Maternal, Fetal and Placental Responses in the Early and Late Onset Preeclampsia

J Infertil Reprod Biol, 2017, Volume 5, Issue 4, Pages: 20-25. https://doi.org/10.47277/JIRB/5(4)/20

Maternal, Fetal and Placental Responses in the

Early and Late Onset Preeclampsia

Mona Sharma , Renu Dhingra , Neerja Bhatla

Assistant Professor, Department of Reproductive Biology, All India Institute of Medical Sciences, New Delhi, India

Professor, Department of Anatomy, All India Institute of Medical Sciences, New Delhi, India

Professor, Department of Obstetrics and Gynaecology, All India Institute of Medical Sciences, New Delhi, India

Received: 17/09/2017

Accepted: 20/11/2017

Published: 20/12/2017

Abstract

Preeclampsia is the pregnancy induced disorder of hypertension and proteinuria manifesting after midgestation. Depending upon

the onset of symptoms, it can be classified as early onset (≤34 wks) or late onset (≥34wks). The objectives of the present study were to

compare the maternal responses (maternal age, gestational age, mode of delivery, blood pressure, proteinuria), the fetal responses

(

birth weight, APGAR score) and placental responses (placental weight, placental morphology, trophoblastic and syncytial knot

apoptotic rates) between the early and late onset preeclamptic women. The study group included early onset (20 placentas), late onset

20 placentas) cases of preeclampsia and control group included 20 placentas from normotensive nonproteinuric pregnant women. For

(

the placental pathological changes, hematoxylin and eosin staining and M30 immunostaining were used. The maternal, fetal and

placental responses were compared between study and control groups. As compared to the control group, the maternal age, blood

pressure and proteinuria were higher in both early and late onset preeclamptic groups. The early onset preeclamptic group was

associated with low placental weight along with premature delivery of low birth weight babies with low APGAR scores as compared

to control and late onset preeclamptic group. The mode of delivery in most of the cases of early onset preeclamptic group was

caesarean section. The fetal and placental responses in late preeclamptic group were comparable to that of control group. The placental

villous and vascular morphology along with apoptotic indices were severely altered in early onset preeclamptic group. Between the

two types of preeclampsia, the early onset preeclamptic group showed poor maternal, fetal and placental responses suggesting its

severity and bad prognosis.

Keywords: Preeclampsia, Maternal age, Placentas, Premature delivery, APGAR Score

Introduction

maternal immune system and contributes to maternal vascular

injury and endothelial dysfunction which centralises the

pathogenetic events of this disorder (5). It can be assumed that

maternal inflammatory response is the final pathway of this

disorder but its initiative routes can vary greatly. Though the

hypothesis pertaining to pathological changes of preeclampsia

revolves around the abnormal trophoblastic apoptosis and

syncytial shedding but the onset of symptoms in preeclampsia

greatly differ. In early onset preeclampsia, the symptoms

appear at ≤34 wks whereas in late onset preeclampsia, the

symptoms appear at ≥34wks of gestation (6). The

trophoblastic apoptosis can be estimated by using various

cytoplasmic and nuclear apoptotic markers such as annexin v

staining, TUNEL, M30 immunostaining. M30 antibody has

been used to identify apoptotic changes specifically in the

cytoplasm. This antibody identifies the cytokeratin breakdown

occurring during apoptosis cascade and it has been used as

apoptotic markers for trophoblastic cells (7, 8).

The pregnancy associated hypertensive disorders are one

of the causes of maternal mortality all over the world.

thorough understanding of the current causes of maternal

mortality is crucial for addressing the challenge of high rates

of maternal mortality. The International Society for the study

of Hypertension in Pregnancy (ISSHP) defines preeclampsia

as the onset of sudden hypertension (systolic blood pressure

≥

140mmHg and diastolic blood pressure ≥90 mmHg) along

with proteinuria ≥300 mg in a 24-hour collection of urine after

weeks of gestation in a previously normotensive,

nonproteinuric pregnant woman. These identifying clinical

features should disappear by the end of third month

postpartum (1).

The pathological features of this disorder have been correlated

with the aberrant trophoblastic life cycle. The exaggerated rate

of trophoblastic apoptosis in preeclamptic placentas leads to

insufficient trophoblastic invasion causing abnormal

implantation and placental vascular insufficiency (2).

Apoptosis is the natural mechanism of trophoblast turnover

process and it involves extrinsic and intrinsic mechanisms (3).

Placental trophoblastic cells form abundant syncytial knots

which get detach from the villous surface into maternal

circulation (4). These syncytial aggregates stimulate the

Preeclampsia remains the target of extensive research in recent

years and more work needs to be conducted to unfold the

underlying pathological events of the subsets of this disorder.

