Health & Fitness

How to build stronger bones in preterm infants

When you hold a newborn baby, despite their sturdy little bodies, you can feel their frailty. Many baby’s bones are partially or fully made of cartilage, which is soft and flexible. Throughout your son or daughter’s childhood and adolescence, bones will fuse and cartilage will be replaced by bone. However, premature babies may struggle to build stronger bones during their first year of life.

What causes bone problems in preterm infants?

Preterm infants are at risk for skeletal weakness due to lower amounts of calcium and phosphorus in their bones. Full-term babies begin life with healthy bones because their mothers’ placentas transfer all the calcium and phosphorus that they need. But because most of the mineral transfer occurs in the last three months of gestation, premature babies miss out on those shared nutrients, creating an increased risk for bone health problems.

Babies who were born before 30 weeks of gestation face a high risk for problems such as infection and complications from the immaturity of the lungs and intestines. They also have problems getting the proper nutrition because of poor sucking ability. This is compounded by the lack of proper mineral stores in their bodies. These issues increase the threat of fractures and poor growth, which are now being recognized as significant risks in babies born before 30 weeks.

Recent advances in the care of preterm infants have led to a decrease in bone health problems, but premature infants require special care to ensure healthy bone development.

What are the treatments for this condition?

Premature infant formulas contain higher amounts of calcium and phosphorus, some having as much as four times the amount as formulas given to full-term babies. Powdered supplements are also available to add to breast milk to provide additional calories, protein, calcium and phosphorus. The use of these newly developed formulas has drastically reduced the rate of bone health problems and fractures in preterm infants.

Infants who cannot receive calories by mouth require parenteral nutrition, through an IV in the vein. As chemical sciences have advanced, larger amounts of calcium and phosphorus have been added to parenteral solutions to maintain normal blood mineral levels and to build up bone mineral stores. However, there is concern that the solutions used in parenteral nutrition may contain some unavoidable components such as aluminum, which can significantly impair bone formation.

Other methods of improving bone health in children with extreme prematurity are being investigated. Light physical therapy, such as passive movement exercise, may help improve bone strength. Experts believe it replicates a fetus’ movement against the wall of his or her mother’s uterus. This movement is believed to stimulate muscle and bone strength. It is now common practice for preterm infants to receive physical therapy while in the intensive care unit.

The evaluation and treatment of bone health problems in babies should be under the care of a special neonatal team composed of physicians, nurses, dieticians, pharmacists and physical therapists. Infants who receive parenteral nutrition require careful monitoring of bone health. Despite the many advances in providing nutrition to babies with extreme prematurity, most are not able to achieve normal amounts of calcium and phosphorus in bone and subsequently develop bone weakness.

Careful follow-ups after discharge

As bone growth continues rapidly in the first few years, preterm babies with bone health concerns will require careful follow-ups with a specialist after discharge from the hospital. Some babies will continue to receive a special formula, vitamin D supplement and physical therapy. These measures are taken to ensure healthy bone development and normal growth in preterm babies.

As most babies will show no physical symptoms of poor bone strength, it’s very important for parents to continue follow-up care with their pediatricians. If your baby does suffer a fracture, don’t panic. With gentle handling and an increase in calcium, phosphorous and vitamin D, most babies will heal quickly.

While your premature baby might be more at risk for fractures during the first year of his or her life, the long-term outlook for your child is bright. Following the guidance of your pediatrician will help ensure that your child lives a happy and healthy life.

Supamit Ukarapong, M.D., is a pediatrician who specializes in endocrinology at UHealth – the University of Miami Health System. For more information, visit