(672) Mid-trimester rupture of the membranes:Irish perspective from a tertiary unit following liberalisation of TOP legislation

Midtrimester pre-mature pre-labour rupture of membranes(MTPPROM) between 14+0-23+6 gestation age(GA) is a rare complication of pregnancy associated with poor maternal and fetal outcomes. This study measures outcomes between 2018-2024 at a tertiary referral centre in Ireland with approximately 7000 deliveries per annum. Since the Health (Regulation of Termination of Pregnancy (TOP)) Act, 2018, parents can opt to TOP after 12+GA where there is a risk to the “life or health” of the woman or where the fetus is “likely to die within 28 days of life”.This legislative change means that accurate data is critical for counselling families. Our objective is to describe the outcomes following MTPPROM and compare to a similar study conducted prior to liberalisation of the TOP legislation.

Study Design:

Retrospective cohort study of consecutive MTPPROM January 2018 to February 2024.

Results:

109 patients met inclusion criteria, at a prevalence rate of 0.2%. The median maternal age was 33 and median GA at MTPPROM was 21+0, with an median latency period of 7 days(IQR 26 days,range 0-147 days). 77% experienced maternal morbidity, with no maternal mortalities. The neonatal survival to discharge (NSTD) was 27.5%. Outcomes are compared to the publication by Linehan et al. paper(Table 1) prior to the Health Act 2018 showing a 5% NSTD rate. MTPPROM between 14+0-19+6 had a lower NSTD compared to those over 20+ GA(10%vs41%, p value=0.0003). These cases also had a higher rate of MROP(30%vs13%,p value=0.02). Anhydramnios was associated with 0% NSTD. Singleton pregnancies with oligohydramnios had a lower NSTD compared to those with normal liquor volume(21%vs51%,p value=0.007).  90% of the patients who opted for TOP had a deepest vertical pool of less than 2cm and had a higher rate of chorioamnionitis(34%vs73%,p value=0.01)(Table 2).

Conclusion:

While NSTD is higher for patients with normal liquor volume and PPROM over 20+ GA, mortality and morbidity still continues to be high. The majority of patients who opted for TOP were diagnosed with chorioamnionitis and oligohydramnios reflecting a higher NSTD percentage post legislation.