The impact of maternal ketonuria with pregnancy outcome and optimal carbohydrate intake in pregnant women

Abstract

Background

Ketonuria during pregnancy, potentially arising from inadequate carbohydrate intake or elevated energy demands, has an uncertain association with adverse outcomes, particularly preterm birth.

Aims

This study aimed to examine the relationship between maternal ketonuria and pregnancy outcomes, and to identify the carbohydrate intake level that may help prevent ketonuria in pregnant women.

Methods

In this prospective study, 349 pregnant women were assessed for ketonuria using the nitroprusside method, categorized into mild, moderate, and severe. Dietary carbohydrate intake was measured via a food frequency questionnaire. Receiver operating characteristic analysis identified trimester-specific carbohydrate thresholds for moderate/severe ketonuria. Logistic regression evaluated associations between ketonuria and preterm birth, adjusting for confounders including prepregnancy body mass index (BMI), smoking, blood pressure, hemoglobin, and glucose levels.

Results

Ketonuria prevalence was 12.6% (mild), 1.7% (moderate), and 2.3% (severe). Ketonuria was associated with higher prepregnancy BMI, smoking history, and increased preterm birth. First-trimester ketonuria significantly increased preterm birth risk (adjusted OR 5.76; 95% CI [1.73–19.1]; p = .004). Carbohydrate intake thresholds predicting moderate/severe ketonuria were 187 g (first trimester), 170 g (second), and 143 g (third).

Conclusions

Early pregnancy ketonuria is independently associated with preterm birth. Adequate trimester-specific carbohydrate intake may help prevent ketonuria, highlighting its importance in prenatal care.