Department of Obstetrics and Gynecology, Institution of Clinical Sciences Malmö, Lund University, Skåne University Hospital, Malmö, Sweden.
Department of Obstetrics and Gynecology, Institution of Clinical Sciences Lund, Lund University, Skåne University Hospital, Lund, Sweden.
Acta Obstet Gynecol Scand. 2019 Dec;98(12):1618-1623. doi: 10.1111/aogs.13689. Epub 2019 Aug 12.
Despite much literature on reference values of acid-base status in umbilical cord blood at birth, there are as yet no studies performed to determine gestational age-dependent references in cord venous blood and no studies on preterm acid-base standards. Similarly, the normal reference range of Apgar scores for term and preterm infants has not yet been determined.
Data were obtained from the maternity units of Skåne University Hospital, Malmö and Lund, Sweden, from 2001 to 2010. Validated paired arterial and venous cord pH values were obtained from 27 175 newborns, of whom 18 584 had spontaneous, non-instrumental vaginal deliveries and a 5-minute Apgar score equal to or greater than the median value for the individual gestational week. Simple linear and polynomial regression analyses were performed. Values were reported as mean ± standard deviation and median with 2.5th and 97.5th percentiles.
Median 5-minute Apgar score was 7 for gestations shorter than 28 weeks, 8 for 28 weeks, 9 for 29-30 weeks, and 10 from 31 weeks onwards. A linear decline in pH for both cord arterial and venous blood was seen with advancing gestational age (P < 0.001).
Median 5-minute Apgar scores were <10 before 31 weeks of gestation. Both umbilical cord arterial and venous pH decreased linearly with increasing gestational age. Further studies are needed to show whether gestational age-related pH reference ranges might be preferred to fixed cut-offs in the estimation of umbilical cord acidemia at birth.
尽管有大量关于出生时脐带血酸碱状态参考值的文献，但目前尚无研究确定脐带静脉血的与胎龄相关的参考值，也没有关于早产儿酸碱标准的研究。同样，足月和早产儿的 Apgar 评分的正常参考范围也尚未确定。
数据来自瑞典斯科讷大学医院马尔默和隆德的妇产科，时间为 2001 年至 2010 年。从 27175 名新生儿中获得了经过验证的配对动脉和静脉脐带 pH 值，其中 18584 名新生儿为自发性、非器械性阴道分娩，且出生后 5 分钟 Apgar 评分等于或大于个体胎龄的中位数。进行了简单线性和多项式回归分析。数值以平均值±标准差和中位数以及 2.5%和 97.5%分位数报告。
胎龄小于 28 周的新生儿 5 分钟 Apgar 评分为 7，胎龄为 28 周的新生儿为 8，胎龄为 29-30 周的新生儿为 9，胎龄为 31 周及以上的新生儿为 10。随着胎龄的增加，脐带动脉和静脉血的 pH 值呈线性下降（P<0.001）。
在 31 周之前，中位数 5 分钟 Apgar 评分<10。脐带动脉和静脉血 pH 值均随胎龄增加呈线性下降。需要进一步研究以表明，在估计出生时脐带酸中毒时，与胎龄相关的 pH 值参考范围是否可能优于固定的截断值。
