P29.09: The use of long‐term indomethacin stabilises cervical length in twin pregnancies

Abstract

To determine if the use of early onset (less than 25 weeks) long-term indomethacin therapy (greater than 48 hours) (LIT) stabilises the cervical length (CL) in dichorionic-diamniotic twin gestations (DCDA-T) that are complicated by a short cervix. DCDA-T pregnancies with short CL (less than 30mm) after 18 weeks were identified. Serial CL measurements, other treatments (17 OH-P, vaginal progesterone, nifedipine) and outcomes were collected. Patients with cervical cerclage were excluded. The degree of cervical shortening from initial to last examination was compared in patients with a short CL and women with a normal CL at same gestational age (GA). Longitudinal analysis of the change in CL was modelled using mixed-model regression analysis and predicted values were compared using comparisons of the slope analysis. Out of 63 patients, 25 (40%) received LIT. The GA at initial ultrasound was similar between groups (P=0.6). There were no differences between the two groups regarding history of preterm birth and use of progesterone or nifedipine. The initial and last CLs were shorter in LIT group (24mm vs 43mm and 10mm vs 36.5mm). The average duration of indocin use was 49 days. A total of 255 (LIT=165, Normal CL=90) longitudinal CL examinations were used for mixed-model regression analysis. CL improved or did not change in LIT group (0-0.6mm/week)(CL= -0.0003GA2 + 0.7292GA - 0.0458, R2=0.046). However, in normal CL group, CL declined by 0.06-1.9mm/w (CL=0.091GA2 - 5.98GA+126.14, R2=0.21)(p<0.001). There were no reportable antenatal side effects. Early onset long-term indomethacin therapy in DCDA-T with a short cervix provides an alternative treatment modality to stabilise cervix.