目的 探讨早产儿生后早期低体温的危险因素以及实施标准复温措施后其复温速率是否为影响早期临床结局的关键因素。 方法 本研究为回顾性队列研究，分析2022年1月至2024年12月由医院新生儿转运团队接诊的区域内早产儿的临床资料。根据转运前体温分为正常体温组（≥36.5 ℃）和低体温组（<36.5 ℃）；低体温组给予统一的复温策略，根据保温干预后的复温速率进一步将低体温组分为复温慢速组（<0.5 ℃/h）和复温快速组（≥0.5 ℃/h）。分别分析在<32⁺⁰周和32⁺⁰~36⁺⁶周两组早产儿早期低体温发生的危险因素，并比较复温慢速组和复温快速组出生后7天内关键临床指标（死亡、肺出血、严重颅内出血、凝血功能异常、使用1种及以上血管活性药物比例）以及7天后仍使用有创呼吸机辅助通气比例的差异。 结果 共纳入来自6家分娩机构的1 016例早产儿，胎龄<32⁺⁰周早产儿250例，214例发生低体温（85.6%）；胎龄32⁺⁰~36⁺⁶周早产儿766例，530例发生低体温（69.2%）。胎龄<32⁺⁰周早产儿的低体温发生率高于胎龄32⁺⁰~36⁺⁶周早产儿（P<0.001）。在所有纳入早产儿中，正常体温组272例（26.8%），低体温组744例（73.2%）；在低体温组中，复温慢速组338例，复温快速组406例。在<32⁺⁰周胎龄早产儿中，与正常体温组相比，低体温组的母亲年龄较大、早产儿出生胎龄较小，出生体重较轻、胎龄别体重Z评分较低，差异均有统计学意义（P<0.05）；在32⁺⁰~36⁺⁶周胎龄早产儿中，低体温组早产儿的出生体重较轻（P<0.05）、产房插管比例较高（P<0.014）。进一步对复温慢速组和复温快速组进行比较，在<32⁺⁰周胎龄早产儿中，复温慢速组辅助生殖比例更低、男性比例更高，差异均有统计学意义（P<0.05）；在32⁺⁰~36⁺⁶周胎龄早产儿中，复温慢速组出生胎龄较小（P<0.05）。在<32⁺⁰周胎龄早产儿中，低体温组7天后仍需有创呼吸机辅助通气比例高于正常体温组（P<0.014）；在32⁺⁰~36⁺⁶周胎龄早产儿中，低体温组和正常体温组短期结局指标未观察到显著差异。在所有胎龄早产儿中，复温慢速组和复温快速组的短期临床结局指标均未观察到显著差异。 结论 区域内早产儿出生后早期低体温发生率较高，<32⁺⁰周胎龄早产儿低体温增加7天后仍需有创呼吸支持概率，尤应强调在产房中对极早产儿生后低体温的预防；在标准复温措施下，早产儿体温上升的快慢并未对生后早期临床结局产生显著影响。

Objective To explore the risk factors of early postnatal hypothermia in premature infants and whether the rewarming rate after the implementation of standard rewarming measures is a key factor affecting early clinical outcomes. Methods This study was a retrospective cohort study, selecting the clinical data of premature infants in the region who were treated by the hospital's neonatal transfer team from January 2022 to December 2024. According to the body temperature before transfer, they were divided into the normal body temperature group (≥36.5 ℃) and the hypothermia group (<36.5 ℃). The hypothermia group was given a unified rewarming strategy. According to the rewarming rate after insulation intervention, the hypothermia group was further divided into the slow rewarming group (<0.5 ℃/h) and the rapid rewarming group (≥0.5 ℃/h). Clinical outcomes within the first 7 days after birth (including mortality, pulmonary hemorrhage, severe intracranial hemorrhage, coagulation abnormalities, and the proportion requiring one or more vasoactive agents) and the proportion of infants still requiring invasive mechanical ventilation beyond 7 days were compared across different gestational age subgroups (<32⁺⁰ weeks and 32⁺⁰-36⁺⁶ weeks). Results A total of 1,016 preterm infants from 6 delivery institutions were included. Among the 250 infants with a gestational age of <32⁺⁰ weeks, 214 developed hypothermia (85.6%); among the 766 infants with a gestational age of 32⁺⁰-36⁺⁶ weeks, 530 developed hypothermia (69.2%). The incidence of hypothermia was significantly higher in the <32⁺⁰ weeks group compared to the 32⁺⁰-36⁺⁶ weeks group (P<0.001). The normal temperature group comprised 272 cases (26.8%), while the hypothermia group included 744 cases (73.2%). Within the hypothermia group, 338 cases were in the slow rewarming group and 406 in the rapid rewarming group. Among preterm infants with a gestational age of <32⁺⁰ weeks, compared with the normal body temperature group, the mothers in the hypothermia group were older, the gestational age of preterm infants at birth was smaller, the birth weight was lower, and the weight-for-gestational-age Z-score was lower. The differences were all statistically significant (P<0.05). Among preterm infants with gestational ages ranging from 32⁺⁰ to 36⁺⁶ weeks, the preterm infants in the hypothermia group had a lower birth weight (P<0.05) and a higher proportion of intubation in the delivery room (P<0.014). Further comparison was made between the slow rewarming group and the rapid rewarming group. Among preterm infants with a gestational age of <32⁺⁰ weeks, the proportion of assisted reproduction was lower and the proportion of males was higher in the slow rewarming group, and the differences were statistically significant (P<0.05). Among preterm infants with gestational ages ranging from 32⁺⁰ to 36⁺⁶ weeks, the slow rewarming group had a smaller gestational age at birth (P<0.05). In preterm infants with a gestational age of <32⁺⁰ weeks, the proportions of infants still requiring invasive mechanical ventilation beyond 7 days were higher in both the slow and rapid rewarming groups compared to the normal temperature group (P<0.014). Among preterm infants with a gestational age of 32⁺⁰ to 36⁺⁶ weeks, no significant differences in short-term outcome indicators were observed between the hypothermia group and the normal body temperature group. Among all preterm infants of gestational age, no significant differences were observed in the short-term clinical outcome indicators between the slow rewarming group and the rapid rewarming group. Conclusions The incidence of early hypothermia in preterm infants within the region is relatively high. Hypothermia in preterm infants with a gestational age of <32⁺⁰ weeks increases the probability of requiring invasive respiratory support 7 days after birth. It is particularly important to emphasize the prevention of hypothermia in extremely preterm infants immediately after birth in the delivery room. Under standard rewarming measures, the speed at which preterm infants' body temperature rises does not have a significant impact on their early clinical outcomes after birth.