Weight gain is commonly cited as a side effect of the birth control pill, but a new study has found that the fear of gaining weight may be so strong for some women that it actually affects their contraceptive choices. Meanwhile, experts still can't definitively link hormonal birth control to weight gain.

The study determined that women who are overweight or obese are less likely to use the birth control pill and other hormonal contraceptive methods. As a result, they may be putting themselves at greater danger for unexpected pregnancy, and may even choose to forgo birth control completely. The reason for this preference gap: fear of weight gain.

"What we think may be happening is that women who are overweight and obese may be more likely to choose methods other than the pill or the shot because of fear of weight gain," Cynthia H. Chuang said in a recent statement. "As a result, they are choosing both more effective methods (LARCS) and less effective, non-prescription methods."

What’s more, of the women in the study who classified themselves as being overweight, only around 42 percent actually were based on their BMI.

Is there any backing to these women’s fear of weight gain? Well, that depends. According to WebMD, although hormonal birth control can lead to slight weight gain, this is very rare. In high amounts, estrogen can increase appetite which may lead to weight gain, but today’s birth control pills have such low levels of this hormone that the risk is very slight. A review of 44 studies showed no evidence of pill-related weight gain in most women, and any perceived weight gain was usually attributed to fluid retention, not fat gain, a temporary side effect of the pill that usually fades within two to three months.

Still, despite the evidence, the fear of weight gain has tangible and possibly detrimental effects on women.

Women may be worried about weight gain when they're making decisions about birth control, so clinicians need to be aware of that," added Chung. "It could be an opportunity to counsel women about LARCs ( long-acting reversible contraceptives), which are more effective forms of contraception."

Source: Bhuva K, Kraschnewski JL, Lehman EB, Chuang CH. Does body mass index or weight perception affect contraceptive use? Contraception. 2016

Read More:

Birth Control Apps Increase Access to Contraception, May Help Reduce Unplanned Pregnancies: Read Here

Birth Control Pill May Alter Woman's Brain Structure; Are There Real-World Consequences? Read Here