High risk px 2023 edited.pptx

MANAGEMENT SESSION ON
EVIDENCE BASED MEDICINE IN TO
DIAGNOSIS AND MONITORING OF
HIGH RISK PREGNANCY
Moderator: Dr. Daniel A. (Gynecologist & Obstetrician)
Presenter: Brukalem (R 3)
MAY, 2023
1

Outline of the session
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 Introduction to high risk pregnancy
 Factors leading to high risk pregnancy
 Selected antenatal conditions leading to high risk
pregnancy
 Evidence based methods for monitoring of high risk
pregnancy

Definition of high risk pregnancy
3
 Pregnancy should be considered a unique, physiologically
normal episode in woman’s life.
 However preexisting disease or un expected illness of the
mother or fetus can complicate the pregnancy
 A pregnancy is defined as high risk when the probability of an
adverse outcome for the mother or child is increased over and
above the baseline risk of that outcome among the general
pregnant population or reference population by the presence
of one or more ascertainable risk factors or indicators.

Conti…
4
 Evaluating a high risk pregnancy has significant
problems.
 Any pregnancy can turn into a high risk one any time
during its course.
 It needs to be diagnosed at an earlier state, often in the
prenatal period for an effective intervention strategy to
deal with its complications.
 It requires maternal and fetal surveillance, helping
management decisions so as to ensure an optimal

Factors leading to high risk pregnancy
5
 Most pregnancies are low risk and have favorable
outcomes.
 We classify any pregnancy in which there is a maternal or
fetal factor that may adversely affect the outcome as high
risk.
 In these cases, the likelihood of a positive outcome is
significantly reduced.
 In order to improve the outcome of a high-risk pregnancy,
we must identify risk factors and attempt to mitigate

Conti…
 Constitutional risk
 Ethnicity
 Socioeconomic status
 Parity
 Age
 Nutrition
 Maternal wt and wt
gain
 Physical activity
 Environmental risk
 Chemicals
 Occupational risks
 Air travel in px
6

Conti…
7
 Ethnicity
 Many diseases and problems that occur during pregnancy
have both ethnic and geographic distributions.
 It is one of the factors that is most strongly associated with low
birth weight.
 Uterine fibroids occur more often in black women than in white
women.
 Nonengagement of the fetal head late in pregnancy is common
in black primigravidae.
 The available data on ethnic differences in the frequency of
dysfunctional labor are inconclusive.

Conti…
9
 Socioeconomic Status
 Lower socioeconomic status is associated with an
increased risk of various adverse pregnancy
outcomes, including perinatal mortality, preterm
birth, and low birth weight.
 Smoking has been suggested as the key factor
underlying socioeconomic differences in low birth
weight and infant mortality.

Conti…
11
 Parity
 nulliparous women constitute approximately half of all
pregnant women
 Birth wt is consistently low in nuliparous women
 Risk of PIH , perineal trauma as a result of either episiotomy or
spontaneous tear increased
 High parity is associated with an increased likelihood of
abnormal fetal presentation and obstetric hemorrhage.
 Parity, however,does not have a significant effect on the
incidence of Down syndrome.

Conti…
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 Age
 Women at both ends of the reproductive-age spectrum have
unique outcomes to consider.
 Reproductive age is the interval from the age of menarche
to the chronologic age at conception
 gynecologic age is the time span from the age of
menarche to the chronologic age at delivery.
 according to the CDC, 3.4 percent of births in the United
States in 2010 were in women aged 15 to 19 years .
 11.9 percent for this age group globally

Conti…
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 These adolescents are at higher risk for anemia, preterm
delivery, and preeclampsia compared with women aged 20
to 35.
 The incidence of sexually transmitted diseases—common in
adolescents is even higher during pregnancy .
 Unfortunately, because most of their pregnancies are
unplanned, adolescents rarely seek preconceptional
counseling.
 Conceptions after age 35 currently constitute approximately
15 percent of pregnancies in the United States
 But they constituted 31 percent of maternal deaths.

Conti…
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 Medical complications associated with adolescent pregnancy
include
 preterm birth and LBW
 perinatal mortality
 short interval to next pregnancy
 and sudden infant death syndrome.
 They are at particular risk for nutritional deficiencies, anemia,
HIV infection, and other STI.
 The increased incidence of PIH is largely explained by
nulliparity.
 It has been suggested that competition for nutrients between
the fetus and the mother could affect pregnancy outcome in

Conti…
17
 Nutrition
 Offer counseling to women at risk for nutritional deficiency.
 Recommend folate supplements (0.4 mg/day) for all women
contemplating pregnancy.
 Offer continuing folate supplementation
 (0.4 mg/day) to all women at increased risk for neural tube
defects in pregnancy.
 The decision to recommend supplements is based on
individual requirements.

