Comparison of Ultrasound Findings Associated with Adverse Fetal, Obstetric, and Neonatal Outcomes in Pregestational Type 1 And Type 2 Diabetes: A Systematic Review.

OBJECTIVE: We aimed to summarize the available evidence examining the association between prenatal ultrasound findings and adverse fetal, obstetric, and neonatal outcomes in pregnancies complicated by type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) and to evaluate whether the predictive value of ultrasound findings for adverse outcomes varies between T1DM and T2DM pregnancies.

DATA SOURCES: We conducted a systematic review of the existing literature through August 12, 2024.

METHODS OF STUDY SELECTION: We included articles in English that reported associations between ultrasound findings and fetal, obstetric, and neonatal outcomes in pregnant people with T1DM and T2DM. Two independent reviewers examined articles at the abstract level and, if eligible, at the full-text level; disagreements were adjudicated by a third reviewer.

TABULATION, INTEGRATION, AND RESULTS: Of the 2,088 unique citations reviewed, 12 studies met the inclusion criteria describing associations between ultrasound findings and fetal, obstetric, and neonatal outcomes among a total of 1,165 pregnant people with T1DM and 489 pregnant people with T2DM. Most studies (10/12) examined the association between ultrasound measures of growth, including estimated fetal weight (EFW) and its individual components, abdominal wall thickness, head circumference to abdominal circumference (HC/AC) ratio, and birthweight, large for gestational age (LGA) or small for gestational age (SGA). Studies did not examine stillbirth, neonatal demise, or maternal outcomes other than cesarean section.

CONCLUSION: This systematic review synthesizes the available literature on ultrasound risk markers of adverse fetal, obstetric, and neonatal outcomes separately in pregnant people with T1DM and T2DM. We identified very few studies that distinguished between pregnant people with T1DM and T2DM, and the majority focused on surrogate outcomes (e.g., LGA, SGA) of morbidity. Our findings highlight the need for further studies investigating these distinct diseases to provide evidence for antenatal management recommendations.