Research Information System
The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians, vol.38, no.1, pp.2508274, 2025 (SCI-Expanded)
Objective: Short cervical length (CL) is a known predictor of preterm delivery (PTD). We aimed
to study the progression of CL as gestational age (GA) advances in patients with short cervix
treated under our long-term Indomethacin therapy (LIT) protocol, and to document the effect of
LIT on the cervix.
Methods: Retrospective cohort study conducted in a single medical center from 2010 to 2020.
Patients with singleton pregnancies and 2nd trimester CL ≤25 mm received LIT per our clinical
protocol which included weekly CL and ultrasound (US) surveillance of amniotic fluid and Doppler
indices. We compared initial cervical length (CLI) once LIT was started to final cervical length (CLF)
once LIT was stopped, and cervical stabilization was defined as CLF-CLI ≥ 0. A longitudinal
analysis of CL as GA progressed was performed using a multivariable linear mixed-effects
regression model. A subgroup analysis was performed on patients whose total serial CL
surveillance period lasted at least 3 weeks, and GA at delivery was analyzed based on cervical
stabilization in this initial 3-week period. Statistical analyses were performed using Stata 16.
Results: 135 patients with short CL treated under our LIT protocol were included. 90 (67%) had
CLF-CLI ≥ 0. Based on the regression model, the rate of CL change with time was 0.04 mm/day.
This did not change when progesterone (both vaginal and intramuscular) use was added as an
interaction term. 105 (78%) delivered >32 weeks, and 68 (50%) delivered at full term. There was
no difference in the rate of delivery >28 weeks between those with CLI ≤10mm and those with
CLI between 11 and 25 mm (78% v 90%, p > 0.05). 112 patients (83%) had at least 3 weeks of US
surveillance. Of those, 76 (68%) had CLF-CLI ≥ 0 and 107 (95.5%) delivered at >28 weeks. The PPV
of CLF-CLI ≥ 0 to predict delivery >28 weeks was 95%.
Conclusion: While normally CL shortens progressively throughout pregnancy, patients with short
CL managed with LIT had no further shortening. There is a need for a randomized controlled trial
of LIT for prevention of PTD in patients with short CL