Will My Breast Milk Supply Decrease If I Get Pregnant?

Posted on April 29, 2026

Introduction
The Hormonal Override: Why Supply Drops
When Does the Supply Drop Usually Happen?
Recognizing the Signs of a Pregnancy-Related Milk Drop
Can You Increase Milk Supply While Pregnant?
Safety and Comfort: Nursing Through the Nausea
The Transition to Colostrum and Tandem Nursing
Making the Best Choice for Your Family
Conclusion
FAQ

Introduction

Finding out you are pregnant while still breastfeeding can bring up a whirlwind of emotions. You might feel a rush of excitement about your growing family, followed quickly by a wave of questions about how this change will affect your current nursing journey. One of the most frequent concerns parents share with us is whether their milk supply will diminish during pregnancy. It is a valid worry, especially if your current nursling is still quite young and relies on your milk for the bulk of their nutrition.

At Milky Mama, we believe that education is the best tool for navigating these transitions with confidence. Understanding why these changes happen can help you make the best decisions for your health and the well-being of both your children. The short answer is that for about 70% of women, milk supply does decrease during pregnancy, often as early as the first trimester. This shift is a normal, biological response to the new life growing inside you.

In this article, we will explore the hormonal shifts that cause a supply drop, when you can expect these changes to occur, and how to manage feeding your little one while expecting another. We want you to know that you're doing an amazing job, and there are ways to support your body through this transition. This post will cover everything from the "progesterone override" to managing nipple sensitivity and the transition to colostrum.

The Hormonal Override: Why Supply Drops

When you become pregnant, your body undergoes a massive internal shift to prioritize the growth of a new life. These changes are primarily driven by hormones, which act as chemical messengers to signal your organs on what to do next. While breastfeeding is typically a process of supply and demand, pregnancy introduces what many lactation professionals call a "hormonal override" that changes the rules for a while.

Progesterone and Prolactin

The main reason for a drop in milk supply during pregnancy is the rise in estrogen and progesterone. During a typical breastfeeding journey, your body produces high levels of prolactin, the hormone responsible for making milk. However, once a new pregnancy begins, the placenta produces significant amounts of progesterone to maintain the pregnancy.

High levels of progesterone actually inhibit the action of prolactin on the milk-producing cells. This is the same reason why your milk doesn't fully "come in" until a few days after birth; the drop in progesterone after the placenta is delivered is what signals your body to start full-scale milk production. When you get pregnant while nursing, that progesterone starts to climb again, which may cause the volume of milk to taper off.

Alveolar Permeability

Another theory regarding the decrease in supply involves the permeability of the milk-producing cells, called alveoli. Some research suggests that rising progesterone makes these cells "leaky" or more permeable. This means they cannot store milk as effectively as they do when you are not pregnant.

At birth, when the placenta is delivered and progesterone levels crash, these cells become impermeable again, setting the stage for the return of a copious milk supply. Until that happens, your body is essentially operating under a different biological blueprint that favors the pregnancy over lactation volume.

Key Takeaway: Milk supply typically drops during pregnancy because rising progesterone levels from the placenta naturally suppress the milk-making process to prioritize the developing fetus.

When Does the Supply Drop Usually Happen?

Every body responds to pregnancy differently, but there are some common timelines that many nursing parents report. While some notice a change almost immediately, others may not see a significant drop until they are further along.

The First Trimester

For some parents, a sudden drop in milk supply is one of the very first signs they are pregnant, sometimes occurring even before a missed period. If you notice your baby acting frustrated at the breast or if you are pumping significantly less than usual without any other lifestyle changes, it might be worth taking a pregnancy test. During these first twelve weeks, your body is working hard to establish the placenta, and the hormonal shift can be quite abrupt.

The Second Trimester

The most common time for a significant supply decrease is between the 10th and 20th week of pregnancy. By the middle of the second trimester, many parents find their milk has transitioned significantly. This is often the point where the milk volume is at its lowest.

The Third Trimester

By the time you reach the third trimester, your body is often already producing colostrum in preparation for the new baby. While the volume is low, the nutritional density is incredibly high. Some parents notice a slight "bump" in what they can express during the final weeks, but this is the concentrated "liquid gold" rather than the mature milk you may be used to.

