It's something no one talks about, but it's embarrassing, awkward and LOUD!
Fanny farts. Or varts. Miff puff if you prefer. They seem to slip out with the most terrible timing. Right at that rare moment when every baby in the class stops squawking - your vagina lets out a loud, long raspberry.
Rest assured you are not alone! It happens to most new mothers. Your vagina is designed to expand and collapse, and a stretchy vagina is great news because it means your baby can slip out. In many yoga postures, particularly inversions, the vaginal canal opens and air rushes in to fill in the empty space.
The problem is that vaginas don't have a ring of muscles that you can squeeze to stop the air rushing back out again. If you feel a regular fart coming in a socially unacceptable situation you can squeeze your anal sphincter and hold it in. But vaginas don't have sphincters. When your vagina expands and lets in the air, the laws of physics require the air to come rushing out again as soon as the vagina is closed again. The solution is to prevent the air from entering your vagina in the first place.
It's particularly common after childbirth because of your more relaxed pelvic floor. Obviously, in the long term, regular exercise and a healthy diet will restore your pelvic floor, but that doesn't help if you want to go back to your yoga class again next week.
My guess is you've tried the obvious - engaging your pelvic floor muscles during yoga, also known as kegels. This is called moolah bandha in yoga, but surprisingly it only makes the situation worse as it sucks, even more, air into your vagina.
The trick is ashwini mudra, which is simply squeezing your anal sphincter, just like when you try to prevent a regular fart. It's the wrong hole, but it does work! The entire pelvic floor is like a sling of muscles all the way under your pelvis from the back to the front, and if you squeeze the whole muscle it will close the vagina from the inside, if that makes sense. Relax you butt cheeks - these muscles have nothing to do with ashwini mudra.
Keep your whole pelvic floor, including your anus, strong and engaged during the offensive postures. You have to do this before the air enters your vagina, and the anal muscles will help to prevent the vagina from opening so wide and sucking the air in in the first place. It can also help to keep your legs a little closer together.
It certainly won't do any harm if you practise this at home before venturing out in public again!
And make sure you see a women's health physiotherapist for a long term solution. They are miracle workers!