The goal of this observational study is to compare fetal liver ultrasound radiomics between pregnancies complicated by type 1 diabetes and healthy controls.

The main questions it aims to answer are:

• Are fetal liver ultrasound radiomic features reproducible?
• Does fetal liver ultrasound radiomics differ between pregnancies complicated by type 1 diabetes and healthy controls?

Participants will undergo ultrasound examination to collect ultrasound data for the analyses.

Gestational diabetes is a growing health concern posing the neonate in the risk of adverse outcomes, such as macrosomia, cesarean delivery, hypoglycemia, respiratory morbidity, and need for neonatal intensive care. Most of these outcomes are either closely or causally related to fetal hyperinsulinemia, which is induced by maternal hyperglycemia. However, the accurate and non-invasive means of estimating fetal hyperinsulinemia are currently lacking.

Given that maternal diabetes and fetal hyperinsulinemia are associated with profound changes in fetal liver blood supply, biometry, metabolism, and lipid content, it was hypothesized that fetal hyperinsulinemia would be detectable by ultrasound using modern computer-aided technologies, i.e., radiomics and machine learning. In this prospective pilot study, the aim is to recruit 20 pregnant women with type I diabetes and compare them to 40 healthy controls. Patients with type 1 diabetes were chosen because their pregnancies are known to be associated with fetal hyperinsulinemia. Study subjects will be recruited at Turku University Hospital and the City of Turku maternity welfare clinics. It is assumed that radiomics analysis of fetal liver ultrasound pictures will indicate fetal hyperinsulinemia in pregnancies complicated by type 1 diabetes at 34 gestational weeks. Simultaneously, the inter- and intraobserver variability for fetal liver ultrasound radiomic features will be characterized.

In the future, non-invasive evaluation of fetal hyperinsulinemia could provide a useful tool in managing pregnancies complicated by maternal diabetes - either pre-gestational or gestational.

Inclusion Criteria:

• Age between 18-45 years
• Capable to give an informed consent
• Singleton pregnancy
• Planning to deliver in Turku University Hospital
• Maternal BMI < 40
• Gestational age should be confirmed by first trimester ultrasound
• Normal oral glucose tolerance test (OGTT) at 24-28 gestational weeks in controls

Exclusion Criteria:

• Major fetal chromosomal, genetic, or structural anomaly
• Fetal growth restriction, or birth weight < 10th centile
• Birth weight > 90th centile or polyhydramnios in the controls
• Non-reassuring fetal status requiring immediate treatment, or intrauterine fetal demise
• Verified fetal infection (e.g. cytomegalovirus, toxoplasma, hepatitis B and C), excluding bacterial infection due to intrapartum chorioamnionitis
• Placenta accreta spectrum disorder
• Major maternal medical condition requiring systemic pharmacological treatment, other than non-severe hypertension, hypothyroidism, asthma, mild psychiatric disorders, etc.
• Alcohol or tobacco use, or substance abuse in pregnancy

Pregnant women will be recruited at Turku University Hospital and Turku maternity welfare clinics during their routine pregnancy follow-up.

To ensure study subject anonymity the study data will not be published.