Recognizing the Signs of a Pregnancy-Related Milk Drop

If you are not regularly pumping, you might not see the physical volume change in a bottle. Instead, you will need to look for other cues from your body and your nursing child.

Physical Changes in Your Breasts

During a standard nursing relationship, your breasts may feel full before a feeding and softer afterward. During pregnancy, you might notice that your breasts feel consistently soft, regardless of when you last nursed. This lack of "fullness" is a common indicator that your storage capacity or production rate has decreased.

Changes in Milk Composition

Around the middle of your pregnancy, your milk doesn't just decrease in volume; it also changes its "recipe." Your body begins to transition from mature breast milk back to colostrum. Colostrum is the thick, concentrated milk that newborns need in the first days of life. It is higher in protein and sodium but lower in lactose (sugar) and potassium than mature milk.

You might notice that the color of your milk becomes more yellow or golden. This transition is a brilliant way for your body to prepare for the new baby's arrival, ensuring they have exactly what they need the moment they are born. Breasts were literally created to feed human babies, and they are simply getting a head start on the next phase.

Behavioral Cues from Your Child

Your nursing child will likely be the first to notice the change. Here is how different ages typically react:

Infants (Under 1 Year): A baby who relies heavily on your milk may become fussier at the breast. They might pull at the nipple, cry during sessions, or want to nurse much more frequently to try to "order" more milk.
Toddlers (Over 1 Year): Older children often react to the change in taste. Because colostrum is saltier and less sweet, some toddlers will naturally start to wean themselves. Others might not mind the taste but may get frustrated with the slower flow of the milk.

Can You Increase Milk Supply While Pregnant?

This is perhaps the most challenging part of nursing while pregnant. Under normal circumstances, we recommend frequent nursing and pumping to boost supply. This relies on the "supply and demand" feedback loop. However, pregnancy-related supply drops are hormonal, not demand-based.

Managing Expectations

Because the drop is caused by high progesterone levels, traditional methods like "power pumping" or nursing more often may not have the same effect they usually do. Your body is receiving a very strong internal signal to prioritize the pregnancy, and that often overrides the external signal of milk removal.

For many parents, no matter how much they pump or how many lactation treats they eat, the supply stays lower than their pre-pregnancy baseline. This can be frustrating, but it is important to give yourself grace. You are growing an entire human being while still nourishing another; that is a monumental feat.

Supporting Your Body with Nutrition

While you might not be able to "force" a high volume of milk during pregnancy, you can support your body so it has the resources it needs. Nursing while pregnant requires a significant amount of energy.

Caloric Intake: You may need an additional 500 to 800 calories per day to support both the pregnancy and lactation. Focus on nutrient-dense foods like avocados, nuts, seeds, and lean proteins.
Hydration: Staying hydrated is essential for both your pregnancy health and milk production. Our lactation drink mixes, including Pumpin Punch™ or Milky Melon™, can be a refreshing way to keep your fluids up while providing extra vitamins and minerals that support nursing parents.
Targeted Support: Some parents find that including oats and flaxseeds in their diet helps them maintain what supply they have. Our Emergency Lactation Brownies are a favorite for a quick, delicious snack that includes these traditional ingredients.

What to do next:

Monitor Output: If your baby is under a year old, keep a close eye on their wet diapers and weight gain.
Supplement if Necessary: If your infant is not yet on solid foods and your supply drops significantly, you may need to supplement with donor milk or formula under the guidance of a pediatrician.
Consult a Professional: A virtual lactation consultation can help you create a plan tailored to your specific situation.

Safety and Comfort: Nursing Through the Nausea

Many parents worry that breastfeeding while pregnant might cause a miscarriage or early labor. For a healthy, low-risk pregnancy, breastfeeding is generally considered safe. While nursing releases oxytocin, which can cause mild uterine contractions, these are usually not strong enough to cause changes in the cervix in a healthy pregnancy.

Nipple Sensitivity

One of the most common physical hurdles is extreme nipple tenderness. This is caused by the hormonal changes of pregnancy and can make nursing feel uncomfortable or even painful. It often feels like the sensitivity you might have experienced in the very early days of nursing a newborn.

To manage this, you can:

Ensure your child has a deep, comfortable latch.
Use a high-quality nipple balm to protect the skin.
Limit the duration of nursing sessions if they become too painful.
Try distraction techniques for toddlers, such as reading a book while they nurse.

