Bottles, Bottles, Bottles – A Handy Guide to Introducing a Bottle to a Breastfed Baby

Published on: March 09, 2020

In the first of a two-part series, Lactation Counsellor and BAMBI Bumps team member Lia Segall Pasternak explains all things bottles. This month Lia discusses introducing a bottle to an exclusively breastfed baby. Next month, Lia will give you information for exclusively bottle-fed babies and explain the safe preparation of formula.


By Lia Segall Pasternak


As a lactation consultant, I often meet mothers who want to introduce their baby to a bottle. Bottles can be an amazing tool to easily and safely feed a baby when a mother needs to be away for a couple of hours for any reason or to prepare for returning to work. Whether you have chosen to breastfeed or combo feed, it is important to know the basics.



When your baby is born, and you want to breastfeed, it is recommended to wait a few weeks before introducing a bottle. Bottle feeding can interfere with breastfeeding because the nipple of the bottle requires that the baby perform different suckling motions. If the baby gets used to this kind of motion, they will not be able to extract enough milk from the breast, or they might damage your nipples.  A baby might also get a flow/nipple preference and reject the breast.  

In addition to this, if you plan to bottle feed expressed breast milk, it is best not to start pumping in the first month. This avoids overstimulation and over-supply if your baby is getting enough from the breast.

To avoid all of these issues, I would recommend waiting to introduce a bottle until the milk supply is well established and any complication is behind, ideally after four weeks and before eight weeks. It is important not to lose this window or wait longer if you are planning on introducing a bottle because then the baby might reject it. When you have introduced the bottle, you should make sure that baby gets three bottles a week, at least so that he/she doesn’t forget how to use it. 



A bottle feed of expressed milk for a breastfed baby should be about the same as what the baby would extract from the breast (not as much as you manage to pump, that’s not a correct measure of how much baby needs). Breasts don’t have a handy ml gauge on the side. Still, research tells us that exclusively breastfed babies take in an average of 750 mL (25 oz) per day between the ages of 1 month and 6 months, so you can divide this amount by the times a baby feeds in one day and get an idea of how much to put in a bottle. For example, a baby that feeds nine times per day should have around 80 ml per bottle. You will also learn how much your baby drinks after a few bottle feeds. Some babies eat less when given a bottle, or eat more at some hours and less at others. After introducing solids the amount changes and it’s different for each baby, but you can keep offering the same and reduce it when baby starts to drink less. 


If you must give a bottle before one month of age; start with smaller amounts and feed baby more often. Breastfed babies feed on demand so you should follow baby’s hunger cues as feeds of 20-40 ml can be normal. What’s important is the total amount of milk that your baby gets throughout the day (between 300-500ml depending on the weight of your baby). Some babies may drink more and some less, so follow your baby’s cues and weight gain and ask for guidance from a lactation professional if you must introduce bottles or top up breastfeeding sessions.



Regular pumping should be delayed until breastfeeding is fully established, if possible, usually by six weeks postpartum. The biggest exception to that rule is if you have low milk supply or your baby isn’t gaining enough weight. In this case you should consult a lactation professional to decide the best plan to increase the milk supply and make sure the baby gets all the nutrition that he/she needs. Also, when a mother needs to return to work before that period, she might want to pump to save some milk prior to her starting date. It is recommended to consult with a lactation professional as well to prevent mastitis or overproduction. For any other cases, avoid pumping. Milk can be extracted by hand expression if needed or by using a Haakka pump. Sometimes it can be hard to pump the same amount that baby would drink from the breast (babies are much better at extracting breast milk than breast pumps). If you aren’t able to pump the amount you need, you should immediately consult with a lactation professional to get help on increasing your supply and how to improve your pumping results.


Preparation of the Bottle

Be sure to sterilize bottles, teats, and pump parts (except the tubes) before the first use, some people will sterilize after each use, and that’s OK. If you can’t sterilize – wash everything thoroughly with water and soap after each use and air dry. Try to keep all the baby feeding equipment (until 6 months of age) away from the sink and use a sponge and/or brush that’s exclusively for this purpose. Always wash your hands before handling a breast pump and preparing a bottle.


