Aims/hypothesis

We aimed to identify potentially modifiable risk factors and causes for preterm delivery in women with type 1 or type 2 (pre-existing) diabetes.

Methods

A secondary analysis of a prospective cohort study of 203 women with pre-existing diabetes (117 type 1 and 86 type 2 diabetes) was performed. Consecutive singleton pregnancies were included at the first antenatal visit between September 2015 and February 2018.

Results

In total, 27% (n = 55) of the 203 women delivered preterm at median 36 + 0 weeks. When stratified by diabetes type, 33% of women with type 1 diabetes delivered preterm compared with 20% in women with type 2 diabetes (p = 0.04). Women delivering preterm were characterised by a higher prevalence of pre-existing kidney involvement (microalbuminuria or diabetic nephropathy) (16% vs 3%, p = 0.002), preeclampsia (26% vs 5%, p < 0.001), higher positive ultrasound estimated fetal weight deviation at 27 gestational weeks (2.7% vs −1.6% from the mean, p = 0.008), higher gestational weight gain (399 g/week vs 329 g/week, p = 0.01) and similar HbA_1c levels in early pregnancy (51 mmol/mol [6.8%] vs 49 [6.6%], p = 0.22) when compared with women delivering at term. Independent risk factors for preterm delivery were pre-existing kidney involvement (OR 12.71 [95% CI 3.0, 53.79]), higher gestational weight gain (per 100 g/week, OR 1.25 [1.02, 1.54]), higher positive ultrasound estimated fetal weight deviation at 27 gestational weeks (% from the mean, OR 1.07 [1.03, 1.12]) and preeclampsia (OR 7.04 [2.34, 21.19]). Two-thirds of preterm deliveries were indicated and one-third were spontaneous. Several contributing factors to indicated preterm delivery were often present in each woman. The main indications were suspected fetal asphyxia (45%), hypertensive disorders (34%), fetal overgrowth (13%) and maternal indications (8%). Suspected fetal asphyxia mainly included falling insulin requirement and abnormal fetal haemodynamics.

Conclusions/interpretations

Presence of preeclampsia, higher positive ultrasound estimated fetal weight deviation at 27 gestational weeks and higher gestational weight gain were independent potentially modifiable risk factors for preterm delivery in this cohort of women with pre-existing diabetes. Indicated preterm delivery was common with suspected fetal asphyxia or preeclampsia as the most prevalent causes. Prospective studies evaluating whether modifying these predictors will reduce the prevalence of preterm delivery are warranted.

Graphical abstract

中文翻译：

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1 型和 2 型糖尿病女性早产的潜在可改变危险因素

目标/假设

我们旨在确定 1 型或 2 型（已存在的）糖尿病女性早产的潜在可改变风险因素和原因。

方法

对 203 名既往患有糖尿病（117 名 1 型糖尿病和 86 名 2 型糖尿病）女性的前瞻性队列研究进行了二次分析。2015 年 9 月至 2018 年 2 月期间的第一次产前检查包括连续单胎妊娠。

结果

总共有 203 名女性中有 27% ( n  = 55) 在中位 36 + 0 周时早产。按糖尿病类型分层时，33% 的 1 型糖尿病女性早产，而 20% 的 2 型糖尿病女性 ( p  = 0.04)。早产妇女的特征是预先存在肾脏受累（微量白蛋白尿或糖尿病肾病）的患病率较高（16% vs 3%，p  = 0.002），先兆子痫（26% vs 5%，p  < 0.001），估计超声阳性率较高妊娠 27 周时胎儿体重偏差（2.7% vs -1.6%，p  = 0.008），更高的妊娠期体重增加（399 g/周 vs 329 g/周，p  = 0.01）和相似的 HbA _1c妊娠早期水平（51 mmol/mol [6.8%] vs 49 [6.6%]，p = 0.22）与足月分娩的女性相比。早产的独立危险因素是预先存在的肾脏受累（OR 12.71 [95% CI 3.0, 53.79]），更高的妊娠期体重增加（每 100 g/周，OR 1.25 [1.02, 1.54]），更高的阳性超声估计胎儿妊娠 27 周时的体重偏差（平均值的百分比，OR 1.07 [1.03, 1.12]）和先兆子痫（OR 7.04 [2.34, 21.19]）。三分之二的早产是有指征的，三分之一是自发的。每个妇女通常都存在一些导致早产的因素。主要适应症为疑似胎儿窒息（45%）、高血压疾病（34%）、胎儿过度生长（13%）和母体适应症（8%）。疑似胎儿窒息主要包括胰岛素需求下降和胎儿血流动力学异常。

结论/解释

先兆子痫的存在、妊娠 27 周时更高的超声估计胎儿体重偏差和更高的妊娠期体重增加是这组已患有糖尿病的女性早产的独立潜在可改变风险因素。提示早产很常见，怀疑胎儿窒息或先兆子痫是最常见的原因。有必要进行前瞻性研究来评估修改这些预测因子是否会降低早产的患病率。

图形概要