POPs are not usually recommended in the first 6 weeks postpartum in breastfeeding women. The timing of postpartum initiation of POPs should consider a woman's breastfeeding intentions.

Rationale: For breastfeeding women, delaying POP initiation for 6 weeks after delivery avoids exposing the newborn to exogenous steroids during the time of greatest neuroendocrine development. In breastfeeding women, the risk of ovulating in the first 6 weeks postpartum is very low. The timing of postpartum initiation of POPs should be dependent on the woman's preference, her previous experience with breastfeeding, and her intentions regarding the duration of breastfeeding (64, 119, 285).

Recommendation: A woman who initially chooses to rely on the Lactational Amenorrhea Method (LAM) is advised to begin POPs or whichever method she chooses to switch to:

• When her menses return, or
• When she is no longer fully or nearly fully breastfeeding, or
• At 6 months postpartum,

Preferably, POP packets are given to the woman before her intended start date to ensure that she is able to begin the method when she needs to. However, if she prefers, POPs can also be started when a woman is still relying on LAM (providing her with dual protection).

Rationale: While relying on LAM, a postpartum woman has at least 98% protection from pregnancy for 6 months if she remains amenorrheic and fully or nearly fully breastfeeds (perfect use-effectiveness rate). Programs sometimes encourage waiting to initiate POPs until reliance on LAM ends because it may be more programmatically affordable and because using POPs while breastfeeding may potentially prolong lactational subfertility (34, 146).

Recommendation: After the first 6 weeks postpartum, POPs can be initiated any time you can be reasonably sure a woman is not pregnant (see How to Be Reasonably Sure the Woman Is Not Pregnant and POP Question 5).

Rationale: Based on current literature, including studies with other progestin-only methods, it is unlikely that there is a significant effect on the growth of breastfeeding infants whose mothers initiate POPs after the sixth postpartum week (187, 213, 241, 311).

Recommendation: Even if POPs are inadvertently initiated during pregnancy, there is no known risk to the fetus.

Rationale: Epidemiologic studies have found no significant effect on fetal development or malformations due to taking hormonal methods in early pregnancy (28, 251, 298).

Recommendation: Nonhormonal methods are preferable to hormonal methods during breastfeeding because they have no effect on breastfeeding and the infant is not exposed to exogenous steroids. However, WHO lists POPs as Category 1 (no restrictions) after 6 weeks postpartum, and women should be given a choice of contraceptive methods.

Rationale: Although the amount of exogenous progestins in breastmilk is extremely low, it is prudent to try to minimize infant exposures to any drug (302, 335).

No back-up method is necessary when the new method is initiated if the woman has been breastfeeding and has been taking the POPs fairly consistently. Estrogen-containing methods should generally not be used by breastfeeding women prior to 6 months postpartum or preferably any time during long-term breastfeeding.

Rationale: As long as the woman is breastfeeding and taking the POPs fairly consistently, she is fully protected through the transition to the new hormonal method (108).

Clinical trial data indicate that the pregnancy protection conferred by POP use during breastfeeding is high, indicating a synergistic pregnancy prevention effect for breastfeeding while using POPs. In addition, women in lactational amenorrhea have additional protection due to their lowered fecundity (69, 147).

Rationale: In general, POPs are highly effective and safe during breastfeeding (69, 188).

Recommendation: Women can continue using POPs after they stop breastfeeding, provided that they have been informed of the advantages and disadvantages of the method and are willing to use the POPs correctly and consistently.

It is not mandatory for a woman to switch from POPs to another family planning method after she stops breastfeeding or at 6 months postpartum.

Rationale: POPs are an effective contraceptive method, even when not breastfeeding, if used correctly and consistently. However, all women should be informed of the advantages and disadvantages of POPs in the absence of breastfeeding, especially that POPs need to be used consistently and correctly to provide effective pregnancy protection and that they often cause irregular menstrual bleeding (188, 285, 302).

Recommendation: Breastfeeding women using POPs should be advised not to switch to COCs or other methods containing estrogen until at least 6 months postpartum.

Rationale: Even low-dose (30 micrograms) COCs decrease breastmilk production and alter its composition (188, 311).

Recommendation: Breastfeeding women can switch to nonhormonal methods at any time, as appropriate.

Rationale: If not inserted with 48 hours of delivery, postpartum IUDs are usually not inserted until uterine involution is complete. Progestin-releasing IUDs are not inserted until 6 weeks postpartum, even if involution is complete before 6 weeks, to avoid the theoretical risks of exposing the infant to steroids. Diaphragms are not fitted until involution is complete (203, 296, 302).

