Student Academic Internship Program, University of Rochester Medical Center, Rochester, NY, USA.
Department of Pathology and Laboratory Medicine, University of Rochester Medical Center and Rochester General Hospital, Rochester, NY, USA.
J Matern Fetal Neonatal Med. 2021 Oct;34(19):3214-3219. doi: 10.1080/14767058.2019.1680631. Epub 2019 Oct 29.
Premature infants are born with lower iron stores and are at risk for iron deficiency during early infancy. To prevent iron deficiency, premature infants are routinely supplemented with 2 mg/kg/day oral elemental iron. Reticulocyte hemoglobin content (RET-He), a measure of iron deficiency, has not been well evaluated prior to discharge in premature infants.
Our objectives were to evaluate RET-He and its correlation with serum ferritin (SF), an index of iron stores, at 35-36 weeks postmenstrual age (PMA) in ≤32 weeks gestational age (GA) infants.
We performed a prospective nested study involving 24-32 weeks GA infants who were receiving 2 mg/kg/day oral elemental iron with full enteral feedings at 35-36 weeks PMA. Infants with the following conditions were excluded: craniofacial malformation, chromosomal disorders, TORCH (toxoplasmosis, other infections, rubella, cytomegalovirus, and herpes simplex), culture-proven sepsis, C-reactive protein >5 mg/l within 10 days of iron status assessment, or erythropoietin therapy. SF and RET-He were measured at 35-36 weeks PMA using chemiluminescence immunoassay and Sysmex XN hematology analyzer, respectively. RET-He <27 pg was deemed indicative of iron deficiency.
Ninety-eight infants were studied, of which 21 infants had RET-He <27 pg. There was a positive correlation between RET-He and SF (coefficient 0.22, = .03) that remained significant after controlling for GA (coefficient 0.21, = .03) and frequency of prior erythrocyte transfusions (coefficient 0.21, = .03). On stratified analysis, there was a positive correlation between SF and RET-He in females ( = 52, coefficient 0.23, = .02), but not in males ( = 46, coefficient 0.05).
Most premature infants receiving 2 mg/kg/day oral elemental iron are iron replete for erythropoiesis at 35-36 weeks PMA. RET-He increases with an increase in iron stores, suggesting that additional iron supplementation prior to discharge to very premature infants with borderline low RET-He may help prevent iron deficiency during early infancy.
早产儿出生时体内铁储存量较低，在婴儿早期有缺铁的风险。为了预防缺铁，早产儿通常每天口服 2 毫克/公斤元素铁进行补充。网织红细胞血红蛋白含量（RET-He）是衡量缺铁的一个指标，在早产儿 35-36 周龄时，其在出院前并未得到很好的评估。
我们的目的是评估≤32 周胎龄（GA）的早产儿在 35-36 周龄时的 RET-He 及其与血清铁蛋白（SF）的相关性，SF 是铁储存的一个指标。
我们进行了一项前瞻性嵌套研究，纳入了正在接受 2 毫克/公斤/天口服元素铁治疗且在 35-36 周龄时已完全接受肠内喂养的 24-32 周 GA 的婴儿。有以下情况的婴儿被排除在外：颅面畸形、染色体异常、TORCH（弓形虫病、其他感染、风疹、巨细胞病毒和单纯疱疹）、培养阳性败血症、铁状态评估前 10 天内 C 反应蛋白>5 毫克/升或接受促红细胞生成素治疗。SF 和 RET-He 分别使用化学发光免疫分析和 Sysmex XN 血液分析仪在 35-36 周龄时进行测量。RET-He<27pg 被认为是缺铁的指标。
研究共纳入了 98 名婴儿，其中 21 名婴儿的 RET-He<27pg。RET-He 与 SF 呈正相关（系数 0.22， = .03），控制 GA（系数 0.21， = .03）和既往红细胞输注次数（系数 0.21， = .03）后仍具有统计学意义。在分层分析中，女性（ = 52）SF 与 RET-He 呈正相关（系数 0.23， = .02），但男性（ = 46）SF 与 RET-He 无相关性（系数 0.05）。
大多数接受 2 毫克/公斤/天口服元素铁治疗的早产儿在 35-36 周龄时的铁储备足以满足红细胞生成的需要。RET-He 随着铁储存量的增加而增加，这表明对于 RET-He 处于低值边缘的极早产儿，在出院前额外补充铁可能有助于预防婴儿早期的缺铁。
