This document discusses various screening tests and potential biochemical markers for predicting preeclampsia (PE). It notes that PE is a two-stage disorder involving inadequate invasion of spiral arteries into the myometrium in stage one, followed by an oxidatively stressed placenta releasing anti-angiogenic factors in stage two. Several biochemical markers are mentioned as showing potential for predicting PE, either alone or in combination with ultrasound measures, including placental growth factor, soluble fms-like tyrosine kinase-1, soluble endoglin, PAPP-A, and inhibin A. The document provides details on studies investigating the sensitivity and specificity of these and other markers for PE prediction.
4. Screening by Maternal History
Rates of preeclampsia depend on: severity of underlying complications&
combinations of risk factors.
Risk %Risk factors
15-40Chronic hypertension/renal disease
10-35Pre gestational DM
10-20Connective tissue disease (lupus, rheumatoid arthritis)
10-40Thrombophilia (acquired or congenital)
10-15Obesity/insulin resistance
10-20Age older than 40 y
10-35Limited sperm exposure
10-15Family history of preeclampsia/ cardiovascular disease
1.5 foldWoman born as SFGA
2-3 foldAdverse outcome in a previous pregnancy: IUGR, abruptio
placentae, IUFD
6. SCREENING TESTS FOR PE (WHO, 2004)
I. Placental perfusion & vascular resistance
dysfunction
Mean arterial blood pressure
Roll over test
Doppler ultrasound
Isometric exercise test
Intravenous infusion of angiotensin II
Platelet angiotensin II binding
Platelet calcium response to arginine vasopressin
Renin
24-hour ambulatory blood pressure monitoring
11. Play a central role in the pathogenesis and
be specific for the condition.
Appear early or before the clinical
manifestations.
Placental factors that can be detected early
in pregnancy are likely to be good
biochemical markers for PE prediction.
12. Correlates with clinical severity of
preeclampsia and perinatal
outcomes.
Despite a good amount of studies,
not of all studies suggest that the
serum uric acid levels may begin to
rise before the onset of hypertension
and proteinuria.
13. an early sign of renal involvement in
preeclampsia- ↓↓ renal clearance
due to altered tubular processing of
uric acid preceding glomerular
affliction.
the discriminatory value of serum
uric acid as a predictor of
preeclampsia remains to be proven
14. .
Recent study- sensitivity of 22%
specificity of 85% for prediction of PE.
The disappointing results of recent studies raises doubts
about usefulness as a continuing test.
15. I. Biophysical
Mean arterial pressure
•Better predictor of PE than S& D BP
(BMJ 200817;336:111; Meta-analysis of 34 RCT)
2nd trimester MA BP ≥ 90 mm Hg had +ve LR 3.5
and –ve LR 0.46
•BP remains the cornerstone of early diagnosis
although it has limitations:
measurement errors associated with sphygmomanometer
effect of maternal posture on BP in pregnant women.
16. • 84% developed PE.
• Microproteinuria > 375mg/l may be significant
•Could be utilized as a screening test for the
early detection of a woman at risk of
developing preeclampsia.
•There is no diagnostic value of
microalbuminuria and the calcium/creatinine
ratio when used alone.
17. Suggested as a predictive first trimester
marker for PE .
Given the low screening performance of the
study, cystatin C is probably not clinically
useful as a single marker but could be useful
in combination with other biochemical
markers.
18. Suggest that possible cellular battle against
mitochondria-originated oxidative stress
test resulting in recovery or apoptosis.
The over expression of chaperonin 60, GST,
VDAC, Erp29 and cathespin D in
PE makes it a ideal marker of predicting
preeclampsia .
19. Women with PE present a unique urine
proteomic fingerprint composed of
SERPINA1 and albumin fragments that
predicts PE in need of mandated delivery
with highest accuracy.
To distinguish preeclampsia from other
hypertensive or proteinuric disorders in
pregnancy.
20. Cell free DNA is a promising new
marker.
Increased before the onset of
disease
Int j Mol Sci 2015
21. Urinary excretion of N-acetyl-beta-
glucosaminidine, a lysosomal enzyme of the
renal tubular cells ↑↑↑ in normal pregnant
women and in woman with transient
hypertension Vs non pregnant healthy
controls.