Therefore, to circumvent the differences in the onset of

cardinal symptoms, we hypothesise that the maternal, fetal and

Corresponding author: Mona Sharma, Department of Reproductive Biology, 2 Floor, Teaching Block, AIIMS, New Delhi, India. E-

mail: dr.mona18sharma@gmail.com

J Infertil Reprod Biol, 2017, Volume 5, Issue 4, Pages: 20-25. https://doi.org/10.47277/JIRB/5(4)/20

placental responses may differ in the early and late onset

preeclampsia.

correction was applied. P value <0.05 was considered

statistically significant. For multiple comparisons, fischer’s

exact test was used with bonferroni correction and P <0.018

was considered statistically significant.

Methods

A total of 60 placentas were collected from the labour

room of Department of Obstetrics and Gynaecology, All India

Institute of Medical Sciences, New Delhi. The ethical

committee approved the protocol of the study. The consent

was taken from each individual for the study groups. Out of

the total samples, 20 placentas were from early onset

preeclamptic pregnant women, 20 placentas were from late

onset preeclamptic pregnant women and 20 placentas were

taken from normotensive nonproteinuric pregnant women.

Preeclampsia was diagnosed according to the ISSHP criteria.

Patients with chronic hypertension, pregestational diabetes,

chorioamnionitis, renal disease, cardiac disease, thyroid

disease, pre-existing seizure disorder and HELLP syndrome

were excluded from this study.

The placental samples were collected immediately after

delivery. The central part of the placental disc was chosen for

taking the samples. The areas of visible infarcts, hematomas

or calcification were excluded. The placental tissue samples

were fixed in 10% formaldehyde and subsequently paraffin

blocks and 5µm tissue sections were prepared. Subsequently,

tissue sections were deparaffinised rehydrated and processed

for hematoxylin and eosin staining and were examined under

light microscope. Standard procedure for immunostaining was

followed according to manufacturer’s protocol. For M30

immunostaining (Roche Diagnostic, Germany), the

subsequent steps were carried out at room temperature in a

Results

Maternal Responses

The systolic blood pressure (SBP) [160±4.6(150-170)] as

well as diastolic blood pressure (DBP) [108±6.5(100-118)]

were more in early onset preeclamptic group as well as in late

onset group [SBP-144±4.4(138-156), DBP-93.9±3.8(90-100)

as compared to control group[SBP-112±8.6(100-124), DBP-

79.7±6.1(70-90)]. The rate of proteinuria was also more in

early onset preeclamptic group [4.1±0.6(3-5)] as well as in late

onset preeclamptic group [1.7±0.6(1-2.9)] as compared to the

control group [0.16±0.04(0.1-0.2)]. Maternal age was more in

early [35±1.9(32-38)] as well as in late onset preeclamptic

groups [34.2±2.2(30-38)] as compared to control group

[27.6±3.6(20-34)]. The early onset preeclamptic group showed

less gestational age [33.6±1.5(31-36)] as compared to the late

onset preeclamptic group [37.7±1.2(36-40)] and control group

[38.2±1.4(36-41)]. In the early onset preeclamptic group, 90%

women were delivered by caesarean sections as compared to

late onset preeclamptic (25%) and control group (10%).

Amongst the two preeclamptic groups, the early onset group

showed higher SBP, DBP and rate of proteinuria (Tables 1-3,

6, 7).

Fetal Responses

The newborns in the early onset group were low weight

2 2

humidified chamber. The 3% H O prepared in methanol was

[

2088±166(1800-2400)] as compared to late onset

preeclamptic group [2825±226(2500-3500)] and control group

2924±260(2500-3500)]. The newborns delivered from early

used for 10 minutes to block peroxidase activity. The

specimens were then incubated in 1-3 drops of serum block

for 2 hours to prevent non-specific binding to collagen and

connective tissue. Further, the specimens were incubated for

[

onset preeclamptic women, 85% of them showed low APGAR

scores as compared to late onset preeclamptic (25%) and

control group (0%) (Tables 2, 4, 6, 7).

4 hrs with M30 antibody (1:50) followed by 1-3 drops of

biotinylated secondary antibody (anti mouse IgG) for 30

minutes. Thereafter, the specimens were incubated in 1-3

drops of HRP-streptavidin complex for 30 minutes. The slides

were then counterstained with hematoxylin and dehydrated by

passing through ascending grades of ethanol. The slides were

then mounted with DPX and were observed under light

microscope. The negative tissue control included eliminating

the primary antiserum and replacing species-specific

antiserum with normal horse serum. Sections of colon

adenocarcinoma were taken as positive controls. Stained

sections showing trophoblastic cells and syncytial knots with

the brown cytoplasmic stain were considered M30

immunostaining positive apoptotic cells. The trophoblastic

and syncytial knot apoptotic indices were calculated (total

number of apoptotic cells per total number of cells multiply by

Placental Responses

The placental weight in early onset preeclamptic group

was less [376.5±67.7(240-490)] as compared to the late onset

preeclamptic [504±50.5(400-600)] and control groups

[524±45(440-630)].The early onset preeclamptic placentas

showed gross areas of infarcts, hematomas and thrombi. On

histological examination, the placental villi showed altered

morphological patterns along with interstitial edema. These

villi were of variable sizes and were lined by

syncytiotrophoblastic cells and less of cytotrophoblastic cells.

