Comparison of serum and cervical mucus hormone levels during hormone-free interval of 24/4 vs. 21/7 combined oral contraceptives.
Contraception
; 87(6): 732-7, 2013 Jun.
Article
in En
| MEDLINE
| ID: mdl-23352800
ABSTRACT
BACKGROUND:
This study analyzes levels of progesterone, estradiol, norethindrone (NET) and ethinyl estradiol (EE) in serum and levels of NET in cervical mucus on the last day of the hormone-free interval (HFI) in users of 24/4 [norethindrone acetate (NETA)/EE-24] vs. 21/7 (NETA/EE-21) regimens. STUDYDESIGN:
This was a randomized controlled, crossover, equivalency trial. Subjects were randomized to receive NETA/EE-24 or NETA/EE-21 for 2 months and then switched between study drugs. Blood and cervical mucus samples were obtained on Days 12-16 and on the last day of the HFI.RESULTS:
From April 2010 to November 2011, 32 subjects were enrolled with 18 subjects completing all study visits. There were no statistically significant differences in either day 12-16 (p=.54) or last hormone-free day (p=.33) cervical mucus NET concentrations between the regimens. On the last day of the HFI, median serum progesterone levels did not differ significantly; however, users of NETA/EE-24 had higher levels of serum NET (p<.001) and users of NETA/EE-21 had higher levels of serum estradiol (p=.01).CONCLUSION:
This data supports the fact that inhibition of the pituitary-ovarian axis occurs during oral contraceptive use and during the HFI. We demonstrated that a reduced HFI of 4 days resulted in better suppression of the ovarian hormone production, thereby reducing the risk of ovulation and potential contraceptive failure.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Ovary
/
Pituitary Gland
/
Progesterone
/
Cervix Mucus
/
Contraceptives, Oral, Combined
/
Contraceptives, Oral, Hormonal
/
Estradiol
Type of study:
Clinical_trials
Language:
En
Journal:
Contraception
Year:
2013
Document type:
Article