Premature baby and meconium plug

Question

I gave birth to twin boys at 28 weeks of gestation. After 23 days twin B was submitted to surgery due to meconium ileus. He was fed through IV for two months. He presented with severe cholestasis, which he overcame after two months. 5 days ago we did an ultrasound investigation and he had gallbladder stones.
I and my husband were checked for the 75% of the CF mutations with negative results, and the baby was checked two times at the maternity ward with negative results.
Today the baby is 6 months old (3 months corrected age), gains weight normally, nearly 1 kilogram/month and has never had a cold. Should he have a sweat test? What are the chances of the test being positive for CF? Could this all be due to the IV feeding?

Answer

Dear friend,
In full term neonates the presence of meconium ileus in 98% of the cases is due to CF (Orenstein & Sterns – Treatment of the Hospitalized Cystic Fibrosis Patient, Lung Biology in Health and Diseaser, 1998, pp 5). In preterm and low birth weight neonates the meconium plug syndrome is related to other causes, such as prematurity, hypermagnesia, hypothyroidism, or it could be an early manifestation of Hirschprung disease, etc. The possibility of CF is always present (Palisano et al 2011, Italian Journal of Paediatrics, Carza-Cox et al, 2004, Paediatrics) .
Twin B was operated on and then given IV feeding, due to that he presented with severe cholestasis and some days ago he also presented with cholelihtiasis.
Furthermore:
(1) You and your husband have been checked for the 75% of CF mutations with negative results, something that means that the possibility of having a baby with CF is very greatly reduced, but not totally eliminated.
(2) The neonates with meconium ileus and CF may have a negative IRT result.

Today, your child is 6 months old, with no respiratory infection and gains weight normally. This evidence supports the view that the child does not suffer from CF.
Personally I believe that you should do a sweat test to the baby, in order to exclude the very small chance of CF. With this test the presence of CF can be safely excluded.
Most probably your child does not have CF, and the presented symptoms are a result of the prematurity, something that is corroborated by the normal weight gain and the absence of cough (infections).
You should contact the CF Center at “Aghia Sofia” Hospital to get an appointment for the sweat test.
Yours friendly,
Dr. Stavros Doudounakis

12.09.2013