INTRODUCTION- 
Ultrasonography is essential investigation in obstetric 
management. Apart from assessment of fetal anomalies, it has 
a key role in assessment of placental anomalies, fetal 
circulation and fetal growth parameters. It has an important role 
in detection of intrauterine growth restriction (IUGR) 
pregnancies (1). IUGR is a common diagnosis in obstetrics and 
carries an increased risk of perinatal morbidity and mortality. 
Identication of IUGR is crucial because proper evaluation and 
management can result in a favourable outcome. Ultrasound 
biometry is the gold standard for assessment of fetal growth 
parameters and identication of IUGR.

Placenta is a fetal organ of pregnancy, which provides oxygen 
and nutrition to the growing fetus and carries out excretory 
functions as well. Ultrasound is the rst line modality in 

 imaging the placenta. Donald introduced placental 
localization by ultrasound in 1965 (2). Apart from site 
localization, measured placental thickness can be used as a 
gestational age indicator due to a linear increase in its 
thickness with advancing gestational age (3,4).

With this background, we planned to conduct a study, where 
we measured placental thickness in pregnant women, who 
were sure of their last menstrual period (LMP) and assessed 
the relationship of placental thickness with gestational age by 
LMP  and compared these ndings in normal and IUGR 
pregnancies to nd whether any signicant difference is 
present between these two groups.

MATERIAL AND METHODS- 
After getting approval from Institutional ethical committee of 
G.S.V.M. Medical College, Kanpur, Uttar Pradesh, India; this 
prospective cross sectional study was conducted in the 
Department of Radiodiagnosis in collaboration with the 
Department of Obstetrics and Gynaecology of same institute 

between  August 2016 to July 2017. All pregnant women who 
thwere sure of their LMP coming for antenatal USG between 18  

thto 40  weeks of gestation were enrolled. USG was performed 
using a SONOACE X8 system with 2-5MHz convex array 
transducer. Placental thickness at cord insertion site was 
measured keeping the plane of transducer perpendicular to 
the placental basal and chorionic plates. We excluded women 
with gestational diabetes mellitus, multiple pregnancies, 
polyhydromnios, diagnosed cases of fetal hydrops and 
pregnancies with any morphological variation in placenta or 
cord insertion. Women with poor visualization of cord insertion 
site were also excluded. Variables like maternal age, previous 
obstetric history, body mass index, placental position, 
hemoglobin level and blood pressure were also recorded. 
Study participants were categorized into two groups i.e. 
Group A (IUGR pregnancy) and Group B (Normal pregnancy) 
based on outcome newborn weight of <2500 grams and  
≥2500 grams respectively. Data were recorded in Microsoft 
excel sheet and was analysed using SPSS software. Mean 
placental thickness (MPT) with standard deviation (SD) were 
computed for each gestational age in both groups. The 
correlation and regression coefcient were calculated to 
quantify the relationship between the gestational age (weeks) 
and placental thickness (mm) in both groups. P value <0.05 
was considered signicant. Unpaired't'-test was applied to 
compare the difference between the means of the two groups 
at each gestational age.

RESULTS- 
Total 627 pregnant women, who were sure of their LMP, were 
enrolled. Out of which 445 participants completed this study 
and 182 were lost to follow-up. Among 445 participants, 147 
were included in group A and 298 study participants in group 
B. Maximum study participants were observed in age group 
21-25 years. (Figure 1)

PLACENTAL THICKNESS MEASUREMENT BY ULTRASONOGRAPHY AND 
IT'S CORRELATION WITH GESTATIONAL AGE IN NORMAL AND 

INTRAUTERINE GROWTH RETARDED PREGNANCY

Original Research Paper

Ashok Kumar 
Verma

MD, Department of Radiodiagnosis; GSVM Medical College, Kanpur; UP, 
India

Radiodiagnosis

Background- Ultrasonography is modality of choice for fetal evaluation, estimation of gestational age 
and detection of fetal growth restriction in pregnancies. 

