Use of hormonal contraception in adolescents: skeletal health issues

Effects of the etonogestrel contraceptive implant (Implanon®) on bone metabolism during lactation: a prospective study

AIM

To evaluate the effects of the etonogestrel contraceptive implant (Implanon^®) on bone metabolism in lactating women using markers for bone formation and resorption.

STUDY DESIGN

This single-centre, prospective cohort study was conducted in Turgut Ozal University Medical Faculty Obstetrics and Gynecology Department with healthy lactating women aged between 24 and 38 years to compare the effect on bone metabolism of 6 months' use of either the implant or a non-hormonal contraceptive method. The study group (n=25) used an implant and the control group (n=25) used a non-hormonal contraceptive intrauterine device inserted 40 days' postpartum. Bone metabolism differences at the time of insertion and after 6 months were assessed quantitatively by biochemical analysis of serum and urine samples.

RESULTS

At baseline, serum levels of bone metabolism parameters were similar for the two groups. In the implant group, serum alkaline phosphatase (ALP) levels decreased (p=0.004) and total protein levels increased (p=0.045) at 6 months. In the control group, serum levels of bone metabolism parameters did not change at 6 months compared to baseline. However, serum levels of phosphorus (p=0.013) and ALP (p=0.003) decreased at 6 months compared to baseline.

CONCLUSION

Six months' postpartum use of Implanon was found to have no deleterious impact on bone turnover in healthy lactating women.

Myths and misconceptions about long-acting reversible contraception (LARC)

PURPOSE

To discuss common myths and misconceptions about long-acting reversible contraception (LARC) among patients and health care providers.

METHODS

We address some of these common myths in an effort to provide clinicians with accurate information to discuss options with patients, parents, and referring providers. The list of myths was created through an informal survey of an online listserv of 200 family planning experts and from the experiences of the authors.

RESULTS

When presented with information about LARC, adolescents are more likely to request LARC and are satisfied with LARC. Clinicians have an important role in counseling about and providing LARC to their adolescent patients as well as supporting them in managing associated side effects.

CONCLUSIONS

This review article can be used as a resource for contraceptive counseling visits and for the continuing education of health professionals providing adolescent reproductive health care.

Teen pregnancy prevention on a LARC: an update on long-acting reversible contraception for the primary care provider

PURPOSE OF REVIEW

This update will highlight recent research and recommendations on long-acting reversible contraception (LARC) in the teen population, in order to make primary care providers more comfortable counseling on these methods in the medical home. LARC methods, which include intrauterine devices (IUDs) and subdermal hormonal implants, are used by only a small minority of sexually active teens, despite their endorsement by professional organizations as effective and well tolerated birth control options in this population.

RECENT FINDINGS

Recent studies show a lack of knowledge about LARC methods among young women, as well as persistent misconceptions among providers regarding who is eligible for LARC use. Existing trials of small numbers of adolescents generally show enthusiasm for its use among teens who are educated about LARC, high satisfaction rates among users of subdermal implants and IUDs, as well as varying pregnancy and continuation rates.

SUMMARY

The existing research on LARC shows promise for these methods in the teen population. However, larger trials are needed to establish accurate data on satisfaction, continuation, and failure rates, as well as to explore other barriers to use. Medical home providers should stay informed of research on LARC in order to improve contraceptive counseling to young women.

Combined oral contraceptives' influence on weight, body composition, height, and bone mineral density in girls younger than 18 years: a systematic review

OBJECTIVE

Combined oral contraceptives (COCs) are increasingly used by adolescents. The aim of this review is to investigate the evidence regarding COCs' influence on weight, height and bone mineral density (BMD) in girls younger than 18 years.

METHOD

Systematic literature search using PubMed/Medline and Scopus (January 1990-February 2012) on COCs for girls under 18 years of age and the possible influence on body parameters. MeSH terms: Oral contraception; Adolescent; Weight; Body composition; Height; Bone mineral density.

RESULTS

There is no evidence that COCs induce weight gain in girls younger than 18 years. Obese girls are not at higher risk of gaining weight. COCs do not cause changes in body fat and lean mass beyond the changes caused by natural development. Moreover, growth and stature are unaffected. Few studies indicate that COCs have a negative impact on BMD, but the evidence is presently too limited for definite conclusions.

CONCLUSION

Studies in young users are few. Presently, there are no indications of a negative impact of COCs on weight, body composition or height. Lesser increases in BMD cannot be excluded. As the demand for COCs is increasing among the youngest girls, there is a need for prospective studies addressing this issue.

Relative importance of body composition, osteoporosis-related behaviors, and parental income on bone speed of sound in adolescent females

INTRODUCTION

Adolescence provides a unique opportunity to employ strategies aimed at optimizing peak bone mass yet there are limited studies on the relationship between specific social constructs, osteoporosis-related behaviors, and bone health status in adolescent females. The purpose of this study was to examine associations between bone speed of sound (SOS) and body composition, osteoporosis-related health behaviors, and parental income in adolescent females.

METHODS

Four hundred forty-two female students in grades 9-12 from schools in Southern Ontario, Canada were measured for height, body mass, and percent body fat and completed a battery of instruments to assess osteoporosis-related health behaviors. Bone SOS was measured by transaxial quantitative ultrasound at the distal radius and midtibia.

RESULTS

Percent body fat was a negative correlate of tibial SOS. No significant correlation was found between physical activity and bone SOS yet physical activity was negatively related to adiposity. Hierarchical regression showed that age and percent body fat were the most important predictors of the variance in tibial SOS scores, with calcium intake having a weaker, yet significant, relationship. Age was the only statistically significant predictor of radial SOS. Users of oral contraceptives had higher radial SOS when controlling for age. Higher parental income was not associated with bone SOS but positive associations between parental income, daily calcium intake, and weekly physical activity were noted.

CONCLUSIONS

Bone SOS is reduced in adolescent females with increased adiposity, whereas it is positively influenced by oral contraceptives and daily calcium intake.