Conti…
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 Routine iron supplementation is warrante in
populations in which iron deficiency is common.
 Avoid excess vitamin A (i.e., more than the daily
allowance).
 Advise supplemental vitamin K (10 mg/day from 36
weeks’ gestation) to women who take antiepileptic
drugs to prevent neonatal hemorrhagic disease.

Conti…
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 Advise women to avoid large amounts of caffeine (>600
mg daily, which is equivalent to six 10-oz cups of coffee).
 Labor and Delivery Postnatal Give a single dose (1 mg) of
either intramuscular or oral vitamin K to the newborn to
prevent classic hemorrhagic disease.
 Vitamin K prophylaxis improves biochemical indices of
coagulation status at 1–7 days

Conti…
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 Maternal Weight and Weight Gain
 For those of under weight
 Advise women with an eating disorder wishing to become
pregnant to wait until the disorder is in remission.
 Use a multidisciplinary approach for eating disorders
 Prenatal- Check for fetal growth restriction.
 Provide multidisciplinary treatment for women with eating
disorders not yet in remission.
 Provide continuous electronic fetal heart rate monitoring if the
fetus is small during labor
 Postnatal-monitor signs of maternal depression, and provide
treatment if indicated.

Conti…
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 For those of over weight
 Provide advice on interventions for weight reduction.
 Explain the risks of HTN, DM, UTI, large fetal size and PPH.
 In the selected group of women, pregnancy following bariatric
surgery is associated with a better outcome than being
pregnant and morbidly obese.
 Avoid attempts to manipulate the diet during pregnancy.
 Screen for hypertension, diabetes, and bacteriuria.
 Monitor the blood pressure with an appropriately sized cuff &
monitor fetal growth with ultrasound

Conti…
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 During labor and delivery maintain vigilance for cephalopelvic
disproportion and shoulder dystocia.
 Cesarean section
 Use regional rather than general anesthesia.
 Give prophylactic antibiotics of higher dose.
 Use thromboprophylaxis.
 There is no evidence for the best incision.
 Subcutaneous fat closure decreases the incidence of wound
dehiscence.
 Subcutaneous drains do not prevent wound complications.

Conti…
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 Postnatal
 Following cesarean section give subcutaneous heparin until
the patient is fully ambulatory.
 Recommend early mobilization.
 Continue with measures to lose weight
 Breast-feeding has a small protective effect against
childhood obesity

Conti…
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 Environmental risk
I. Chemicals
 Highly chlorinated PCB congeners persist in the
environment, the air, drinking water, and food.
 Accumulate in the liver after rapid absorption.
 They also cross the placenta and are excreted in breast
milk.
 Formula milk is free of PCBS.
 Much concerns are may induce long-lasting neurologic
damage.

Conti…
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II. Occupational Risk
 Occupational exposure to risk can be anesthetic agents,
laboratory chemicals, organic solvents, and pesticides.
 A meta-analysis of studies of working conditions in pregnancy
concluded that physically demanding work is significantly
associated with preterm birth, fetal growth restriction and
hypertension or preeclampsia .
 Other occupational exposures significantly associated with
preterm birth include prolonged standing and shift and night

Conti…
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 Precautions to protect women against specific occupational
risks(e.g., toxic chemicals or radiation).
 As Physical violence is a major contributor to women’s health
risks, either in the home or in the formal workplace, so
 Avoid long hours of standing and walking.
 Avoid excess lifting and exercise.
 Patients can continue to work if they wish and are not unduly
tired
 There is no evidence that video display units (VDUs) are

Conti….
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III. Air Travel in Pregnancy
 Little evidence exists, and recommendations are typically
based on common sense rather than scientific evidence.
 risks
-radiation risks
-fetal and maternal hypoxia
- venous thrombosis
- pre term labor
- seat belt for unpredicted air turbulence
- vaccine and malaria prophylaxis

Diagnosing and identifying
high risk pregnancy
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 By reassessing the risk factors before pregnancy, during
pregnancy and during parturition,
 it is possible to identify that segment of the high risk group
which is bound to have morbidity and mortality.
 To facilitate the identification of high risk pregnancies,
prenatal records should be systematically recordeded.
 Aim : To identify high risk factors which may benefit from
active intervention or referral to specialist of maternal fetal

High risk factors
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 High risk factors are poor predictors, individually, of adverse
outcome.
 Each factor has its own likelihood ratio; the higher its value,
the stronger its association with an adverse outcome. E.g
 A cervical length of less than 1.5 cms is associated with
preterm delivery in less than 7 days with a likelihood ratio of
8.7.
 However, the predictive value in unselected population (no
history of preterm births) is as less as 11%.
 But 35% in high risk cases ( previous hx of still birth)

Obstetric High Risk
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 The major objective of obstetric practice has been the
prevention of obstetric-maternal mortality.
 With advancements in managing the primary problems of
maternal mortality like
 Anaesthesia, blood transfusion, improved surgical
techniques, the focus has now shifted to obtaining best
possible fetal outcome.
 This has shifted the focus for the obstetrician from being a
care provider not only for the mother but for the fetus too.

