In Cameroon, the breast, one of the most conspicuous signs of a woman’s femininity, is a target for ritual mutilation. Breast ironing, a practice that involves flattening a young girl’s breasts with highly-heated stones, pestles, spatulas or coconut shells among other objects, is often carried out by an older female relative on a victim.

It is considered a human rights violation by the Friends of the United Nations Population Fund (UNPFA).

According to UNPFA, one out of every four girls in Cameroon has been affected by breast ironing, equating to nearly 4 million young women. Breast ironing is primarily practiced in the Christian and Animist south of Cameroon, and less frequently in the Muslim north, where only 10 percent of women are affected. It is also practiced in Guinea-Bissau, Chad, Togo, Benin, and Guinea among African countries.

As a 14-year-old girl, Chi Yvonne Leina, now 32, became a witness to this custom, which is practiced by all 200 ethnic tribes in Cameroon. She often went to her grandmother’s hut after school, which is located in the Northwest region of Cameroon, and usually heard the sounds of her cousins playing.

But one particular day, the hut was eerily quiet.

“[W]hen I approached the hut I heard my cousin crying inside,” Leina told theGrio. “I was curious, so I peeped through a small crack in the door.”

What Leina saw next would change her life forever. “I heard my cousin groaning and I saw my grandmother warming a small grinding stone. [G]randma was using that small stone, which she warmed on the fire, to press my cousin’s breast, and was pressing hard on the breast, and she was crying.”

That was Leina ’s first encounter with breast ironing. Although this practice can result in physical damage in addition to retarding developing breasts, many elders condone it. Mothers or close relatives of young girls who perform the practice believe breast ironing will deter sexual predators.

Those who carry out breast ironing hope to minimize young girls’ sexual activity, so they get an education and become financially independent. Teen pregnancy out of wedlock is on the rise in the region. Such a life event curtails any hope a young woman has of pursuing a lucrative career.

In its 2011 human rights report on Cameroon, the U.S. State Department explained the cultural motivation for stunting breast growth among adolescent girls. “The procedure was considered a way to delay a girl’s physical development, thus limiting the risk of sexual assault and teenage pregnancy,” the report states. “Girls as young as nine were subjected to the practice, which resulted in burns, deformities, and psychological problems.”

Yet, there is strong evidence that breast ironing does not achieve the desired goals. “Statistics confirm that in addition to being a human rights violation, the practice is ineffective in deterring pre-marital pregnancy,” according to a Friends of the UNPFA press release. “One-third of unwanted pregnancies occur between the ages of 13 and 25, with more than half falling pregnant after their first sexual encounter.”

For many women, including Leina’s cousin, the negative effects can be deep, long-lasting, and counterproductive to personal growth.

“All I know is she became suddenly a shy person, which she wasn’t before,” Leina said. “And she fell out of school and got pregnant some years after.”