Prems need more fluid and calories per pound of body weight than do full-terms, and small-for-dates babies have a lot of catching up to do, too.

Small babies can manage only small feeds, partly because digestion uses a lot of their available energy, so they need feeding frequently. They need high quality food for growth and development and to combat infections and stress. And they may need feeding by IV line, tube or cup before they progress to the breast (or bottle).

Choice of milk

You have three options: breast milk, formula or both.

Breast milk

This is the best food for babies old enough to digest milk, and is particularly important for prems. A wonderful thing about your milk is that its composition will change as your baby grows. The few drops of the very first milk -- creamy, yellowish-white colostrum -- are rich in the very things he most needs, including valuable minerals, such as zinc, anti-infective factors (including live cells, enzymes, hormones, lactoferrin and lysozyme), growth factors and protein. Having colostrum makes a baby less likely to become jaundiced.

The thinner-looking milk which comes next contains 30 per cent more protein than the milk you'll make as your baby nears 40 weeks post-conception age. It also has more of certain minerals (magnesium, phosphorus, sodium and ionised, easy-to-use calcium) and more anti-infective substances (lactoferrin, lysozyme, antibodies and live cells).

Milk fat is well absorbed and provides 50 per cent of the calories your baby needs. And, most important, it's rich in the long-chain polyunsaturated fatty acids DHA (docosahexaenoic acid, an omega-3 fatty acid) and AA (arachidonic acid, an omega-6 fatty acid). These are important for brain, eye and nerve development.

It's particularly important for a premature baby to get plenty of DHA. Prem babies miss out on the large amount of DHA which passes across the placenta in the last weeks of a full-term pregnancy and therefore need good supplies.

Fortifying breast milk -- after the first four weeks, your milk's protein level will fall. If necessary the paediatrician will recommend fortifying it with protein, vitamins (such as E) and minerals (calcium, copper, iron, phosphorus and zinc) to aid your baby's growth and development.

Formula

Pre-term formula is better than standard formula for premature babies younger than 34 weeks post-conception age. Manufacturers try to copy pre-term breast milk, which is why they've recently added DHA, but they can't add such things as a mother's live cells and antibodies.

Benefits of breast milk compared with formula

Breast milk provides these important benefits for premature babies:
• The right nutrients in the right proportions for a baby's post-conception age
• Better digestion, particularly of fat and calcium. Breast milk stimulates bowel function, movement, and hormone and enzyme production, and encourages a healthy population of micro-organisms (the 'bowel flora')
• Good growth rate, of around the rate a baby would have grown had he stayed in the womb, or a little slower. Small-for-dates babies who are breastfed grow faster in the first year than those who are formula-fed. And in the first three months their heads grow faster, probably reflecting better brain growth
• Less illness
• Fewer infections, such as pneumonia, gastroenteritis and ear infection
• Fewer allergic problems, such as asthma and eczema
• Lower risk of anaemia, because iron is better absorbed
• Reduced risk of meconium ileus (bowel paralysis, generally in babies with cystic fibrosis, caused by sticky bowel contents)
• Reduced risk of necrotising enterocolitis, a dangerous reaction to a bowel infection which kills up to two in five affected babies, and is six to ten times more common in babies fed on formula alone compared with those fed on breast milk alone. Babies on formula plus breast milk have a lower risk than formula-only babies, but three times the risk of those on breast milk alone
• Higher development and intelligence test results
• Better visual development and eyesight.

And research suggests that breast milk also reduces the risk of:
• 'Stop-breathing' (apnoea) attacks
• Convulsions
• Unexplained cot death.

Can mothers of premature babies make enough milk?

Women who deliver early can certainly breastfeed. Indeed, many women report making two or three times as much milk as their small baby needs and enjoy the privilege of donating the excess to a milk bank.

However, making enough milk and breastfeeding a prem can sometimes be difficult, because:

• Expressing milk is time-consuming and less immediately rewarding than breastfeeding.

• The lack of the presence and smell of her baby when he can't leave the incubator removes a powerful stimulus for the milk to be 'let down' (to flow spontaneously).

• The ups and downs of a small baby's progress can be stressful and, at worst, can affect the let-down of breast milk.

• The SCBU's stark, clinical, high-tech environment makes some mothers doubt their ability and feel tense and uneasy.

• The SCBU may have a bottle-feeding ethos, with staff paying lip-service to the value of breast milk, but preferring formula because it's 'easier'.

Intravenous (IV) feeding

The smallest (under 1000g -- 2lb 3oz) and most unwell babies, including those on a ventilator, have liquid feed via a fine tube into a vein (IV line). At first this contains glucose and salts and later, perhaps, amino acids, vitamins, minerals and fats, too. The IV line is moved frequently to avoid irritating any one vein.

When the nurses think he's ready, he can have a few drops of your colostrum down a feeding tube into his stomach. Colostrum stimulates the production of hormones which help the digestive system to mature. When a baby can digest milk and breathe unaided, he can progress to tube-feeding.

Tube-feeding

If a baby's digestive system is ready for oral feeds, but he can't yet drink efficiently, he can have milk via a tube into his stomach (or duodenum).

Babies are tube-fed if they:
--Are less than 32 weeks post-conception age
--Breathe faster than 75 breaths a minute
--Can't yet co-ordinate sucking, swallowing, breathing and gagging.