Storage and Use of Breastmilk

You can give breastmilk at room temperature or a bit warmer. If frozen, you can thaw it by leaving it in the fridge overnight or, if you need it right away, place it in a bowl with warm (not boiling) water. Never use the microwave to heat breast milk. Thawed milk cannot be frozen again, and heated milk cannot be returned to the fridge. If unconsumed, it must be discarded after three hours.

For this reason, I recommend using amounts little by little to minimize waste. Give 20-30 ml the first few times, then adjust. Expressed milk can be stored in a fridge (less than 4°C) for up to seven days, or in a fridge-freezer compartment for 3-4 months (store it at the back, not by the door), and a deep freezer (less than -18°C) for up to six months. 


How to Give a Bottle

Breastfed babies regulate their own intake at the breast. As they must work to extract the milk from the breast, they can pause during their feed and unlatch when they are done. When tipped at an angle less than 180°, a bottle will provide a constant drip/flow which disrupts the physiological process. Paced Bottle Feeding is a method of bottle feeding that allows the infant to be more in control of the feeding pace, slowing down the flow of milk into the nipple and the mouth, allowing babies to regulate their intake. Always use a slow flow nipple, which is closest to breastfeeding. A lactation professional can help you to introduce pace feeding, and there are also useful videos and instructions online. 


Bottle Rejection

Sometimes a baby that has been only breastfed will have a hard time learning how to use the bottle, it might seem like he/she will never take it, but in most cases, they eventually do. The first thing to do is not panic. Even if you have to leave your baby, that doesn’t mean that your baby won’t be fed; a baby can be fed in many ways. A spoon, a cup, or a syringe are the easiest when a baby is refusing to use a bottle –  it’s not ideal, but it works.

How to Help Baby to Accept the Bottle?

-Because of the thrust reflex, babies appear to push the bottle out of their mouth. Be patient, let them get used to it. If you are pace feeding, this limits the effect of tongue thrust.

-Always try the bottle when they are not too tired or too hungry, and in a quiet environment that isn’t too stimulating for them. It is something completely new, and it can be frustrating for a hungry/tired baby if they are forced to learn something new. The best time to try is about one hour after the last feed up to half an hour before the next feed.

-Be calmly persistent. Remember – this is a new skill, and baby and you need opportunities to practice in a positive environment. If baby doesn’t accept a bottle on day one and cries, stop and try again the next day. Try in a different setting, and you can even try a different bottle, but don’t get frustrated. You want to avoid negative associations with the bottle as your baby can feel when you’re stressed.

-Have someone other than you offer the bottle when you’re not at home. A baby will be much more likely to take the bottle then.

-If baby is over four months old, you can try introducing an age-appropriate soft spout sippy cup and skip the bottle. It doesn’t make any difference as long as baby gets his/her milk, right?

-Use movement like walking, wearing baby in a carrier, a bouncer, a stroller, or a physio ball to soothe baby while feeding.

-Try feeding the baby when he/she is about to sleep or has just woken up. You can switch the breast for the bottle if baby is on the last minutes of a feed, or try a dream feed.

-Don’t put more than 10 ml of breastmilk inside a bottle when you’re in the learning process. You don’t want to waste milk that baby might not take.


If your baby is reluctant to take a bottle, reach out to a lactation professional for individual guidance that suits you and your baby best. You’ve got this, and soon you will look back at this time and be proud of you and baby. 


More information

Lactation Counseling Bangkok:

Breastmilk calculator:

Paced Bottle Feeding:


About the Author

Lia was born and raised in Mexico, she moved to Israel in 2010, got married and had a son in 2014 who made her fall in love with breastfeeding.

Lia quit her job and went to study to become a lactation counselor.  After moving to Thailand in February 2017, Lia started volunteering with BAMBI Bumps and Babies and Bangkok Breastfeeding Cafe. She had Maya, her daughter, and continues to give all mothers a human approach and support on their breastfeeding journey.

The views expressed in the articles in this magazine are not necessarily those of BAMBI committee members and we assume no responsibility for them or their effects.

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