Selected antenatal conditions
leading to high risk pregnancy
34
I. Maternal anemia
 WHO defines anemia in pregnancy as a hemoglobin
concentration of less than 11 g/dl.
 The cutoff point suggested by the cdc is 10.5 g/dl in the
second trimester.
 The incidence of anemia in pregnancy ranges widely from 40–
80 percent in the tropics compared to 10–20 percent in the
developed countries.
 Responsible for 20 percent of maternal deaths in the third
world countries.

Conti…
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 Iron requirements substantively rise during pregnancy.
 Of ~300 mg of iron transferred to the fetus and placenta and
the 500 mg incorporated into the expanding maternal
hemoglobin mass, nearly all is used after mid pregnancy.
 Iron requirements imposed by pregnancy and maternal
excretion total approximately 7 mg/d .
 Few women have sufficient iron stores or dietary intake to
supply this amount.
 Thus, the AAP and the ACOG (2017) recommendation at
least 27 mg of elemental iron be supplemented daily to
pregnant women.
 Who recommended 30-60mg daily elemental iron.

Conti…
36
 Most studies of anemia during pregnancy deal with
nutritional anemia, specifically those due to iron
deficiency.
 Risks of Anemia on pregnancy include:
 Low birth weight.
 Preterm birth.
 SGA infants.
 Lower mental development.

CONTI…
37
 Diagnosis
 Low HGB, HCT, RBC counts
 Low MCV, MCH & MCHC
 Low serum iron & ferritin
 High Transferrin level
 Low TFN saturation ( 2.5%)
 High TIBC
 Absent iron stores
 Low BM iron stain
 Brisk response to therapeutic trial.
 Blood film

So the causes of anemia based on MCV
38

Conti…
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 CHRONIC HYPERTENSION
 Maternal and Fetal Risks
 Depending on the population studied and the criteria used the
incidence in pregnancy is 0.5% to 3%.
 90% of cases of chronic hypertension associated with
pregnancy are essential HTN
 Causes of secondary hypertension include renal
diseasase(glomerulonephritis, nephropathy, renovascular
disease), endocrinologic disorders (diabetes with vascular
involvement, thyrotoxicosis, pheochromocytoma), and
collagen vascular disease (systemic lupus

Conti…
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 For the purpose of clinical management,
 it may also be divided into
 a low risk group (hypertension with no end-organ
damageor associated significant comorbidities) or
 a high risk group (hypertension with end-organ damage or
associated morbidities)
 Superimposed preeclampsia and abruptio placentae
are the two most common complications
 Superimposed preeclampsia complicates approximately 5%
to 50% of pregnancies of women with chronic hypertension.

Conti…
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 In patients with risk factors, the incidence of SPE is 25% to
50%.
 The incidence of AP is 0.5% to 2% in patients with mild,
uncomplicated hypertension and 3% to 10% in those with
severe hypertension.
 The incidence of SPE or abruption is not affected by
antihypertensives.
 Fetal morbidity and mortality rates are directly related to the
severity of hypertension.

Conti…
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 They are particularly high in patients with SPE and AP .
 Decreased uteroplacental perfusion (often iatrogenic) can
lead to IUGR.
 Spontaneous or iatrogenic preterm birth adds the
compounding complications of prematurity.
 The risk of mid-trimester death in utero is higher in patients
with chronic hypertension, especially those who do not
receive prenatal care.

Conti…
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 Thrombophilia
 In general, no demonstrable link has been found between
inherited thrombophilia and risk for fetal death.
 Although initial reports seemed to support an association
between fetal death and thrombophilia, such as
 factor V Leiden mutation and
 prothrombin gene mutation,
 large prospective trials have failed to substantiate this

Conti…
50
 The presence of circulating maternal antiphospholipid
antibodies—
 lupus anticoagulant,
 anticardiolipin antibodies, and
 anti–β2-glycoprotein I antibodies in the antiphospholipid
antibody syndrome have been associated with a variety of
adverse pregnancy outcomes, including fetal loss.
 The mechanism of these adverse outcomes remains
unclear but likely includes
 inflammation,
 thrombosis, and
 placental infarction.

Conti…
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 Diabetes Mellitus
 Although historically, IDD has been a major risk factor for
fetal death, the fetal death rate in women with optimal
glycemic control now approaches that of women without
diabetes.
 However, the relationship between glycemic control and
fetal death remains uncertain.
 Poor glycemic control is associated with increased
perinatal mortality, in large part as a result of
• congenital anomalies
• indicated preterm deliveries and
• Sudden unexplained fetal death.

