Emily Oster

2 min Read Emily Oster

Emily Oster

Should I Throw Away Old Formula Powder?

Q&A on Unused Formula

Emily Oster

2 min Read

The standard guidelines say to throw out unused formula powder after 30 days. I’m supplementing, so we don’t go through a full can in 30 days, and throwing out this not-inexpensive formula feels so wasteful. Have there been any studies done? Why do I have to throw it out?

—Supplementing Sally

During the formula shortage last year, this was an extremely popular question. The idea of throwing away expensive formula in any circumstance is tough, and during the shortage it was even harder. Yet even in that situation, regulators were urging people to throw away formula rather than use expired formula. Why?

There are two primary reasons to be worried about formula stored over long periods. One is that bacteria can be introduced and multiply, and make a baby sick. This is a larger concern for infants who are preterm or immunocompromised, but it can be a risk for any infant. A second concern is that the nutrients in formula break down over time. This happens as a result of the breakdown of the polyunsaturated fatty acids that fortify formulas.

There are studies. Here’s one, using a sample of European formulas, that looked carefully at the degradation of formulas with storage time. The study looked both at storage unopened and storage once opened. Reassuringly, the researchers find the formula is fairly stable when unopened, supporting the general expiration timing. However, once opened, the formula degraded much more quickly, supporting the relatively short usage window.

Is there something magic about 30 days? No, of course not. But the general idea of using within a few weeks does seem to be supported by the evidence on degradation.

Formula companies: Please consider smaller packages!

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Prevention is key! I suggest:
⭐ Regular tick checks
⭐ Using bug sprays with DEET 
⭐ Wearing long sleeves and pants in the woods

Some parents worry about DEET, but repellants with up to 30% DEET are recommended by both the CDC and AAP. The data says you’re in the clear, so go for it. Enjoy your summer!

#parentdata #emilyoster #tickseason #bugbites #bugspray

Bug season is upon us. Besides annoyance, this can bring up safety concerns, particularly with ticks. They are carriers of diseases, most notably Lyme disease. So what’s the best course of action?

Prevention is key! I suggest:
⭐ Regular tick checks
⭐ Using bug sprays with DEET
⭐ Wearing long sleeves and pants in the woods

Some parents worry about DEET, but repellants with up to 30% DEET are recommended by both the CDC and AAP. The data says you’re in the clear, so go for it. Enjoy your summer!

#parentdata #emilyoster #tickseason #bugbites #bugspray
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What are some pregnancy rules you chose to bend after being empowered by data?

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👉Comment “Link” for a DM to an article that summarizes all of the best potty training advice we collected.

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Do you brand things a certain way to get your kid to accept it? Like calling carrots “rabbit popsicles”? Or telling them to put on their “super speed socks” in the morning? Share your rebrands in the comments below! You never know who you might be helping out 👇

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Comment “Link” for a DM to an article on the data around sun and heat exposure for babies.

#sunsafety #babysunscreen #babyhealth #parentdata #emilyoster

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OUT NOW: My new book “The Unexpected: Navigating Pregnancy During and After Complications” is available on April 30th. All of my other books came out of my own experiences. I wrote them to answer questions I had, as a pregnant woman and then as a new parent. “The Unexpected” is a book not to answer my own questions but to answer yours. Specifically, to answer the thousands of questions I’ve gotten over the past decade from people whose pregnancies were more complicated than they had expected. This is for you. 💛 Order now at my link in bio! ...

OUT NOW: My new book “The Unexpected: Navigating Pregnancy During and After Complications” is available on April 30th. All of my other books came out of my own experiences. I wrote them to answer questions I had, as a pregnant woman and then as a new parent. “The Unexpected” is a book not to answer my own questions but to answer yours. Specifically, to answer the thousands of questions I’ve gotten over the past decade from people whose pregnancies were more complicated than they had expected. This is for you. 💛 Order now at my link in bio!

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OUT NOW: My new book “The Unexpected: Navigating Pregnancy During and After Complications” is available on April 30th. All of my other books came out of my own experiences. I wrote them to answer questions I had, as a pregnant woman and then as a new parent. “The Unexpected” is a book not to answer my own questions but to answer yours. Specifically, to answer the thousands of questions I’ve gotten over the past decade from people whose pregnancies were more complicated than they had expected. This is for you. 💛 Order now at my link in bio!

OUT NOW: My new book “The Unexpected: Navigating Pregnancy During and After Complications” is available on April 30th. All of my other books came out of my own experiences. I wrote them to answer questions I had, as a pregnant woman and then as a new parent. “The Unexpected” is a book not to answer my own questions but to answer yours. Specifically, to answer the thousands of questions I’ve gotten over the past decade from people whose pregnancies were more complicated than they had expected. This is for you. 💛 Order now at my link in bio! ...

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Sources:
📖 #ExpectingBetter pp. 160-163
📈 Robert M. Silver et al., “Prospective Evaluation of Maternal Sleep Position Through 30 Weeks of Gestation and Adverse Pregnancy Outcomes,” Obstetrics and Gynecology 134, no. 4 (2019): 667–76. 

#emilyoster #pregnancy #pregnancytips #sleepingposition #pregnantlife

Is side sleeping important during pregnancy? Comment “Link” for a DM to an article on whether sleep position affects pregnancy outcomes.

Being pregnant makes you tired, and as time goes by, it gets increasingly hard to get comfortable. You were probably instructed to sleep on your side and not your back, but it turns out that advice is not based on very good data.

We now have much better data on this, and the bulk of the evidence seems to reject the link between sleep position and stillbirth or other negative outcomes. So go ahead and get some sleep however you are most comfortable. 💤

Sources:
📖 #ExpectingBetter pp. 160-163
📈 Robert M. Silver et al., “Prospective Evaluation of Maternal Sleep Position Through 30 Weeks of Gestation and Adverse Pregnancy Outcomes,” Obstetrics and Gynecology 134, no. 4 (2019): 667–76.

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#pregnancy #pregnancycomplications #pregnancyjourney #preeclampsiaawareness #postpartumjourney #emilyoster
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Only two weeks until our book “The Unexpected” is here! Preorder at the link in my bio. 💙

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Only two weeks until our book “The Unexpected” is here! Preorder at the link in my bio. 💙
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