Contraceptive failure is the primary cause of unintended pregnancy in the United States. With obesity rates at epidemic proportions, any association between obesity and strategies that prevent undesired pregnancies constitutes a significant public health and economic concern. Evidence from recent epidemiological studies and our preliminary data (sub-therapeutic levels of steroid hormones due to drug clearance and half-life) suggest that obesity reduces oral contraceptive efficacy. Further studies are necessary to investigate whether these obesity related changes can be resolved. Such an understanding is critical to finding a contraceptive strategy with better efficacy for these women. The overall goal of this grant is to test several intervention strategies in order to reverse obesity-related pharmacokinetic differences in an effort to improve contraceptive efficacy for these women. The main hypothesis for this proposal is that increased Body Mass Index (BMI) alters oral contraceptive metabolism in a manner which results in inadequate hypothalamic-pituitary-ovarian axis suppression during oral contraceptive use in obese women. Reproductive-aged, ovulatory women of obese (BMI >30 kg/m2), will be placed on oral contraceptives for 2 months, then randomized into two intervention arms for an additional 2 months. At several key time points, synthetic steroid pharmacokinetics, gonadotropins (LH, FSH) and ovarian hormone levels (estradiol, progesterone), ovarian follicular activity by ultrasound monitoring, and cervical mucus testing will be monitored.

Public Health Relevance

Contraceptive failure is the primary cause of unintended pregnancy in the United States. With obesity rates at epidemic proportions, any association between obesity and strategies that prevent undesired pregnancies constitutes a significant public health and economic concern. Evidence from recent epidemiological studies suggests that obesity increases oral contraceptive failure resulting in unplanned pregnancies. Our preliminary data provide the rationale for testing several intervention strategies to provide greater contraceptive efficacy in obese women.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD061582-02
Application #
7937701
Study Section
Integrative and Clinical Endocrinology and Reproduction Study Section (ICER)
Program Officer
Kaufman, Steven
Project Start
2009-09-30
Project End
2012-08-31
Budget Start
2010-09-01
Budget End
2012-08-31
Support Year
2
Fiscal Year
2010
Total Cost
$460,240
Indirect Cost
Name
Oregon Health and Science University
Department
Obstetrics & Gynecology
Type
Schools of Medicine
DUNS #
096997515
City
Portland
State
OR
Country
United States
Zip Code
97239
Edelman, Alison B; Cherala, Ganesh; Munar, Myrna Y et al. (2014) Correcting oral contraceptive pharmacokinetic alterations due to obesity: a randomized controlled trial. Contraception 90:550-6
Edelman, Alison B; Cherala, Ganesh; Munar, Myrna Y et al. (2013) Prolonged monitoring of ethinyl estradiol and levonorgestrel levels confirms an altered pharmacokinetic profile in obese oral contraceptives users. Contraception 87:220-6
Edelman, Alison; Munar, Myrna; Elman, Miriam R et al. (2012) Effect of the ethinylestradiol/levonorgestrel combined oral contraceptive on the activity of cytochrome P4503A in obese women. Br J Clin Pharmacol 74:510-4
Edelman, Alison B; Jensen, Jeffrey T; Hennebold, Jon D (2010) A nonhormonal model for emergency contraception: prostaglandin synthesis inhibitor effects on luteal function and lifespan, a pilot study. Contraception 81:496-500