Vol.3, No.12, 709-711 (2011)
opyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
Does conventional phototherapy have any effect on
platelet count in full term neonates with indirect
Alireza Monsef1, Fatemeh Eghbalian2*
1Pathology Department, Hamadan University of Medical Sciences, Hamadan, Iran; *Corresponding Author: eghbalian_fa@ahoo.com
2Pediatric Department, Hamadan University of Medical Sciences, Hamadan, Iran
Received 2 August 2011; revised 12 October 2011; accepted 22 October 2011.
This study evaluates the platelet count changes
in neonates with hyperbillirubinemia who re-
ceived phototherapy. In this Prospective Descri-
ptive-cross sectional study 144 full term new-
borns with indirect hyperbillirubinemia who re-
ceived phototherapy in neonatal ward of Bessat
hospital in Hamedan province of Iran were stu-
died from September 2007 to February 2008 for
evaluation the effect of phototherapy on platelet
count. The platelet had counted by cell counter
and it had controlled by slide platelet counting.
The data were analyzed using spss version. 13
and compared with paired-samples T test. 58
neonates (40.3%) were boys and 86 (59.7%)
were girls. The mean age of neonates was 7.04
+/– 5.49 days (2 - 29 days). The mean (± SD)
platelet counts were 287833.3 + 92332.4 before
and 299444.4 + 98565.2 after phototherapy. Ana-
lysis of data with paired T test showed signifi-
cant difference in platelet count before and after
phototherapy. Mean platelet count after photo-
therapy was higher than that before treatment.
The study had propounded that mean platelet
count increased with extended mean photothe-
rapy time. This study had propounded this hy-
pothesis that phototherapy in full term icteric
newborns leads to increased platelet count. It
may be due to accelerated platelet turnover in
peripheral microvasculature with adequate pla-
telet reserve.
Keywords: Newborn, Photothera py, Platelet Coun
Phototherapy is the most widely used therapeutic mo-
dality in infants with neonatal jaundice. In nearly all
infants, phototherapy reduces or blunts the rise of serum
bilirubin concentration regardless of maturity, presence
or absence of hemolysis or degree of skin pigmentation
[1-3]. Generally, phototherapy is very safe and may have
no serious long-term effects on neonates; however, the
following adverse effects and complications have been
noted: increase insensible water loss, loose stools, retinal
damage, hypocalcemia, patent ductus arteriosus (PDA)
and skin rash. The combination of hyperbilirubinemia
and phototherapy can produce DNA-strand breakage and
other effects on cellular genetic material. In vitro and
animal data have not demonstrated any indication for
treatment of human neonates [1-4]. Other adverse effects
and complications of phototherapy which have been
noted in vitro included: Copper retention, abnormal por-
phyrine metabolism, diminished head growth without
effect on neurologic function, decrease erythrocyte-
oxygen coupling capacity, mild increase IgM and reduc-
tion of IgG [4-6]. The effect of phototherapy on blood
elements is unknown. There are limited studies with
different results regarding the effect of conventional
count [6-9]. Some animal and human studies suggest
that hyperbilirubinemia and phototherapy may lead to
thrombocytopenia [10,13]. Maurer et al. found that rab-
bits exposed to phototherapy phototherapy on platelet
had decreased platelet count [9]. Sakha et al. study sug-
gests that hyperbilirubinemia and phototherapy may lead
to increase the platelet count [7]. In another study Karim
showed there is not any correlation between photother-
apy and platelet cont [6]. According to limited studies
with controversial results, the aim of this research was
evaluating the hypothesis that conventional phototherapy
is able to change platelet count in neonates with indirect
In this Prospective Descriptive-cross sectional study
144 newborns with indirect hyperbillirubinemia who
A. Monsef et al. / Health 3 (2011) 709-711
Copyright © 2011 SciRes. Openly accessible at http:// www.scirp.org/journal/HEALTH/
received phototherapy in neonatal ward of Bessat hospi-
tal in Hamedan province of Iran were studied from
September 2007 to February 2008 to evaluate the effect
of phototherapy on their platelet count. The including
criteria were: age 2 to 29 days, full term newborn weight
2500 to 4000 gr, indirect hyperbilirubinemia, absence of
hemolysis, ABO or Rh incompatibility, negative coomb’s
test, reticulocyte count less than 5%, negative CRP (C
reactive protein). The excluding criteria were; laboratory
results of hemolysis, ABO or Rh incompatibility, platelet
less than 150,000/mm3, exchange transfusion, fever and
mild dehydration (less than six diaper per day) and ill
The sample size had calculated according to this for-
mula and previous studies :
11 12
144NZ Z
 
40% dp0.085
Following case selection, the study was explained to
patient’s parents, and written parental consent was ob-
tained according to ethical committee permission of
Hamadan University of Medical Sciences. The platelet
was counted by Sysmex K x-21 cell counter and con-
trolled by platelet counting on peripheral blood smear
slid. Phototherapy was performed by 5 newly changed
white light lamp of Tusan company (Tehran-Iran), 30
centimeter away from the patients whose eyes and geni-
talia had been covered for protection. Before photother-
apy and 24, 48 and 72 hr after it, blood collected and
platelet had counted. Data such as birth weight, sex, the
duration of phototherapy, and bilirubin level was in-
cluded in the questionnaire list. The data were analyzed
using SPSS (version 13) and compared with paired-
samples T test. P value less than 0.05 was considered
144 newborn infants with indirect hyperbilirubinemia
were entered the study, from them 86 (59.7%) and 58
(40.3%) were females and males respectively. Mean age
of studied newborns was 7.09 + 5.49 days, (range: 2 - 29
days, SD = 3.65 ). Mean Duration of hospitalization (day)
was 2.63 + 1 – (1 - 7 day). Mean Duration of photothe-
rapy was 2.58 + 1.08 – (1 - 7 day). The mean (± SD)
platelet counts were 287833.3 + 92332.4 before and
299444.4 + 98565.2 after phototherapy. Data analysis
with paired T test showed significant difference between
platelet count before and after phototherapy. Mean
platelet count after phototherapy was more than before
(P Value = 0.015) (Table 1). The study showed that
mean platelet count significantly increased with extended
mean phototherapy time. As its P value after 2 - 3 days
phototherapy was 0.001 and after 3 days of phototherapy
was 0.002 (Table 2).
