| a) In general? CICs can be started anytime the provider can be
reasonably sure the woman is not pregnant.
There are two views on when Cyclofem and Mesigyna should
be initiated, one based on the initiation period of the clinical trials studying the
efficacy of these CICs, and the other on the analogy between the two lower dose CICs and
combined oral contraceptives (COCs) (and on the analogy between an older CIC and COCs).
World Health Organization (WHO) and other experts
recommend that Cyclofem and Mesigyna (Norigynon) are given within the first 5 days of the
menstrual cycle. If this is done, no back-up method is required. If the provider is
reasonably sure that the woman has not been exposed to the risk of pregnancy during that
cycle, CICs can be started after the first 5 days, provided that a back-up method is used
for 7 days.
Other experts recommend that if these CICs are given
within the first 7 days of the menstrual cycle, no back-up method is necessary. If CICs
are started after the first 7 days of a cycle and the provider is reasonably sure that the
woman has not been exposed to the risk of pregnancy since her last menstrual period, or if
the woman does not have menstrual cycles, a back-up method is recommended to be used for 7
days. |
a) Since lower dose CICs are
only now becoming more widely available, current WHO recommendations are based on the
results of clinical trials. For Cyclofem and Mesigyna (two newer, lower dose formulations
of CICs), all clinical trials have used the first 5 days of the cycle as the period for
initiation. But the possibility of extending the window for the first injection to day 7
of a menstrual cycle is under investigation. However,
some experts believe that the lower dose CICs are effective at least as promptly as COCs,
and could be safely initiated within the first 7 days of the menstrual cycle. These CICs
have slightly less of an estrogen effect and more of a progestin effect than COCs, and it
is presumed that their effect on cervical mucus is at least as prompt as the effect of
COCs. In addition, starting within the first 7 days of the menstrual cycle lowers the
possibility of beginning CICs while the client is already pregnant.
Analogous to COCs, the higher dose CIC, Deladroxate, is
begun within the first 7 days of the cycle: Koetsawang states that Deladroxate should be
given within the first 7 days of the cycle (and notes that in his review of 19 efficacy
studies, no pregnancies occurred in more than 30,000 woman-months of use).
- Koetsawang S. Once-a-month injectable
contraceptives: efficacy and reasons for discontinuation. Contraception 1994;49(4):387-98.
- Coutinho EM, Spinola P, Barbosa I,
Gatto M, Tomaz G, Morais K, et al. Multicenter, double-blind, comparative clinical study
on the efficacy and acceptability of a monthly injectable contraceptive combination of 150
mg dihydroxyprogesterone acetophenide and 10 mg estradiol enanthate compared to a monthly
injectable contraceptive combination of 90 mg dihydroxyprogesterone acetophenide and 6 mg
estradiol enanthate. Contraception 1997;55:175-81.
|
| b) Postpartum for
breastfeeding women? CICs can be started 6
months postpartum. Because they contain estrogen, WHO considers the health risks from
using CICs during breastfeeding from 6 weeks to 6 months postpartum to generally outweigh
the benefits (Category 3), unless other methods are not available or acceptable. Before 6
weeks postpartum, the risks are considered to be unacceptable (Category 4).
Postpartum for non-breastfeeding women?
CICs can be started in the third week postpartum or at the
first postpartum menstruation. |
b) There are no data on the
effects of combined injectables used during lactation. The following rationale is based on
what is known about COCs. Even low dose (30 mcg)
COCs decrease breastmilk production; it may be that estrogen-containing injectables,
although they have a lower estrogen dose than COCs, will have a similar effect but this
has not been studied.
- WHO Task Force on Oral Contraceptives.
Effects of hormonal contraceptives on milk volume and infant growth. Contraception 1984;30(6):505-21.
- World Health Organization. Improving
access to quality care in family planning: medical eligibility criteria for contraceptive
use. Geneva: WHO, 1996.
Blood coagulation and fibrinolysis are essentially
normalized by 3 weeks postpartum (and are close to normal at 2 weeks postpartum). Although
CICs have minor effects on blood coagulation, in the immediate postpartum period there may
be an increased risk of venous thromboembolism, though less than that associated with COCs
in this period.
- Dahlman T, Hellgren M, Blomback M.
Changes in blood coagulation and fibrinolysis in the normal puerperium. Gynecologic and
Obstetric Investigation 1985;20(1):37-44.
- Giwa-Osagie O, WHO Task Force on
Long-Acting Systemic Agents for Fertility Regulation. Metabolic effects of once-a-month
combined injectable contraceptives. Contraception 1994;49(5):421-33.
- World Health Organization. Improving
access to quality care in family planning: medical eligibility criteria for contraceptive
use. Geneva: WHO, 1996.
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