Breast Feeding

Breast feeding an article for health professionals. Topics covered:

  • Advising patients about the medical advantages of breast feeding
  • How to assess a breastfed baby with regard to adequate intake
  • How to advise a mother on how to increase her milk supply if necessary
  • How to diagnose and treat medical conditions associated with breast feeding in the mother and baby
  • About Prescribing safely to the breastfeeding mother.

This article provides evidence based information on:

  • The advantages of breast feeding for the infant and the mother
  • Normal feeding patterns for a breastfeeding baby
  • Assessing the feeding relationship
  • Helping a mother increase her milk supply
  • General principles when prescribing for breastfeeding mothers
  • Diagnosis and management of candidiasis, hyperbilirubinaemia, and lactational mastitis.

Most breastfeeding problems can be solved with adequate knowledge of the science and process of breast feeding. Lack of breast feeding, especially if compounded by inappropriate complementary feeding practices, has a lifelong impact on the health of mothers and children. Optimum nutrition is a crucial, universally recognised component of a child's right to enjoyment of the highest attainable standard of health, as stated in the United Nations Convention on the Rights of the Child:

"Breast feeding is considered optimum nutrition for infants with significant beneficial health, economic, and environmental effects."

Key points

Formula feeding is associated with major health disadvantages particularly with regard to:

  • Respiratory illness, both infectious and allergic
  • Cardiovascular disease
  • Diabetes (type 1 and 2)
  • Gastroenteritis
  • Urinary tract infection.
  • Childhood leukaemias

Women who do not breast feed are at increased risk of:

  • Breast cancer
  • Ovarian cancer
  • Type 2 diabetes


Low rates and early cessation of breast feeding result in important adverse health and social implications for women, children, society, and the environment.

The World Health Organization recommends exclusive breast feeding for six months, with appropriate complementary foods to 2 years of age. Public health measures, such as the UNICEF UK Baby Friendly Initiative, have been effective in increasing breastfeeding initiation rates by promoting best breastfeeding practice in healthcare facilities.

GPs and other health professionals have a significant impact on initiation and maintenance of breast feeding provided they have basic knowledge of the the benefits and sufficient skills to support breastfeeding mothers.

What is the evidence for the benefits of breast feeding?

Breast feeding reduces health inequalities

Children from lower socio-economic groups who receive breast milk and who experience later introduction to solid food have health outcomes that are similar to, or better than, the health outcomes of more affluent children who receive formula milk and earlier introduction to solid food (before 6 months).

Breast feeding reduces hospital admissions

In the UK six months of exclusive breast feeding was associated with a 53% decrease in hospital admissions for diarrhoea and a 27% decrease in respiratory tract infections each month. Partial breast feeding was associated with 21% and 25% respectively.

Breast feeding prevents cancer

In 2007 the World Cancer Research Fund published a comprehensive report on the links between cancer, diet, physical activity, and weight. One of their 10 recommendations was that women should breast feed exclusively for six months as there is convincing evidence that breast feeding protects against pre- and postmenopausal cancer and ovarian cancer. The report was produced by nine academic institutions around the world and included 7000 studies.

Respiratory illness

  • The probability of respiratory illness occurring at any time in childhood is significantly reduced if a child is exclusively breast fed and receives no solid food for 15 weeks 
  • Babies fed milk other than breast milk before 4 months of age are at significantly increased risk of asthma
  • Babies exclusively breast fed for four months have less asthma, atopic dermatitis, and allergic rhinitis up to age 2 
  • Infants less than 1 year who were exclusively breast fed for greater than four months had reduced hospital admissions for lower respiratory tract infections compared to formula fed infants
  • One month of exclusive breast feeding conferred protection against allergic food intolerance and respiratory allergens. Protection was evident in children up to age 17 years 