144 neonates were admitted in this study. Results had
propounded this hypothesis that concomitant effect of
phototherapy and hyperbilirubinemia increase the plate-
let count and it has direct correlation with duration of
phototherapy. Mild dehydration and relative hemocon-
centration had ruled out because an excluding criteria in
our study was less than six diaper per day. Our result is
similar with Sakha et al. report [7]. An overview on pre-
vious study about effect of phototherapy on platelet
count shows different results [6-14]. It is not clearly de-
fined the effect of phototherapy on blood cells because
of limitation of investigations and controversy about
effect of lamp on platelet in vivo studies. Photochemical
reactions in platelet of newborn had proved in vitro. De-
crease in platelet count may be due to sequestration of
damaged platelet in the spleen [4,9,10]. In 1966 prior to
the introduction of phototherapy for treatment of neona-
tal hyperbilirubinemia Zieve et al. described the effect of
white light on human platelet in vitro. Platelets, which
had been exposed to high-intensity, white lights loss the
ability to aggregate and released potassium, acid phos-
phatase, serotonin and adenosine triphosphate [11]. Some
authors point to mild thrombocytopenia due to photo-
Table 1. Mean platelet count before and after phototherapy.
P Value*
After phototherapyBefore phototherapy Platelet count
p = 0.015
t = 2.45
df = 143
299444.4 ± 98565.2287833.3 ± 92332.4 Means ± SD
*Paired T test.
Table 2. Mean platelet count and its variation according to phototherapy duration, before & after.
Duration of phototherapy Mean plt before phototherapyMean plt after phototherapyplt variation P Value*
1 - 2 day (N = 84) 289071.4 ± 92407.2 288428.6 ± 94251.4 642.8 P = 0.34
2 - 3 day ( N = 36) 295777.8 ± 98386.1 318277.8 ± 107617.7 22500.0 P = 0.001
>3 day (N = 24) 271583.3 ± 84142.1 309750.0 ± 98040.9 0 38166.7 P = 0.002
Paired T test; : platelet increase; : platelet decrease; Plt = platelet.
A. Monsef et al. / Health 3 (2011) 709-711
Copyright © 2011 SciRes. Openly accessible at http:// www.scirp.org/journal/HEALTH/
therapy and hyperbilirubinemia [4,10,12]. The cause of
thrombocytopenia had not clearly defined, probably de-
struction of platelet in cutaneous microvasculature ex-
posed to phototherapy has a major role [12]. It is con-
comitant with Maurer et al. experience. They had ex-
posed plasma rich platelet to blue fluorescent light for 110
minutes and by electron microscope. They observed de-
crease in glycogen granules, platelet swelling and de-
formity [9]. In another research they had reported in-
creased platelet turn over during low birth weight (LBW)
neonate’s phototherapy for 96-hour period. Regarding to
low platelet reserve in LBW neonates bon marrow, the
increased turn over results to thrombocytopenia [13].
However Karim et al. in a study in 1981 showed that
phototherapy did not have any effect on platelets [6].
Photodynamic damage on platelets had studied by Tozzi-
Ciancar et al. via measuring LDH level [14]. They ex-
posed platelets rich plasma to visible light and measured
LDH level after 2 hours. They found 20% increase of
LDH level and they explained that it is due to photody-
namic side effect associated with hyperbilirubinemia on
platelets [14]. In a study Sakha et al. at 2007, on 150 full
terms, healthy neonates that hospitalized for treatment of
hyperbilirubinemia, showed increase of platelets and
white blood cells (WBC) during Phototherapy. Accord-
ing to their study increase of WBC correlate with patient
age and increase platelet count related to phototherapy
duration [7]. In another study on 101 newborn, Pishva et
al. showed 49.5% thrombocytopenia in treated patients.
They concluded increased platelet turnover and damage
during phototherapy as the responsible mechanism [8]. In
our study the newborns were full term with adequate plate-
let reserve. Increased platelet turnover and release of bone
marrow seems to be responsible mechanism for platelet
count rise. Although we find a meaningful difference (P =
0.015) in platelet count before and after phototherapy, but it
was in the normal reference range and we did not have any
bleeding tendency nor hyper-coagulability state in them. It
was not accessible for us to mesure thrombopoetin in this
study, so we propose it to other researchers. The limitations
of this study was lack of high technology cell counter
based on flowcy-tometry evaluation.
Present study state the hypothesis that phototherapy in
full term icteric newborns leads to rise in platelet count.
This may be due to accelerated platelet turnover in peri-
pheral microvasculature with adequate platelet reserve in
marrow. Based on our results and controversial studies,
platelet count measuring before and after phototherapy is
suggested as a routine protocol. Also more future multi
centric and case-control studies in preterm and full term
newborns should be done to evaluate this hypothesis.
The authors would like to acknowledge the office of Vice chancellor
for research of Hamadan University of Medical Sciences for financial
support of this study. Also we would like to thank Dr M. Fallah for his
assistance in statistical analysis, Dr S. Shabani and staff of neonatal
ward for their contribution and collaboration.
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