Rationale: Breastfeeding women have additional protection due to their lower fecundity. Clinical trial data indicate that the pregnancy protection conferred by POP use during breastfeeding is extremely high. The synergistic pregnancy protection by POP use in combination with breastfeeding should sufficiently eliminate a client's risk of conception, even if she takes POPs at different times of the day (39, 64, 188, 317).

Recommendation: However, if a woman continues taking POPs after breastfeeding cessation, then it is important to take the POP at the same time every day, preferably late afternoon or 4 to 5 hours before the usual time of sexual activity, so that the pill's effect on the cervical mucus is at its maximum by the time sexual activity occurs.

With the exception of rifampin/rifampicin, antibiotics are unlikely to significantly reduce the effectiveness of POPs in breastfeeding women.

If the breastfeeding woman is taking rifampin/rifampicin, she should know that rifampin/rifampicin:

• Passes through breastmilk (with potential side effects on the infant) and
• May increase breakthrough bleeding, lower progestin levels, and possibly reduce effectiveness of POPs.

Rifampin/rifampicin, which is used primarily for treating tuberculosis, induces hepatic enzymes and increases the liver metabolism of progestins, thus decreasing the effectiveness of POPs. The enzyme-inducing effects of rifampin/rifampicin last about 4 weeks after short-term use and 8 weeks after long-term use.

Griseofulvin, an antifungal antibiotic and another hepatic enzyme inducer, has not been proven to reduce POP effectiveness in humans but may increase menstrual irregularities.

Rifampin/rifampicin is passed in breastmilk (milk:plasma ratio of 0.2 to 0.6). Griseofulvin may also be passed in breastmilk. Infant exposure to rifampin/rifampicin or griseofulvin is appropriate only when the maternal benefits outweigh the potential risks to the infant (16, 85, 93, 302, 329).

Additionally, because anticonvulsants are excreted in breastmilk, and because there is a potential for serious adverse reactions in nursing infants, women taking hydantoins, barbiturates, or carbamazepine for chronic seizure control may be advised to explore safe alternatives to breastfeeding.

Injectable contraceptives, such as Depo-Provera, will be effective despite anticonvulsant use, but infant exposure to the anticonvulsants will continue.

Nonhormonal methods will continue to be effective despite anticonvulsant use.

Rationale: The hepatic enzyme-inducing effects of most anticonvulsants probably decrease pregnancy protection and increase rates of irregular bleeding among some POP users. It should be noted, however, that POPs may decrease the probability of seizures among users of anticonvulsants.

Because of the dangers of fetal exposure to most anticonvulsants, full protection against pregnancy is essential. Although increased doses of POPs might be effective, they might also further increase bleeding irregularities (185).

If a woman ingests hydantoins, barbiturates, or carbamazepine, her breastmilk will contain significant quantities of these substances. In areas where safe alternatives to breastfeeding exist, and where maternal seizures cannot otherwise be controlled, women on long-term antiseizure medications may be advised to consider safe alternatives to breastfeeding to avoid chronic infant drug exposure (9, 302, 326).

Chloroquine and related antimalarials are excreted in breast milk.

Rationale: Chloroquine, primaquine, and tetracycline have not shown any effect on oral contraceptive hormonal levels and are not known to reduce the effectiveness of POPs.

A nursing infant may consume about half of a mother's 300 mg chloroquine dose over 24 hours; the maternal milk:blood ratio may be about 0.36. Children are especially sensitive to chloroquine and primaquine.

Since the nutritional value of the milk to the child outweighs the effects of the chloroquine, clients are usually not advised to stop breastfeeding while on antimalarial treatment unless safe alternatives to breastmilk are available (9).

Rationale: The cervical mucus thickens enough to prevent sperm penetration within 24 hours. Also, the synergistic protection against pregnancy conferred by concurrent POP use and breastfeeding should sufficiently eliminate a client's risk of conception. Thus, a back-up method for a full 7 days may not be necessary (39, 148, 194).

For a breastfeeding woman who has already returned to menses, if 2 or more pills are missed, the woman should:

• Resume taking a pill as soon as she remembers and the next one at the regular time that day (for added protection).
• Use a back-up method or abstinence for 48 hours (some programs recommend use of a back-up method for up to 7 days).

The most immediate effect of POPs is on cervical mucus, each tablet offering protection for approximately 24 hours. Clinical trial data indicate that the pregnancy protection conferred by POP use during breastfeeding is high, indicating a synergistic pregnancy prevention effect for breastfeeding while using POPs. In addition, women in lactational amenorrhea have additional protection due to their lowered fecundity (14, 69, 148).

If a breastfeeding woman has resumed menstruating, some programs recommend use of a back-up method for 48 hours or for 7 days after the severe vomiting or diarrhea stops.