The villous core composed of mesenchyme and blood vessels.

There was increased capillarisation seen in these villi which

made their surface deformed. The intervillous space was more

in these placentas. The fibrin deposits were seen on the

trophoblastic surface. The nuclei of trophoblastic cells

aggregated and formed excessive of syncytial knots (figures 1-

00). The maternal responses (maternal age, gestational age,

mode of delivery, blood pressure, urinary protein), fetal

responses (birth weight, APGAR scores) and placental

responses (placental weight, placental morphology by

hematoxylin and eosin staining, trophoblastic and syncytial

knot indices by M30 immunostaining) were compared among

the study groups. Statistical analysis was done using Stata

). The trophoblastic apoptotic index was more in these group

of placentas [91.3±6.3(80-99)] as compared to late onset

preeclamptic [62.3±13.8(38-85)] and control groups

1.9±14.4(37.3-87.9)]. The syncytial knot apoptotic index was

also more in early onset preeclamptic group [87.7±10.1(70-

00)] as compared to late onset preeclamptic [43±16.2(10-70)]

and control groups [36.9±20.2(0-66.6)]. There were no

[

.0/Data analysis software (college station, Texas). Data were

presented as in Mean ±SD (range). For comparison among the

study groups, one way ANOVA test with bonferroni

J Infertil Reprod Biol, 2017, Volume 5, Issue 4, Pages: 20-25. https://doi.org/10.47277/JIRB/5(4)/20

significant pathological changes observed in the placentas of

Table 1: Comparison of Maternal responses in the study groups

late onset preeclamptic group (Tables 2, 5-7).

Parameters

Early Onset Preeclampsia (n= 20)

160±4.6(150-170)

Late Onset Preeclampsia (n=20)

144±4.4(138-156)

P value

<0.0001

Systolic BP (mm Hg)

Diastolic BP (mm Hg)

Proteinuria (g/day)

108±6.5(100-118)

4.1±0.6(3-5)

93.9±3.8(90-100)

1.7±0.6(1-2.9)

n = number of subjects, Data is presented in Mean ±SD (range), One way ANOVA test with bonferroni correction; P<0.05, statistically significant

Table 2: Comparison of Maternal and fetal responses in the study groups

Parameters

Early Onset Preeclampsia (n= 20)

35±1.9(32-38)

Late Onset Preeclampsia (n=20)

34.2±2.2(30-38)

P value

0.9

<0.0001

Maternal Age (yrs)

Gestational Age (wks)

Birth Wt (gms)

33.6±1.5(31-36)

2088±166(1800-2400)

376.5±67.7(240-490)

37.7±1.2(36-40)

2825±226(2500-3500)

504±50.5(400-600)

Placental Wt (gms)

n = number of subjects, Data is presented in Mean ±SD (range), One way ANOVA test with bonferroni correction; P<0.05, statistically significant

Table 3: Comparison of Maternal parameters (mode of delivery) in study groups

Study groups

Percentage

Overall

p-value

Multiple comparison (p value <0.018)

Gp 1 Vs Gp 2

<0.0001

Gp 1 Vs Gp 3

0.407

Gp 2 Vs Gp 3

<0.0001

Control Group

Gp1

NV-18(90)

CS-2(10)

<0.0001

Early Onset PE

Gp2

NV-2(10)

CS-18(90)

Late Onset PE

Gp3

NV-15(75)

CS-5(25)

Fischer’s exact test, statistical significance: P<0.05;

Multiple comparison with bonferroni correction, statistical significance: P<0.018 (NV: normal vaginal delivery; CS: caesarean section)

Table 4: Comparison of Fetal parameters (APGAR score) in study groups

Study Groups

Percentage

Overall

p-value

Multiple comparison (p value <0.018)

Gp 1 Vs Gp 2

<0.0001

Gp 1 Vs Gp 3

0.047

Gp 2 Vs Gp 3

<0.0001

Control Group

Gp1

≤7-0(0)

≥7-20(100)

<0.0001

Early Onset PE

Gp2

≤7-17(85)

≥7-3(15)

Late Onset PE

Gp3

≤7-5(25)

≥7-15(75)

Fischer’s exact test, statistical significance: P<0.05

Multiple comparison with bonferroni correction, statistical significance : P< 0.018

Table 5: Comparison of Placental responses in the study groups

Parameters

Trophoblastic Index (%)

Syncytial Knot Index (%)

Early Onset Preeclampsia (n= 20)

91.3±6.3(80-99)

Late Onset Preeclampsia (n=20)

62.3±13.8(38-85)

P value

<0.0001

87.7±10.1(70-100)

43±16.2(10-70)

n = number of subjects, Data is presented in Mean ±SD (range), One way ANOVA test with bonferroni correction; P<0.05, statistically significant