CARDIOVASCULAR JOURNAL OF AFRICA • Volume 25, No 2, March/April 2014
AFRICA
73
Intra-uterine growth restriction as a risk factor for
hypertension in children six to 10 years old
Agata Zamecznik, Katarzyna Niewiadomska-Jarosik, Agnieszka Wosiak, Justyna Zamojska,
Jadwiga Moll, Jerzy Stańczyk
Abstract
Introduction:
Intra-uterine growth restriction (IUGR) is
present in about 3–10% of live-born newborns and it is as
high as 20–30% in developing countries. Since the 1990s, it
has been known that abnormalities during foetal growth may
result in cardiovascular disease, including hypertension in
adulthood.
Methods:
This study evaluated blood pressure parameters
(using ambulatory blood pressure monitoring) in children
aged six to 10 years old, born as small for gestational age
(SGA), and compared them to their healthy peers born as
appropriate for gestational age (AGA).
Results:
In the SGA group, an abnormal blood pressure
level (prehypertension or hypertension) was present signifi-
cantly more often than in the AGA group (50 vs 16%,
p
<
0.01). This relationship also occurred in association with the
type of IUGR (asymmetric
p
<
0.01, symmetric
p
<
0.05).
Conclusion:
In SGA children, abnormal blood pressure
values occurred more frequently than in AGA children.
Keywords:
birth weight, children, hypertension, intra-uterine
growth restriction, small for gestational age
Submitted 28/6/13, accepted 20/2/14
Cardiovasc J Afr
2014;
25
: 73–77
DOI: 10.5830/CVJA-2014-009
Intra-uterine growth restriction (IUGR) is an important issue for
both neonatologists and paediatricians. It occurs in about 3–10%
of live-born newborns. The most serious problem of IUGR
exists in developing countries where it concerns up to 20–30%
of liveborns.
1
In 1967, the American Academy of Paediatrics introduced
nomenclature according to neonatal birth weight as follows:
appropriate for gestational age (AGA), located between the 10th
and 90th percentile; large for gestational age (LGA), above the
90th percentile; and small for gestational age (SGA), below
the 10th percentile.
2
IUGR affects many newborns with birth
weights below the 10th percentile.
There are two types of IUGR. The first, which accounts
for approximately 20–25% of all cases, is called symmetrical
IUGR. The disturbances occur in the first or second trimester
of pregnancy, during organogenesis. There is a decrease in all
dimensions of the foetus’s body and internal organs, usually
accompanied by a permanent reduction in growth potential.
The second type is asymmetrical IUGR, constituting 75–80%
of all cases of IUGR. This develops in the late second and third
trimester of pregnancy and is the result of abnormal cell growth,
rather than their quantity. In this type, infants have a low birth
weight while other parameters remain normal (body length,
head circumference). Due to this, Rohrer’s ponderal index [PI
=
birth weight
×
100/length
3
(g/cm
3
)] in this type is lower than in
symmetrical IUGR.
3
Published in the 1990s, ‘Barker’s hypothesis’ states that
growth disorders appearing in intra-uterine life result in the
later occurrence of cardiovascular disease, including high blood
pressure.
4,5
This is due to the fact that the developing foetus
adapts to the undernutrition and insufficient amounts of oxygen
through ‘metabolic programming’ and adaptation of the structure
and function of certain organs (e.g. compensatory hypertrophy of
the nephrons).
6,7
In Europe, hypertension affects about 2–5% of children, and
among teenagers and young adults it reaches 10%.
8
The most
common type among children under the age of seven years is
secondary hypertension. The frequency of primary hypertension
increases with age.
9
Based on previous reports, it is known
that children born with IUGR are likely to develop primary
hypertension much earlier and more frequently than their peers
with normal birth weight.
10
The aim of this study was to compare blood pressure
parameters in children born as SGA and compare them with their
healthy peers born as AGA, and to determine the prevalence of
prehypertension and hypertension in both groups, taking into
consideration the type of hypotrophy (symmetrical/asymmetrical)
and birth weight percentile (
≤
5th percentile/5–10th percentile).
Methods
This was a prospective study carried out between 2010 and 2012
in the Department of Children’s Cardiology and Rheumatology
of the 2nd Chair of Paediatrics at the Medical University of Lodz
in Poland. The study group consisted of 50 children aged six to
10 years (mean 7 years 11 months
±
1 year 4 months) born at
Department of Children’s Cardiology and Rheumatology of
the 2nd Chair of Paediatrics, Medical University of Lodz,
Poland
Agata Zamecznik, MD,
Katarzyna Niewiadomska-Jarosik, MD, PhD
Justyna Zamojska, MD, PhD
Jerzy Stańczyk, MD
Institute of Information Technology, Lodz University of
Technology, Poland
Agnieszka Wosiak, PhD, MSc
Department of Cardiology, Polish Mother’s Memorial
Hospital Institute, Lodz, Poland
Jadwiga Moll, MD, PhD
