R. Steward

University of Southern California, Los Ángeles, California, United States

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Publications (7)21.16 Total impact

  • Contraception 09/2014; 90(3):324-325. DOI:10.1016/j.contraception.2014.05.111 · 2.93 Impact Factor
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    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. STUDY DESIGN: 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.
    Contraception 12/2012; DOI:10.1016/j.contraception.2012.12.006 · 3.09 Impact Factor
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    ABSTRACT: BACKGROUND: Few studies have examined the action of combined oral contraceptives (COCs) on cervical mucus. We hypothesized that midcycle cervical mucus of women taking COCs is of poor quality when compared to their own midcycle mucus prior to initiating COCs. We sought to compare the effect upon quality and sperm penetration of the cervical mucus on the last hormone-free day with a 24/4 regimen to a 21/7 regimen. METHODS: This is an open-label, investigator-blinded, randomized, controlled, crossover equivalency study. All subjects received, in random order, 2 months of a 21/7 regimen and 2 months of a 24/4 regimen, each containing 20 mcg ethinyl estradiol and 1 mg norethindrone acetate. Analysis of cervical mucus quality (CMQ) and sperm penetration took place midcycle and on the last day of the hormone-free interval during the second month of each COC treatment. RESULTS: From April 2010 to November 2011, 18 subjects completed all study visits. Mean midcycle CMQ was poor (mean CMQ=1) and did not differ between 24/4 and 21/7 regimens (p=.92). On the last day of the pill-free interval, the quality and sperm penetration were poor with both regimens. CONCLUSION: This study indicates that thickening of cervical mucus is a major mechanism of contraceptive action of COCs and that both 21/7 and 24/4 regimens result in poor quality and impenetrable mucus on the last day of the pill-free interval.
    Contraception 06/2012; 86(6). DOI:10.1016/j.contraception.2012.05.004 · 3.09 Impact Factor
  • Contraception 03/2012; 85(3):328. DOI:10.1016/j.contraception.2011.11.062 · 3.09 Impact Factor
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    ABSTRACT: Many abortion providers use digoxin to induce fetal demise prior to dilation and evacuation (D&E). Our primary objective was to examine the frequency of infection and extramural delivery following digoxin use. We conducted a retrospective single-cohort study. Inclusion criteria were all women between 18 and 24 weeks of estimated gestational age who received digoxin in preparation for D&E at our outpatient facility. We queried two electronic databases to collect data on the frequency of extramural delivery and the rate of perioperative infection. From January 1, 2000, to December 31, 2008, 4906 abortions were performed between 18 and 24 weeks of estimated gestation with digoxin injection administered as feticidal agent 1 day prior to D&E. Extramural delivery frequency was 0.30%, and infection frequency was 0.04%. There were no significant differences in the frequency of extramural deliveries across procedure year (p = .2), estimated gestational age (p = .3), race/ethnicity (p = .2) or maternal age (p = .3). Rates of extramural delivery and infection are acceptably low following digoxin use prior to scheduled D&E.
    Contraception 02/2011; 85(2):150-4. DOI:10.1016/j.contraception.2011.01.005 · 3.09 Impact Factor
  • R. Steward, M. Gatter, D. Nucatola
    Contraception 08/2010; 82(2):184-184. DOI:10.1016/j.contraception.2010.04.029 · 2.93 Impact Factor
  • Contraception 08/2010; 82(2):202-202. DOI:10.1016/j.contraception.2010.04.097 · 2.93 Impact Factor