Some Hormonal Contraceptives May Impact Childrens’ Bone Health, Case Study Warns

New research suggests hormonal methods of birth control may have a negative impact on the bone health of young girls, leading to lowered bone mass and an increased risk of bone fractures and osteoporosis that may extended long into adulthood.

Overall, most types of hormonal contraceptives are thought to be safe for bone health. However, this is the first extensive research conducted to look into the effects of various birth control methods, such as shots, pills and implants, on the ability of teens to reach their genetically determined peak bone mass.

In a study published this month in the Contemporary OB/GYN Journal, researchers warn teen use of hormonal birth control like DepoProvera or Implanon may reduce bone mass during adolescence, increasing the risk of bone fractures and osteoporosis.

Researchers conducted an analysis of literature that focused on hormonal birth control and adolescent bone density.

The study also highlighted a case report involving a 14-year-old girl with heavy periods, dysmenorrhea, and acne. She began her period at 12 years old, but has heavy bothersome periods. Her medical history includes two traumatic lifetime fractures to the upper body and she is lactose intolerant, which can also play a factor in the inability to reach peak bone density. Her mother also has painful periods and was diagnosed with osteopenia, a condition marked by weaker than normal bones.

Birth Control Bone Risks

Many patients ask about the side effect of contraceptive use on fertility and potential cancer risks, but few ask about how it may affect bone density, which could be a key factor health factor for adolescent users.

Roughly, 40-60% of adult bone mass is accrued in adolescence. Having just a 10% increase in bone mass during adolescence can reduce adult fracture risk by 50%, making optimal bone mass during adolescent years is important.

Depot medroxyprogesterone acetate (DMPA), also sold as the DepoProvera contraceptive shot, is the only hormonal contraceptive agent with a black box warning about the potential bone risks.

Prior studies demonstrate DMPA use can lead to bone loss during use by causing the body to favor bone resorption instead of bone formation. The research indicates that side effects of DepoProvera may negatively impact adolescent bone health and may not be a suitable choice for teens seeking birth control.

The researchers also found evidence that the hormonal birth control implants Implanon and Jadelle also reduce bone mass over 18 months of use during adolescence.

Other research focusing on the Norplant implant indicates the estrogen levels are not affected much. Similarly, hormonal IUDs like Mirena do not suppress estrogen production to effect bone mass.

However, the research is unclear if progestin-only birth control pills would affect bone mass. Those birth control methods are understudied in teens. Combined hormonal contraceptives, with greater than 30 mg of ethinyl estradiol, appear to support bone health better than low-dose pills, the researchers found.

Bone Health Should Be Addressed Early in Life

Medicare costs in the U.S. related to adult osteoporosis and bone fractures exceed $50 billion annually, including indirect costs such as productivity loss and caregiving. It is important that bone health and bone mass are considered early in adolescence, not just later in adulthood.

In addition to recommending contraceptives that don’t affect bone health, researchers said doctors should recommend teens do strength training, avoid substance abuse, and eat a well-balanced diet to optimize bone health.

“Optimizing child and adolescent bone health can reduce morbidity and mortality associated with adult osteoporosis, so considering and discussing bone health with adolescents is essential,” the researchers wrote. “Unfortunately, it is challenging to fully understanding the impacts of all available hormonal contraceptives on adolescent bone health given inherent limitations in research to date.”