Karolinska Institutet, Stockholm, Sweden, Örebro University Hospital, Örebro, Sweden, University of Nottingham, Nottingham, United Kingdom, and Columbia University College of Physicians and Surgeons, New York, New York (J.F.L.).
Karolinska Institutet, Stockholm, Sweden (M.N., J.S., O.S.).
Ann Intern Med. 2019 May 21;170(10):691-701. doi: 10.7326/M18-1974. Epub 2019 Apr 23.
Maternal type 1 diabetes (T1D) has been linked to preterm birth and other adverse pregnancy outcomes. How these risks vary with glycated hemoglobin (or hemoglobin A1c [HbA1c]) levels is unclear.
To examine preterm birth risk according to periconceptional HbA1c levels in women with T1D.
Population-based cohort study.
Sweden, 2003 to 2014.
2474 singletons born to women with T1D and 1 165 216 reference infants born to women without diabetes.
Risk for preterm birth (<37 gestational weeks). Secondary outcomes were neonatal death, large for gestational age, macrosomia, infant birth injury, hypoglycemia, respiratory distress, 5-minute Apgar score less than 7, and stillbirth.
Preterm birth occurred in 552 (22.3%) of 2474 infants born to mothers with T1D versus 54 287 (4.7%) in 1 165 216 infants born to mothers without diabetes. The incidence of preterm birth was 13.2% in women with a periconceptional HbA1c level below 6.5% (adjusted risk ratio [aRR] vs. women without T1D, 2.83 [95% CI, 2.28 to 3.52]), 20.6% in those with a level from 6.5% to less than 7.8% (aRR, 4.22 [CI, 3.74 to 4.75]), 28.3% in those with a level from 7.8% to less than 9.1% (aRR, 5.56 [CI, 4.84 to 6.38]), and 37.5% in those with a level of 9.1% or higher (aRR, 6.91 [CI, 5.85 to 8.17]). The corresponding aRRs for medically indicated preterm birth (n = 320) were 5.26 (CI, 3.83 to 7.22), 7.42 (CI, 6.21 to 8.86), 11.75 (CI, 9.72 to 14.20), and 17.51 (CI, 14.14 to 21.69), respectively. The corresponding aRRs for spontaneous preterm birth (n = 223) were 1.81 (CI, 1.31 to 2.52), 2.86 (CI, 2.38 to 3.44), 2.88 (CI, 2.23 to 3.71), and 2.80 (CI, 1.94 to 4.03), respectively. Increasing HbA1c levels were associated with the study's secondary outcomes: large for gestational age, hypoglycemia, respiratory distress, low Apgar score, neonatal death, and stillbirth.
Because HbA1c levels were registered annually at routine visits, they were not available for all pregnant women with T1D.
The risk for preterm birth was strongly linked to periconceptional HbA1c levels. Women with HbA1c levels consistent with recommended target levels also were at increased risk.
Swedish Diabetes Foundation.
母体 1 型糖尿病（T1D）与早产和其他不良妊娠结局有关。糖化血红蛋白（或血红蛋白 A1c [HbA1c]）水平如何影响这些风险尚不清楚。
研究 T1D 女性围孕期 HbA1c 水平与早产风险的关系。
基于人群的队列研究。
瑞典，2003 年至 2014 年。
2474 名 T1D 母亲所生的单胎婴儿和 1165216 名无糖尿病母亲所生的参考婴儿。
早产（<37 孕周）风险。次要结局是新生儿死亡、巨大儿、巨大儿、婴儿出生损伤、低血糖、呼吸窘迫、5 分钟 Apgar 评分<7 分和死胎。
2474 名 T1D 母亲所生的婴儿中有 552 名（22.3%）发生早产，1165216 名无糖尿病母亲所生的婴儿中有 54287 名（4.7%）发生早产。在围孕期 HbA1c 水平低于 6.5%的女性中，早产的发生率为 13.2%（调整后的风险比[aRR]与无 T1D 的女性相比，2.83 [95%CI，2.28 至 3.52]），在 HbA1c 水平为 6.5%至<7.8%的女性中为 20.6%（aRR，4.22 [CI，3.74 至 4.75]），在 HbA1c 水平为 7.8%至<9.1%的女性中为 28.3%（aRR，5.56 [CI，4.84 至 6.38]），在 HbA1c 水平为 9.1%或更高的女性中为 37.5%（aRR，6.91 [CI，5.85 至 8.17]）。（n=320）经医学指征的早产相应 aRR 为 5.26（CI，3.83 至 7.22）、7.42（CI，6.21 至 8.86）、11.75（CI，9.72 至 14.20）和 17.51（CI，14.14 至 21.69），分别。（n=223）自发性早产相应的 aRR 分别为 1.81（CI，1.31 至 2.52）、2.86（CI，2.38 至 3.44）、2.88（CI，2.23 至 3.71）和 2.80（CI，1.94 至 4.03）。HbA1c 水平升高与研究的次要结局相关：巨大儿、低血糖、呼吸窘迫、低 Apgar 评分、新生儿死亡和死胎。
由于 HbA1c 水平在常规就诊时每年登记一次，因此并非所有 T1D 孕妇都可获得。
早产风险与围孕期 HbA1c 水平密切相关。HbA1c 水平符合推荐目标水平的女性也有更高的风险。
瑞典糖尿病基金会。