In PE, the increase was much higher than
corresponding to their gestational age
22. Pre-eclampsia Vs gestational
hypertension or chronic
hypertension.
↑↑↑Thrombomodulin may serve
as a clinical marker to
differentiate preeclampsia from
other disorders of pregnancy.
23. •in the first trimester is a example where a
combination of ultrasound and biochemical
markers are used.
• Measurement of other indices with inhibin
A can produce a test with greater sensitivity
for PE as occurs with triple or quadruple
blood tests for Down's syndrome ?
24. Inhibin A is the best predictor of Pre-eclampsia
out of unconjugated estriol,beta hcg at second
Trimester.
A more sensitive marker for the prediction of
preeclampsia than hCG.
hCG + inhibin did not improve the screening
efficiency for preeclampsia
suggesting that inhibin-A and hCG are markers of
the same underlying pathological process
Fetal Diag Therapy 2011
25. Midtrimester beta-hCG levels alone
correlated significantly with the
severity of preeclampsia.
Combination of Maternal Serum
hCG levels, BMI,parity and age as a
predictive test for preeclampsia was
far superior to hCG alone.
Sensitivity of 70% , Specificity of 71
%.
26. Serum levels of collagen synthesis,
procollagen I, carboxy- terminal peptide
(PICP) and procollagen111 amino-terminal
peptide (PIIIP), in patients with
preeclampsia and controls.
The markers were mildly elevated in
preeclampsia, but unlikely to be useful in the
prediction of preeclampsia
27. Preeclampsia is a 2 stage disorder
Stage 1
Invasion of Spiral Arteries
into myometrium is
inadequate.Stage 2 in late
pregnancy
Oxidatively stressed placenta
releases antiangiogenic proteins
Tyrosine kinase 1 ,PGs and
Cytokines.Hypoxic placenta reduces
the production of pro angiogenic
factors –Placental Growth Factor
PIGF,VEGF
28. Glycoprotein synthesized in the placenta
Maternal plasma conc. increases through out
pregnancy.
PAPP-A ,b-hCG and nuchal translucency
thickness, to screen for trisomy 21, 13 and
18 at 11 to 13 weeks GA.
In fetuses with normal chromosomes ↓ PAPP-
A in 1st trimes - ↑↑↑ risk for PE, IUGR, SGA
and preterm delivery
29. when used as a single biochemical marker, is
only about 10 to 20 % Sensitive.
Combined with Doppler ultrasound, PAPP-A
is a powerful predictive biochemical marker
of PE
prediction rates of 70% at false positive
rates of 5%.
At term, plasma PAPP-A have been shown to
increase in pregnancies complicated by PE
and HELLP, but its concentration is still not
predictive
30. a member of the galectin family
produced by the placental trophoblast cells
and is associated with normal placentation.
In normal pregnancies, serum PP13 slowly rise
with GA.
↓↓ levels in the first trimester in pregnancies
that subsequently develop PE.
31. Serum screening + Doppler ultrasound
pulsatility index (PI),
Prediction rate 71% at a false
positive 10%
PP13 was concluded to be a
reasonable biochemical marker for
early onset and preterm PE but a
weak marker for PE at term
32. Endoglin is homodimeric transmembrane
glycoprotein .
33. The levels correlate with the time
of onset of clinically manifest PE
and partly with disease severity.
Early-onset PE exhibits higher levels
of sFlt
↑↑ is observed ~5 weeks before
onset of PE
34. .
.
soluble endoglin (s-Eng) . sEng+ Doppler
ultrasound (PI) and PlGF, the prediction
rate for early onset PE was 77.8% at a false
positive rate of 5%
sFlt-1 levels are stable during early &
mid gestation ,then increase
significantly during late stages
35. Maternal plasma sEng and
Uterine artery PI are ↑↑.
PIGF and PAPP-A are ↓
Uterine Artery PI was ↑↑ .but no
significant difference in the
maternal plasma conc.of sEng or
sPAPP-A
Late PE
36. .
Low increase in PlGF in early pregnancy
,independent of change in sFlt-1 is
associated with high risk –PE.
Low or no ↑↑ in serum free PlGF , VEGF & high
conc. of sFlt-1 a strong predictor of early PE.