Conti…
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 A 2014 population-based study of over 1 million births in
Ontario, Canada, revealed an odds ratio of 2.3 for fetal
death among women with pregestational diabetes
compared with those without diabetes.
 No evidence suggests that gestational diabetes controlled
by diet alone is associated with increased rates of
intrauterine fetal death,
 while data are mixed regarding any increase in the odds of
fetal death attributable to gestational diabetes requiring
treatment with hypoglycemic agents.

Conti…
53
 Renal Disease and Systemic Lupus Erythematosus
 With chronic maternal renal disease, perinatal outcome is
largely associated with the degree of renal dysfunction and
 the presence of coexisting hypertension or diabetes.
 Although data are limited by lack of prospective studies with
appropriate control groups,
 the greatest risk for fetal death appears to be in mothers
with severe renal impairment (i.e., serum creatinine levels
>2.4 to 2.8 mg/dL).

Conti….
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 the prognosis for fetal outcome in women with SLE is
dependent on disease state and comorbid conditions,
including
 hypertension,
 circulating autoantibodies, and
 renal involvement.
 Prognosis for fetal survival in pregnancies complicated by
both maternal renal disease and maternal SLE has

Conti…
55
 Multiple Gestations
 The higher rate of perinatal mortality in multiple gestations
compared with singletons is related both to complications
unique to multiple gestations,
 such as twin-to-twin transfusion syndrome, and
 to more general complications, such as fetal abnormalities
and
 growth restriction.
 Chorionicity is of paramount importance in determining fetal
risk, and rates of adverse outcomes are higher among

Conti…
56
 Additionally, many women who carry more than one fetus
have maternal risk factors for increased perinatal mortality,
including
 advanced maternal age and use of ART, and are subject to
development of complications such as
 preeclampsia and preterm delivery.
 Optimal timing of delivery between 37 and 38 weeks has
been considered for twins
 compared with 39 to 40 weeks among singletons, because

Conti…
57
 Amniotic Fluid Abnormalities
 The predictive value of either oligohydramnios or polyhydramnios
for adverse pregnancy outcomes, in particular fetal death,
typically lies in their association with other abnormal conditions,
such as
 maternal diabetes mellitus,
 hypertensive disorders,
 rupture of membranes,
 fetal growth restriction, or

Conti…
58
 Isolated oligohydramnios has not been conclusively linked
to increased risk for fetal death,
 whereas isolated polyhydramnios has been identified as
independently associated with fetal death in at least one
large population-based study.
 Evaluation of amniotic fluid volume (AFV) as a marker of
long-term fetal health status is a mainstay of antepartum
fetal evaluation

Conti…
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 Fetal Growth Restriction
 IUGR is a well-known risk factor for perinatal death that has
historically been underrecognized before fetal death.
 Placental dysfunction is commonly implicated in nonmalformed
and chromosomally normal IUGR fetuses

Conti….
60
 Post term Pregnancy
 The definition of postterm pregnancy has been reevaluated
in the past decade based on reappraisal of the peak time of
fetal risk in relation to the 40-week mark .
 The pathophysiology of increased fetal death risk is thought
to be mediated by
 impaired placental oxygen exchange and
 is often associated with oligohydramnios.

Conti…
61
 Traditionally oligohydramnios has been used as a marker
for increased risk in the postterm pregnancy for which
intervention in the form of delivery is thought to be
necessary,
 Although as described previously, whether
oligohydramnios is independently associated with fetal
death in pregnancies after 40 weeks’ gestation is
unproven

 NST
 CST
 CCTG
 BPP
 OBS US
 Fetal echocardiography
 Doppler velocimetry
 Chorionic blood sampling
 Amniocentesis
 Fetal blood sampling
 Clinical methods
 Serial assessment of maternal
wt gain
 Maternal BP
 Serial assessment of uterine
62
Biophysical methods Biochemical
Evidence based methods for monitoring of
high risk pregnancy

Conti…
63
 Assessment of the wellbeing of fetus(es) during
pregnancy especially after the fetus is considered
viable.
Goals:
1. primary - to prevent fetal death.
2. secondary - to avoid fetal neurologic injury.

Conti…
64
 diagnosing high risk factors during antenatal period leads to
a unique opportunity to integrate new methods for their
monitoring.
 These methods of monitoring, are, unfortunately,
characterized by low positive and high negative predictive
values.

Conti…
65
 When to start fetal monitoring (surveillance)?
 Most studies show efficiency of antepartum fetal surveillance
techniques around near term or term pregnancies.
 Very few techniques have shown, in studies, to be effective
before 32 weeks of gestation.
 Most of the tests evaluate or depend upon the maturity of the
fetal CNS and its synchronicity with other systems, which
would not have developed before 32 weeks.
 It is necessary to understand that testing an extremely
preterm fetus can give rise to possible false-positive result.

