Emily Oster

2 min Read Emily Oster

Emily Oster

Does Breastfeeding Reduce My Chances of Conceiving?

Q&A on fertility

Emily Oster

2 min Read

My first child is 11 months old, and my husband and I would like to try for another. I feel like we are ready both mentally and physically, and financially it would work better for us to have a smaller age gap. I am still breastfeeding my 11-month-old twice a day. Is there any data on whether this is likely to reduce my chance of falling pregnant? I would like to continue to breastfeed her as long as possible, but if it will significantly impact my chance of falling pregnant, I would consider cutting down or stopping.

—In a rush

How exciting! I wish you all the luck with two under 2!

The answer is in many ways simple: If you are getting a period, you can get pregnant. If not, you may not be able to until that returns.

Ovulation and menstruation return more slowly if you’re breastfeeding than not. Estimates vary, but they suggest that ovulation resumes between 45 and 90 days after birth if you are not breastfeeding, and more like six months or even a year if you are. You cannot get pregnant if you are not ovulating, so if you have not had signs of that (namely, if you’ve not gotten your period back), then you may not be able to get pregnant. In that case, it might be necessary to stop nursing in order to resume fertility. 

lady breastfeeding a child
Dave Clubb / Unsplash

If you are ovulating and getting a period, then breastfeeding shouldn’t interfere with your ability to get pregnant.  

Note: For those of you trying not to get pregnant, please remember that ovulation happens before a period. So you could get pregnant before you’ve had a period, which is why you want to use birth control if you are hoping to avoid pregnancy. 

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A
3 months ago

I found this page on Breastfeeding and Fertility to be helpful: https://kellymom.com/ages/older-infant/fertility/ — particularly the section lower on the page on “The transition to full fertility.”

In my personal experience, my period returned after baby #1 at 12 months PP, it was wonky for a few months, and we conceived baby #2 after 6 months of trying. (For reference, baby #1 only took 2 months of trying.) I was still breastfeeding twice a day at that point. After baby #2, my period returned at 13 months PP and then was in the “ovulation without luteal competence” phase for 5 cycles. I don’t know how old you are, but keep in mind that the time to conception does tend to be longer as you age.

All the best to you! Its a hard decision, whatever you decide to do.

Trex moma
Trex moma
3 months ago

I got pregnant while still breastfeeding my older one when she was 2 years and a bit. I got my period back when the older was almost 2 years. My period was also irregular so it makes it hard to time ovulation.

Liz
Liz
3 months ago

Just wanted to share my personal experience that I started TTC my second while bfing right after my period came back around 9 months and was unsuccessful for 6 months. My obgyn said I could be “subfertile” due to bfing and fully weaned and immediately got pregnant. Certainly there are people who successfully get pregnant while bfing but wanted to share this experience in case it’s helpful. Good luck!

J
J
3 months ago
Reply to  Liz
3 months ago

Thank you or sharing – this is interesting! I have not heard the use of “subfertile”. Did you receive any explanation about what that means given that you were getting a period? Did you try to partially wean first? I am curious, as I have partially weaned but seem to be having irregular cycles based upon OPKs. Thanks again!

Liz
Liz
3 months ago
Reply to  J
3 months ago

I did try to partially wean. My first few cycles were wonky but they got normal for a few months of trying while I was still bfing. I did notice my luteal phase go from 10-13 as I went from frequent bfing to fully weaned. (Its been 14 when not bring)

kate9
3 months ago
Reply to  Liz
3 months ago

Similar story for me. I got my period back at 6 months and 4 months, but my luteal phase was very short until I cut back nursing. I got pregnant with my second right after I cut back breastfeeding to once a day and pregnant with my third after I stopped altogether.

Marisa
Marisa
3 months ago
Reply to  Liz
3 months ago

My experience as well! Period returned at 12 months pp while breastfeeding on demand, though my cycle was irregular (short luteal phase etc). Tried to conceive for 7 months with no luck (by the end I was only nursing about 1-2x per day). My OB advised me to wean because she said some women are just particularly sensitive to the prolactin hormone released while breastfeeding. I weaned and got pregnant 6 weeks later. Our second is now 16 months old, I’m still breastfeeding and my cycle has done almost the exact same thing this time around!

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