Hughes Ruth C E, Williman Jonathan A, Gullam Joanna E
Department of Obstetrics and Gynaecology, University of Otago, Christchurch, New Zealand.
Biostatistics and Computational Biology Unit, University of Otago, Christchurch, New Zealand.
Aust N Z J Obstet Gynaecol. 2018 Aug;58(4):411-416. doi: 10.1111/ajo.12738. Epub 2017 Nov 2.
In New Zealand, haemoglobin A1c measurements are routinely offered at booking, preferably before 20 weeks gestation, to detect pre-existing hyperglycaemia. A haemoglobin A1c <5.9% (41 mmol/mol) is considered normal based on the reference range for the non-pregnant population.
To determine pregnancy-specific haemoglobin A1c centiles by gestation and ethnicity.
This is a population-based observational study of pregnancies uncomplicated by diabetes (pre-existing or gestational) with ≥1 haemoglobin A1c measurement. Haemoglobin A1c centiles were calculated from data extracted from electronic laboratory and clinical records for pregnancies during 2008-2010.
Included were 6800 pregnancies, European 80% (5462), Māori 6% (415), Pacific Islander 3% (196) and 11% (727) 'Others' (mostly Asian). Haemoglobin A1c levels fell with increasing gestation, reaching a nadir at 24 weeks, a trend verified by longitudinal data from 112 women. The 97.5th centile for haemoglobin A1c in European women was 5.76% (39.5 mmol/mol) at 8 weeks, 5.70% (38.8 mmol/mol) at 16 weeks, and 5.65% (38.3 mmol/mol) at 24 weeks. Non-European women had both higher plasma glucose levels (although within the range considered normal) and higher mean haemoglobin A1c levels compared with Europeans; mean (SD) difference in haemoglobin A1c in Māori +0.13% (0.05) (+1.4 mmol/mol (0.5)), Pacific +0.20% (0.03) (+2.2 mmol/mol (0.3)), 'Others' +0.10% (0.03) (+1.1 mmol/mol (0.3)).
The New Zealand haemoglobin A1c cut-point ≥5.9% (41 mmol/mol) for identifying hyperglycaemia in early pregnancy is greater than the 97.5th centile in European and 'Other' women. Utilising population haemoglobin A1c centiles adjusted by gestation may thus better guide management decisions.
在新西兰，孕期检查时通常会常规检测糖化血红蛋白（HbA1c），最好在妊娠20周之前进行，以检测既往存在的高血糖情况。根据非妊娠人群的参考范围，HbA1c<5.9%（41 mmol/mol）被认为是正常的。
按孕周和种族确定特定于妊娠的HbA1c百分位数。
这是一项基于人群的观察性研究，研究对象为无糖尿病（既往存在或妊娠期糖尿病）并发症且至少进行过一次HbA1c检测的孕妇。从2008 - 2010年期间妊娠的电子实验室和临床记录中提取数据，计算HbA1c百分位数。
纳入6800例妊娠，其中欧洲裔占80%（5462例），毛利人占6%（415例），太平洋岛民占3%（196例），“其他”占11%（727例）（大多为亚洲人）。HbA1c水平随孕周增加而下降，在24周时达到最低点，112名女性的纵向数据证实了这一趋势。欧洲女性HbA1c的第97.百分位数在8周时为5.76%（39.5 mmol/mol），16周时为5.70%（38.8 mmol/mol），24周时为5.65%（38.3 mmol/mol）。与欧洲女性相比，非欧洲女性的血糖水平更高（尽管在正常范围内），平均HbA1c水平也更高；毛利人HbA1c的平均（标准差）差异为+0.13%（0.05）（+1.4 mmol/mol（0.5）），太平洋岛民为+0.20%（0.03）（+2.2 mmol/mol（0.3）），“其他”为+0.10%（0.03）（+1.1 mmol/mol（0.3））。
新西兰用于识别孕早期高血糖的HbA1c切点≥5.9%（41 mmol/mol）高于欧洲和“其他”女性的第97百分位数。因此，使用根据孕周调整的人群HbA1c百分位数可能更好地指导管理决策。
