Human Milk Fortifiers Can Cause Constipation in Infants
Yes, human milk fortifiers (HMF) can cause constipation in infants, particularly in premature infants who commonly receive these nutritional supplements. 1, 2
Mechanisms and Evidence
- Human milk fortifiers are commonly added to breast milk for premature infants to provide additional nutrients, as breast milk alone may not meet their nutritional needs for optimal growth 3
- As intake of fortifiers increases, stools tend to become harder, as demonstrated in randomized controlled studies comparing different types of fortifiers 2
- In some extreme cases, HMF has been associated with bowel obstruction due to intestinal concretions, particularly in extremely premature infants with birth weights under 1000 grams 1
- The type of fortifier matters - studies comparing bovine colostrum fortifiers to conventional fortifiers found that while both caused harder stools with increased use, bovine colostrum fortifiers resulted in slightly less stool hardening 2
Risk Factors and Considerations
- Extremely premature infants (25-27 weeks gestational age) appear to be at higher risk for severe constipation and potential complications from HMF 1
- Infants with a history of necrotizing enterocolitis may be particularly vulnerable to constipation and other gastrointestinal complications from HMF 1
- The calcium, protein, and fatty acid concentration in fortifiers may contribute to constipation issues and should be carefully considered 1
- Bovine milk-based fortifiers may cause more gastrointestinal issues than human milk-based fortifiers, though evidence on constipation specifically is limited 4
Management Approaches
- For infants showing signs of constipation with HMF:
- Monitor stool patterns using standardized assessment tools like the Amsterdam Stool Scale 2
- Watch for signs of feeding intolerance, including bilious aspirates, abdominal distension, and obstipation 1
- Consider adjusting the concentration or type of fortifier if constipation occurs 2
- Laxatives may be required in some cases, though studies show they were prescribed later in infants receiving bovine colostrum fortifiers compared to conventional fortifiers 2
Clinical Implications
- Healthcare providers should be aware that HMF is an important nutritional intervention for premature infants but carries gastrointestinal side effects including constipation 3, 1
- Regular monitoring of bowel habits is essential when using HMF, with particular attention to extremely premature infants 1, 2
- The benefits of fortification (improved growth and development) must be weighed against potential gastrointestinal side effects 5
- Alternative fortification methods may be considered to minimize gastrointestinal issues while still providing necessary nutrients 6
Prevention Strategies
- Consider using human milk-based fortifiers rather than bovine-based ones when possible, though evidence for constipation prevention specifically is limited 4
- Implement gradual introduction of fortifiers rather than sudden increases in concentration 2
- Monitor stomach appearance scores and bowel gas restlessness as early indicators of developing constipation 2
- For breastfed infants showing signs of constipation, a maternal exclusion diet (restricting milk and eggs) for 2-4 weeks may be beneficial 7