• The letdown reflex

You may experience fleeting pain in your breasts when your milk “lets down”. The letdown reflex, also known as the milk ejection reflex, is caused by the action of the hormone, oxytocin. Oxytocin stimulates the muscles of the breast to squeeze out milk. In the first few days after the birth, the hormone is released in response to your baby suckling. Later, anything that makes you think about your baby, or feeding your baby, can trigger this hormone release. Some mothers find that their breasts leak when this happens.

The letdown reflex feels different to different mothers. Some feel a slight tingling, some feel immense amounts of pressure and slight pain or discomfort and others feel nothing at all.

Most mothers are unaware of the letdown reflex in the early days of breastfeeding, although they may be aware of “afterpains” – the pains experienced after birth as their womb contracts down to its pre-pregnancy size – which is caused by the same hormone. They may be more aware of the letdown when their baby is a few weeks old. As time goes by and breastfeeding becomes established, most mothers become less and less aware of it.

• Producing too much milk

Some women who produce an abundance of milk have painful twinges deep in the breast after feeds. Provided your baby latches on well each time he feeds, your milk supply should quickly step down to match your baby’s needs exactly.

• Thrush

If yeast enters the milk ducts, (as a result of thrush) it can make breastfeeding painful. Unlike letdown pain, which is short-lived, thrush pain persists throughout the feed and is usually even worse after feeds. However, thrush in the milk ducts is uncommon – read our article on thrush for more information.

• Engorgement

Engorgement can over-distend the milk-producing cells of the breast, making letdown difficult and sometimes painful.

• Mastitis or blocked ducts

Mastitis or blocked ducts can cause an area of the breast to become red, sore, hard and inflamed.

Other possible causes of breast pain are:

• poor breast pump usage. See our article on expressing for tips on how to do it.

• a badly-fitting bra. The side seams should be on your ribs, not your breast, and the cups should not compress your breasts. Go to a department store or old-fashioned lingerie shop and ask an assistant to measure you properly.

• premenstrual pain. If your periods have started again, you may experience premenstrual pain. This pain should go once your period begins and stays away for the next week or two. The pain then starts to build up again after ovulation. Most women will recognise this cyclical pattern if their breast pain is related to their menstrual cycle.

• fibrocystic breast pain. Some women have a condition called fibrocystic breast disease – lots of lumpy areas in their breasts which can fill with fluid and feel tender and painful. This is a benign (harmless) condition but if you suspect you have it, it’s important to see your doctor so that other causes can be ruled out.

What can I do?

If you learnt breathing or other relaxation techniques during your antenatal classes, try using them as you breastfeed. They may help you cope with discomfort during letdown. If your breasts are engorged, your baby may not be able to latch on well enough to remove the milk effectively. You may need to start off with gentle hand expressing or pumping until your baby is able to draw your breast in sufficiently.

If your pain is caused by excess milk, it may be difficult to latch your baby well to your over-full breast. When your baby starts to suckle, and triggers the strong letdown, he may come off coughing and spluttering. Try this technique: put your baby to your breast as usual. When you feel your milk first let down, gently break the suction and allow the initial spurt to spray into a towel. Let your baby latch on again, better, when the flow slows down a bit. The more often the baby latches on well, the more quickly your supply will settle down and you should be more comfortable.