Morning-after pills should be used only as a last resort (whether you are breastfeeding or not).
There are currently two types of products on the market packaged specifically as "morning-after pills:"
* a combination pill containing estrogen and progestin (Preven, Ovral)
* a progestin-only pill (Plan B).
Milk supply: Estrogen, in particular, has been linked to low milk supply in nursing moms. There may be a slight drop in milk supply a few days after taking the morning-after pill, but milk levels should rebound thereafter. See Increasing Low Milk Supply for additional info on increasing milk supply. Talk to your health care provider and/or lactation consultant about using an herb that increases milk supply (fenugreek, for example) to reduce any adverse effects on supply.
Safety: The morning after pill is considered compatible with breastfeeding, but should only be used rarely. Not the first choice for routine birth control, it should be used only as a last resort (whether breastfeeding or not). Both progestin and estrogen are considered compatible with breastfeeding by the AAP. See below for additional information on side effects related to lactation.
Summary of Use during Lactation:
This record contains information specific to levonorgestrel used alone. Users with an interest in a combination oral contraceptive should consult the record entitled, "Contraceptives, Oral, Combined."
Although nonhormonal methods are preferred during breastfeeding, progestin-only contraceptives such as levonorgestrel are considered the hormonal contraceptives of choice during lactation. Fair quality evidence indicates that levonorgestrel does not adversely affect the composition of milk, the growth and development of the infant or the milk supply.
The timing of initiation of postpartum contraception with levonorgestrel is controversial. The product labeling states that it should be started no sooner than 6 weeks postpartum, based on data submitted for product approval. Starting sooner theoretically could affect the newborn infant adversely because of slower metabolism of the drug than older infants. Of concern is that no data exist on the effects of exogenous progestins on brain and liver development at this age. Administration sooner than 3 days postpartum could inhibit lactogenesis and interfere with the establishment of lactation. One small study found that Norplant use caused a reduction in infant thyroid-stimulating hormone serum levels. Norplant is no longer available in the United States and oral levonorgestrel tablets and IUDs deliver a lower amount of hormone to the infant through breastmilk than Norplant, so this effect, if real, may not occur with levonorgestrel tablets or IUDs, but studies are lacking.
 With the current state of knowledge, expert opinion holds that it is preferable to initiate levonorgestrel contraception at 6 weeks postpartum, especially if the mother is exclusively breastfeeding. In certain cases, the physician and patient may elect to start the drug sooner, but is prudent to give it no sooner than 3 days postpartum after lactation is established.
Use of 2 doses of 0.75 mg of levonorgestrel 12 hours apart for postcoital contraception has not been studied, but data from a study on a single 1.5 mg dose indicate that nursing can be resumed 8 hours after a large dose.
For women who meet the criteria (listed below), LAM is 98% effective during the first six months postpartum.
* Breastfeeding must be the infant’s only (or almost only) source of nutrition. Feeding formula, pumping instead of nursing, and feeding solids all reduce the effectiveness of LAM.
* The infant must breastfeed at least every four hours during the day and at least every six hours at night.
* The infant must be less than six months old.
* The woman must not have had a period after 56 days post-partum (when determining fertility, bleeding prior to 56 days post-partum can be ignored).
Ecological breastfeeding is a stricter form of LAM developed by Sheila Kippley, one of the founders of the Couple to Couple League. Studies have shown it has a 1% failure rate in the first six months postpartum, and a 6% failure rate before the woman’s first postpartum menstruation. The Seven Standards of ecological breastfeeding are slightly different from the LAM criteria:
* Breastfeeding must be the infant’s only source of nutrition – no formula, no pumping, and (if the infant is less than six months old) no solids.
* The infant must be pacified at the breast, not with pacifiers or bottles
* The infant must be breastfed often. The standards for LAM are a bare minimum; more frequency is better. Scheduling of feedings should be avoided.
* Mothers must sleep with their infants – in the same room, if not in the same bed.
* Mothers must not be separated from their infants for more than three hours a day.
* Mothers must take daily naps with their infants.
* The woman must not have had a period after 56 days post-partum (bleeding prior to 56 days post-partum can be ignored).