Things are going well between you and your baby. You’re bonding, you’re breastfeeding — but you’re suddenly starting to get the yearning for another newborn. If you’re turning to in vitro fertilization as a way to grow your family, you might have heard that nursing is a no-no if you want a successful implantation. So will you have to stop breastfeeding to do an embryo transfer? Like most things in life, it’s all about timing.
When it comes to embryo transfers and breastfeeding, the most important player is prolactin. Ultimately, your prolactin levels will affect your fertility, Healthline reported. So what exactly is prolactin? “The main hormone that supports the production of breast milk is prolactin,” Dr. Jessica Bauer, M.D., MS, FACOG, a board certified OB/GYN and infertility specialist, tells Romper. “And a specific hormone environment is paramount to the implantation process.”
That’s where prolactin comes into play. “In pregnancy, the placenta produces high concentrations of estrogen and progesterone, while the brain produces high levels of prolactin,” Dr. Tanmoy Mukherjee, a board-certified gynecologist and reproductive endocrinologist, tells Romper. “These hormones work together to get the breasts primed to make milk.” That’s all fine and good — until you’re considering having another baby via IVF but want to continue breastfeeding. “The high prolactin level, along with the nipple stimulation of breastfeeding, inhibits the hormones that control the menstrual cycle,” says Mukherjee. “These spikes in prolactin levels may be enough to impact fertility, and can decrease the success of a subsequent treatment, such as a frozen embryo transfer or a fresh IVF cycle.”
And having a regular period is paramount when you’re about to start the IVF process. “Depending on how exclusively the patient is breastfeeding, many women do not have a menstrual cycle while breastfeeding,” says Dr. Bauer. That’s why, more often than not, it’s recommended that women complete breastfeeding before undergoing IVF. “It’s suggested that women stop breastfeeding and demonstrate resumption of menses for three months in a row, and that the prolactin hormone level is not elevated,” says Dr. Bauer. “The success of the process relies heavily on a regimented hormone cocktail and any deviation from that — like an elevated prolactin level — can jeopardize the entire process.”
But that doesn’t mean that you’ll have to quit breastfeeding altogether. Depending on the frequency of your nursing sessions, you still might be able to breastfeed your baby and have a successful embryo transfer, too. “It's fairly unlikely that the once or twice-a-day breastfeeding that many babies after 9-10 months of age engage in for comfort has an impact,” says Dr. Mukherjee. “So we typically tell patients that once or twice a day of breastfeeding can continue with presumably no negative effect.”
Although nursing a newborn or an infant might impede the IVF process, you may not have to halt breastfeeding your baby. It’s best to speak with your OB/GYN or fertility specialist to understand what you’ll need to do to continue breastfeeding if that’s your goal, and have a successful implantation experience as well.
Dr. Jessica Bauer, M.D., MS, FACOG
Dr. Tanmoy Mukherjee, a board-certified gynecologist and reproductive endocrinologist