Objective- This study was conducted with the aim of evaluating placental thickness, its role in estimation of gestational age of 
the fetus and in predicting normal and fetal growth restriction as outcome.
Methods- th thUsing Ultrasonography placental thickness was measured at cord insertion site from 18  to 40  weeks of gestation. 
Study participants were categorized as normal and intra uterine growth restriction based on birth weight of newborns. 
Correlation of placental thickness with gestational age was calculated and compared in both groups to nd any signicant 
difference.
Results- A positive correlation was observed between placental thickness and gestational age in both groups. Pearson's 
correlation coefcient (r) was calculated for both groups. It was 0.3221 and 0.7450 in intra uterine growth restriction and normal 

ndgroup respectively. In normal group placental thickness (mm) corresponds to gestational age (weeks) upto 32  weeks. After 
th th th ththat mean placental thickness remains nearly stationary upto 40  weeks with average thickness 31 mm. In 18  , 19  and 26  

weeks of gestation, placental thickness was more in IUGR group (22.5±4.2 ,28.1±5.2 and 31±5.5) as compared to normal 
group (18.7±1.6, 19.6±1.9 and 26±3.1).
Conclusion- Measured placental thickness at the umbilical cord insertion site can be used as an early sonographic parameter 
in detection of intrauterine growth restriction in singleton normal pregnancies.

ABSTRACT

KEYWORDS : Ultrasonography, placental thickness, gestational age, intrauterine growth restriction.

Rajlakshmi Yadav*
MD, Department of Radiodiagnosis; GSVM Medical College, Kanpur; UP, 
India*Corresponding Author

Rahul Chavhan
MD, Department of Radiodiagnosis; GSVM Medical College, Kanpur; UP, 
India

VOLUME-8, ISSUE-9, SEPTEMBER-2019 • PRINT ISSN No. 2277 - 8160 • DOI : 10.36106/gjra

90 X GJRA - GLOBAL JOURNAL FOR RESEARCH ANALYSIS



Total 445 measurements were taken. Minimum number of 
measurements recorded (at any single gestational week) was 
1 and 4 and maximum were 15 and 28 in Group A and Group B 
respectively. (Figure 2)  MPT was calculated for each 
gestational week in both groups. (Table 1) 

A positive correlation was observed between MPT and 
gestational age in both groups. Pearson's correlation 
coefcients (r) were 0.3221 and 0.7450 in Group A and Group B 
respectively; showing more strength of correlation in Group B.
Mean placental thickness in different gestational age shows 
linear relation in both groups. (Figure 3)

thIn group A, MPT is higher than gestational age till 29  weeks of 
st th thgestation excluding 21 , 28  and 34  week, where it 

thcorresponds to the gestational age. Beyond 29  week, MPT is 
thlower than the gestational age till 40  week. However, in group 

B, placental thickness corresponds to gestational age up to 
nd th32  week. After that it remains nearly stationary till 40  week 

with average thickness of 31 mm. 

Regression analysis yielded a linear equation of relationship 
between placental thickness in mm (X) and gestational age in 
weeks (Y) for both groups:

Group A→ Y=22.1068+0.2692X
Group B→   Y=6.062+0.7947X
Minimal placental thickness measured in Group A and Group 

thB were 17 mm and 16 mm respectively at 18  weeks of 
gestation; while maximum thickness measured was 49mm 

thand 44mm at 36  gestational weeks.

th th thMean placental thickness at 18 , 19  and 26  weeks is 
signicantly more in Group A (22.5±4.2 ,28.1±5.2 and 31±5.5) 
as compared to Group B (18.7±1.6, 19.6±1.9 and 26±3.1) with 
'p' value <0.05. An increased placental thickness in these 
gestational weeks can suggest abnormal fetal outcome.

In the total 445 study participants range of haemoglobin 
distribution was 4.3gm% to 12.7gm%. Haemoglobin range of 9 -
10gm%is seen in maximum number of cases (35.9%) and range 
12-13gm% in minimum number of cases (1.3%). (Table 2)

DISCUSSION- 
From previous studies it has been seen that placental size 
increases linearly with advancing gestational age. Any 
abnormaly thin or thick placenta may be an indicator of 
abnormal fetal outcome or any pathological condition. Elsa 

 et alreported that placental thickness less than 25 mm in third 
trimester is subnormal and may be associated with 
intrauterine growth retardation and placental thickness more 
than 40 in third trimester is abnormally thick and may 
represent pathological condition like maternal diabetes 
mellitus, fetal hydrops, intra uterine infections (5).