Fetal movement or “kick counts”
66
 Decreased fetal movement may precede fetal death by several
days .
 ~ 50% of those with IUFD have no risk factors and thus no
formal antepartum surveillance, some have recommended kick
counts for all patients .
 Several studies of intervention after decreased movements
have been associated with decreasing the IUFD rate.
 Defining what constitutes “decreased movement” varies, and
regardless of the method, once decreased fetal movement has
been diagnosed, a back-up test is employed.
 One evaluation of maternal perception of kick counts used 10
movements in 2 hours.

Conti…
 Loss of fetal movements is commonly followed by
disappearance of FHR within next 24 hours
 Maternal hypoglycemia is associated with
increased fetal movements
 Peak time for fetal movement → 9:00 pm – 1 : 00
am.
 No strong recommendation to use fetal movement

Conti…
 Count 10’ formula:
 Abnormal if
 Less than 10 movements occur during 12 hours on 2
successive days or
 No movement is perceived after 12 hours in a single day
 Daily fetal movement count (DFMC)
 Abnormal if
 Less than 10 in 12 hours or
 Less than 3 in each hour

Conti…
 The Cardiff methods
 Mother count FM once/day
 <10 movement over 12 hours is alarming
 Rayburn method
 Count once per day for 60 minutes
 <3 movement/1 hour for two consecutive days is
alarming
 Sadovsky method
 Mother count FM 2-3 times daily
 <3 movement/1 hour is alarming

Non stress test
FHR accelerations are observed during fetal movement.
Non-invasive & can be performed with an electronic fetal
monitor.
There are no direct maternal or fetal risks.
Initiated when the fetal neurological maturity enables FHR
accelerations to occur (typically at 26-28 wks)
Woman should be in left lateral position and tracing will be
observed for 40min

Conti…
 There is an observed association of FHR
acceleration with fetal movements, which when
present, indicates a healthy fetus
 The test is valuable to identify the fetal wellness
rather than illness
 Combination of fetal movements and FHR
acceleration provides the basis of the nonstress test
(NST)
 Reactive/Reasuring/Negative → Good
 Nonreactive/Nonreasuring/Positive →Bad

Conti…
 Different for term and preterm
 Term: 2 accelerations / amplitude of 15 beats/15
seconds/in 20-30 minutes
 Preterm: 2/15 beats/10 seconds/30minutes
 A reactive NST is associated with perinatal death of about
5 per 1000
 But perinatal death is about 40 per 1000 is when the NST
is nonreactive

Conti…
 Testing should be started after 30 weeks and frequency
should be twice weekly
 The test has a false negative rate of 0.5% and false positive
rate of 50%
 May show
 Unsuspected spontaneous late decelarations
 Variable decelerations

Interpretation
 Normal
 Moderate variability
 Accelerations associated with maternal palpation
 FMs (accelerations graded for gestation) on 20-
minute NST)
 ≥2 episodes of acceleration of 15 bpm and of ≥ 15 s
associated with fetal movement in 20 min
 Abnormal
 FM and accelerations not coupled
 Insufficient accelerations, absent accelerations, or
decelerative trace
 Minimal or absent variability

Conti…
75
 Variable decelerations during an NST are not infrequent and
may occur in up to 50% of those undergoing testing.
 If variable decelerations are non repetitive, lasting less than 30
seconds, and occur in the setting of an otherwise reactive NST,
there is no need for intervention
 3 or more variable decelerations in 20 minutes have been
associated with increased cesarean rates for nonreassuring
FHT
 Decelerations lasting more than 60 seconds have been
associated with IUFD and cesarean for nonreassuring FHT
 A nonreactive NST over a 40-minute testing period may indicate
fetal compromise, but the gestational age must be considered
because in one study 50% of healthy fetuses between 24 and 28
weeks had a nonreactive NST .
 At 28–32 weeks, only 15% of normal fetuses were not reactive

Conti…
 NST might be affected by
 Fetal sleep cycle
 Maternal smoking
 Maternal medications
 Hypoxia

Vibroacoustic Stimulation
 Stimulating the fetus with a noxious vibration and noise is
effective in
 Producing a state change,
 Fetal startle movements, and
 Increased FHR variability, thereby shortening the time it
takes to demonstrate fetal well-being → acoustic
stimulation nonstress test
 A positive response is defined as the rapid appearance
of a qualifying acceleration following stimulation

Conti…
 Decrease incidence of nonreactive NST to
69%
 Nonreactive NST after VAS → worse
outcome than nonreactive without
stimulation
 No long term effect on the fetal ears

Conti…
79
 The nonreactive NST has a false positive rate (fetal
survival >1 week after a nonreactive NST) of up to
50%, requiring back-up testing (e.G., Cst/bpp.
 Poor fetal outcome (e.G., Perinatal death, low 5-minute
apgar score, late decelerations during labor) occurs
only in 20% of cases with a nonreactive NST.

