Continue in App Continue in App

continue to mobile site

What you Really Need to Know about Pregnancy

Emily O.
EMILY O.
Fill 1 Created with Sketch. Fill 1 Created with Sketch. Fill 1 Created with Sketch. Fill 1 Created with Sketch. Fill 1 Created with Sketch.

Join Emily Oster, author of Expecting Better: Why the Conventional Pregnancy Wisdom Is Wrong-and What You Really Need to Know, for a Q&A about questioning the "rules" pregnant moms are often told to abide by. Learn what her research taught her about pregnancy and everything from caffeine to bed rest, and more!

Show more
Emily O. photo Group 2 Created with Sketch.
Have your own question?

Ask Emily, our Economist, Author and Mother!

Message Emily
Thank you, Emily Oster!
TINYHOOD, PARENT OF 5 YEAR OLD

Thank you for such thoughtful and informative answers, Emily! Check out Emily's book, Expecting Better: Why the Conventional Pregnancy Wisdom Is Wrong-and What You Really Need to Know, here: https://www.amazon.com/Expecting-Better-Conventional-Pregnancy-Wrong/dp/0143125702/ref=tmm_pap_swatch_0?_encoding=UTF8&qid=&sr=

It's a great Mother's Day gift! We will be selecting five winners to receive a free copy of the book and will reach out via email this week. Thank you to all attendees for coming!

EMILY ADDED A NEW COMMENT!
Quantity of fish
SARA

Hi Emily! Loved the book and your matrix on fish was especially helpful to me. Many of the sources I am reading say to limit all fish consumption to 12 oz or less a week--does it still make sense to do that even when you're mostly eating salmon and cod? Thank you!

Emily
EMILY

Hm...I cannot see why. Fish is good. This sounds made up.

Oh, here we go: here is a nice summary from Slate discussing how the FDA guideliens now say 8 to 12 ounces per week, like as a minimum, rather than saying do not have more

http://www.slate.com/articles/health_and_science/medical_examiner/2017/05/pregnant_women_should_eat_more_fish_not_less.html

And these guidelines do not specify type. They are likely to be conservative since mostly people eat tunafish, which has the mercury issue.

In conclusion: please ignore this.

SARA

Thank you! It's funny, after reading the Slate article you linked, I see now that I was definitely interpreting the 12oz as a limit instead of as a goal. Our brains become so limit-focused during pregnancy that it's hard not to see it that way. Thanks again!

Emily
EMILY

You're welcome! I totally agree. It's hard to step out of the "what are they telling me not to do now" mindset!

EMILY ADDED A NEW COMMENT!
Alcohol while breastfeeding
SHELLY

Loved your book, the only one I read while pregnant! My question for you - What does the research actually indicate about drinking alchocol (day a glass of wine) while breastfeeding?

Emily
EMILY

I am glad you asked since people seem to have a lot of thoughts about this. It will be in book #2 but ...

In moderation, it is fine.

The concentration of alcohol in breast milk is very low even if you drink a ton. There is an ice paper where they measure the concentration after 4 shots of tequila (DO NOT DO THIS IF YOU ARE PARENTING). It is still extremely low, too low to be a problem.

By extension, if your question is whether you can have a glass of wine (or, say, one tequila shot) the answer is yes. The alcohol concentration in breast-milk would be similar to that in orange juice.

If you do want to totally avoid exposing your baby to this AT ALL you can wait two hours after a drink for the alcohol to clear. 4 hours for two drinks. there is no need to pump and dump.

EMILY ADDED A NEW COMMENT!
Alcohol during 2-week-wait
CHARLOTTE

Hi Emily,

Thanks so much for your wonderful book! I know you say that alcohol in moderation is fine during the two-week-wait, in that it won't negatively affect your baby down the line, but I've also read that even a couple drinks a week can make it harder to conceive. Do you have a sense of how much alcohol is necessary to meaningfully reduce the likelihood of conception? Is a glass of wine OK, or am I halving my chances? (So hard to find accurate info online!)

Emily
EMILY

Yes, this is hard to find good information about.

My sense of the literature is that binge consumption is bad, since it can lead to (effectively) embryonic destruction. But a glass of wine with dinner - we just have nothing in the data to suggest that is a problem for conception.

Emily
EMILY

Probably the best evidence on this is from a Danish study (editorial discussion it here https://www.bmj.com/content/354/bmj.i4540) which shows that there is MAYBE some evidence that 14 or more drinks a week lowers fertility, but below that there is no effect.

CHARLOTTE

Phew—14 drinks is definitely more than I was planning on. Thanks for the response!

Emily
EMILY

Yes, I should have put in that 14 drinks a week is above what they'd recommend to anyone - pregnant or not. So, don't do that anyway!