Nursing Aversion and Agitation

Some parents experience a phenomenon called "nursing aversion" or "nursing agitation" during pregnancy. This is an intense feeling of irritability or the urge to "get the baby off" as soon as they latch. It is a biological response that some believe is the body’s way of protecting its resources.

If you feel this way, please know that you are not a bad parent. It is a very real, physiological response. Taking deep breaths, staying hydrated, and ensuring you are getting enough rest can help, but it is also okay to decide that weaning is the best choice for your mental health. Every drop counts, but your well-being matters too.

The Transition to Colostrum and Tandem Nursing

A common myth is that an older child will "use up" all the colostrum before the new baby arrives. This is not true. Your body will continue to produce colostrum throughout the end of your pregnancy and the first few days after birth.

Preparing for the Newborn

Once your baby is born, the delivery of the placenta will trigger your mature milk to "come in" again. This usually happens within two to five days after birth. During those first few days, you should prioritize the newborn’s access to the breast to ensure they get the colostrum they need for immunity and digestion.

Tandem Nursing Benefits

If you choose to continue nursing both children after the birth (tandem nursing), you may find that your milk supply is more robust than ever. The combined demand of two children often leads to a very healthy supply. Tandem nursing can also help reduce engorgement in those early weeks and can be a beautiful way for siblings to bond.

Fun Fact: Breastfeeding in public—covered or uncovered—is legal in all 50 states, whether you are nursing one child or tandem nursing two!

Making the Best Choice for Your Family

There is no "right" way to handle breastfeeding during pregnancy. Some parents find that the supply drop and nipple sensitivity make weaning the most logical choice. Others feel strongly about continuing the nursing relationship and are happy to push through the challenges.

When to Consider Weaning

You might consider weaning if:

The pain or sensitivity is affecting your quality of life.
You are experiencing severe nursing aversion.
Your healthcare provider advises it due to a high-risk pregnancy (such as a history of preterm labor or carrying multiples).
Your child loses interest due to the change in taste or flow.

When to Continue

You might choose to continue if:

Nursing is still a primary source of comfort for your child.
You want to tandem nurse after the birth.
The challenges are mild and manageable for you.

Whatever you decide, remember that the relationship you have with your child is about so much more than just milk. Whether you nurse for two months or two years, the bond you’ve built is lasting.

Conclusion

The journey of pregnancy while breastfeeding is a testament to the incredible strength and adaptability of the human body. While it is very likely that your milk supply will decrease due to the hormonal shifts of pregnancy, this is a natural process. By focusing on your nutrition, staying hydrated with options like our lactation drinks, and listening to your body’s cues, you can navigate this transition smoothly.

Listen to your body: Nipple pain and aversion are real signals that you may need to adjust your nursing routine.
Prioritize nutrition: Eating for three is a big job—don't skip those nutrient-dense snacks.
Watch the baby: Ensure your youngest nursling is staying hydrated and growing well.

At Milky Mama, we are honored to be a part of your village. Whether you are looking for support through a supply drop or preparing for tandem nursing, we are here to provide the education and products you need to feel empowered. You are doing an incredible job growing your family, one drop at a time.

This product is not intended to diagnose, treat, cure, or prevent any disease. Consult with your healthcare provider for medical advice, especially when considering new supplements during pregnancy.

FAQ

How early in pregnancy does milk supply decrease?

For many parents, a decrease in milk supply can happen as early as the first month of pregnancy. In some cases, a dip in supply or changes in nipple sensitivity are among the very first symptoms of a new pregnancy, often occurring before a positive pregnancy test.

Does the taste of breast milk change when you get pregnant?

Yes, the taste of breast milk usually changes during the second trimester as it transitions from mature milk to colostrum. The milk typically becomes saltier and less sweet due to an increase in sodium and a decrease in lactose, which may lead some toddlers to wean themselves.

Is it safe to take lactation supplements while pregnant?

While many ingredients in lactation treats, like oats and flaxseed, are safe during pregnancy, you should always consult your healthcare provider before taking concentrated herbal supplements. Products like Lady Leche™ or Pumping Queen™ contain herbs that should be reviewed by your midwife or OB-GYN to ensure they are appropriate for your specific situation.

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