Why You Should Re-Think Your Lube If You’re Trying To Get Pregnant

“Some lubricants can have a negative impact on a sperm’s morphology and motility—how sperm looks and how it moves, which can negatively impact a woman’s ability to get pregnant,” says Leah Millheiser, M.D., a clinical assistant professor in the department of obstetrics and gynecology and director of the Female Sexual Medicine Program at Stanford University Medical Center.

Related: 5 Surprising Factors That Affect How Fertile You Are

Take an oft-cited study in the journal Fertility and Sterility. It looked at the impact of various over-the-counter lubes on sperm function, finding that many popular products (including Astroglide and KY lubes) negatively impacted the life of sperm and how well sperm swam. Sesame oil also appeared to hamper fertility in the study.

Mostly, research blames high concentrations of toxic chemicals and pH levels that make it harder for sperm to get to where they need to go. (BTW, here are four ingredients that should never come close to your vagina.)

While these ingredients might not be true spermicides as the word is defined—Mary Jane Minkin, M.D., a clinical professor of obstetrics, gynecology, and reproductive sciences at Yale University notes that a spermicide kills sperm—she explains: “Most of the lubricants available today are indeed not sperm friendly.”

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Related: Khloe Kardashian Just Got More Bad News About Her Fertility—Here’s What It Means

The thing is, not everyone’s aware of that. Some research finds that while about 30 percent of couples who were trying to get pregnant knew not to use lubrication, about 26 percent still used it often or always (and 40 percent of those people used KY jelly and Astroglide—a big no-no).

(Naturallove USDA Organic Personal Lubricant is made without harsh chemicals—buy it now from the Women’s Health Boutique.)

So what’s the fix? Well, first, it’s important to remember that *anything* you put in your vagina has the possibility of throwing off sperm function, notes Millheiser.

But back to that study in Fertility and Sterility—it found that Pre-Seed, a fertility-friendly lube, as well as canola, mustard, and baby oil had no negative effect on sperm.

But, not so fast—Millheiser suggests sticking with either natural lubrication or Pre-Seed. Canola oil, for one, might not be harmful to sperm—but it’s not great to put in your vagina, either, she notes. “It may increase inflammation and increase your risk of yeast infection.” Not fun. (Here are seven other things you should never use as lube.)

Related: This 31-Weeks-Pregnant Reddit User Says No Doctors Will Take Her—Here’s Why

The bottom line: Lubes can be super effective at reducing discomfort during sex, yes—but if you’re truly trying to make a baby, consider what you’re putting down there, first.

Pre-Seed, for one, was specifically formulated as a lube for fertility. Says Millheiser: “There’s data to support the use of products like Pre-Seed and the avoidance of other products around the time of conception.”