Our study showed a linear relation between placental 
thickness and gestational age (by LMP) in both normal and 

th thIUGR cases from 18  week to 40  week. In Group B, placental 
thickness (mm)  is almost corresponding with gestational age 

th nd(weeks) from 18   to 32  week, after that placental thickness  
slightly decreases and remains nearly constant with average 

thplacental thickness of 31mm till 40  week. Maximum  MPT  in 
th  normal group was 33mm at 36  week.   Hoddick et al found 

average placental thickness was increasing with advancing 
menstrual age (6). Mital P and Hooja N also found an 
increasing MPT with advancing  gestational age and between 

nd th22   to 35  week of gestation,  the placental thickness coincide 

almost exactly with the gestational age (weeks) (2,7). 
 Anupama Jain et al reported similar correlations between 

placental thickness and gestational age (8). They found 
placental thickness (mm) almost matched gestational age 

th rd  (weeks) from 27  to 33  weeks of gestation. Grannum et al
reported that placental thickness would increase linearly until 

rd33  weeks of pregnancy, after which there was gradual 
thinning (9). Berkowitz et al reported gradual decrease in 
placental size after 32 weeks until term (10).

In Group B, we nd stronger linear relation between placental 
thickness and gestational age. However in Group A, placental 

stthickness does not coincides with gestational age except in 21 , 
th th28  and 34  gestational weeks. More diverse value of placental 

thickness was seen in IUGR cases as compared to normal cases 
indicating that thin or thick both type of placenta are associated 
with intrauterine growth retardation. Statistically signicant 
difference in the MPT of IUGR and normal group was seen only 

th th thin 18 , 19 and 26  gestational weeks, with mean values more in 
IUGR as compared to normal group (22.5±4.2, 28.1±5.2 and 
31±5.5 vs 18.7±1.6, 19.6±1.9 and 26±3) suggesting earliest 
identication of IUGR pregnancy is possible by antenatal USG 
in these gestational weeks.

Cross sectional prospective study of correlation between 
placental thickness and gestational age is done in both 

 normal and IUGR group by Mathai et alin India (1). They also 
found positive correlation between placental thickness and 
ultrasonographic gestational age in both normal and IUGR 
groups. In their study statistically signicant difference in the 

th thMPT in both groups were seen in 26  and 30  ultrasonographic 
gestational weeks with MPT lower in IUGR group as compared 
to normal group.

CONCLUSION- 
Antenatal ultrasonographic measurement of placental 
thickness at cord insertion site would help in predicting 
outcome (normal/IUGR) of the pegnancy. Therefore, 
abnormal placental thickness in a particular gestational age 
can be used as an addition tool in early detection of IUGR in 
singleton pregnancy.

Acknowledgments- 
The authors acknowledge the support of Ashok Kumar Verma 
for his valuable guidance in designing this study; Shyam 
Madheshiya, Deepak Thangraj, Ravindra Pandey and 
Nachiket Mangaraj in enrolling study participants for this 
study. We also acknowledge the support of study particpants 
who came forward to be a part of this study.

Table 2. Distribution of haemoglobin concentration in both 
groups

IUGR¶- Intra uterine growth retarded

VOLUME-8, ISSUE-9, SEPTEMBER-2019 • PRINT ISSN No. 2277 - 8160 • DOI : 10.36106/gjra

Haemoglobin 
(gram%)

Group A 
(IUGR¶)

Group B 
(Normal)

Number of 
cases

4-5 10 0 10

5-6 8 1 9

6-7 14 5 19

7-8 33 39 72

8-9 42 78 120

9-10 29 131 160

10-11 6 30 36

11-12 3 10 13

12-13 2 4 6

Total no. of cases 147 298 445

Table 1. Relationship between gestational age and placental thickness in both groups
GA* (Weeks) Group A (IUGR¶) Group B (Normal) p-value

