Both the Swiss study and replicated versions have proven that women on hormonal birth control—those studied were all on the Pill, not localized hormonal options like the NuvaRing or IUDs—are attracted to the scent of men whose MHC genes are most similar to their own. In other words, men who are bad DNA matches. So what gives?

The Pill and other hormonal birth control prevent ovulation. This signals to a woman's body that she's pregnant, a state in which a woman is better off being around smells that indicate family—those with DNA similarity—for protection rather than scents with less DNA similarity, which indicate potential suitors. As Brown University professor and one of the world's leading scent researchers, Rachel Herz, puts it, "[The Pill] hormonally mimics a state of pregnancy and kin is better to be around during this vulnerable period."

While both scientists and lay persons have since surmised that this poses both fertility and compatibility risks for couples who meet while the woman is on hormonal birth control, tagging it as "the divorce pill" overstates the effect.

"I have seen female patients who are less attracted to their husband and facing fertility issues after going off the pill," says Dr. Diana Kirschner, a clinical psychologist whose been practicing for more than 25 years and the founder of Love in 90 Days workshops. "But there are a lot of other factors that contribute to the lack of desire."

Furthermore, as Herz points out, emotional attachment can beget scent attachment, even if the scent is that of cologne or deodorant.

"Axe commercials have a bonanza on their hands," she says. "For women, how a man smells is the most important factor in her sexual attraction after his level of pleasantness." While the Pill can't be blamed for divorce, its effects on scent and attraction are enough for DNA matchmaking sites like scientificmatch.com to turn down female clients who take it.

"DNA compatibility doesn't seem to influence how well we get along, how well we play chess or travel together," Herz says. But would she recommend a woman looking to find a reproductively compatible mate stay off hormonal birth control? Absolutely.

Rumor 3: Ugly Side Effects
Two American Heart Association-endorsed 2007 studies revealed that a woman's risk of heart disease increases 20 to 30 percent for every 10 years she takes birth control pills, which only strengthens doctors urgings that women—especially over the age of 35—not smoke while on the Pill. According to the National Cancer Institute, while the Pill's been proven to lower the risk of endometrial and ovarian cancers, there's a possible increased risk of breast cancer associated with it. As Dr. Blumberg says, patients are evaluated based on preexisting and pre-inclined conditions.