I was really disheartened to hear, via the Academy of Breastfeeding Medicine, that new CDC guidelines on the use of birth control in the postpartum period may spell doom for breastfeeding for some women.
The CDC's new guidelines sanction the use of progesterone-only birth control in the immediate postpartum period, and combined progesterone-estrogen birth control starting at 4 weeks postpartum. Previous CDC policy recommended that progesterone-only birth control not be used prior to six weeks postpartum, and combined birth control not be used until after six months.
Why is this a problem? Because the trigger for the onset of mature milk ('milk coming in') is the rapid decrease in progesterone which occurs once the placenta is delivered. Progesterone and prolactin have a kind of inverse relationship. During pregnancy progesterone keeps our prolactin levels low, and once progesterone levels drop, prolactin levels go up, bringing in our mature milk. If progesterone birth control is started in the immediate postpartum period, it could keep prolactin levels low, jeopardizing milk supply. As to the use of combined progesterone-estrogen birth control, I think we all know that estrogen is linked to low milk supply, especially when started early on.
A statement from the Academy of Breastfeeding Medicine notes:
The new guidelines ignore basic facts about how breastfeeding works,” says Dr. Jerry Calnen, president of the Academy of Breastfeeding Medicine. “Mothers start making milk due to the natural fall in progesterone after birth. An injection of artificial progesterone could completely derail this process.”
Clinically, breastfeeding support providers report a negative impact on breastfeeding when these methods are introduced too early, and one preliminary study found dramatically lower breastfeeding rates at 6 months among mothers who underwent early insertion of progesterone-containing IUDs, compared with insertion at 6-8 weeks postpartum.
“The data are limited,” says Calnen, “but for now, the state of the science suggests that early progesterone exposure undermines breastfeeding.”
The Academy wrote to the CDC about this issue, and received a response stating that the new recommendation reflects “the best interpretation of the existing evidence.”