title: Delayed first injection of the once-a-month injectable contraceptive containing 25 mg medroxyprogesterone acetate and 5 mg estradiol-cypionate: effects on cervical mucus.
abstract: The objectives of this study were to assess whether women who were administered the first injection of the once-a-month contraceptive containing estradiol cypionate and 25 mg depot-medroxyprogesterone acetate (MPA+E(2)C) on Day 7 of their menstrual cycle (delayed injection) exhibit the same degree of cervical mucus changes as women who receive it on Day 5 of their menstrual cycle. This was a multicenter, randomized, controlled clinical trial. A total of 158 women, aged between 18 and 38 years (inclusive), who, were willing to use MPA+E(2)C as their contraceptive method participated in the trial. Participants received a MPA+E(2)C injection on Day 5 (control group, n = 41) or Day 7 (delayed-injection group, n = 117) of their menstrual cycle. Participants who received MPA+E(2)C on Day 5 of their menstrual cycle (control group) exhibited fair or poor mucus quality and poor sperm penetration. Of those women who received MPA+E(2)C on Day 7 of their menstrual cycle (delayed-injection group), 3 (3%) showed good mucus or good sperm penetration at some time point during follow-up. It is possible to conclude that the first injection of MPA+E(2)C given on Day 7 of a menstrual cycle does not provide the same degree of inhibition of mucus quality and sperm penetration as that observed if it is administered on Day 5. However, the theoretical risk of pregnancy after receiving MPA+E(2)C on Day 7 would be expected to be low.
authors.affiliation: Department of Obstetrics and Gynecology, Universidade Estadual de Campinas, Campinas, Brazil
authors.forename: C A
authors.initials: CA
authors.lastname: Petta
authors.forename: M
authors.initials: M
authors.lastname: Hays
authors.forename: V
authors.initials: V
authors.lastname: Brache
authors.forename: R
authors.initials: R
authors.lastname: Massai
authors.forename: Y
authors.initials: Y
authors.lastname: Hua
authors.forename: F
authors.initials: F
authors.lastname: Alvarez-Sánchez
authors.forename: A
authors.initials: A
authors.lastname: Salvatierra
authors.forename: C
authors.initials: C
authors.lastname: d'Arcangues
authors.forename: L A
authors.initials: LA
authors.lastname: Cook
authors.forename: L
authors.initials: L
authors.lastname: Bahamondes
mesh_terms: D000328:Adult; D002582:Cervix Mucus / Q000187:drug effects* / Q000502:physiology; D003271:Contraceptive Agents, Female / Q000494:pharmacology*; D003277:Contraceptives, Oral, Combined / Q000494:pharmacology*; D003692:Delayed-Action Preparations / Q000494:pharmacology; D004334:Drug Administration Schedule; D004338:Drug Combinations; D004958:Estradiol / Q000031:analogs & derivatives / Q000097:blood / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D017258:Medroxyprogesterone Acetate / Q000494:pharmacology*; D010053:Ovary / Q000187:drug effects / Q000502:physiology; D013084:Sperm-Ovum Interactions / Q000187:drug effects; D013997:Time Factors
chemical_list: D003271:Contraceptive Agents, Female; D003277:Contraceptives, Oral, Combined; D003692:Delayed-Action Preparations; D004338:Drug Combinations; D004958:Estradiol; C034528:CycloProvera; C007630:estradiol 17 beta-cypionate; D017258:Medroxyprogesterone Acetate