EMILY ADDED A NEW COMMENT!
Caffeine and kicking
ALEX

Hi Emily! Also loved the book. Based on everything I have read, it seems like a cup of coffee a day is no problem. I stuck with that for the first ~22 weeks of my pregnancy. But now that I can feel the baby kick, I have noticed that when I drink any caffeine the baby starts kicking like crazy! Do you know if there is any reason to be concerned by this? Should we be trying to pay attention to what the baby responds to? Thanks!!!

Emily
EMILY

This is interesting!

It might be that the baby is responding to the caffeine (or the sugar?) but there is no reason to think it would be a problem. Babies often move more when you eat something, or are sitting down. So, in short, no you shouldn't worry. The baby is getting some caffeine, since it crosses the placenta, but (see evidence) there is no reason to think it's a problem.

One note: some people find that if they are breastfeeding and they have coffee their kids get irritable. If you actually think your baby is responsive to caffeine, it could carry over. For your sake, I hope not.

EMILY ADDED A NEW COMMENT!
Bed rest
EDWARD, PARENT OF 23 MONTH OLD, 23 MONTH OLD

I appreciated your section in the book that shows there’s no evidence that bed rest helps avoid premature birth. Are there specific activities that one should avoid in the 20+ week range that would be supported by research? I’m thinking specifically of driving or exercising.

Emily
EMILY

Not really, no.

There are a few activities you do not want to do - skiing, tackle football, basically anything where trauma is possible. And your ligaments get looser during pregnancy so it can be easier to get injured exercising. However: if it feels okay, and you are having a normal pregnancy there is no medical reason not so.

One caveat is that there are some placental issues (previa, specifically) where sex is not recommended. These are usually detected around 20 weeks. So, that is a limitation. Hopefully you are not in that boat.

EDWARD

Thanks again.

EMILY ADDED A NEW COMMENT!
Marijuana safe during pregnancy?
COREY

Hi Emily! Have you done any studies around marijuana usage and pregnancy? I've been suffering from terrible morning sickness (even though I'm now well into my second trimester). I have been reading that in countries outside the US that they recommend marijuana for morning sickness! Is this something I can look into? Thank yoU!

Emily
EMILY

This is a good question! i think the answer is we do not yet really have enough data to know.

The NY Times actually did a little thing on the risks of marijuana a couple of days ago (https://www.nytimes.com/2018/05/07/upshot/its-time-for-a-new-discussion-of-marijuanas-risks.html) and included some discussion of pregnancy. The bottom line is we do not have much evidence in either direction for safety or not, and it's hard to know given that smoking pot is often associated with other behaviors.

I am guessing we'll know much more about this in a few years now that this is legal...

COREY

Yah, that makes sense. Thanks

EMILY ADDED A NEW COMMENT!
Sushi during pregnancy
SUSAN, PARENT OF 4 YEAR OLD, 23 MONTH OLD

Hi Emily! I'm in my second pregnancy and for my first I stayed away from sushi. Is it safe for me to eat? And what are the worries? It seems that a lot of my pregnant friends still eat it without an issue.

Thanks!

Emily
EMILY

There are basically two worries. First, that sushi can carry food-bourne illness like salmonella. This is true, although the risks are no greater than if you were not pregnant. What I say in the book is that you should make sure your sushi is from a high quality vendor - like, no gas station sushi - but this is true whether or not you are pregnant.

A second issue is that some sushi fish can contain a lot of mercury. Specifically, tuna and swordfish (or at least these are the most common high mercury fish). Mercury is not good during pregnancy (bad for baby's brain) so you should avoid these particular fish.

But if you are craving a salmon roll, go for it.

SUSAN

Thank you, Emily! I'm excited to learn about and read your book!

EMILY ADDED A NEW COMMENT!
Cough Drops
CALVIN

Loved the book! Any significant risks with cough drops?

Emily
EMILY

Thanks!

Not that there is any evidence for, no. Standard things like Halls, Riccola, etc, are all considered fine.

EMILY ADDED A NEW COMMENT!
Parental leave
EDWARD, PARENT OF 23 MONTH OLD, 23 MONTH OLD

One more for you (perhaps beyond the scope of pregnancy) but on the top of our minds - any good sources showing better outcomes for infants whose parents take longer leave? Could be good fuel for discussions with our employers. Thanks again!

Emily
EMILY

I'll talk about this some in the new book but, yes, there is some evidence that maternity leave in the first few months of life is good for babies.

Here is a somewhat dense paper on this (https://web.stanford.edu/~mrossin/RossinSlater_maternity_family_leave.pdf, by an economist, which summarizes the literature. Maybe you can give it to your employer and see if they want to wade through it.

The bottom line is that something like 3 to 4 months has been show to be good for babies in short and long term, although longer than that doesn't seem to matter.

EDWARD

Excellent, thank you.