Obesity and Oral Contraceptive Failure
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. Furthermore, preliminary analysis suggested that a sub-group of obese women, defined by their own birth weight, are at higher risk of contraceptive failure. Further studies are necessary to investigate whether birth weight, a surrogate marker of in utero growth restriction, is a useful diagnostic marker for the identification of women prone to contraceptive failure. Such an understanding is critical to finding a contraceptive strategy with better efficacy for these women.
The overall goal of this project is to test pharmacokinetics of oral contraceptive agents in obese women with low birth weight and compare to obese women with normal birth weight. The main hypothesis for this proposal is that an adverse in utero environment programs the expression and function of enzymes and transporters that underlie pharmacokinetics of oral contraceptives, and leads to contraceptive failure.
Reproductive-aged, ovulatory women of obese BMI >30 kg/m2 with normal birth weight (5.5-8 lbs; n=10) and low birth weight (<5.5 lbs; n=10), will be placed on oral contraceptives for 1 month. At several key time points, synthetic steroid pharmacokinetics, gonadotropins (luteinizing hormone, follicle-stimulating hormone) and ovarian hormone levels (estradiol, progesterone) will be monitored.
|Contraception Fetal Growth Retardation Infant, Small for Gestational Age Obesity|
|Study Design:||Observational Model: Cohort
Time Perspective: Prospective
|Official Title:||Prenatal Growth Programs Oral Contraceptive Metabolism and Effectiveness|
- Measure pharmacokinetic parameters of oral contraceptives including drug clearance. [ Time Frame: on day 21 of oral contraceptive use ]Serum concentration-time data for each subject will be analyzed using a non-compartmental model assumption. Serum concentrations below the lower limit of quantitation (LLOQ) at the beginning and end of the profile will be set to zero. Serum concentration-time profiles will be summarized using descriptive statistics and graphical display. Student t-tests will be used to test whether the average values of each of the pharmacokinetic parameters, including free concentrations, differ between the four groups of women.
- Measure levels of gonadotropins and ovarian hormones [ Time Frame: Days 21-25 of oral contraceptive use ]To compare gonadotopin levels, average leutinizing hormone and follicle stimulating hormone levels measured for days 21-25 will be calculated. In addition, the follicle stimulating hormone/leutinizing hormone ratio will be calculated at each time point. The average levels of these measures will then be compared between the four groups of women using a student's t-test.
Biospecimen Retention: Samples With DNA
|Study Start Date:||August 2013|
|Estimated Study Completion Date:||December 2015|
|Primary Completion Date:||April 2015 (Final data collection date for primary outcome measure)|
|Low birth-weight, obese|
|Low birth-weight, normal body weight|
|Normal birth-weight, obese|
|Normal birth-weight, normal body weight|
Please refer to this study by its ClinicalTrials.gov identifier: NCT01944306
|United States, Oregon|
|Oregon Health & Science University|
|Portland, Oregon, United States, 97239|
|Principal Investigator:||Ganesh Cherala, PhD||Oregon Health and Science University|