Cardiovascular disease and risk factors in later life

  • Breast feeding influences the three major cardiovascular risk factors: lipid profile, blood pressure, and weight.
  • Children who have been exclusively breast fed during the first 10 days of life had a healthier lipid profile and glucose tolerance at age 50
  • Two meta-analyses evaluated 26 and 28 studies and showed a reduction in total and LDL cholesterol in adults who were ever breast fed compared to formula fed
  • Breast feeding is associated with lower systolic blood pressure at age 7
  • Breast feeding is associated with lower levels of blood pressure in term and preterm babies.
  • Premature babies fed breast milk had lower blood pressure at age 13-16 years
  • Because blood pressure tracks from childhood into adult life with amplification of early differences, the blood pressure difference between breastfed and non-breastfed populations is likely to be substantially greater in adult life
  • Meta-analysis has estimated that in a non-hypertensive population, the potential benefit of breast feeding is greater than the benefit from all other non-pharmacological means of lowering blood pressure, such as weight loss, salt restriction, or exercise
  • Two meta-analyses evaluated 26 studies with 13 studies common to both and found a reduction in blood pressure in adults who were ever breast fed compared with formula fed
  • Breastfed adolescents and adults are less likely to be obese

Infectious disease

Bottle feeding is associated with an increased incidence of:

  • Lower respiratory tract infection
  • Otitis media
  • Gastroenteritis
  • Urinary tract infection.

The protective effect of breast feeding against infectious disease extends beyond the period of breast feeding itself.

Necrotising enterocolitis

Breast feeding reduces the risk of necrotising enterocolitis compared with formula feeding in pre-term infants.


Exclusive formula feeding increases the risk of type 2 diabetes.

Any breast feeding for greater than three months compared with breast feeding for less than three months reduced the risk of childhood type 1 diabetes in later life.

Cognitive development

There is no definite conclusion on whether breast feeding increases cognitive abilities as reflected in childhood intelligence tests, A meta-analysis of 14 studies in 1999 showed that bottle feeding is associated with significantly lower scores for cognitive development than is breast feeding, after adjusting for appropriate key cofactors. Differences were noted at ages 6 to 23 months and were stable across ages. Differences were greater for low birthweight infants and increased with increased duration of breast feeding.

A further meta-analysis in 2000 of more than 75 studies examining pre-term infants did not come to a definitive conclusion.

An analysis of seven higher quality cohort studies and one randomised controlled trial in 2000 demonstrated that performance in childhood intelligence tests was higher in children who had been breast fed for greater than one month compared to those who had not.

Cognitive benefits are thought to be due to the effects of long chain polyunsaturated fatty acids (LCPFAs) present in breast milk. These are necessary for optimum development of neural tissue. Newborn infants cannot synthesise LCPFAs and until recently they were not added to formula milk.

Maternal health

  • The relative risk of breast cancer is reduced by 4.3% for every 12 months of breast feeding in addition to a reduction of 7% for each birth
  • Having been breast fed is associated with a lower risk of pre- and postmenopausal breast cancer
  • Any breast feeding was associated with a reduced risk of ovarian cancer compared with never breast feeding
  • For women without gestational diabetes each additional year of breast feeding was associated with a reduced risk of developing type 2 diabetes.

Common presenting problems for breastfeeding mothers

Perceived insufficient milk supply

Mothers commonly worry that their baby is not getting enough milk. This is the most frequent reason given by mothers for weaning and supplementing with formula feeds. They may not know what to expect with regard to frequency of feeds, duration of each feed, whether to feed from one or both breasts, or when a baby should be "sleeping through the night."

The mother may not be offering their breast to the baby frequently enough or feeding time may be restricted because the mother expects the breastfed baby's feeding pattern to resemble that of a formula fed baby.

Crying after a feed, feeding every two or three hours, or having periods of unsettled behaviour on a daily basis can all be interpreted as hunger and lead a mother to doubt her ability to produce enough milk for her baby.

Assessing a baby and reassuring the mother that her baby is exhibiting normal development and patterns of behaviour may be all that is needed to reassure her and to encourage her to continue breast feeding. Understanding the basic physiology of milk production helps GPs give correct advice should a mother need this reassurance.

Normal feeding pattern and weight gain for a breastfed baby

  • Weight gain is the best indicator of adequate milk intake up to age 3 months.

