Does Pregnancy Cause Milk Supply to Drop? What to Expect
Posted on April 09, 2026
Posted on April 09, 2026
Finding out you are pregnant while still breastfeeding your older child can bring up a whirlwind of emotions. You might feel excited about the new addition, but also anxious about how this change will affect your current nursing relationship. One of the most common questions we hear from parents in this situation is: does pregnancy cause milk supply to drop?
The short answer is yes, for many parents, a decrease in milk production is one of the earliest signs of a new pregnancy. This shift can feel discouraging, especially if your little one isn't quite ready to wean or if you had planned on tandem nursing—which is the practice of breastfeeding two children of different ages at the same time. At Milky Mama, we believe that education is the best tool for navigating these transitions with confidence.
In this article, we will explore why these supply changes happen, when you might notice them, and how you can support your body through the demands of both pregnancy and lactation. Our goal is to help you understand the science behind these shifts so you can make the best decisions for your growing family. Every drop counts, and your well-being matters just as much as the nutrition you provide.
It is estimated that up to 70% of breastfeeding parents experience a noticeable decrease in milk supply during pregnancy. This isn't usually due to anything you are doing "wrong," but rather a biological response to the new life growing inside you. While breastfeeding is typically governed by the law of supply and demand, pregnancy introduces a hormonal override that changes the rules.
During pregnancy, your body undergoes a massive hormonal shift. Levels of estrogen and progesterone rise significantly to support the developing fetus and maintain the pregnancy. Progesterone, in particular, is known to inhibit the production of milk.
In a typical breastfeeding journey, the removal of milk from the breast triggers the release of prolactin, the hormone responsible for making milk. However, the high levels of progesterone during pregnancy can interfere with how your breast tissue responds to prolactin. This means that even if your older child is nursing frequently, your body may not be able to maintain the same volume of milk it once did.
As you move into the second trimester, usually around the fourth or fifth month, your breasts begin to transition from producing mature milk back to producing colostrum. Colostrum is often called "liquid gold" because it is a thick, concentrated, antibody-rich milk designed specifically for a newborn’s first days of life.
Because colostrum is produced in much smaller quantities than mature milk, this transition naturally results in a lower volume of liquid. This shift is a programmed part of lactogenesis, which is the clinical term for the process of milk production. Your body is essentially "resetting" itself to ensure that the new baby has exactly what they need the moment they are born.
While every person is different, most parents notice a dip in supply quite early. Some even notice the change before they have a positive pregnancy test. For others, the supply drop is more gradual and becomes more apparent as the pregnancy progresses.
For many, the supply drop begins in the first trimester. This is often accompanied by other common pregnancy symptoms like fatigue and nipple sensitivity. Because your body is working overtime to build a placenta and support a new embryo, it may divert resources away from milk production.
By the middle of the second trimester, the hormonal changes are in full swing. This is typically when the transition to colostrum occurs. You may notice that your breasts feel softer and less full. If you are pumping, you might see a significant decrease in the number of ounces you collect during a session.
If you are still nursing a toddler or an older infant, they will likely be the first to tell you that the supply has changed. Since you cannot always see how much milk is being produced when breastfeeding directly, paying attention to your child's behavior and your own physical cues is key.
Children react to a supply drop in different ways. Some of the most common behaviors include:
You might also notice changes in your own body, such as:
Key Takeaway: A supply drop during pregnancy is primarily driven by hormones, not a lack of effort. Understanding that your body is prioritizing the new pregnancy can help alleviate the guilt many parents feel when their supply dips.
Nursing while pregnant is a physical feat. You are nourishing a child on the outside while growing one on the inside. This requires a significant amount of energy and patience.
Pregnancy hormones can make your nipples incredibly sensitive. For some, the sensation of nursing can become "skin-crawling" or painful. This is sometimes called "nursing aversion." To help manage this:
For personalized guidance with latch, nipple pain, or other breastfeeding challenges, consider booking a virtual lactation consultation with a certified lactation consultant.
Your body’s caloric requirements skyrocket when you are both pregnant and breastfeeding. You may need an additional 500 to 800 calories per day to support both processes. If you aren't eating enough, your body will prioritize the pregnancy, which can further impact your milk supply.
Focus on nutrient-dense foods, including:
Our Emergency Lactation Brownies are a popular choice for parents looking for a convenient, delicious snack packed with ingredients like oats and flaxseed that can support your energy levels and overall well-being during this demanding time.
For more ideas about nourishing your body, explore this guide to eating for your breastfeeding journey.
