COmputerized CTG Self-MOnitoring Versus Standard Doppler Assessment in Late-onset FGR: COSMOS Study

COmputerized CTG Self-MOnitoring Versus Standard Doppler Assessment in Late-onset FGR: Study Protocol for a Randomized Controlled Trial

Fetal growth restriction is one of the major causes of perinatal morbidity, mortality and adverse neurological outcome. Growth restricted fetuses do not reach their potential due to multiple factors. Although early (<32 weeks' gestation) FGR is associated with the highest risk of adverse outcomes, late FGR (≤ 32 weeks' gestation) is more common in daily maternal-fetal medicine care. Despite its' prevalence, optimal standard for monitoring differs between the centers and may be difficult in case of limited access to advanced perinatal care. We present a protocol for COmputerized CTG Self-MOnitoring versus Standard Doppler assessment in Late-onset FGR (COSMOS) trial, which is a prospective, cross-over, open-label and randomized trial that compares two different protocols for late-onset FGR observation.

All women carrying fetuses with late-onset FGR with positive end-diastolic flow in umbilical artery will be invited to participate in the randomized trial. Patients will be randomly divided into two groups: CTG - a group that will receive electronic device for cCTG home assessment, and Doppler - a group that will be monitored according to standard Doppler velocimetry criteria. Further management will depend on the arm of the study. Pregnancy and neonatal outcomes will be collected and analyzed.

Inclusion Criteria:

• women aged 18 years or older,
• singleton pregnancy,
• ≥32+0 and ≤36+6 weeks' of gestation,
• fluent in Polish or English,
• diagnosed with late-onset FGR based of the Delphi criteria,
• with positive EDF in UA,
• with macroscopically normal fetus on ultrasound assessment.

Exclusion Criteria:

• multiple pregnancy,
• fetal malformations,
• abnormal genetic testing results (if available),
• uncertain pregnancy dating,
• indication for immediate delivery within 48 hours after enrollment,
• preterm prelabour rupture of membranes.