General guidelines regarding weight gain during infancy and childhood for infants with growth parameters that were appropriate for gestational age at birth include the following:

  • Term infants may lose up to 10% of their birth weight in the first few days of life and typically regain their birth weight by 10-14 days
  • Infants gain approximately 30 g/day until 3 months of age.
  • Infants gain approximately 20 g/day from 3-6 months
  • Infants double their birth weight by 4 months and triple it by 1 year
  • Compared to formula fed infants, exclusively breastfed infants gain weight relatively rapidly for the first three to four months of life and relatively slowly thereafter
  • WHO has devised new international Child Growth Standards for infants and young children up to 5 years of age. These growth standards supercede the National Centre for Health Statisics Growth Charts which have been in use since 1970. They are recommended for use for all children. In the UK only the WHO growth curves for children from birth to 4 years have been adopted for use. They can be downloaded from

The following would be normal for a breastfed baby:

  • Eight to 12 feeds per 24 hours
  • "Cluster feeds" - feeding every hour for two to three hours, usually in the evening, then sleeping for four to five hours
  • Six to eight wet nappies per day
  • Three to six bowel motions per day
  • Stool changes from meconium on day four
  • Growth spurts at 10 days, 3 weeks, and 6 weeks, with increased frequency of feeds for 24-48 hours.

Reasons for perceived insufficient milk supply

When a baby is not gaining adequate weight or not exhibiting normal output it is common for both the mother and the doctor to assume that the milk supply is inadequate and recommend additional calories from an alternative source. While this may solve the immediate problem it does not uncover the cause, which can lie with the mother, the baby, or, most commonly, the mother-baby interaction. Most breastfeeding problems are physiological rather than pathological in origin and are rarely addressed by looking at the mother or baby in isolation.

Milk production in the first five days post-partum is very variable. It appears to occur without reference to the baby's size. In the next three to five weeks milk output is progressively calibrated to the baby's needs, in most cases building up to meet them, but in some cases down regulating to match needs.

In some women the process of down regulation is irreversible during current lactation, so anything that interferes with the baby's needs at this critical stage may mean the mother never reaches peak milk output. Offering calories other than breast milk can cause irreversible down regulation. So can the overuse of pacifiers, which satisfies a baby's desire for sucking and can lead to decreased demand for breast milk.

Frequent feeds (up to 12 per day) may be necessary to stimulate adequate milk supply. Milk supply may be inadequate as a result of inadequate demand by a sleepy baby. You may need to advise the mother on expected frequency and duration of feeds, as outlined above, and reassure her that actual insufficient milk output is rare.

Maternal factors

In some cases the baby may be feeding frequently but the mother has sore nipples and may be restricting the time at the breast, so the baby is not receiving the high calorie hind milk necessary for normal weight gain.

Mothers commonly experience painful nipples in the early stages of lactation. The commonest cause is poor latch on, which in turn leads to ineffective removal of milk from the breast. Milk production and milk quality (fat content of the milk) depend on effective removal of milk from the breast.

Effective milk removal is primarily a function of the quality of mouth to breast apposition (positioning and attachment) and to the duration of access to the breast permitted to the infant. When a baby is not gaining a satisfactory amount of weight, you may simply need to advise the mother about technical improvements to the physical process of breast feeding.

It may be helpful to watch a feed, with particular emphasis on positioning and attachment. This could be done by a doctor or nurse with a knowledge of good breastfeeding technique or a trained lactation specialist, if available. A careful history of frequency, duration of feeds, and persistent nipple pain throughout a feed should uncover any easily rectifiable problems.

When should you refer?

At the Bristol Breastfeeding Clinical Support Service, a project investigating breast milk insufficiency, 85% of referrals for poor milk supply were amenable to correction by offering individual specific help on improving positioning and attachment, optimising feed management, and providing support and encouragement.

No more than 2% of referrals had a pathophysiological cause. The 15% who did require supplementation were supported to continue breast feeding.

Supplementation with artificial formula can have a detrimental effect on the breastfeeding process and signal the end of that particular breastfeeding relationship. Offering a baby calories from an alternative source, such as supplemental formula, in the early phase of lactation can have a detrimental effect on milk production.

You should regard perceived insufficient milk supply as resolvable in most cases. However, the following indicate situations where a baby is not receiving adequate nutrition, and prompt intervention is necessary to uncover the cause and reverse the process:

  • An infant younger than 2 weeks who is more than 10% less than birth weight
  • An infant whose weight is less than birth weight at 2 weeks.
  • An infant who has no urine output in any given 24 hour period
  • An infant who does not have yellow milk stools by the end of the first week
  • An infant who has clinical signs of dehydration
  • An infant between 2 weeks and 3 months with a weight gain of less than 20 g/day or who has unexplained weight loss
  • An infant older than 3 months, with a completely flat or decelerating growth curve.

