Motherhood is a transformative process. From the beginning of your pregnancy to the day your little one is weaned, your body is working to meet the needs of you and your growing baby.

The orchestraters of your transformation to motherhood are hormones. Hormones aren’t just the pesky chemicals that make you cry at paper towel commercials – they direct cells in your body to change, create, contract and relax. At the first pangs of pregnancy hormones are influencing your body and breasts to prepare to care for your new baby. When your little one arrives and the placenta is expelled, a sharp drop in the hormone progesterone occurs. Progesterone is crucial to maintaining your pregnancy, but after birth it is no longer needed. This sharp drop in progesterone signals your milk making cells to prepare to get to work. (Fun fact: this hormonal signal is so strong; mothers that adopt infants can induce lactation by taking progesterone for a period of time and then abruptly stopping. Thus mimicking pregnancy and delivery, and inducing lactation!)

Your body prepares for lactation months before your due date. Cells in our breasts begin to wake up during the first trimester thanks to another hormone, prolactin. For most moms, breast tenderness and swelling are the first symptoms of pregnancy. The breast changes you feel even before your baby bump starts to show are your breast cells preparing to make milk, thanks to exposure to prolactin. This preparation to make milk involves programming of dormant, or sleeping, breast cells. (Another fun fact: this programming of cells into milk producers provides protection from breast cancer later. Research shows breast tissue cells that have been activated to produce milk are less likely to grow into cancer in the future.) Prolactin tells your breast cells to make milk and if progesterone is present the hormones cancel out and only small amounts of colostrum is produced. But after your baby and placenta are delivered, progesterone drops and prolactin takes over! Oxytocin is another hormone that plays a big part in breastfeeding – known as ‘the mothering hormone’ it helps you relax and release your milk when your baby is at the breast.

After your baby is born, hormones still play a big role in milk production, although the laws of supply and demand are the determinants of your milk supply. To set yourself up for breastfeeding success, put your baby to breast as soon as possible after birth. No baths or swaddling – just a quick wipe off and skin to skin with you for the first breastfeeding session! Early breastfeeding is another signal that tells your body to start milk production. It can take 50-75 hours for mature milk production to begin, and putting your baby to breast helps create more milk, faster.

Pregnancy and breastfeeding cause our bodies to change in profound ways and hormones are the invisible directors of this transformation process.