TABLE 1

Clinical characteristics

Case	Sex	Ethnicity	Neonatal course							Postnatal PH^# course
			GA weeks BW g Z-score	Clinical presentation	ECMO days	iNO days	MV days	Home days	Medication	Initial diagnosis		Tissue sample	Cardiovascular medication	Age at follow-up/death: outcome
1	Male	Caucasian	36 2000 −1.70	PPHN^¶ RDS	Yes 12	Yes 35	Yes 45	Yes 60	O₂ PDE5i	E	3 months: hypoxaemia 4 m: RSV infection, HRF, ECMO	4 month biopsy	O₂, PDE5i	5 months: death from hypoxic respiratory failure
2	Male	Caucasian	38 3090 −0.15	Omphalocele Transient tachypnoea	No	No	Yes	Yes 17	No	E	5 months: hypoxaemia	-	O₂	4 years: stable mild PH, ILD
3	Female	Caucasian	36 2790 0.42	PPHN	No	Yes 6	Yes 6	Yes 41	O₂	E	2 months: hypoxaemia	-	PDE5i, ERA	10 years: stable mild PH
4	Female		40	Normal	No	No	No	Yes		C	4 years: intermittent hypoxaemia 5 years: PDA closure Lack of follow-up until age 18	-	O₂, PDE5i, treprostinil	29 years: death from refractory PH
5	Female		40	PPHN Pneumothorax	Yes 10	Yes	Yes	Yes 45	No	E	2.5 months: hypoxaemia	-	O₂, PDE5i, treprostinil, epoprostenol, CCB	15 years: stable PH
6	Female	Caucasian	39 1/7 3.136 −0.27	RDS	No	No	No	Yes 12	O₂	C	6 months: hypoxaemia, dyspnoea	-	ERA, PDE5i, O₂	11 years: severe PH
7	Female	Caucasian	37 4/7 1890 −2.34	PPHN	No	Yes 1	Yes 13	Yes 180	O₂	E	1.5 months: hypoxaemia, dyspnoea	3 month biopsy	O₂, iNO, PDE5i, digoxin	8 months: death, PH crisis during surgery (Meckel's diverticulectomy)
8	Female	Caucasian	40	Normal	No	No	No	Yes	No	C	3 years: dyspnoea, fatigability, syncope	-	O₂, s.c. treprostinil, PGE5i	12 years: severe PH
9	Female	Caucasian	40⁺	PPHN MAS	Yes 5	Yes	Yes 15	Yes 30	No	C	2.5 years: hypoxaemia, syncope	-	O₂, PDE5i, ERA, s.c. treprostinil	7 years: severe PH
10	Male	Caucasian	40 3490 −0.17	PPHN	Yes 2	Yes 2	Yes 5	Yes 30	O₂	C	18 months: hypoxaemia	2 years: biopsy 18 years: explant	O₂, ERA, PDE5i, CCB	18 years: end-stage PH, heart–lung transplantation
11	Female		40	Normal	No	No	No	Yes	No	C	8 years: PDA right to left	-	ERA
12	Female	Caucasian	39 1/7 3450 0.13	PPHN OI: 40 RDS Pneumothorax	No	Yes	Yes 11	Yes 64	O₂	E	2.5 years: hypoxaemia, chILD^§	2 months: biopsy	O₂, PDE5i, ERA	11 years: end-stage chILD, heart–lung transplantation
13	Female	Caucasian	40 3/7 3510 0.04	PPHN OI: 78 RDS	No	Yes 7	Yes 10	Yes 27	O₂	E	1 month: chILD	1.5 months: biopsy	O₂	4 years: severe chILD, mild PH
14	Male	Caucasian	40 3/7 3820 0.33	PPHN OI: 57 RDS	No	Yes 5	Yes 5	Yes 14	No	E	1 month: persistent tachypnoea	-	PDE5i	3 months: chILD, no PH, short follow-up
15	Female	Caucasian	39 2950 −0.62	RDS Pneumothorax	No	No	No	Yes 15		E	5 months: persistent chILD following RSV infection	-	No	7 months: bronchiolitis 10 years: chILD, no PH
16	Female	Caucasian	40	RDS Pneumothorax	No	No	No	Yes 7	No	E	1 month: persistent tachypnoea	-	PDE5i	10 years: no residual PH
17	Male	Caucasian	38 2040 −2.65	Normal	No	No	No	Yes	No	C	12 years: hypoxaemia during knee surgery	-	O₂, PDE5i, ERA, i.v. treprostinil	21 years: moderate PH
18	Male	Caucasian	36 5/7 2450 −1.00	PPHN OI: 58 RDS	No	Yes 6	Yes 9	Yes 92	O₂	E	7 years: chILD	7 years: biopsy	O₂, PDE5i, ERA	9 years: moderate PH
19	Female	Caucasian	40 3075 −0.71	Normal	No	No	No	Yes	No	E	5 months: chILD	7 years: biopsy	O₂	10 years: ch ILD, moderate PH

PH: pulmonary hypertension; GA: gestational age; BW: birth weight; ECMO: extracorporeal membrane oxygenation; iNO: inhaled nitric oxide; MV: mechanical ventilation; PPHN: persistent pulmonary hypertension of the newborn; RDS: respiratory distress syndrome; O₂: oxygen therapy; PDE5i: phosphodiesterase 5 inhibitor; E: echocardiography; RSV; respiratory syncytial virus infection; HRF: hypoxic respiratory failure; ILD: interstitial lung disease; ERA: endothelin receptor antagonist; C: cardiac catheterisation; PDA: patent ductus arteriosus; MAS: meconium aspiration syndrome; CCB: calcium channel blocker; s.c.: subcutaneous; OI: oxygenation index; chILD: childhood interstitial lung disease. ^#: PH was defined by a mean pulmonary artery pressure >25 mmHg >3 months of age; each of these children had a pulmonary artery wedge pressure <15 mmHg and pulmonary vascular resistance index >3 WU·m² consistent with pulmonary arterial hypertension, requiring right heart catheterisation for accurate, quantitative diagnosis, although Doppler echocardiography provides reliable qualitative data with the benefit of less invasiveness [25]; ^¶: the echocardiography criteria for PPHN were estimated right ventricle systolic pressure ≥ 2/3 systemic pressure by direction and velocity of ductus arteriosus flow and/or two-dimensional interventricular septum position and/or peak tricuspid regurgitant jet velocity [52]; ⁺: maternal methamphetamine use; ^§: chILD was diagnosed per American Thoracic Society criteria (at least three of the following four criteria are present: 1) respiratory symptoms (cough, rapid and/or difficult breathing, or exercise intolerance), 2) respiratory signs (tachypnoea, adventitious sounds, retractions, digital clubbing, failure to thrive or respiratory failure), 3) hypoxaemia and 4) diffuse abnormalities on a chest radiograph or computed tomography scan, after exclusion of the common diseases that can cause developmental lung disorders as the primary diagnosis [53]).