If you cannot solve the problem after trying all the measures discussed above, the best option is to refer the mother to a specialist breastfeeding service. Unfortunately, there are currently very few referral centres.


In breastfeeding women, the onset of sore, burning, or painful nipples, painful breastfeeding, or pain radiating or "shooting" into the axilla, has for years been diagnosed as ductal candidiasis. The diagnosis is usually made without supporting laboratory findings. Signs may be minimal with little or no rash visible, or the mother may present with a red nipple rash with satellite lesions on the surrounding breast.

Superficial, nipple candidiasis can be treated with clotrimazole or miconazole, applied to the nipple three to four times daily. The baby should be treated with nystatin or miconazole orally.

Ductal candidiasis has been treated systemically with fluconazole, 200-400 mg as a loading dose followed by 100-200 mg daily for two to three weeks, depending on severity. (This dosage is outside of the current licence but corresponds to best practice and is not known to be harmful to mother or baby.)

A recent study has cast doubt on candida as the causative organism of the above symptom complex. (1-3)-B-D-Glucan is a sensitive indicator of candida growth and is a useful diagnostic test for systemic candidiasis. In one small study (n=18) this test failed to isolate candida from the breast milk of women suffering from the symptoms typically attributed to ductal candidiasis. The authors concluded that this symptom constellation represents a different pathology or multiple pathologies and suggest further research.


Jaundice occurs in most newborns and is generally benign. Successful breast feeding reduces the incidence of severe hyperbilirubinaemia. For the great majority of newborns with jaundice and hyperbilirubinaemia breast feeding can and should be continued without interruption. In rare instances of severe hyperbilirubinaemia, breast feeding may need to be interrupted temporarily for a brief period. 

Late onset hyperbilirubinaemia usually peaks between days 7 and 15. The cause is unknown and is still under investigation. It has a familial tendency. Babies with this condition are usually thriving, feeding well, with normal bowel motions. The traditional way to treat this was to stop breast feeding for 12-24 hours and substitute with formula milk. This should not be done without consulting a specialist and measuring bilirubin. There is no consensus on the level at which substitution should occur. Mothers need advice on pumping their milk and should be reassured that it is safe to give this milk to their baby at a later date.

Drugs and breast feeding

  • It is rarely necessary to stop breast feeding in order to prescribe medications
  • Drugs that have a safety concern usually have a safe alternative
  • Medications penetrate the milk more during the colostral phase than during the mature milk phase but as the amount of colostrum ingested is small the total amount of drug delivered to the baby is still small
  • Herbal drugs, high dose vitamins (including high dose vitamin D), and unusual supplements are best avoided
  • Choose drugs that have published data rather than newer drugs
  • Premature babies require a greater degree of caution
  • Evaluate the baby before and after administration and note any unexpected behaviour
  • Lipid soluble drugs such as sedatives or hypnotics transfer more readily into milk.
  • Prolonged use of these medications is not recommended.
  • Paediatric approved drugs usually have a good safety history and are safe
  • With drugs with a short half life, it is possible to reduce the infant's exposure by waiting two or more hours after ingestion before feeding the infant

Drugs contraindicated in breast feeding (This is not an exhaustive list)

  • Amiodarone
  • Antineoplastic agents
  • Chloramphenicol
  • Ciprofloxacin
  • Doxepin
  • Ergotamine
  • Gold salts
  • Iodides
  • Indomethacin
  • Lithium
  • Oestrogens (will decrease milk supply)
  • Pethidine (multiple doses)
  • Radioactive isotopes
  • Vitamin D (high dose only - maintenance doses of vitamin D are safe)

Further information on prescribing in breast feeding is available at

Depression and breast feeding

What should you do if a breastfeeding mother needs an antidepressant?

