Re: Managing infants who cry excessively in the first few months of life
There has been a trend to inappropriate diagnosis of lactase insufficiency or lactose intolerance in unsettled babies in the first weeks and months of life, accompanied by treatment with either lactase or a lactose-free formula.1 While a decline in lactase-specific activity commonly occurs as early as 3-5 years of age in humans, congenital lactase deficiency is extremely rare. Babies may, however, acquire a transient, secondary lactose intolerance resulting from damage to the intestinal villi, most commonly due to gastroenteritis or cow’s milk allergy. In formula-fed infants, secondary lactose intolerance may respond to lactose-free formula (although babies with cow’s milk allergy who are mistakenly diagnosed with lactose intolerance could experience perpetuation of their gut lesion if the lactose-free formula contains cow’s milk protein). Weaning is not indicated in breastfed babies with secondary lactose intolerance, although a cow’s milk allergy maternal elimination diet may have a role. Functional lactose overload should not be confused with either congenital lactase insufficiency, or secondary lactose intolerance. Functional lactose overload does not result from abnormality of either the mother’s milk or the infant’s lactase production, but is a common breastfeeding management problem.
Signs of functional lactose overload occur in a baby when breastfeeds consistently contain inadequate amounts of fat. When the lipid fraction of a breastfeed reaches the stomach, high levels of plasma cholecystokinin are triggered, resulting in feelings of satiety. Lipid also slows down milk transit through the intestine. A breastfeed that has too little “cream” results in both poor satiety, and rapid gut transit without time for the milk to be properly digested by the existing lactase so that lactose ferments in the colon, causing low-grade inflammation and crying.2
The volume and constitution of breastmilk, including the relative lipid concentration, is dynamic, and dependent on the way each unique mother-baby pair manage their feeding. The best way to ensure breastfeeding homeostasis is to encourage cue-based feeding, which may be very frequent in the first weeks. These very frequent feeds in the first days postpartum–“if the baby isn’t sleeping, it’s feeding”–prime the breasts for good supply in the weeks and months to come, and prevent engorgement and mastitis. Cue-based feeding trains the breast to meet each baby’s unique and variable need. Some examples of breastfeeding management advice that limit the transfer of low-volume, cream-rich milk are:
1. Don’t allow “comfort suckling” (when the baby makes frequent rhythmic flutter-like sucks and only periodic swallows toward the end of a feed).
2. Only allow “ten minutes a side”–or similar instructions to limit the feed
3. Always offer the fuller side first
4. Always feed from both sides
These instructions create other feeding difficulties that may entrench crying behaviours, in addition to functional lactose overload. For example, they ensure that the factors underlying excessively long feeds remain unidentified.
Babies who do not achieve good satiety due to inadequate lipid intake may quickly want more milk. In older breastfed babies, this can result in a cycle of overproduction. The baby feeds very frequently, stimulating the breast to produce more milk, yet still receives inadequate “cream”. Because a breastpump acts as a vacuum but does not extract much of the low volume, lipid-rich milk, babies receiving significant amounts of expressed breastmilk may also develop functional lactose overload.
Optimal management of functional lactose overload is more likely to be achieved through individual assessment and management by a feeding expert, rather than through a “one-size-fits-all” solution. Certainly mothers should be encouraged to offer cue-based care and be informed of the importance of the creamy “dessert”. They should also be encouraged to pay attention to breast comfort as they decide which breast to offer first, without adhering to any particular rule. They can be reassured that the cluster feeds so commonly required by babies in the evenings are usually low-volume high lipid feeds that result in good satiety and help with sleep. Properly taught breast massage may have a role, to help mobilise the lipid fraction. Simplistic instructions to feed only from the one breast over a stipulated period of time can result in other problems e.g. inadequate supply or mastitis. In older babies with functional lactose overload and high maternal supply, a range of strategies may be advised, including pumping once or twice a day to “empty” the breasts, and feeding the baby expressed breastmilk on occasions to allow the breasts to be fuller than usual until the supply settles. Again, other problems may arise if this management is not individually tailored to fit the mother and baby’s situation.3
Functional lactose overload is just one of a range of feeding difficulties that remain unidentified and unmanaged in (both breastfeeding and non-breastfeeding) crying babies. In the same way a clinician refers to a physiotherapist once a musculoskeletal problem has been identified in order to optimise outcomes, referral to an appropriately qualified feeding expert should occur, if at all possible, when indicators of feeding difficulty emerge.
1. Douglas P, Hiscock H. The unsettled baby: Crying out for an integrated, multidisciplinary, primary care intervention. Med J Aust. 2010; 193: 533-536.
2. Evans K, Evans R, Simmer K. Effect of the method of breastfeeding on breast engorgement, mastitis and infantile colic. Acta Paediatr. 1995; 84: 849-852.
3. Smillie CM, Campbell SH, Iwinski S. Hyperlactation: How 'left brained' rules for breastfeeding can wreak havoc with a natural process. Newborn and Infant Nursing Reviews. 2005; 5: 49-58.
Competing interests: No competing interests