Conti…
80
 In the largest series of patients (n=5861) undergoing
antepartum surveillance with the NST, the false negative (fetal
death <1 week after a reactive NST) rate was 3.1/1000,
 While others have found similar results (1.9–5/1000)however,
the use of the NST is “widely integrated into clinical practice”
and
 Despite no definitive evidence of a beneficial effect on fetal
mortality it will probably continue to be utilized liberally in
modern obstetric practice

Conti…
 NST frequency
 Daily
 For severe preeclampsia
 2x weekly and addional testing compeleted for
maternal or fetal detorioration regardless of time
elapsed from the last test
 Postterm pregnancy
 DM
 IUGR
 Multifetal gestation
 Gestational hypertension

Conti…
 Causes of death of a fetus within 1 week of
normal NST
 Meconium aspiration
 Intrauterine infection
 Abnormal cord position and cord accidents
 Placental abruption

Conti…
83
 Modified BPP (NST/AFI) The risk of short-term hypoxemia is
addressed with the NST.
 Measuring the AFI is a surrogate for fetal renal perfusion and
reflects long-term placental function via the amniotic fluid status.
 The AFI acts as a measure or redistribution of fetal bloodflow as
hypoxemia can lead to decreased renal perfusion,urine output, and
oligohydramnios.
 The modified BPP has a lower false negative rate than the NST
alone, 0.8/1000, but the false positive rate (i.e., a normal fetus
despite a positive
 test result) remains 60%.

Conti….
84
 When utilizing the MBPP, a back-up test must be performed
for any of the following:
 nonreactive NST,
 significant variable or late decelerations, or
 AFI <5cm.
 MBPP is similar in its incidence of adverse outcomes
following a negative result
 risk of fetal mortality after a negative test result compared
with CST with a risk of IUFD of approximately 1 in 1000 in
both tests.
 The modified BPP is probably currently the primary means for
antenatal surveillance

Biophysical profile
85
 It consists of an NST with ultrasound observation of the fetus
for up to 30 minutes, and
 Reflects potential acute and chronic fetal hypoxia.
 The BPP has five separate variables: the NST, FB ,
movement, tone, and the AFI .
 The AFI is the chronic marker while the other four
components reflect acute asphyxia.

Conti…
86
 Each component scores either 0 or 2 points.
 Each component score is tallied and a composite score is
given, yet not all measures are equal.
 Indeed, low afi is independently associated with increased
level of acidemia .
 The BPP can be employed for primary antepartum
surveillance, follow-up on nonreactive NST , or for further
information after positive or suspicious CST.

Contraction stress test
89
 The CST is a measure of fetal response to stress.
 The uterus contracts and the spiral arteries are occluded,
decreasing flow to the intervillous space and resulting in
decreased oxygenation of the fetus.
 In the suboptimally oxygenated fetus, the baseline O2
deficit will be worsened and late decelerations on the FHT
will be apparent

Conti…
90
 The advantage of the CST is that subtle hypoxia prior to
acidosis is more easily detected when compared with the
BPP/NST, and the CST is helpful in predicting tolerance of
labor.
 The CST is performed with the patient in the semi-Fowler
position.
 An adequate test is assessment of the FHT and uterine
contractions with three contractions in 10 minutes, each
lasting at least 40 seconds in duration.

Conti…
91
 Oxytocin can be employed for uterine contractions (0.5 mU/min,
increased every 20 minutes to a maximum of 10 mU/min) or
manual stimulation of the maternal nipple may be used.
 This is done by rubbing one nipple through the clothing for 2
minutes or until a contraction begins.
 If no contractions are observed after 2 minutes, a second
stimulation is performed after 5 minutes.
 An alternative technique is to apply warm packs to the breasts for
a maximum of 2 minutes followed by a 5-minute interval prior to
restimulation.

Conti…
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 Nipple stimulation was approximately 50% faster than
intravenous oxytocin in one evaluation of the time to an
adequate CST .
 Contraindications to the CST include
 Preterm labor,
 PPROM
 abnormal vaginal bleeding, and
 contraindications for vaginal delivery (e.g., placenta previa,
prior classic cesarean, extensive uterine surgery)

Conti…
93
 The CST test result is “negative” if there are no late
decelerations or significant variable decelerations in the
setting of a normal baseline fetal heart rate.
 After three adequate contractions occur in 10 minutes, a
negative and reactive CST has a false negative rate of
0.4–1/1000 and more than 99% survival over a week .
 A CST is deemed positive if more than 50% of uterine
contractions have associated late decelerations.
 A positive CST is associated with a 50% rate of poor
perinatal outcome including perinatal death, increased
cesarean for nonreassuring fetal status, and low 5-minute
Apgar score.

