Pulmonary Hypertension in preterm children born at gestational age <30 weeks: Prevalence, risk factors and outcome.

The development is not complete in premature born children. For example, the
lungs are not fully developed. This is associated with shortness of breath and
an increased oxygen need. Some of these children will need ventilation support
and develop the condition Bronchopulmonary dysplasia (BPD). BPD is considered
with lung injury and more than 28 days of ventilation support. These children
have more need for oxygen and are extra sensitive for infections.

In the present era, BPD most often occurs in extremely premature infants born
at 24*28 weeks* post menstrual age, who have showed less severe acute
respiratory symptoms and require less respiratory support than BPD patients
have traditionally had in the past. Histological examination of these *new BPD*
patients suggests that the extreme preterm birth in combination with perinatal
lung injury affects the normal growth of the lung development, resulting in
disrupted vascular growth and impaired alveolarization, which could result in
PH, a high blodd pressure in the lungs. The causal relation among prenatal
factors, prematurity, BPD and PH are not fully known yet.

In premature newborns, < 30 weeks, the prevalence of BPD has been estimated to
be 30-60% , while the prevalence of occurrence of PH received significantly
less attention and estimates vary from 18% in the total group and up to 30% in
the BPD-group and 50% in the severe BPD-group. The development of PH
complicates the postnatal course of extreme premature infants. Both early and
late PH are associated with poor outcomes among preterm infants, with and
without BPD. Recent reports suggests that morbidity and late mortality of PH
in the *new BPD* is high, with up to 48% mortality 2 years after diagnosis of
PH.

The pathogenesis of BPD is complex and known risk factors for the development
of severe BPD includes maternal and neonatal factors, such as childbearing
history, male gender, smoking mother during pregnancy, chorioamnionitis,
low-birth-weight, gestational age, cholestasis and acute lung injury by high
ventilator settings. Risk factors for the development of PH in extreme preterm
infants are not well defined.

Knowledge of prevalence and risk factors of PH in extreme premature infants
will allow evidence-based screening guidelines for the infants. Also
potentially leading to prevention of this complicating condition in the future,
since an earlier intervention will be possible under guidance of known risk
factors. Early detection will lead to early and thus potentially better
treatment of PH in preterm born infants.

Is to identify the incidence and prevalende of PH in premature born infants. In
addition we will identify possible risk factors for the development of PH and
we want to determine the prognosis and survival of these patients.


Primary

To determine the incidence and prevalence of PH in these premature infants
(with and without BPD) in the first year of life,

Secundary

To define risk factors for the development of PH in these infants during the
first 2 years of life.


Other:

To characterize morbidity, quality of life and mortality associated with PH in
these infants during the first 2 years of life.

Study design: Cohort study. Inclusion 2015-2018,
neonatology/poli/functioncenter UMCG
participants: About 100-120 children a year born after <30 weeks and/or <1000
grams are hospitalized at the department of Neonatology UMCG. Most children are
born in the UMCG, however most mothers were redirected to the UMCG with preterm
birth. After several weeks at the neonatal intensive care, the children will be
dismissed to several regional hospitals. Frequently to Post-IC/High Cares in
Martini hospital and MCL, or to other hospitals in the region. After
dismission, the children will be seen at the UMCG for standardized care at: 6,
12 and 24 months corrected age.

For Neolifes-Heart echocardiography and transcutaneous oxygen measurement will
be performed at the following moments: 1) first week after birth, 2) 3 months
corrected age, 3) 12 months corrected age.

The total burden of the patients are kept as low as possible. Most of our
measurment moments are at the same time as the moments of standardized care.
One measurement moment will not be at the same time as the standardized care,
this moment will take place 3 months corrected age.
Furthermore, there are no risks of burden for patients and/or their parents.