Low increase in PlGF & low ↑↑ in sFlt are
associated with 10 fold higher risk of pre term PE
37. In the unaffected group, multiple
regression analysis - at 30-33
weeks serum sEng for third-
trimester log10 sEng was
significantly lower in women of
Afro-Caribbean racial origin than in
Caucasians ,
higher in nulliparous than in parous
women.
Consequently sEng must be
adjusted for these variables before
comparing with pathological
pregnancies
38. Higher sEng in women developing PE and the
inverse relation between the level of sEng and
GA at delivery for PE is compatible with the
role of this anti-angiogenic factor in inducing
vascular endothelial cell injury and dysfunction
before the clinical onset of the disease
39. sEng+ Doppler ultrasound (PI) and
PlGF, the prediction rate for early
onset PE was 77.8% at a FP rate of
5%
40.
41.
42.
43. As a single biochemical marker, PlGF has
been shown to predict 53.5% of early onset
PE at a false positive rate of 5%
at a false positive rate of 10% in late first
trimester.
44. PlGF could be a promising
biochemical marker even in the first
trimester particularly if combined with
HbF and A1M.
45. Increase in sFlt -1 ,↓PIGF and VEGF .
sFlt-1 soluble vascular endothelial growth factor
receptor-1
47. 0.01 0.1 0.2 0.5 1 2 5 10
Progesterone 0.21 (0.03, 1.77)
Nitric oxide donors and precursors 0.83 (0.49, 1.41)
Diuretics 0.68 (0.45, 1.03)
Antiplatelets 0.81 (0.75, 0.88)
Antihypertensives v none 0.99 (0.84, 1.18)
Marine oils 0.86 (0.59, 1.27)
Magnesium 0.87 (0.57, 1.32)
Garlic 0.78 (0.31, 1.93)
Energy/protein restriction 1.13 (0.59, 2.18)
Isocaloric balanced protein supplementation 1.00 (0.57, 1.75)
Balanced protein/energy intake 1.20 (0.77, 1.89)
Nutritional advice 0.98 (0.42, 1.88)
Calcium 0.48 (0.33, 0.69)
Antioxidants 0.61 (0.50, 0.75)
Altered dietary salt 1.11 (0.46, 2.66)
Rest alone for normal BP 0.05 (0.00, 0.83)
Exercise 0.31 (0.01, 7.09)
Bed rest for high BP 0.98 (0.80, 1.20)
Ambulatory BP
1
4
4
43
19
4
2
1
2
1
3
1
12
7
2
1
2
1
0
128
170
1391
33439
2402
1683
474
100
284
782
512
136
15206
6082
631
32
45
228
0
Relative Risk (95% Confidence Interval)
RR (95% CI)Intervention No of RCTs No of women
Primary Prevention Of PE
48. Uterine artery Doppler ultrasound
Impaired trophoblastic invasion of the spiral
arteries: reduction in uteroplacental blood flow}
•High pulsatility index and/or Notch in 1st & 2nd
trimesters: poor predictor of PE(Papgeorghiou & Leslie, 2007)
Uterine artery Doppler plus biochemical markers
•Promising results
•Current data do not support this combination for
routine screening for PE (Barton& Sibai, 2008).
50. Clinical
examination
Sensitivity Specificity
Body mass index
(BMI)
BMI ≥ 25 47%(33-61) 73%(64-83)
BMI ≥ 30 19%(19-20) 90%(88-93)
BMI ≥ 35 21%(12-31) 92%(89-95)
Blood pressure in
the first trimester
Mean arterial
pressure ≥90mmHg
62%(35.89) 82%(72-92)
Hemodynamic
investigations
Uterine artery
doppler in second
trimester
High PI and
notching in low-risk
23%(14-35) 99%(98-99)
High PI and
notching in high-risk
83%(36-100) 96%(90-99)
51. HbF and A1M play a role in the
pathophysiology of PE .
The biochemical markers appear as early as 10
weeks of gestation .
can be measured with basic ELISA techniques
and show a high prediction rate at a low
false positive level.
52. Serum HbF and A1M ↑↑ at 10 to
16 weeks’ who subsequently
developed PE.
HbF and adult hemoglobin
(HbA) significantly correlated to
maternal BP in patients with
established PE
53. Maternal plasma free HbF
correlate well with severity, i.e.
blood pressure, in term PE
pregnancies .
