巨細胞病毒（Cytomegalovirus, CMV）感染很普遍，新生兒在不同階段皆可受到 感染，包括子宮內、周產期或產後感染。CMV 也可以透過母乳被分泌出來，早產兒 尤其是感染的高危險族群。母乳造成的黃疸，是大家所熟知新生兒延長性黃疸的原因 之一，但其致病機轉並未被完全釐清，感染性疾病是可能的原因之一。我們報告一位 足月兒在出生後就純餵母乳的案例，他在出生後39 小時即出現間接型黃疸，之後又陸 續住院了三次，每次都以間接型黃疸表現。該新生兒在第三次入院時血球檢查就開始 出現中性球偏低且淋巴球增多情形，且在第四次入院時更為明顯。此外，該新生兒每 次入院透過照光、暫停母乳，黃疸就得以緩解，出院後恢復母乳哺餵，黃疸便再復發。 第四次入院時我們以聚合酶連鎖反應（polymerase chain reaction, PCR）檢查了母乳的 CMV，結果呈現陽性反應（8,293 copies），故出院後我們建議暫停母乳至新生兒年紀 滿60 天大，此後黃疸便未再復發。權衡母乳對新生兒的好處、以及避免新生兒受到母 乳的感染是個兩難的議題，但也極度重要，因此我們針對產後經由母乳傳染的新生兒 黃疸做文獻回顧。結論是，兒科醫師對於母乳哺餵的新生兒，若反覆出現延長性黃疸 時需要更加地警覺，在這種情況下母乳中的CMV 須要列入考量。

Cytomegalovirus (CMV) infection causes disease around the world. Transmission can occur in utero or anytime during the perinatal period in infants. CMV can be secreted in the breast milk of infected mothers; preterm infants are at high risk for infection. The role of infectious microorganisms in the pathogenesis of breast milk jaundice, a contributing factor to prolonged jaundice, is still not clear. We report here the case of a full-term neonate presenting indirect hyperbilirubinemia since the first 39 hours after birth. After that, she was hospitalized on four occasions and every time the laboratory results revealed idiopathic indirect hyperbilirubinemia. Neutropenia and lymphocytosis were noted during the third time, and the levels got worse by the time of the fourth admission. During each hospitalization, the jaundice was resolved after stopping breast milk intake and applying phototherapy. However, jaundice recurred upon resuming breast feeding. Finally, during the fourth hospitalization, we checked the maternal breast milk for CMV using a PCR test and saw a positive result with 8,293 copies/ mL. Given all this information, we suggested the mother to stop breastfeeding her neonate for the first 60 days of life and she complied. Thereafter, jaundice did not recur. The dilemma between benefiting from a breast milk diet and avoiding the deleterious effects of infectious diseases transmitted via the milk is an important one in caring for neonates. It is clear studies are needed but based on our experience we recommend that pediatricians remain watchful of CMV-related problems in all infants fed exclusively with breast milk and having prolonged and recurrent neonatal jaundice.