Journal of Rehabilitation Medicine 51-1CompleteIssue | Page 55

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J. Yuan et al.
1.95–2.79%). This is the frst large-scale study to
estimate the prevalence of CP in China, since a study
published in 1997 of the prevalence of CP in Jiangsu
province (13). In the 1997 study, the epidemiology
results revealed that the prevalence of CP in childhood
(age < 7 years) was 1.6 per 1,000 live births, which was
significantly lower than in the present study. The hig-
her prevalence found in our study can be attributed to
advances in obstetric and neonatal rescue techniques,
since many infants with very low birth-weight and
gestational age less than 28 weeks now survive. This
interpretation is consistent with Liu et al.’s finding
that the prevalence of CP documented in their 1997
study increased continually over the study period (9).
In 2013, Oskoui et al. (7, 8) conducted a meta-analysis
comprehensively analysing data on the prevalence of
CP collected since 1985. The overall prevalence was
estimated to be 2.11%, which is similar to our findings.
In the current study, the true positive rate (TPR) of
screening was 14.60%, the main reason for the low
TPR was the wide standard for positive screening.
The diagnostic results proved this: 235 were regarded
as normal, and 436 were diagnosed with transient
transient developmental delay, out of 822 children who
were regarded as positive in the screening.
CP prevalence in male and female children was
2.76% and 1.91%, respectively, according to our study.
A χ 2 test indicated that this difference in prevalence
between sexes was not significant. The relationship bet-
ween sex and prevalence of CP remains controversial.
Some researchs, the present study included, have found
no statistically significance between male and female
(14–16). However, some other studies have found a
higher prevalence of CP in male than female children
(14, 17, 18). The exact relationship between sex and
prevalence may vary considerably in different districts.
Further research, including much larger sample sizes,
will be needed to elucidate the relationship between
sex and CP prevalence.
The present study implicated neonatal asphyxia,
moving into a newly painted room, complication with
maternal concomitant diseases during pregnancy, high
gravidity (≥ 3), low birth-weight (< 2,500 g), and HIE
to be risk factors for CP.
Studies have found that CP-related risk factors include
low socioeconomic status (6), gestational diabetes, ma-
ternal infection (19), low gestational age, multiple births,
family history of genetic diseases, breech presentation,
antepartum bleeding, multiple miscarriages, smoking,
illicit drug use (18), etc. (9, 20, 21). In a previous
study, Garfinkle et al. analysed outcomes for neonates
with suspected asphyxia using the Canadian Cerebral
Palsy Registry. They noted that neonatal asphyxia
was significantly correlated with CP (22). Sukhov et
www.medicaljournals.se/jrm
al. (20) conducted a retrospective population-based
cohort study of children registered in California over
a 10-year span. They found that premature birth was a
major risk factor for CP, and that neonatal asphyxia and
adverse intrapartum events contributed significantly to
the development of CP (20). Low birth-weight was also
considered a risk factor for CP (1, 23). In the current
study, low birth-weight (< 2,500  g) was identified as
a statistically significant risk factor in both univariate
and multivariate analysis. However, premature birth
(≤ 37  weeks) did not reach statistical significance.
Beaino et al. reported similar findings (24). The defini-
tive effects of intrauterine growth retardation on cerebral
development are undetermined at present.
In the current study, high gravidity (≥ 3) was iden-
tified as a high-risk factor, whereas parity was not
significant. Similarly, in a previous systematic review
by McIntyre et al., there was no significant association
between parity and CP (25). A possible explanation
for this could be that gravidity was confounded with
the number of abortions and maternal gestational age;
mothers with high gravidity (≥ 3) were relatively older
and usually had experienced multiple miscarriages.
Pollutants, such as formaldehyde and benzene, in
decorative materials may impair neonatal cerebral
development. Recently, other studies have found that
moving into a newly decorated room during pregnancy
is associated with congenital disease, such as congeni-
tal cardiovascular disease, Formaldehyde may cause
the permanent damage to the brain and kidneys of the
pregnant mother and benzene may cause the feotus
malformation, especially in the first trimester-the the
critical stage of fetal organ formation, although further
research is needed (26). Some authors have proposed
that plurality may be a risk factor for CP (18, 27). How­
ever, in the current study, no statistically significant
evidence was detected.
In order to reduce the risk of CP, measures should be
taken to maintain a healthy lifestyle, mothers should
not move into a newly painted room, and healthcare
personnel should be aware of neonatal asphyxia, low
birth-weight, and HIE in children. If neonatal asphyxia
or HIE is found, early intervention is recommended.
In conclusion, this is the first large prevalence study
of CP since 1997 in China, and the first of risk factors
for CP in a geographically defined area of China. The
study further elucidates CP in China and provides some
suggestions for preventing CP.
The current study has some limitations, however.
The number of children investigated was limited and
some high-risk factors did not have abundant sample
sizes. As a cross-sectional epidemiological investiga-
tion, Gross Motor Function Classification System level
1 (GMFCS-1) CP might be omitted because of atypical