  • The benefits of breast feeding generally outweigh the relatively small risk of psychotrophic medication for infants and mothers
  • Mothers should be offered the choice to breast feed on medication when possible
  • Levels of psychotrophic medications in the plasma of babies of mothers taking therapeutic doses are often undetectable. Sertraline and paroxetine, are the drugs of choice in women whose psychiatric disorder is successfully managed by these drugs
  • If the woman was taking a different antidepressant successfully during pregnancy it is advisable to continue this drug
  • Fluoxetine (which has a long half life) and citalopram (which has high breast milk and plasma concentrations) should be used with caution and only in patients who had good results with these medications during pregnancy or a previous depressive episode
  • Escitalopram is not recommended as first line due to lack of information on its safety
  • Medications should be given two to three hours before the next feed, when possible, and the baby should be monitored clinically for individual adverse effects
  • No untoward effects have been noted in several studies of breastfeeding women taking amitriptyline or most of the other tricyclic antidepressants. There is one documented case of respiratory depression in an infant exposed to doxepin. This resolved when the drug was stopped, but for this reason it is best not to prescribe it
  • Transdermal oestrogen is not an effective treatment for postnatal depression and may decrease the mother's milk supply
  • Trazodone, venlafaxine, duloxetine, and bupropion are all effective in postnatal depression and while there are no reports of adverse effects in breastfeeding infants it is best not to prescribe first line
  • There is no information available on mirtazapine in breastfeeding women
  • Benzodiazepines should be used with caution in breastfeeding women. If they are considered necessary, low dose clonazepam or lorazepam would be drugs of choice with careful monitoring of the infant for sedation or withdrawal effects.

Lactational mastitis

close up of inflamed breast of 36 year old breast feeding woman with mastitis

Above: A close up of the inflamed breast of a 36 year old woman affected by mastitis during breast feeding.

Symptoms of mastitis include swelling, tenderness, pain, redness, and engorgement of the breast with milk.

Mastitis is an inflammatory condition of the breast that may be accompanied by infection.

It occurs in up to 33% of breastfeeding women. It is most common in the first 12 weeks postpartum, but can occur at any time. It is also more common in first breastfeeding experiences.

Untreated, infectious mastitis can lead to breast abscess.


Mastitis is the result of ineffective removal of milk from the breast. This results in milk stasis in an area of breast tissue. This sets up an inflammatory response leading to pain, erythema, and pyrexia. If it is not resolved the inflamed area can become infected. Infection is more likely to occur if the mother has cracked nipples because this provides a portal of entry for infectious organisms.

Predisposing factors

Feeding history may uncover the cause. For example:

  • The mother may have had reason to decrease frequency or duration of feeds
  • The mother may have initiated weaning or gone back to work, or the baby may have started to sleep through the night, allowing milk to accumulate in the breast
  • The baby may have been ill and decreased the demand for breast feeds
  • The mother may have had a blocked duct that prevented milk from being removed from part of the breast
  • The mother may be suffering from stress or fatigue, which interferes with the production of prolactin and inhibits the milk ejection reflex.

Other predisposing factors include:

  • Anaemia
  • Poor fitting bra
  • Previous breast surgery
  • Over abundant milk supply.


Symptoms include:

  • Mild tenderness to severe breast pain
  • Fever
  • Malaise
  • Flu-like symptoms
  • Myalgia.

Examination may reveal wedge shaped areas of breast, which are pink, hot, swollen, and tender.

Breast abscess occurs in 5-10% of patients and is often associated with delayed or inadequate treatment of mastitis.


The frequency and duration of feeds from the affected breast should be increased to remove milk from the breast. It may be necessary to express milk from the breast temporarily to relieve symptoms. This can be done by hand or with an electric breast pump. It may help the mother if a healthcare professional watches a feed, gives reassurance, and encourages her if her feeding technique is correct.

Analgesia (paracetamol or ibuprofen) is safe and effective. Rest is important because it stimulates release of prolactin and allows the mother to feed more frequently and for longer periods.

Most patients with mastitis need antibiotics. The most common organisms found are Staphylococcus aureus and Staphylococcus albus. Bilateral mastitis is more likely to be due to streptococci.

Antibiotic treatment options include:

  • Flucloxacillin (first line)
  • Erythromycin (penicillin sensitivity)
  • Cephalexin (second line)
  • Co-amoxiclav (third line).

You should prescribe antibiotics for 10 to 14 days to prevent recurrence. Shorter courses are prone to cause relapse, although no controlled studies have evaluated the maximum duration of treatment.

