HBO in the treatment of intrauterine growth retardation
Pasquale Longobardi - Centro Iperbarico Ravenna
To evaluate the efficacy of HBO in the treatment of intrauterine growth retardation (IUGR).
IUGR , is defined as less than 10 percent of predicted fetal weight for gestational age (1). It occurs in 3% to 10% of all pregnancies (2, 21) [23% to 34% in multiple-gestation pregnancies (3)] and is caused by genetic disorders, fetal infections, uteroplacental insufficiency, and by all conditions which determine inadequate supply of oxygen to the fetus.
IUGR is associated with significant perinatal morbidity and mortality (3, 22), being the incidence of intubation at birth, seizures during the first day of life and sepsis significantly increased among term infants with birth weight at or below the 3rd percentile (4). Recent studies have also shown that IUGR is linked with a higher prevalence of raised blood pressure, non-insuline-dependent diabetes and cardiovascular diseases in late adult life (5).
There is no proven evidence of any medical treatment for IUGR (3).
Many studies have shown the non toxicity of HBO, if administered according to proper schemes, neither for the mother nor for the fetus in the third quarter of the pregnancy, excluding the typical complications of this therapy (6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18).
Besides, there is encouraging evidence of the efficacy of the use of normobaric (19, 20) and hyperbaric (16, 17) oxygen as treatment of IUGR, which apparently need further search.
The major endpoint of this study is to evaluate the therapeutic efficacy of HBO to correct IUGR .
MATERIALS AND METHODS
The study population will be represented by singleton pregnant females, normal-weight, free from concomitant pathologies, under medical treatment by the Department of Obstetrics and Gynecology.
The necessary sample size is estimated at about 100 patients. Study duration: 3 years.
IUGR diagnosed after 28 weeks of gestation by flussimetric and antropometric index, not related to genetic anomalies (gestational age valued by 20 weeks of gestation by measuring of C.R.L.).
Will be monitored the following parameters:
Shepard formula to calculate fetal weight by Bi-parietal diameter and abdominal circumference; ultrasonographic determination of fetal transverse cerebellar diameter (TCD)/abdominal circumference (AC) ratio; Cardiotocographic non-stress test of 20 minutes; doppler flussimetry of umbilical and middle cerebral artery (C/U ratio).
Baseline examinations as ECG, ORL visit, routine blood-test and haemo-gas analysis will be performed at the moment of the enrolment and the non corresponding to the average normality range will be considered an exclusion criteria. Smokers and Diabetics are excluded as well.
Women accepted to the study have to sign informed consensus.
After diagnosis of IUGR will be selected two groups: one group will receive HBO, the other group will receive standard treatment. We are still discussing the precise criteria to adopt, any suggestions are welcome.
Patients belonging to the intervention group will receive cycles of daily HBO treatment, consisting in:
(a suggested different scheme is welcome).
A multiplace chamber, demand-breathing of oxygen in facial mask will be used.
After 1 week the cycle will be repeated up to the born of the baby.
No medical therapy will be administered.
Oxygenation level of women during HBO treatment will be monitored by transcutaneus oxymetry.
The developing of maternal-fetal parameters will be monitored according to the following schemes:
Measure of flussimetric an cardiotocographic index at alternate days; mesure of antropometric index once a week.
Single blinding: IUGR parameters taken by physician unaware of the treatment. Analysis by independent "third party".
Parameters to be measured and criteria for improvement:
Study protocol NOT finalised !!!