Irregular periods after birth

A mother holding a new baby against her chest in a red blanket

If you’ve just had a baby, you might be wondering when your menstrual cycles will return, and when they do, how regular they will be and if they’ll be different to pre-pregnancy (heavier, more painful, etc). Read on to find out more about what to expect from your first postnatal menstrual cycle and the consequent cycles thereafter. 

Are periods irregular after pregnancy?

Some women do experience irregular periods after giving birth, particularly if your period returns while you’re still breastfeeding .  You can find more information on breastfeeding and how it can affect your menstrual cycle in the next section.

A period is considered irregular  when the cycle is less than 21 days or more than 35 days.  The average cycle is 28 days, but also considered normal if it falls between 23 to 35 days.  

After giving birth, you may experience postpartum bleeding that is known as lochia. It’s generally heavier than your period and is the body’s way of shedding the uterus’ lining after birth. It can last anywhere from two to six weeks but shouldn’t be considered a period. The lochia bleeding will gradually slow down until it stops altogether. Your first period would be considered the bleed after this.  

Irregular periods and breastfeeding

Breastfeeding can have an impact on your menstrual cycle and this is because the hormone that is required to produce breast milk is also responsible for stopping your period.   When higher levels of prolactin are produced, oestrogen production is reduced or may even stop altogether  .

One particular study showed that around 20% of women will ovulate by six months and 64% will ovulate by 12 months. This means around 46% of women may not get a period in the first year postpartum if they’re regularly breastfeeding. The report also showed that there was an average anovulation period (where you don’t release an egg at all) of 322 days.   

If you’re exclusively breastfeeding, including during the night without also supplying dummies or milk in a bottle, then your period may not return until you start to reduce the amount you breastfeed. This usually happens when you start to wean your baby onto solid foods, reduce night-time feeds or switch your baby to formula or cow’s milk.  

Breastfeeding can be used as a natural contraceptive, with just a 1.1% chance of becoming pregnant when exclusively breastfeeding in the first six months postpartum  , however many women choose to use additional contraceptives instead of natural family planning (NFP) as it’s hard to track cycle length during this time. Ovulation can also occur before your period returns, but you wouldn’t necessarily know you’d ovulated.  

When will my periods regulate post-birth?

There isn’t much research that definitively states when a woman’s periods will regulate post-birth, however one report shows that once a woman’s period returned after birth, most women experienced an average cycle length of 26 to 35 days by three months postpartum.  

If you are worried about irregular, heavy or painful periods after birth, we recommend that you seek advice from a healthcare professional.