Efficacy of Long Term Indomethacin Therapy in Prolonging Pregnancy After Fetoscopic Laser Surgery for Twin-to-Twin Transfusion Syndrome: a Collaborative Cohort Study

Objective: To evaluate the efficacy of long-term indomethacin therapy (LIT) in prolonging pregnancy and reducing spontaneous preterm birth (PTB) in patients undergoing fetoscopic laser surgery (FLS) for the management of twin-to-twin transfusion syndrome (TTTS). Design: Retrospective cohort study of prospectively collected data. Setting: Collaborative multicenter study Population: 557 consecutive TTTS cases that underwent FLS Methods: LIT was defined as indomethacin use for at least 48 hours. Log-binomial regression was used to estimate the relative risk (RR) of PTB in LIT compared to non-LIT group. Cox regression was used to evaluate the association between LIT use and FLS-to-delivery survival. Main outcome measures: gestational age (GA) at delivery Results: Among the 411 pregnancies included, a total of 180 patients (43.8%) received LIT after FLS and 231 patients (56.2%) did not. Median GA at fetal intervention did not differ between groups (20.4 weeks). Median GA at delivery was significantly higher in the LIT group (33.6 weeks) compared to the non-LIT group (31.1weeks), p<0.001. FLS-to-delivery interval was significantly longer in the LIT group (P<0.001). The risk of PTB prior to 34, 32, 28, and 26 weeks gestation were all significantly lower in the LIT group compared to the non-LIT group (RR=0.69, 0.51, 0.37, and 0.18, respectively). The number needed to treat (NNT) with LIT to prevent one PTB<32 weeks gestation was 4, and to prevent one PTB<34 weeks was 5. Conclusion: Long-term indomethacin after FLS for TTTS was found to be associated with prolongation of pregnancy and reducing the risk for PTB.

Preoperative Cervical Length Predicts the Risk of Delivery within One Week after Pleuroamniotic Shunt in Fetuses with Severe Hydrothorax

<b><i>Objective:</i></b> The objective of this study was to assess the predictive performance of preoperative cervical length (CL) for delivery within 1 week after pleuroamniotic shunting (PAS) in fetuses with severe hydrothorax. <b><i>Methods:</i></b> A prospective cohort of fetuses with severe hydrothorax referred to our fetal surgery center in Querétaro, Mexico from January 2012 to July 2020. Severe fetal hydrothorax was diagnosed as an accumulation of fluid within the fetal pleural space accompanied with severe bilateral lung compression, mediastinal shift, polyhydramnios, and/or hydrops. Transvaginal CL was measured immediately before PAS, and a short cervix was defined as that &#x3c;25 mm. The interval from fetal intervention to delivery, prevalence of preterm prelabor rupture of membranes (PPROMs), and associations with delivery within the first week after PAS according to a short or a normal CL, were evaluated. <b><i>Results:</i></b> Thirty-five pregnancies with severe fetal hydrothorax treated with PAS were evaluated. Median gestational age at PAS was (weeks + days) 31⁺² (range, 26⁺⁰–36⁺¹). Two (5.7%) and 7 (20.0%) cases delivered within the first 24 h and 1 week after PAS, respectively. Ten (28.6%) women had a short cervix before PAS, while 25 (71.4%) had normal preoperative CL. Women with a short cervix showed lower mean interval between fetal intervention and delivery (2.4 vs. 5.5 weeks, <i>p</i> = 0.01), and higher prevalence of PPROM (50 vs. 12%, <i>p</i> = 0.01), as compared to women with a nonshort cervix. Preoperative short cervix was associated with significantly higher risk of delivery within the first 24 h (20.0 vs. 0%, respectively, <i>p</i> &#x3c; 0.05) and 1 week after PAS (50.0 vs. 8.0%, respectively, <i>p</i> &#x3c; 0.01) compared with pregnancies with normal preoperative CL. <b><i>Conclusion:</i></b> In pregnancies with severe fetal hydrothorax candidates for pleuroamniotic shunt, identification of a short cervix before fetal intervention can predict delivery within 1 week after the surgical procedure.