title: Pooled analysis of two randomized, open-label studies comparing the effects of nomegestrol acetate/17β-estradiol and drospirenone/ethinyl estradiol on bleeding patterns in healthy women.
abstract: OBJECTIVE
  To obtain more precise and detailed information regarding the bleeding patterns of nomegestrol acetate (NOMAC)/17β-estradiol (E2) and drospirenone/ethinyl estradiol (DRSP/EE) and to identify whether baseline demographic characteristics were associated with unscheduled bleeding, absent scheduled bleeding, or amenorrhea.
  
  
  METHODS
  This analysis pooled results from two pivotal open-label, randomized trials that compared bleeding patterns of NOMAC/E2 and DRSP/EE. In the two studies 4317 women aged 18-50 years from 24 countries across the Americas, Europe, and Asia underwent treatment.
  
  
  RESULTS
  2835 women taking NOMAC/E2 (2.5 mg/1.5 mg) in a 24/4-day regimen and 938 women taking DRSP/EE (3 mg/30 μg) in a 21/7-day regimen had at least 1 evaluable cycle for vaginal bleeding analyses. The frequency of absent scheduled bleeding was higher (p<.0001) for women using NOMAC/E2 than DRSP/EE across all 11 cycles (cycles 2-12), ranging between 17.6% and 31.6% and between 3.4% and 5.8%, respectively. For women who had absent scheduled bleeding in cycles 2, 3, or 4 the incidence of absent scheduled bleeding in subsequent cycles was high and ranged between approximately 50%-60% for NOMAC/E2 and approximately 40%-50% for DRSP/EE. Amenorrhea increased over time with both regimens, being higher with NOMAC/E2. Both absent scheduled bleeding and amenorrhea with NOMAC/E2 were more common in older women, overweight women, switchers, and smokers; unscheduled bleeding was more common in starters, but had no association with age, body mass index, and smoking.
  
  
  CONCLUSIONS
  NOMAC/E2 is associated with a higher prevalence of absent scheduled bleeding compared with DRSP/EE. Absent scheduled bleeding and amenorrhea were associated with age, body weight, switching and smoking. Unscheduled bleeding was more common in starters.
  
  
  CONCLUSIONS
  Information about the factors associated with bleeding patterns may help clinicians provide guidance to women considering use of the NOMAC/E2 oral contraceptive.
authors.affiliation: Department of Sexual Health, New Croft Centre, Newcastle Hospitals, Community Health, Market Street (East), Newcastle upon Tyne, NE1 6ND, UK. Electronic address: dianamansour@nhs.net.
authors.forename: Diana
authors.initials: D
authors.lastname: Mansour
authors.affiliation: Department of Obstetrics and Gynecology, Columbia University, 630 West 168 St., New York, USA. Electronic address: clw3@cumc.columbia.edu.
authors.forename: Carolyn
authors.initials: C
authors.lastname: Westhoff
authors.affiliation: Merck & Co., Inc., Kenilworth, NJ 07065, USA. Electronic address: Uma_Kher@Merck.com.
authors.forename: Uma
authors.initials: U
authors.lastname: Kher
authors.affiliation: MSD Oss N.V., Oss, The Netherlands. Electronic address: tjeerd.korver@merck.com.
authors.forename: Tjeerd
authors.initials: T
authors.lastname: Korver
mesh_terms: D000293:Adolescent; D000328:Adult; D000568:Amenorrhea / Q000139:chemically induced* / Q000523:psychology; D000736:Androstenes / Q000009:adverse effects*; D003277:Contraceptives, Oral, Combined / Q000009:adverse effects*; D004958:Estradiol / Q000009:adverse effects*; D004967:Estrogens; D004997:Ethinyl Estradiol / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008535:Megestrol / Q000009:adverse effects*; D008597:Menstrual Cycle; D008796:Metrorrhagia / Q000139:chemically induced* / Q000523:psychology; D008875:Middle Aged; D009649:Norpregnadienes / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D000736:Androstenes; D003277:Contraceptives, Oral, Combined; D004967:Estrogens; D009649:Norpregnadienes; C534342:drospirenone and ethinyl estradiol combination; D004997:Ethinyl Estradiol; D004958:Estradiol; C038501:nomegestrol acetate; D008535:Megestrol
keywords: 17β-estradiol; Amenorrhea; Bleeding patterns; Nomegestrol acetate; Spotting; Withdrawal bleeding