I receive many calls regarding low milk supply, a sudden drop in milk supply or a baby's poor weight gain or sudden drop or standstill in weight. One of my first questions is : "Are you taking any birth control pills?" Many times the answer is "Yes". Since many doctors are prescribing without warnings or just ill-advised, here is the "skinny" on Hormonal Contraceptives and their impact on breastfeeding. So you are able to make an informed choice yourself regarding what type of birth control method to use.
In NeoReviews, the official journal of the AAP, Thomas Hale, PhD states in his article Pharmacology Review: Drug Therapy and Breastfeeding (2005;6;e233-e240)
"Birth control products probably produce more complications than any other medication used by breastfeeding mothers. Estrogen-containing birth control products have been found to reduce human milk synthesis significantly in some mothers. Therefore, progestin-only products are greatly preferred in this population. However, even progestin-only products may reduce milk synthesis in some mothers, and great cautions should be used following their initial use. All mothers should be advised that these hormonal products may reduce milk synthesis, and they should discontinue their use immediately if they note a decrease in milk production. The use of medroxyprogesterone (Depo injection) early postpartum should be avoided until milk production has been established. Some mothers anecdotally report complete shutdown of milk production following its use."
The Drugs and Lactation Database (LactMed) HYPERLINK "http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT" states that "nonhormonal (contraceptive) methods are preferred during breastfeeding". The hormonal contraceptive choices in question are progestin-only oral contraceptives,
Depo Medroxyprogesterone (DMPA) injection, Mirena IUD, and Implanon/Norplant implant.
Estrogen-containing contracrptives continue to be contraindicated for breatfeeding mothers.
Progestin-only oral contraceptives (Micronor, Camila, Errin, Jolivette, Nora-BE, Nor-OD)
Although touted as the preferred oral contraceptive for breastfeeding mothers, in the 2010 edition of Medications and Mothers' Milk, Thomas Hale states that "recent reports claim that Micronor can be assocoiated with decreased milk production". Also these drugs "may reduce lactose content and reduce overall milk volume and nitrogen/protein content, resulting in lower infant weight gain" Milk levels increase for most of these women when this contraceptive is stopped.
Depo Medroxyprogesterone (DMPA)
Common injection given to clinic moms in the hospital during their postpartum stay. Hales rates this as an L4 or Possibly Hazardous if given within 3 days of birth. LacMed states that "Administration sooner than 3 days postpartum could inhibit lactogenesis and interfere with the establishmnet of lactation."
If if this injection is given later, it can be a problem for women sensitive to progestin since it cannot be removed or stopped.
Even though, Mirena produces the lowest plasma levels of progestin thus becoming more popular, it is not without concern. Hale does note that "some caution is recommended as I've received three accounts of milk suppression following insertion of Mirena IUDs"
This involves placing six match-size, flexible capsules under the skin of a woman's upper arm. These release a low dose of synthetic progestin continuously for up to five years. I recently saw a client who experienced a decrease in milk supply after receiving this contraceptive - which again is difficult to remove.
This is an extended-cycle oral contraceptive but due to it's estrogen content , caution is recommended in breastfeeing mothers due to potential reduced milk supply.
Plan B, Levonelle or NorLevo
This is a post-coital emergency contraception. The mother should not breastfeed for the first 8 hrs, or at the most 24 hrs to reduce the estimated dose to the infant via breastmilk.
So am not advocating no birth control but there are enough "red flags" to use them with great caution.
Milk supply and infant weight gain needs to be carefully monitored. It is difficult to sit with a mother who is suddenly struggling with her milk supply and suspecting that her birth control method prescribed by her doctor may be responsible. It has high-emotional, physical and economic consequences for the mother and baby that should not be ignored or placated.