What you need to know about your newborn's poo and wee in the first week of life

What is meconium?

Meconium is the thick, sticky, dark-green or black stool babies pass in the days immediate after birth. It's made up of matter which has been swallowed by the baby in the womb before he was born - intestinal cells which were shed into the gut, lanugo (or hair), mucus, amniotic fluid and water, bile.

• During the birth, amniotic fluid stained with meconium is a possible sign of foetal distress, which will be closely monitored by your health professionals.

• If your pregnancy goes more than 40 weeks pregnant, you might also have meconium-stained amniotic fluid as you give birth without fetal distress. Your health professionals will be closely monitoring your situation.

Most babies pass their first meconium in the first 24 hours of life, and the majority have passed all their meconium within 48 hours. Some babies only have one really large meconium stool. Others have many, and are also normal. When baby starts swallowing and digesting his milk, the milk mixes with the dark tarry green meconium so it becomes a lighter green.

When can you expect your baby to have milk stools?

After the meconium is cleared, then your baby pass only milk stools, which are usually yellow or mustard colour. This occurs by day four or five of life. Again, there's a wide range of normal colour, amount, consistency, frequency of milk stool. Milk stool often has small curds which look like cottage cheese.

If you think of a palmful of stool as the amount of stool that would cover the palm of your hand if the hand was laid flat against the nappy, then you can estimate how many palmfuls of stool your baby is passing over a 24-hour period. As a general rule, newborns pass a total of about three or four palmfuls of stool in a 24-hour period once they have good milk throughput, after your milk comes in.

This might be passed in 'skids' of stool in the nappy, or frequent small amounts of stool. Many babies do more infrequent stool, and then pass a very large one. This is normal, too.

Green stool and mucous in the stool are normal variations, not a sign of problems (including of allergy or lactose overload). You can find out about green stool and mucous in the stool here.

This is something to discuss with your health professionals if you have any concerns or queries.

How much urine will your newborn pass?

Lots of parents are told in their antenatal classes that there needs to be one wee on day one, two wees on day two, and three wees on day three. But again, this an estimate only and varies between newborns.

All babies pass urine (except in the rare situation of a serious medical condition). The urine might be hard to see in the nappy amongst the meconium. Once your milk is in, your baby's urine output increases. Healthy babies, once the milk is in, are having multiple wet nappies per day, often calculated as five heavy wet nappies in a 24-hour period.

Urate crystals in the wee appear pinkish or orange in baby's nappy. These are quite common in the first three days of life, but if they occur after this, they could be a sign that your baby is not getting enough milk or hydrating adequately. Please discuss the appearance of urate crystals in baby's nappy with your midwife or GP.

Contact your doctor straight away if your baby has pale or clay coloured stool

Babies with liver disease may have poo that looks very pale or the colour of clay. This colour is different from the normal yellow, green, or brown of milk stool (whether breast milk or commercial infant formula). If your baby has pale or clay coloured poo, see a doctor immediately.