A feed of breast milk (or formula) may be allowed to drip from a syringe down the tube. Feeds are frequent and small. A 900g (2lb) baby, for example, might have only 10:15 ml (2:3 teaspoons) of milk an hour.

Feeds are pushed from the syringe down the tube for some babies. For others an electric pump continuously propels milk down the tube.
Most babies don't seem to mind the feeding tube remaining in place between feeds. But if yours objects, a new one can be inserted each time.
You may notice your baby opening and closing his mouth, putting out his tongue or sucking his fingers during a tube-feed. This shows he is ready to practise sucking at the breast.

Practice sucking at the breast for tube-fed babies

If your baby is well enough to come out of the incubator, give him lots of opportunities to be at your breast so he can enjoy its proximity and, when he's mature and interested enough, start licking milk and, eventually, practice-sucking. It's a good idea to have him by the breast while he's receiving a tube-feed.

He won't breastfeed 'properly' and take much milk until he's mature enough to co-ordinate breathing, sucking and swallowing. But although sucking practice is 'non-nutritive', it's important to his digestion, growth and well-being, and boosts your milk supply.

Practice sucking for formula-fed babies

If you're intending to bottle-feed, your baby can use a dummy for sucking practice.

Feeding by mouth

Your baby can start learning to drink by mouth if he's not on a ventilator, can co-ordinate breathing, swallowing and sucking, and has an efficient gag reflex. As he grows he may use several methods, for example:

For a breast milk-fed baby:
-- Cup alone
-- Cup and breast. Ideally it's best to start cup and breastfeeding together
-- Cup, breast and supplementer (read more on using a supplementer)
-- Breast and supplementer
-- Breast alone.

For a formula-fed baby:
-- Cup and bottle
-- Bottle alone.

For a baby fed both breast milk and formula:
-- Any of the above.

Cup-feeding (from 30-32 weeks)

Start teaching your baby to cup-feed with the feeding tube in place, which means he may be tube- and cup-fed for several weeks.

If you're supplying breast milk:

1 Shake the container of expressed breast milk and put some into a sterilised baby cup. Hold your baby on your lap -- preferably by your naked breast so he smells you and your milk -- and put a drop of milk on his tongue so he tastes its sweetness.
2 Gently tilt the cup so it touches the lower lip and a little milk enters his mouth -- but take care not to swamp him. Within a few days or weeks he'll start lapping the milk like a kitten, or sipping or sucking it. Don't worry how much he takes; the nurses will work out whether he needs a top-up by tube.
3 Make this time as peaceful and relaxed as possible, so he associates cup-feeds with pleasure and tranquillity.

If your baby is formula-fed:
Do as above, but with formula instead.

During the next few weeks your baby will take increasing amounts of milk from a cup and can start feeding from breast or bottle. He'll gradually need less and less by tube and the day will arrive when it can come out.

Some mothers never cup-feed, but start teaching their babies to breastfeed with the tube in place.

Some units don't encourage cup-feeding.

Breastfeeding and bottle-feeding

Most babies need to weigh over 1500g (3lb 5oz) or be 32:34 weeks post-conception age to breastfeed or bottle-feed effectively, though some manage before. However, many babies start learning sooner than this.
If you want to bottle-feed, the nurses will advise you what sort of teat to use. As he becomes used to sucking milk from the bottle, and as he grows stronger, he'll take more and more at each feed until he can eventually stop cup-feeding.

You or someone else could bottle-feed your baby with breast milk, but it isn't wise. A baby who learns to suck from a bottle may have difficulty adjusting to the different and more complex skills needed to suck and 'milk' the breast, and to adjust its flow.

How about another mother's milk?

If your baby is very small, if you can't provide enough milk, even with skilled help, and if he isn't doing well on formula, then it's wise to give him donated breast milk (though it's an excellent idea to continue giving as much of your milk as you can).

Babies who particularly benefit from donated breast milk include:
-- Very-low-birthweight tube-fed babies, especially in their first week, when they tolerate human milk better than formula
-- Those not growing or thriving well
-- Those who've had bowel surgery
-- Those with a poorly functioning immune system, for example those who've already had an infection
-- Those with diarrhoea
-- Those with necrotising enterocolitis. This is six to ten times more common in formula-fed babies, but donated milk is as protective as a mother's own milk. (Read more on necrotising enterocolitis.)

Donated milk should ideally come from the mother of a baby of the same maturity as yours, so the composition of her milk is appropriate. However, such milk may be hard to find because most donated milk comes from mothers of full-term babies.

Donated milk is usually 'drip' milk -- milk that drips from one breast while the mother is expressing or breastfeeding from the other. This is relatively low in fat and contains only two-thirds of the calories of expressed milk. Ideally, your baby should have expressed milk.

Does a breastfed baby need formula?

A breastfed baby doesn't need formula unless his mother can't provide enough milk. If your baby can't yet feed directly from the breast, you may find it difficult to produce enough. However, you can make more if you know how -- ask the SCBU staff or a La Leche League leader or a National Childbirth Trust breastfeeding counsellor. And anyway, a little breast milk is always much better than none.

Your baby can have top-ups of pre-term formula unless there's a special reason for having donated milk. Babies fed breast milk and pre-term formula grow faster than those given breast milk and donated milk, possibly because donated milk is usually drip milk (see How about another mother's milk?, above), and because it is pasteurised, which destroys the fat-releasing enzyme lipase.

Donation