54. bind and degrade heme
Free radical-scavenger properties , protect
tissues against extracellular Hb, heme and ROS .
Pathogenic role of Hb and protective role of A1M
in PE is supported by placenta perfusion
experiments .
Maternal serum HbF and A1M- predictive and
diagnostic markers for PE, have shown
promising results .
55. The genes on which the errors were
identified (MCP factor I and factor H) play a
role in regulating immune response .
This could explain their possible link to PE
Women with lupus and other autoimmune
diseases - in the study - ↑↑ed risk of PE.
57. Biomarker 1st trim 2nd trim Symptomatic Combination Also
correlated
with
PAPP-A ↓ ↓ ↓ SGA
PP-13 ↓ ↑ ↑ US UIGR,preter
m
Fdna ↑ ↑ ↑ Inhibin-A IUGR,
polydramios
trisomy
21,18
preterm
DNA ↑
SFlt-1 ↑ ↑ sEng, PIGF,
VEGF, US
PIGF ↓ ↓ ↓ sEng,sFit-1 SGA
sEng ↑ ↑ sFit-1,PIGF,US IUGR, HELLP
P-selectin ↑ ↑ ↑ Activin A,sFit-1
PTX-3 ↑ ↑ ↑ IUGR
Summary of Potential Serum Biomarkers for Prediction of Preeclampsia
58. There is no proven
effective method for
prevention of
Preeclampsia
59. Pharmacological
prophylaxis
Nutritional
supplement
Lifestyle
intervention and
diet
Antiplatelet
agents
Nitric oxide
agents
Low-molecular
weight heparin
Antihypertensive
s for mild and
moderate
hypertension
Progesterone
Diuretics
Calcium
Antioxidant
Folic acid
Magnesium
Marine oil and
prostaglandin
precursors
Rest
Exercise
Altered dietary
salt
Energy and
protein intake
Garlic
CAN COMBINED SCREENING LEAD TO TRAGETED PREVENTATIVE THERAPY?
Treatments evaluated for preeclampsia prevention
60. Aspirin
Largely ineffective, except in subgroup of
“clinically” high-risk women
Nitric oxide donors Ineffective
Diuretics ineffective
Progesterone ineffective
Low-molecular weight heparin
Largely ineffective, except in small subgroup
of thrombophiliac
Recombinant investigational
Calcium
Largely ineffective, except
in setting of low dietary
calcium intake (<600
mg/day or corresponding to
less than two dairy servings
per day)
Magnesium Ineffective
Folic Acid Ineffective
Antioxidants (vitamin C&E) Ineffective
Efficacy of medications proposed to prevent preeclampsia
Efficacy of dietary supplements proposed to prevent preeclampsia
61. Folic 0.46(0.16-1.31)
Magnesium 0.87(0.57-1.32)
Marine oil 0.86(0.59-1.27)
Lifestyle interventions
Rest 0.05(0-0.83)
Exercise 0.31(0.01-7.09)
Altered dietary 1.11(0.46-2.66)
Energy and protein intake 1.2(0.77-1.89)
Garlic 0.78(0.31-1.93)
63. At 11-13 weeks aim for early prediction of
early PE
BECAUSE PREVALENCE CAN BE
POTENTIALLY REDUCED BY THE
PROPHYLACTIC USE OF LOW-DOSE
ASPIRIN (started before 16 weeks
Gestation
64. What are the cut-offs? Gestational age specific? sFlt-
1/PIGF or PIGF/sFlt-1 ratio?
When to start the testing, and at what interval?
Preeclampsia is a heterogeneous disease. The disease
with an earlier onset (<32 Weeks’) is more
homogeneous and more predictable.
Incorporation into first or second trimester selecting
for fetal Down syndrome? Genetic susceptibility must
be taken into account.
Expectant management of second preeclampsia
(prediction of disease progression)?
Can serum antigenic peptides help selecting suitable
candidate and predict the perinatal outcomes?
65. There is no clinically useful test to predict
Pre-eclampsia at present
Care must be given to cost effectiveness and
applicability to general practise
66. When U know something, to hold
that you know it &
when U don’t know something,
to allow that you don’t know it,
that is Knowledge
Confucius ( 55BC – 479
BC)
