 Reproductive-aged, ovulatory women of obese BMI 30 kgm2 with normal birth weight 5.5-8 lbs; n10 and low birth weight 5.5 lbs; n10, 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. 