples and qualitative mutual attractiveness rating could tackle it these days.
There is some psychology to this. I mean someone that is already healthy is more likely to do a greater amount of sexual things. If you're sick you're not going to be as sexual. Also, being sickly more common or unwell should already put you on unsteady ground when carrying a baby.

Additionally, a woman who has had more intimate exposure to her husband is probably less likely to have negative reactions to a fetus which they have created, judging from basic adaptive immunology.

> OR 95%CI 0.25-0.97

Talk about a weak result! They're 95% confident that women with recurrent miscarriages are at least 3% less likely to perform oral sex.

While this is a very interesting finding, I suspect p-hacking. https://en.wikipedia.org/wiki/Data_dredging

Imagine the awkwardness when someone tries to get funding to confirm.

Data dredging is usually establishing a causation or pattern of two loosely correlated variables with no clear undesrstanding of why one have effects on the other. (correlation != causation).

In this particular case they seem to have a clear hypothesis on why there could be a strong link between one and the other: > "Oral sex might induce maternal tolerance towards paternal antigens of the fetus".

Anyway. This doesn't mean that this is a strong study. Just pointing out that at least they seem to have a theory on why oral sex can protect against miscarriages.

We don't know how many different things did they ask for on the survey? Maybe they had 100 different things that they were just spitballing might have some possible effect.
My friend and I were talking about the same thing.

"association became weaker" with a p=.21

doesn't matter - now that this has been reported it is fact
And increases chance of oral cancer...
Why is this downvoted? This is both absolutely true and incredibly important. It's literally a matter of life and death.

edit: If you are downvoting this as an emotional reaction to something you haven't considered before, please consider calming down and examining the evidence with a rational mind. Your health and that of the people you love are at risk.

First, hardly a matter of "life and death". It merely increases still very small odds.

Second, it's not oral sex that increases the odds, it's papillomavirus, which can be transmitted through oral sex (but also through other means of sex, including kissing).

You could have oral sex with someone that doesn't have the papillomavirus as often as you want, and you wouldn't get cancer from. In fact even sticking to a single oral partner (e.g. your spouse) reduces the (already small) odds heavily, even if you're not sure whether they have HPV or not.

I know that HPV causes it, not oral sex by itself, I just didn't elaborate enough.

It is true that vigorous kissing can maybe lead to HPV, but you have to get the virus to the mouth in the first place...

This is an overly simplistic, optimistic view of disease. Method of exposure matters significantly. Note how heterosexual couples virtually never have to worry about HIV, for example, if you're unfamiliar with this concept.
>Note how heterosexual couples virtually never have to worry about HIV, for example, if you're unfamiliar with this concept.

Yeah, that's not how HIV (or heterosexual couples) work...

I'm sorry, I do not understand what you're trying to imply.
> Note how heterosexual couples virtually never have to worry about HIV

I think you may be in for some bad news.

Please elaborate if you have the opportunity.

How many strictly heterosexual couples have been infected with HIV in the history of mankind? I'm aware there must be some due to IV drug abuse.

If you are worried about it get the Gardasil vaccine. It is 600$ in my country and I got it out of pocket because I think it's a great idea for anyone mildly active sexually.
Gardasil is only effective if you haven't been exposed to HPV yet, so excellent for young people, less effective in preventing cancer for older people.

It also doesn't prevent all strains of HPV.

Vaccination is recommended before one's first sexual encounter, which happens at a very young age for many people. I was a goner before I even knew about it. I don't want other people to suffer the same fate.

People should be making a bigger deal out of HPV, not dismissing it like elsewhere in this thread.

I agree that everybody should be vaccinated, but Gardasil only immunizes against a few strains of cancer-inducing HPV.
(Disclaimer: I'm not the author of this paper nor do I know them - I saw this on Twitter and found it an interesting if flawed read so I thought I'd share.)
This is junk science. Can’t believe it made it past the review process.
> via seminal fluid to oral mucosa

To these people, 'oral sex' seems to mean implicitly mean a female giving and a male receiving. Typical.

Title of the paper should probably have specified
It's quite obvious that that's what they're referring to. Article titles necessarily require brevity.

Anyway, flagged in 5, 4, 3, 2, ...

aren't you supposed to reject p-values under 0.05?
Why is this flagged? I feel HN has been deviating from its official charter in avoiding remotely controversial topics. This is a medical research article from a reputable journal. If we can't discuss something like this, I'm looking for a new forum.
It's obvious p-hacking. This study is crap.
That's a convenient excuse. I suspect the real issue is people don't want to see scholarship on female microchimerism regardless of quality.