Preterm infants with late retinopathy of prematurity receive less dietary omega-3 and omega-6 the first two weeks of life

Abstract

Purpose : Long chain polyunsaturated fatty acids (LC-PUFAs) are critical in retinal function and development. During the third trimester, a massive transfer of some of these fatty acids takes place from mother to fetus. Endogenous synthesis of LC-PUFAs in humans is insufficient and dietary sources are required. We hypothesized that low dietary omega-3 and 6 LC-PUFA intake and serum levels correlate with ROP.

Methods : In 78 infants born at gestational age <28 weeks, cord and/or venous blood samples were obtained at ages 1, 7, 14, and 28 days and at postmenstrual age (PMA) 32, 36, and 40 weeks. Fatty acids were transmethylated and measured by gas chromatography–mass spectrometry. Longitudinal phospholipid fatty acid levels were correlated with ROP development. All infants received parenteral and enteral nutrition according to clinical outline. Total daily intake of arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), protein (mg/kg/d) and energy (kcal/kg/d) were prospectively recorded from birth to 2 weeks of age. ROP screening began at 5–6 weeks of age but not before 31 weeks PMA. ROP was classified according to the international classification.

Results : Seventeen infants developed no ROP, 30 mild (stage 1-2) and 31 severe ROP (stage 3). Infants who developed severe ROP had significantly less dietary intake of AA, EPA and DHA in the first two weeks, than infants without ROP, but no difference in energy or protein intake. Infants with later severe ROP versus no ROP, had increased serum fraction of omega-6 FA linoleic acid (LA) and decreased levels of its product AA from week one to four after birth. We also found increased fraction of omega-3 LC-PUFA alpha-linolenic acid (ALA) and decreased serum fractions of its products DHA and EPA at 32 weeks PMA, which correlated with ROP.

Conclusions : Less dietary LC-PUFAs DHA, EPA and AA the two first weeks of life were associated with an increased risk of ROP. Lower serum levels of AA during the period corresponding to the first phase of ROP and lower DHA week 32 corresponding to the beginning of the second, proliferative phase of ROP were associated with an increased risk of severe ROP. Since high levels of LA and ALA affect their conversion to LC-PUFA, studies on how to optimize lipid supply to very preterm infants are needed.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.