ISPD 2017

Presenter finalist for the Joe Leigh Simpson Award for Best Early Career Investigator, which will be announced on Wednesday, 12 July 2017, during the Closing Plenary.

2-5 Persistent pulmonary hypertension of the newborn in Twin-Twin Transfusion syndrome: a case-control study

All Authors: 
Manon Gijtenbeek, Leiden University Medical Center (Primary Presenter) 
Monique C Haak, Leiden University Medical Center, Department of Obstetrics and Fetal Medicine 
Derk jan Ten Harkel, Leiden Universitary Medical Center 
Arjan Te Pas, Leiden University Medical Center 
Annemieke Middeldorp, Leiden Universitary Medical Center 
Frans Klumper, Leiden Universitary Medical Center 
Nan van Geloven, Leiden University Medical Center 
Dick Oepkes, Leiden University Medical Center 
Enrico Lopriore, Leiden Universitary Medical Center 

Objectives: 

Persistent pulmonary hypertension of the newborn (PPHN) results from failure of the normal circulatory transition after birth and is associated with severe morbidity and mortality. Twin-twin transfusion syndrome (TTTS), which complicates 10-15% of monochorionic twin pregnancies, is suggested to increase the risk of PPHN. In TTTS recipients, chronic volume loading might cause remodeling of the pulmonary vasculature and cause neonatal PPHN. The aims of this study were: 1) to describe the incidence of PPHN in TTTS twins and 2) to identify risk factors in TTTS survivors for the development of severe PPHN, in particular in recipient twins. 

Method: 

Cases with severe PPHN were extracted from our monochorionic twin database (2002-2016). Severe PPHN was defined as severe hypoxemia requiring mechanical ventilation and inhaled Nitric Oxide (iNO) treatment, confirmed by strict echocardiographic criteria. First, an analysis was performed to estimate the incidence of PPHN in both TTTS and uncomplicated monochorionic twins. Second, a case-control comparison was conducted to identify risk factors for PPHN within neonates with TTTS.

Results: 

The incidence of PPHN was 4% (24/597) in TTTS twins and 0.4% (2/493) in uncomplicated monochorionic twins (OR 10.3, 95% CI 2.4-43.9, p < 0.001). Three risk factors were associated with PPHN: lower gestational age at birth (29 weeks vs. 33 weeks, OR 1.4 for each week less, 95% CI 1.2-1.6), recipient status (75% vs. 49%, OR 3.1, 95% CI 1.3-7.3) and anemia at birth (25% vs. 8%, OR 3.8, 95% CI 1.4-10.4). In TTTS recipients, also post-laser twin anemia polycythemia sequence (indicating incomplete laser-surgery) was associated with PPHN (35% vs. 13% of recipients after laser-surgery, OR 3.8, 95% CI 1.4-10.4). 

Conclusions: 

Clinicians caring for neonates with (treated) TTTS should be aware of the 10-fold increased risk of PPHN compared to uncomplicated monochorionic twins. PPHN occurs more often in ex-recipients, after premature delivery and in case of anemia at birth. As the development of severe PPHN is difficult to predict, we advise that all TTTS twins should be delivered in a tertiary care center with iNO treatment possibilities.