According to the American Academy of Family Physicians, or AAFP, approximately 90 percent of pregnant women get stretch marks. This is one of the most common skin conditions that affect pregnant women, and many try to avoid getting these marks through the use of lotions containing cocoa butter.
Stretch marks, also known as striae gravidarum, can occur any time the skin needs to stretch rapidly. However, skin stretching alone isn't responsible for the marks, according to the AAFP, there are also hormonal factors involved. Many people believe that using cocoa butter to moisturize the skin will make it more supple and less likely to get stretch marks as the skin stretches over the expanding belly of a pregnant woman.
Two recently published studies indicate that cocoa butter does not prevent stretch marks. The first, led by H. Osman and published in 2008 in the "British Journal of Obstetrics and Gynaecology," assigned Lebanese women in their first pregnancies to use either cocoa butter lotion or a placebo starting in their first trimester. The results showed no difference between the groups in either prevalence or severity of stretch marks.
The second study, led by K. Buchanan and published in 2010 in the "International Journal of Gynaecology and Obstetrics," was a similar study conducted in Jamaica. It found that among Afro-Caribbean women younger women with larger babies were more likely to get stretch marks, and the cocoa butter group did not have any fewer incidences of stretch marks.
The Mayo Clinic states that although cocoa butter probably won't help to prevent stretch marks, it isn't likely to be harmful either. However, the Purdue University Center for New Crops and Plants Products notes that there have been some incidences of comedogenic and allergenic properties in animals.
Although cocoa butter might not help to prevent stretch marks in pregnant women, it is an effective lotion, so it can help to fight the dry skin and itching that occurs sometimes during pregnancy.
The Mayo Clinic notes that stretch marks really don't need any treatment. They will naturally fade over time, though they won't go away entirely. Those who really want to minimize the appearance of the stretch marks after pregnancy can try tretinoin cream or laser treatments, although these are usually only partially effective.