Placental thickness (Mean±SD) N** Placental thickness (Mean±SD) N**

18-18.6 22.5±4.2 4 18.7±1.6 28 <0.05

19-19.6 28.1±5.2 6 19.6±1.9 15 <0.05

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Figure-1 Maternal age distribution

Figure-2 Number of cases at different gestational age

Figure-3. Mean placental thickness in different gestational 
age

REFERENCES-
1. Mathai BM, Singla SC, Nittala PP, Chakravarti RJ, Toppo JN. Placental 

thickness: its correlation with ultrasonographic gestational age in normal 
and intrauterine growth-retarded pregnancies in the late second and third 
trimester. J Obstet Gynaecol India. 2013 Aug;63(4):230-3.

2. Donald I. On launching a new diagnostic science. Am J Obstet Gynecol 
1968;103:609-28.

3. Mital P, Hooja N, Mehndiratta K. Placental thickness - A sonographic 
parameter for estimating gestational age of the fetus. Ind J Radiol Imag 

2002;12:553-4.
4. Jain A, Kumar G, Agarwal U, Kharakwal S. Placental thickness - A 

sonographic indicator of gestational age. J Obstet Gynaecol India 
2001;51:48-9.

5. Elsa AA, MagdoleinSA, CarolineEA, AbdelmoneimSA. Prediction of fetal 
growth by measuring the placental thickness using Ultrasonography. Journal 
of Gynecology and Obstetrics. 2014; 2(2): 26-31.

6. Hoddick WK, Mahoney BS, Callen FW, Filly RA. Placental thickness. J 
Ultrasound Med. 1985; 4: 479-482.

7. Mital P, Hooja N, Mehndiratta. Placental thickness – a sonographic parameter 
for estimating gestational age of the fetus. Ind J Radiol Imag. 2002; 12( 4): 553-
554.

8. Anupama Jain, Ganesh Kumar, Agarwal U, Kharakwal S. Placental thickness 
– a sonographic indicator of gestational age. Journal of obstetrics and 
gynaecology of India. 2001; 51(3): 48-49.

9. Granum PAT, Hobbins JC. The placenta. Radiol Clin North Am. 1982; 20: 353.
10. Granum PAT, Berkowitz RL, Hobbins JC. The ultrasonic changes in the 

maturing placenta and their relation to fetal pulmonic maturity. Am J Obstet 
Gynecol. 1979; 133: 915-922.

VOLUME-8, ISSUE-9, SEPTEMBER-2019 • PRINT ISSN No. 2277 - 8160 • DOI : 10.36106/gjra

20-20.6 23.4±5.2 5 20.6±2.8 19 >0.05

21-21.6 22±1 3 21.6±2.7 12 >0.05

22-22.6 25±0 1 23.1±6.1 11

23-23.6 29±0 1 23.8±2.6 16

24-24.6 27±0 1 25±1.9 13

25-25.6 27±4.8 4 25.5±3 10 >0.05

26-26.6 31±5.5 15 26±3.1 12 <0.05

27-27.6 30.2±5.2 8 27±2.1 11 >0.05

28-28.6 28.5±4 9 28.1±3.3 11 >0.05

29-29.6 31±5.3 10 28.5±2.5 6 >0.05

30-30.6 28.2±3.8 4 29.1±2.7 16 >0.05

31-31.6 27.4±5.4 5 30.7±3.3 16 >0.05

32-32.6 30.4±9.7 9 32±5.4 25 >0.05

33-33.6 28.3±3.9 5 30.9 ±5.8 15 >0.05

34-34.6 34.1±8.5 15 31.8±2.9 16 >0.05

35-35.6 30.6±7.5 9 31.2±4.8 16 >0.05

36-36.6 32.4±7.2 13 33±5.1 14 >0.05

37-37.6 33.6±8.5 11 29.8±5 8 >0.05

38-38.6 33±9.2 4 31.5±3.7 4 >0.05

39-40 28.8±6.7 5 30.5±7 4 >0.05

Total 147 298

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