Primary insufficient milk syndrome

Primary insufficient milk syndrome occurs in approximately 5% of breastfeeding women. This means they are unable to produce an adequate milk supply despite establishing a correct feeding pattern and technique. 

Breast surgery, especially procedures that involve periareolar breast incisions, have been associated with insufficient lactation.

A past history of excisional biopsies, breast abscess drainage, breast reduction surgery, and augmentation mammoplasty, all place a woman at increased risk of primary insufficient lactation.

Women who report only minimal or no breast enlargement during pregnancy have been shown to be more likely to exhibit primary insufficient lactation.

On examination such women may have breast hypoplasia with marked reduction of glandular tissue in one or both breasts. While some asymmetry in breast size is normal for most women, marked asymmetry is more likely to be associated with poor milk supply.

Women with this problem may also report little or no engorgement in the postpartum period. Babies of mothers with primary lactation insufficiency may continue to breast feed but will need additional supplementation throughout the breastfeeding period.

Maternal diet and liquid intake do not have a major influence on milk production. Mothers should be advised to eat well for their own benefit and to drink to thirst, but milk production is minimally affected by diet unless severe malnutrition is present.

Diabetic ulcer

a diabetic ulcer on the breast of a 42 year old woman who is breast feeding

Above: Here is a diabetic ulcer on the breast of a 42 year old woman. She has type 1 diabetes mellitus.

Teenage mothers

Pregnancy during adolescence poses additional health risks for both mother and baby. Teenagers are more likely to:

  • Have poor nutritional habits
  • Experience inadequate weight gain during pregnancy
  • Use drugs and alcohol
  • Delay seeking antenatal care.

Teenagers have higher rates of low birthweight infants.

Teenage mothers are physiologically capable of producing milk of sufficient quality and quantity to feed their baby. It is important to discuss this with them in the antenatal period. If possible, you should offer antenatal classes with other teenagers and you should provide evidence based information and advice about breast feeding.

Emphasising that breast feeding will help them return to normal weight more rapidly may be a strong motivating factor for this age group, but you should support this with advice on adequate nutrition and sufficient calorie intake.

It can be helpful to identify a key person in the mother's life to share in the education and support.

Secondary insufficient lactation

Secondary insufficient lactation refers to inadequate milk supply that results from or is secondary to one or more breastfeeding difficulties.

Large full term infants usually nurse much better then small, premature, or small for dates infants. Studies of readmission rates to hospital show that infants born at less than 37 weeks' gestation are more likely to be readmitted for morbidities related to poor feeding than infants born at term.

Many of these infants seem to feed satisfactorily in the first two days of life when milk transfer consists of small amounts of colostrum. When the mother's milk supply increases, these smaller infants are unable to effectively remove the quantity required to stimulate maximum milk production, so the milk supply gradually decreases.

With many mothers and babies being discharged from hospital within 72 hours of delivery, this problem may only be detected in the community. Because of this the American Academy of Pediatrics now recommends that infants discharged less than 48 hours after delivery are assessed by a knowledgeable healthcare professional at age 2 to 4 days. This assessment would ideally include checking the infant's weight and observing a breast feed.

Any abnormality of the infant's oral structures can interfere with their sucking ability and lead to unsatisfactory removal of milk from the breast.

Tight frenulum (tongue tie) occurs in approximately 3% of children. It is a recognised cause of feeding difficulties for both breast and bottle fed babies. Frenulotomy (division of tongue tie) is a simple low risk procedure which leads to improved breastfeeding outcomes in affected cases.

Minor abnormalities of oral structure, such as micrognathia, can give rise to difficulties removing milk from the breast. In addition, the mother may develop sore nipples as a result of an incorrect latch on. This may lead her to feed less frequently and so further diminish milk production.

Any infants with hypotonia, hypertonia, cardiac disorders, or respiratory disease have an increased risk of secondary lactation insufficiency because of poor feeding technique.

But mothers of twins can produce enough milk for both babies provided they do not have any additional risk factors for secondary lactation insufficiency.

close up of the breast of a 42 year old woman showing mastitis - she is breast feeding

Above: A close up of the breast of a 42 year old woman showing mastitis, an inflamed area of the breast caused by a bacterial infection.