Conti…
94
 A reactive, positive CST is one with normal FHT variability
and baseline but late decelerations after more than 50% of
contractions.
 This generally calls for delivery, or close follow-up
surveillance at a very early gestational age.
 A test is equivocal or suspicious is one in which there are
50% or fewer late decelerations variable decelerations (i.e.,
possibly indicating IUGR, oligohydramnnios), or an
abnormal FHR baseline.
 These can be managed by delivery or more frequent
testing, depending on gestational age.

Conti…
95
 If there are five or more uterine contractions in 10 minutes
or contractions lasting more than 90 seconds in the setting
of fetal heart rate decelerations then the CST is
equivocal—hyperstimulation.
 Finally, a tracing is considered unsatisfactory if there are
fewer than three contractions or the FHT is of poor quality.

DOPPLER VELOCIMETRY
 Blood flow velocity measured by Doppler ultrasound
reflects downstream impedance.
 Three fetal vascular circuits—umbilical artery, middle
cerebral artery, and ductus venosus—are currently
assessed to determine fetal health and to aid in the
decision to intervene for growth-restricted fetuses.
 Maternal uterine artery Doppler velocimetry has also been
evaluated to predict placental dysfunction, with the goal to
balance stillbirth against the risks of preterm delivery

Doppler Blood Flow Velocity
 Of the small placental arterial channels, 60 to 70 percent need
to be obliterated before the umbilical artery Doppler waveform
becomes abnormal.
 more than 40 % of the combined fetal ventricular output is
directed to the placenta, obliteration of placental vascular
channel increases afterload and leads to fetal hypoxemia.
 This in turn leads to dilatation and redistribution of middle
cerebral artery blood flow.
 Ultimately, pressure rises in the DV due to afterload in the right
side of the fetal heart.
 Increased umbilical artery blood flow resistance - decreased
middle cerebral artery impedance followed ultimately by abnormal
flow in the ductus venosus
 Clinically, abnormal Doppler waveforms in the DV are a late
finding in the progression of fetal deterioration due to chronic
hypoxemia

Umbilical Artery Velocimetry
 The umbilical artery S/D ratio is considered abnormal if it is
above the 95th percentile for gestational age or if
diastolic flow is either absent or reversed.
 Absent or reversed end-diastolic flow signifies increased
impedance to umbilical artery blood flow
 It is reported to result from poorly vascularized placental
villi and is seen in extreme cases of fetal-growth restriction
 The perinatal mortality rate for absent end-diastolic flow
was approximately 10 percent, and for reversed end-
diastolic flow, it approximated 33 percent.
 No benefit has been demonstrated other than in IUGR.

Middle Cerebral Artery Doppler
velocimetry
 MCA Doppler velocimetry interrogation of the MCA has
received particular attention because of observations that
the hypoxic fetus attempts brain sparing by reducing
cerebrovascular impedance and thus increasing blood
flow.
 Such brain sparing in growth-restricted fetuses has been
documented to undergo reversal (Konje, 2001).
 Investigators reported that 8 of 17 fetuses with this
reversal died.

Ductus Venosus
 The use of Doppler ultrasound to assess the fetal venous
circulation is the most recent application of this technology
 DV velocimetry was the best predictor of perinatal outcome.
 Importantly, negative or reversed flow in the ductus venosus
was a late finding because these fetuses had already
sustained irreversible multiorgan damage due to
hypoxemia.
 Also, gestational age at delivery was a major determinant of
perinatal outcome independent of ductus venosus flow.
 Specifically, 36 percent of growthrestricted fetuses
delivered between 26 and 29 weeks succumbed compared
with only 5 percent delivered from 30 to 33 weeks.

Uterine Artery
 Vascular resistance in the uterine circulation normally
decreases in the first half of pregnancy due to invasion of
maternal uterine vessels by trophoblastic tissue.
 This process can be detected using Doppler flow
velocimetry, and uterine artery Doppler may be most helpful
in assessing pregnancies at high risk of uteroplacental
insufficiency (Abramowicz, 2008).
 Persistence or development of high-resistance patterns has
been linked to a variety of pregnancy complications
 Because standards for the study technique and criteria for
an abnormal test are lacking, they noted that uterine artery
Doppler studies should not be considered standard practice
in either low- or high-risk populations.

Conti…
102
 Chorionic Villus Sampling and
Amniocentesis
 The indications for invasive testing include the following:
 Advanced maternal age (more than 35 years)
 Positive serum screening testing
 Birth of previous child with chromosomal anomalies
 Pregnancy at risk for Mendelian disorder
 A parent with a balanced chromosome rearrangement

Conti…
103
 CVS Either by transcervical or transabdominal approach,
 Under ultrasound guidance,
 the first trimesters’ developing chorionfrondosum is
aspirated and the retrieved chorionic villus are either
cultured or directly analyzed to identify
 fetal cytogenetic,
 biochemical or
 molecular disorders.

