Vitamin K status of preterm infants with a prolonged prothrombin time

Area of Science:

• Neonatology
• Pediatric Hematology
• Nutritional Biochemistry

Background:

• Preterm infants are at increased risk for vitamin K deficiency, which can lead to prolonged prothrombin times (PT).
• Standard vitamin K prophylaxis is administered at birth, but abnormal PT can persist in some preterm infants.
• The cause of prolonged PT in these infants requires further investigation.

Purpose of the Study:

• To assess the vitamin K status of preterm infants presenting with a prolonged PT within the first month of life.
• To determine if vitamin K deficiency is the underlying cause of abnormal PT in this vulnerable population.
• To clarify the etiology of prolonged PT in preterm neonates despite adequate prophylaxis.

Main Methods:

• Studied 21 preterm infants (<32 weeks gestation) with abnormal PT despite receiving 0.2-0.5 mg of vitamin K1 at birth.
• Assessed vitamin K status through measurement of vitamin K1 concentrations and PIVKA-II levels.
• Correlated vitamin K status markers with prothrombin time results.

Main Results:

• All infants exhibited normal or even supraphysiological levels of vitamin K1.
• Undetectable or insignificant levels of PIVKA-II were observed in all infants.
• These findings indicate that vitamin K status was adequate in all studied preterm infants.

Conclusions:

• A prolonged PT in the first month of life for preterm infants (<32 weeks gestation) receiving at least 0.2 mg of vitamin K1 after delivery is unlikely to stem from vitamin K deficiency.
• The etiology of prolonged PT in these infants warrants further investigation beyond vitamin K status.
• This study suggests that alternative diagnostic approaches are necessary for preterm infants with persistent coagulopathy despite prophylaxis.