Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
ICES, Toronto, Ontario, Canada.
JAMA Netw Open. 2020 Dec 1;3(12):e2030207. doi: 10.1001/jamanetworkopen.2020.30207.
Prepregnancy diabetes is associated with higher perinatal and maternal morbidity, especially if periconception glycemic control is suboptimal. It is not known whether improved glycemic control from preconception to early pregnancy and midpregnancy periods can reduce the risk of adverse perinatal and maternal outcomes.
To determine whether a net decline in glycated hemoglobin A1c (HbA1c) from preconception to the first half of pregnancy is associated with a lower risk of adverse outcomes for mother and child.
DESIGN, SETTING, AND PARTICIPANTS: This population-based cohort study was completed in all of Ontario, Canada, from 2007 to 2018. Included were births among women with prepregnancy diabetes whose HbA1c was measured within 90 days preconception and again from conception through 21 weeks completed gestation (early pregnancy to midpregnancy). Statistical analysis was performed from July to September 2020.
Net decrease in HbA1c from preconception to early pregnancy and midpregnancy.
The main outcome was a congenital anomaly from birth to age 1 year. Other outcomes included preterm birth or perinatal mortality among offspring as well as severe maternal morbidity (SMM) or death among mothers. Adjusted relative risks (aRRs) were calculated per 0.5% absolute net decline in HbA1c from preconception up to early pregnancy and midpregnancy, adjusting for maternal age at conception, preconception HbA1c and hemoglobin concentration, and gestational age at HbA1c measurement.
A total of 3459 births were included, with a mean (SD) maternal age of 32.6 (5.0) years at conception. Overall, the mean (SD) HbA1c decreased from 7.2% (1.6%) preconception to 6.4% (1.1%) in early pregnancy to midpregnancy. There were 497 pregnancies (14.4%) with a congenital anomaly, with an aRR of 0.94 (95% CI, 0.89-0.98) per 0.5% net decrease in HbA1c, including for cardiac anomalies (237 infants; aRR, 0.89; 95% CI, 0.84-0.95). The risk was also reduced for preterm birth (847 events; aRR, 0.89; 95% CI, 0.86-0.91). SMM or death occurred among 191 women (5.5%), with an aRR of 0.90 (95% CI, 0.84-0.96) per 0.5% net decrease in HbA1c.
These findings suggest that women with prepregnancy diabetes who achieve a reduction in HbA1c may have improved perinatal and maternal outcomes. Further study is recommended to determine the best combination of factors, such as lifestyle changes and/or glucose-lowering medications, that can influence periconception HbA1c reduction.
孕前糖尿病与围产期和产妇发病率较高相关，尤其是如果围孕期血糖控制不理想。目前尚不清楚从孕前到孕早期和孕中期血糖控制的改善是否可以降低不良围产期和产妇结局的风险。
确定从孕前到妊娠早期和中期糖化血红蛋白（HbA1c）的净下降是否与母婴不良结局的风险降低相关。
设计、地点和参与者：这是一项基于人群的队列研究，于 2007 年至 2018 年在加拿大安大略省进行。研究对象包括孕前糖尿病妇女的分娩，其 HbA1c 在孕前 90 天内和妊娠期间至 21 周妊娠（妊娠早期至中期）再次测量。统计分析于 2020 年 7 月至 9 月进行。
孕前至孕早期和孕中期 HbA1c 的净下降。
主要结局是出生后 1 年内出现先天性异常。其他结局包括后代早产或围产儿死亡以及母亲出现严重产妇并发症（SMM）或死亡。每降低 0.5%的 HbA1c，调整后的相对风险（aRR）从孕前到妊娠早期和中期计算，调整了母亲受孕时的年龄、孕前 HbA1c 和血红蛋白浓度以及 HbA1c 测量时的孕龄。
共纳入 3459 例分娩，受孕时母亲的平均（SD）年龄为 32.6（5.0）岁。总体而言，HbA1c 从孕前的 7.2%（1.6%）下降至妊娠早期至中期的 6.4%（1.1%）。共有 497 例妊娠（14.4%）出现先天性异常，HbA1c 每降低 0.5%，aRR 为 0.94（95%CI，0.89-0.98），包括心脏畸形（237 例婴儿；aRR，0.89；95%CI，0.84-0.95）。早产的风险也降低（847 例；aRR，0.89；95%CI，0.86-0.91）。191 名妇女（5.5%）发生 SMM 或死亡，HbA1c 每降低 0.5%，aRR 为 0.90（95%CI，0.84-0.96）。
这些发现表明，孕前糖尿病妇女如果 HbA1c 降低，可能会改善围产期和产妇结局。建议进一步研究确定哪些因素的组合，如生活方式的改变和/或降血糖药物，可以影响围孕期 HbA1c 的降低，从而影响围孕期和产妇结局。