Staying hydrated is critical. Your body needs water to produce milk and to maintain the amniotic fluid for your developing baby. We recommend drinking at least 12–16 cups of fluid a day. If plain water feels boring, especially if you are dealing with pregnancy nausea, our Pumpin Punch™ and Milky Melon™ drink mixes can be a refreshing way to stay hydrated while incorporating lactation-supporting ingredients.
This is the most challenging part for many parents to hear: because the supply drop is hormonal, traditional methods of increasing supply—like power pumping or nursing more frequently—may not be as effective as they were before you were pregnant.
While you may not be able to return to your pre-pregnancy volume, you can work to maintain the supply you do have. For additional information, read this gentle guide to breastfeeding and pumping.
This product is not intended to diagnose, treat, cure, or prevent any disease. Consult with your healthcare provider for medical advice.
While pregnancy is a major cause of supply drops, it isn't the only factor. Sometimes, a dip happens for other reasons, and it’s important to rule those out.
The first trimester of pregnancy is notoriously exhausting. Chronic stress and lack of sleep can negatively impact your milk supply. When your body is in a state of high stress, it produces cortisol, which can interfere with the hormones needed for milk production.
Getting a cold or the flu while pregnant can temporarily lower your supply. Additionally, some medications commonly used for pregnancy symptoms or allergies, such as decongestants containing pseudoephedrine, can cause a significant dip in milk volume. Always check with your doctor before taking any over-the-counter medications.
If your older child has changed their nursing habits—perhaps due to their own developmental milestones—they may not be removing milk as effectively. Remember, if milk is left in the breast, it sends a signal to your body to slow down production.
For the vast majority of people, breastfeeding while pregnant is perfectly safe. The old myth that breastfeeding causes miscarriage or preterm labor in healthy pregnancies has been largely debunked by research.
It is true that nipple stimulation releases oxytocin, which can cause mild uterine contractions. However, in a normal, low-risk pregnancy, the uterus is not sensitive to these small amounts of oxytocin until very close to the end of the pregnancy. These contractions are usually similar to Braxton Hicks and are not strong enough to trigger labor.
You should discuss breastfeeding with your healthcare provider if you:
If your goal is to continue nursing through your pregnancy and feed both your toddler and your newborn, you are embarking on the journey of tandem nursing. This can be a beautiful way to help your older child bond with their new sibling.
Once your new baby arrives, your milk supply will likely increase dramatically as your body enters the stage of lactogenesis II (when your milk "comes in"). Your toddler may suddenly become very interested in nursing again because the volume is higher and the milk is sweet mature milk once more.
While you can nurse both children, it is important to ensure the newborn gets the colostrum they need in those first few days. Many parents choose to nurse the newborn first to ensure they get the "prime" milk before the toddler has their turn.
If you’ve noticed your supply dropping and you’re feeling overwhelmed, here are a few steps you can take:
Key Takeaway: Every breastfeeding journey is unique. Whether you nurse all the way through your pregnancy or decide to wean, you are making the best choice for your family at this moment.
Navigating a milk supply drop during pregnancy can be an emotional and physical challenge. It is important to remember that your body is doing something incredible—supporting two different stages of human development at the same time. The decrease in supply is a normal, hormonal response, and while it can be frustrating, it does not mean your breastfeeding journey has to end if you aren't ready.
At Milky Mama, we are here to support you every step of the way, whether you need a boost of hydration from our Milky Melon™ drink mix or a supportive community to talk through your concerns. Remember, you're doing an amazing job, and your worth as a parent isn't measured in ounces.
Take a deep breath and give yourself grace. You are providing a beautiful foundation for both of your children. If you need more personalized support, consider booking a virtual lactation consultation with our team to help you navigate your specific situation.
Most parents notice a decrease in milk volume during the first trimester, often between weeks 6 and 12. By the second trimester, around week 16 to 20, the milk usually transitions to colostrum, which is produced in much smaller amounts.
Yes, the composition of your milk changes as you move through pregnancy. Mature milk is generally sweet, while colostrum is higher in sodium and protein, giving it a saltier, less sweet taste that some toddlers may find surprising.
While galactagogues can support your body, they often cannot fully override the hormonal shift caused by pregnancy. It is essential to consult your healthcare provider before using any supplements, as some herbs are not recommended during pregnancy. You can also explore Milky Mama’s lactation supplement collection after discussing your options with a qualified professional.
Yes, this is very common. Your toddler may be seeking comfort during a time of change, or they may be "cluster feeding" in an attempt to signal your body to produce more milk, even if the hormonal dip prevents a large increase.