Q: I’m breastfeeding my new baby and don’t want to get pregnant again, at least for a while. Can I take birth-control pills while nursing? I’m worried about secreting extra hormones in my breast milk.
A: If the Pill is the only contraception you want to consider, you may — but not until you are at least six weeks postpartum and your milk flow is fully established.
The reason for delaying is probably not what you are thinking. Doctors’ concern about taking the Pill while breastfeeding is not so much about what the milk may contain as how much is produced.
Traditionally, doctors have limited medication for breastfeeding women out of concern that everything going into your body goes out through your breast milk.
It now seems that we may have been barking up the wrong tree. Breast milk itself does contain maternal hormones, but taking the Pill does not seem to make a difference in the level of hormones present in breast milk.
Rather, the worry is that the hormones in the Pill that prevent conception will also inhibit milk production. A lack of milk could adversely affect the weight and health of your newborn.
Lactation 101First, some background on lactation: By the sixteenth week of pregnancy, the breasts are fully capable of producing milk (hence their larger size). However, the increased amounts of estrogen and progestin produced by the placenta inhibit the lactation hormone, prolactin, which is made in the brain's pituitary gland.
But once the baby (and placenta) is out of the uterus — and estrogen and progesterone levels drop — the pituitary gland is “allowed” to produce its prolactin, therefore stimulating milk production.
This process, though, will quickly stop if the baby doesn’t nurse. Suckling on a regular basis stimulates the pituitary gland to continue secreting prolactin, ensuring adequate levels for milk production.
The problem with the PillNow to the issue at hand with oral contraceptives: It’s believed that the combined estrogen and progestin in birth-control pills blunt the effect of the hormone drop that occurs after delivery. This can cause ongoing suppression of prolactin levels and hence diminish the milk supply. Less milk can mean less weight gain for the baby.
Meanwhile, there is another quid pro quo at work — that the diminished hormone level associated with breastfeeding is a quite effective form of contraception. Indeed, women in many societies rely on breastfeeding as their sole means of birth control. This natural process, called lactational amenorrhea — the absence of a period while breastfeeding — is more than 95 percent effective, but only under very limited conditions: A) that the woman has not resumed menstruating; B) that she is exclusively breastfeeding with no supplementation; and C) that her baby is less than six months old.
During these six months, the continued lactation keeps prolactin levels elevated, and elevated prolactin prevents ovulation. However, there can be “breakthrough” ovulation if you are not totally consistent in breastfeeding or if you have passed the six-month mark.
Contraceptive alternativesRather than dealing with hormones, you might want to consider other forms of contraception that have no effect on milk quantity. These include:
- such as the condom and diaphragm. (Remember, though, that a diaphragm cannot be appropriately fitted for six to eight weeks postpartum, due to anatomical changes.)
- An IUD will not affect milk production.
- The IUS (Mirena is the brand name), which secretes minute amounts of progestin into the uterine cavity, will have no effect on lactation. (It appears to be estrogen, not progestin, that inhibits milk production.)
- Progestin-only pills, also called the mini-pill, have not been shown to decrease milk volume.
I’m glad you are looking out for your baby’s health by continuing to breastfeed. In addition, your are right to be thinking about your own reproductive health, because contraception after childbirth is a real issue — most women resume sexual activity quickly, with about two-thirds of women being sexually active by the fourth week after giving birth and 88 percent by the eighth week.
Dr. Reichman’s Bottom Line: You should seriously consider the non-Pill forms of birth control outlined above. If, however, the combined (estrogen and progestin) Pill is the only one you want to use, don’t start it for at least six weeks postpartum, to ensure a rapid and adequate onset of milk production. The initial drop in postpartum hormones that allows prolactin to get into your system is important. And once you are on the Pill, make sure the baby is getting enough milk and gaining weight.
Dr. Judith Reichman, the “Today” show's medical contributor on women's health, has practiced obstetrics and gynecology for more than 20 years. You will find many answers to your questions in her latest book, "Slow Your Clock Down: The Complete Guide to a Healthy, Younger You," published by William Morrow, a division of .
PLEASE NOTE: The information in this column should not be construed as providing specific medical advice, but rather to offer readers information to better understand their lives and health. It is not intended to provide an alternative to professional treatment or to replace the services of a physician.