Getting pregnant (or not!) while breastfeeding

Whether you're planning for another baby, or hoping to avoid pregnancy, you'll find all the information you need about breastfeeding and your fertility here.

Women who aren't breastfeeding may ovulate (release an egg) as early as 5 to 6 weeks after the birth. However, if you’re breastfeeding, your hormones don't return to pre-pregnancy levels until much later, and this delays ovulation and the return of periods.  

Breastfeeding mums start menstruating again at different times after giving birth. For some it takes months, for others it can take years. It can depend on your baby’s breastfeeding pattern and on the sensitivity of your body to breastfeeding hormones.  

The return of periods can happen when: 

• your baby starts to breastfeed less or for shorter times, especially if this is sudden 

• you start offering formula top-ups 

• your baby starts sleeping for longer or sleeping through the night  

• your baby starts solids.  

When your periods do return, they may not be regular at first. Compared with other mothers, breastfeeding women whose periods have returned have fewer regular cycles. They are also less likely to get pregnant in the first year after their baby's birth.   

Any change in your vaginal mucus or any bleeding may be a sign of a change in your hormone levels and a return to being fertile. Unless you know your signs of ovulation very well, you probably won’t know for sure that you are fertile again until you have your first period after giving birth. 

The answer is ‘possibly’. If your periods have returned and you are ovulating, your fertility levels may be high enough to get pregnant and weaning will not usually help any further. You can check if you are ovulating with a temperature chart, the Billings Method of cervical mucus changes and/or a home ovulation test kit. 

If you have problems ovulating, or the second half of your menstrual cycle is not long enough to begin a pregnancy, you may need to wean your child for the best chances of success. Women whose periods don’t return until they have fully weaned their babies may also need to wean to allow ovulation to occur. 

If you will need to use IVF treatment it can be a difficult decision whether to wean your child to try again. Parents seem to approach this in two different ways. Some decide they will do anything that might improve their chances of success. This includes weaning. If it doesn’t work, they will know that they did everything possible and not be left to wonder if breastfeeding was stopping pregnancy. Other parents may decide to wait until their child weans. This avoids the stress of weaning early but there is a risk that treatment may not work.