Conti…
104
 The procedure is done between 10 weeks and 13 weeks 6
days gestation.
 The transabdominal method, is more common, uses a
20 gauge spinal needle inserted directly in the chorionic
frondosum.
 Once in place, a 20 ml syringe containing 5 ml of media is
attached ‘to and fro’ aspirations from the chorionic
frondosum are necessary

Conti…
105
In the transcervical approach,
 patient is in lithotomy position and vagina is prepped with
a povidone-iodine solution.
 Bladder is partially filled for adequate visualization of
uterus and cervix.
 A specially designed polyethylene catheter with a
malleable stainless steel stylet having a blunt rounded tip
is used for sampling.
 It is usually 27 cms long.

Conti…
106
 Under ultrasound guidance
 the catheter is passed along the internal os in the chorion frondosum
 parallel to the chorionic membrane taking care to avoid piercing the
membrane or going deep in the decidua basalis, which would cause
bleeding.
 The catheter goes smoothly when in the right plane through a sufficient
length of chorionic frondosum.
 The stylet is removed, a 20 ml syringe containing 5 ml tissue culture
media is attached and suction applied as catheter is withdrawn.

Conti…
107
 The patient is made aware of
 post procedure bleeding or spotting.
 Rhesus negative women are given Rh immunoglobulin.
 Patient is asked to report if there is any leakage of amniotic
fluid, fever, chills or foul discharge per vaginum within 2
weeks.

Conti…
108
 The most common complication is spotting or a small
amount of vaginal bleeding occurring more frequently with
transcervical approach than transabdominal approach.
 Other serious complications include acute rupture of
membranes and chorioamnionitis.
 These complications are rare and adequate care may be
taken by having continuous ultrasoun guidance during
procedure and giving prophylactic antibiotic

Conti…
109
 The risk of miscarriage between transcervical approach
and transabdominal approach is nearly the same in
experienced hands.
 The risk of miscarriage is around 1 in 200 to 1 in 300 at
good centers.
 For fetal safety, procedure of CVS is delayed until 70 or
more days post-LMP.
 Oromandibular and limb hypogenesis is uniquely
associated with performing CVS before this period.
 CVS results reflect those of the fetus in approximately
98% of cases.
 Discrepancy may rarely occur with contamination of the
sample with maternal decidual tissue.

Conti…
110
 Amniocentesis
 The genetic amniocentesis is ideally done between 17 and 20
weeks gestation.
 Performing the procedure before 18 weeks usually leaves
enough time to complete cell cultures and evaluate laboratory
tests, as in some countries the legal gestational age for
termination of pregnancy is below 20 weeks.
 Technique: Performed using a 22 gauge spinal needle, under
ultrasound guidance.
 The needle is inserted over the prepped abdomen.
 Care is taken to avoid the placenta and fetal parts.
 Stylet is removed and amniotic fluid is aspirated.
 Initial some ml may be discarded as it may contain maternal
cells. Approximately 20 ml is aspirated.

Conti…
111
 In case of twins’ gestation, indigo carmine solution is
injected into the sac after the fluid specimen to act as a
marker.
 The fluid is stored into sterile tubes and stored at room
temperature.
 Demonstration of fetal heart post procedure is reassuring
for the mother.
 In Rh negative women, Rh immunoglobulin is given.
 The risk of miscarriage is nearly the same as in CVS;

Conti…
112
 Amniocentesis may be indicated in the third trimester.
 The technique for aspiration does not differ but certain
other risks increase during the procedure.
 Certain indications for third trimester amniocentesis in
high risk pregnancies are as follows.

Conti…
113
1. To confirm fetal pulmonary maturity by doing
 lecithin: sphingomyelin ratio or phosphotidylglycerol presence
in amniotic fluid
 surfactant:albumin ratio,
 foam stability index (shake bubble test),
 lamellar body counts and
 amniotic fluid density.
2. Evaluation of fetal infection which may be the cause for growth
restriction.
3. Bilirubin levels in amniotic fluid for Rh isoimmunized pregnancy.
4. Genetic karyotyping for evaluating the fetus which may have a
detected anatomical anomaly in the third trimester or unexplained
growth restriction or fetal amniotic fluid volume abnormalities.

References
1. High risk pregnancy 4th edition
2. Management of high risk pregnancy: evidence based
approach.
3. Arias practical guide to high risk pregnancy and delivery
5th edition
4. Protocols for high risk pregnancy 7th edition , an evidence
based approach
5. Gabbe, Normal and Problem Pregnancies., 7th edition
6. Williams Obstetrics, 26 th edition
7. Duta text book of obstetric 8th edition
8. Danforth’s Obstetrics and Gynecology, 9th edition
9. Uptodate 2018

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