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Children's Health

THE FIRST SIX WEEKS OF LIFE - a parent's guide


Newborns experience many changes in the first six weeks of life. This article provides a thorough overview of normal biological behaviour with advice on feeding, bowel motions, and common illnesses.

the first six weeks of life


The first six weeks of life are an important time for both parent and baby. Although the adaptation from intrauterine life to postnatal life takes place in the first few minutes and then hours from a cardiorespiratory point of view, the gastro-intestinal, renal and neurological adaptation takes much longer.

From a helpless infant whose responses are relatively immature and disorganised the baby becomes an assertive individual who is clearly able to indicate his/her needs, who may smile, initiate a type of conversation, listen and track visually by six weeks.

The success of this venture relies to a large extent on a good maternal-infant relationship, and that in turn depends on adequate support from other family and community members.

Feeding & Growth

Infants will lose weight in the first few days of life. They are born with some extra body fluid to enable this to happen and the initial milk (colostrum) is high in calories which compensates for the low volume.

Weight loss is acceptable up to 10% of the total body weight. For a baby weighing 3kg this represents 300g. By 5-7 days most babies will have regained their birth weight. Over the next few weeks an average weight gain of 150-200g a week is normal so that by 6 weeks of age an average term infant will be approximately 1kg above birth weight.

It is important to acknowledge that babies in utero grow according to the nutritional transfer from the mother. This seems to be more important at this stage than the direct influences of hormones (such as growth hormone) and genetic influences.

Following birth the baby may therefore show a shifting growth pattern catching up or down according to how big their parents are (genetics). One should not be alarmed if the baby therefore starts off at the top of a graph and moves downwards towards the middle or vice versa over the first few months provided they are well.

Babies tend to settle into a rhythm of feeding by the end of the first week but this is variable and it may be normal for a baby to feed every 2 hours or alternatively feed every 6 hours. The vigour and success of feeding may be an indicator of general health and babies who feed poorly may be unwell (e.g. heart problems or an infection).

Bowel Motions

Babies who are breastfed may have bowel motions with every nappy change or alternatively may only have one bowel motion every 6-10 days. Either pattern is normal. Some babies will seem to squirm and get a little uncomfortable after several days without a bowel motion, but the stool itself is soft when it arrives and therefore is not true constipation.

Occasionally babies will develop constipation particularly if they have been mildly dehydrated at any time. An occasional bottle of diluted prune juice might help with this. Drugs to relieve constipation should be avoided unless they have been prescribed by the doctor. Occasional green bowel motions are of no concern if the baby is feeding well and there is no vomiting.


Many babies will spill small amounts after feeds and this is not necessarily abnormal. Unlike adults, it is not uncommon or particularly abnormal for babies to have gastro-oesophageal reflux, i.e. reflux of stomach contents into the mouth. This does not necessarily need treatment provided the baby is not suffering extreme discomfort, losing weight or the vomitus does not contain blood. Before drug treatment is prescribed it is usual to try simple measures such as slowing down of feeds, 'winding', propping after feeds, and using thickened feeds if not breastfeeding.

More obvious vomiting of large amounts is not normal and may represent either a surgical obstruction in the bowel or indicate the baby has another systemic illness such as urinary infection or meningitis. Green vomiting (bile) is particularly abnormal and regarded as needing immediate assessment by a doctor (possible bowel obstruction) and then surgical referral.

There is one condition called pyloric stenosis which comes on at between 3 and 6 weeks. These babies have projectile vomiting and if not treated will lose weight and become quite sick. They have an overdeveloped muscle at the exit of the stomach (the pylorus) and the treatment for this is a minor surgical operation to release the tight muscle. This condition is more common in boys but can occur in girls and there is often a family history.


There have been many studies on the amount of crying that is acceptable in babies in the first weeks of life. Up to two hours a day is not uncommon. You are lucky if your baby has regular biological rhythms and will wake/feed/sleep without much crying. Crying may indicate the baby has needs to be met however, e.g. they are in discomfort because they are wet or dirty, they are hungry, they want company or occasionally because they have other pain which might be regarded as pathological.

Before deciding that such babies have colic it is important that they are thoroughly examined by a doctor who will look for herniae etc. Infantile colic tends to come on in the 2nd - 3rd week, be more common in the afternoons and evenings, their nighttime sleep pattern is usually normal and they are babies who are otherwise thriving.

Colicky babies tend to have a lot of wind and will cry, arch themselves back or draw their legs up as if in discomfort. Babies with severe gastro-oesophageal reflux will also cry and it is sometimes difficult to decide which is contributing to the unsettled behaviour.


Infants are born with immature enzyme systems in the liver and often become jaundiced (yellow) on the 2nd or 3rd day of life. This usually peaks at around 3-5 days and resolves between 1-2 weeks. Babies are more likely to get jaundiced if they are very bruised after delivery because there are increased red blood cells breaking up and releasing the yellow pigment into the circulation.

Any jaundice in a term baby beyond 2 weeks should be evaluated. The most common cause is 'breast milk' jaundice. This is benign and self limiting and usually lasts for approximately 2 months. It is due to substances in the milk which cause a delay in the metabolism of the jaundice pigment. No treatment is necessary. It is however a diagnosis of exclusion.

There are other more serious causes of prolonged jaundice which do need to be looked for. The presence of normal coloured bowel motions and clear urine is reassuring as the more serious causes of jaundice in the newborn infant tend to have abnormal bowel motions and very dark urine. However it is important to check the type of bilirubin in any baby with prolonged jaundice and refer to a specialist if abnormal.

