Did you know that many of us will notice a supply drop right before our period is going to start and lasts through the period? This is caused by hormone shifts in your body. As supply dips, the milk flow slows. Research shows that the composition of breast milk changes around ovulation (mid-cycle). The levels of sodium and chloride in the milk go up while lactose (milk sugar) and potassium go down. So, the breast milk becomes saltier and less sweet during this time. Some babies become frustrated with this change. They may grab the nipple with their mouth and shake their head back and forth. Pop on and off the breast. Knead or beat the breast with their hands or become extra fussy at the breast. They may even cluster feed and act as if they’re still hungry. They’re trying all the strategies to get your milk to flow how they prefer.
Also around the time of ovulation and just before the start of your period, estrogen and progesterone levels change which can affect your breasts and your breast milk. When estrogen and progesterone levels go up, it can make your breasts feel full and tender.
Higher estrogen levels can also interfere with milk production. Studies also show that calcium levels in the blood go down after ovulation. The lower level of calcium may also contribute to the drop in the milk supply. Lower levels of calcium may also cause your nipples to feel sore, making breastfeeding during your period uncomfortable or sometimes painful.
This is a temporary dip but can be surprising the first time it happens. Remember: this dip can happen once or twice before you actually have a period as your hormones are shifting back into baby making mode. If your baby is older than 6 months and eating lots of solids, you may not notice a difference. The strongest behaviors are seen under 6 months when babies need an exclusive milk diet. You may also notice the dip if you’re a pumper.
Having your period start again may not have any effect on your baby or your milk supply. Some babies continue to breastfeed well. Others will not like the taste of the breast milk or the drop in the amount of breast milk that can happen when your period returns. Your baby may:
- Become fussier than normal
- Want to breastfeed more due to the lower milk supply
- Breastfeed less because there is less breast milk and it tastes different
- Nursing strike
What can you do about it? Knowing it can happen is the first step. Stay well hydrated and eat quality nutrition. Many find adding in a calcium/magnesium supplement (1000mg of calcium/500mg magnesium per day split into 3-4 “doses”) can help combat the drop. Others find adding in lactation specific herbs or supportive foods help. Iron rich foods like dark leafy greens and red meat and milk making foods like oatmeal, almonds and fennel can really help. Keep offering the breast or pumping frequently. It will get better and your supply will come back up as soon as your hormones shift again after your period. It usually only lasts a few days.
Word to the wise: You can release an egg from your ovary (ovulate) before your period returns. If you’re involved in an intimate relationship, and you’re not using birth control, you can get pregnant again without ever getting your first period even while you’re breastfeeding. If you notice a very drastic drop in milk supply, consider taking a pregnancy test.