One of the more potentially serious causes of early jaundice is when the baby has a different blood group from the mother and the Coomb's test is positive. This tells us that the baby's blood cells have antibodies on them which are causing them to break up and release jaundice pigment. The antibodies have been made by the mother in the pregnancy against the baby's blood cells. After delivery they wear off quickly but the baby may need treatment to keep the jaundice levels safe.

Very high levels of jaundice have the potential to damage the brain and cause hearing loss which is why we institute treatment. Treatment consists of phototherapy, light at a particular wave length which changes the jaundice pigment (bilirubin) to a less toxic and more easily eliminated product. Babies need to have their eyes covered for protection during phototherapy.

Skin Rashes

The most common rash we see is called toxic erythema neonatorum. These spots occur randomly over the whole body. They often look like little insect bites, raised yellow centres surrounded by an area of redness. They will come and go for several weeks and probably represent a minor allergic phenomenon as the baby reacts to new substances in their environment and feeding. No treatment is necessary for them.

On some occasions similar looking yellow pustules may occur in the so called dirty areas, e.g. under the armpits, in the groin, in the nape of the neck. These might represent a skin infection due to staphylococcal bacteria and should be swabbed and treated with an antiseptic if the infection is confirmed. Occasionally an oral antibiotic syrup may be necessary.

Other areas which are also vulnerable include the umbilical stump. Any redness, swelling or discharge from the umbilical stump should be seen by a health professional and treated appropriately. Infection of finger and toenails (paronychia) that presents as red and peeling fingers and toes around the nail is also a sign of staphylococcal infection needing treatment.

Nappy rashes are common. These are usually just the skin sensitivity to ammonia and other products in the stools and urine. The best initial treatment is to expose the areas as much as possible. Barrier creams can be used to keep water off the skin. Occasionally thrush (candida infection) can occur and this will need treatment with an anti-fungal agent. Swabs should be taken first by the doctor.

Thrush can also present in the mouth as white plaques on the tongue or sides of the cheeks. An oral anti-thrush agent needs to be used in these circumstances. If the baby is breastfeeding, the mother may also need to apply an anti-fungal cream to her nipples.

Another common skin rash is cradle cap or seborrheic dermatitis. This occurs as a scaly brownish plaque and rash occurring in the scalp, occasionally on the eyebrows. It is a dry skin condition. Soap should be avoided and it can be treated with adding oil to the skin. There are several available baby lotions that can be used or a simple oil such as olive oil or almond oil can also be applied.

Eczema which occurs in the elbow creases and behind the knees and other similar places does not usually occur before six weeks of life. This will usually need treatment with hydrating creams and occasionally steroids.

Snuffles & Fevers

A fever in a baby under six weeks of age is always abnormal. The normal temperature is somewhere between 36.8¬?C and 37.4¬?C. Temperatures over 38¬?C may indicate a serious infection and the baby should be seen by a doctor immediately. Low grade fevers around the 37.4 mark are of less concern if the baby is clinically well.

Babies may get colds, develop nasal snuffliness. They should also be seen by a doctor but not necessarily need any treatment. If another family member also has a cold at the time, this is often a clue as to what might be the cause.

Fast breathing (above 50 breaths/min) is also of concern. Parents need to be aware however that babies have periodic breathing so that short bursts of panting or fast breathing may be quite normal. In such babies the panting breathing will be followed by periods of normal breathing. In the pathological situation where there might be an illness or pneumonia the fast breathing is more persistent and not accompanied by slowing down. Breathing difficulty that interferes with feeding is severe enough to warrant assessment by a doctor.


Babies, particularly boy babies, may develop inguinal herniae. These are lumps in the groin or in the scrotum which represent bowel coming down through a weakness in the abdominal wall. They should be seen by the doctor immediately and usually surgical correction is offered within a two week period.

They can occasionally strangulate and cut off the blood supply to the bowel in the hernia, which is why they need repair. Scrotal swellings may also indicate a hydrocele which is simply fluid in the scrotum. This will resolve without treatment, but obviously a hernia needs to be ruled out.

Occasionally the testicle may twist on its axis and strangulate. This causes intense pain and there will be redness and swelling as well. This is a medical emergency and a Paediatric Surgeon will need to intervene as soon as possible to relieve the strangulation otherwise the testis may die.

Umbilical herniae are very common and do not need any treatment. They never strangulate and more than 95% of them will resolve without any intervention within two years. If they persist beyond this period of time they may require a simple operation to correct them.


Over the first six weeks an infant develops a social smile. This may be seen as early as the first few days of life but more commonly babies are seen to smile in their sleep rather than in response to social interaction. Some babies will be delayed with their social and visual responses and parents need not be overly concerned particularly if the baby has been born preterm.

Other developmental milestones to be achieved by six weeks include being able to fix on a face and follow a moving object through an arc. Some babies will also have some head control although the head may still lag when being pulled to the sitting position.

It is reassuring to see infants of 4-6 weeks of age showing an interest in the human face, i.e. studying their parent or caregivers face intensely. Babies that do not do this may either be receiving inadequate stimulation or have a neurological problem.


At six weeks of life the baby normally has a medical check. It is important to discuss with the doctor any concerns you have, and this is the time where the first immunisations are given.

The paediatric recommendations are that immunisations are not delayed beyond this time, particularly because whooping cough and meningitis protection is needed early to prevent the complication of these conditions which are most severe in the very young. If the baby has a mild respiratory infection, i.e. snuffles without fever, it may still be possible to proceed with the immunisations.

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