Fetal Growth Restriction - Clinicals, Diagnosis, and Management

Fetal Medicine

Clinicals - History

Fact Explanation
History of intra uterine infection / chromasomal abnormalities Herpes, cytamegalo virus, rubella, toxoplasmosis can give rise to fetal growth restriction ( <10% of all cases of fetal growth restriction).
Trisomies 13,18,21 and malformation syndromes can cause growth impairment due to reduced cell number.
History of intra uterine infection / chromasomal abnormalities
Herpes, cytamegalo virus, rubella, toxoplasmosis can give rise to fetal growth restriction ( <10% of all cases of fetal growth restriction).
Trisomies 13,18,21 and malformation syndromes can cause growth impairment due to reduced cell number.
Multiple gestation Can cause fetal growth restriction (FGR) due to decreased placental mass, abnormal placentation and placental vascular defects. Multiple gestation
Can cause fetal growth restriction (FGR) due to decreased placental mass, abnormal placentation and placental vascular defects.
History of abnormal placentation Abruptio placentae, Placenta previa, Infarction, Circumvallate placenta,
Placenta accretia can cause growth retardation due to poor blood supply
History of abnormal placentation
Abruptio placentae, Placenta previa, Infarction, Circumvallate placenta,
Placenta accretia can cause growth retardation due to poor blood supply
Maternal diseases Maternal vascular disorders (diabetes, hypertension) , collagen disorders such as SLE, antiphospholipid syndrome can cause FGR as vascular diseases cause reduced utero-placental blood flow Maternal diseases
Maternal vascular disorders (diabetes, hypertension) , collagen disorders such as SLE, antiphospholipid syndrome can cause FGR as vascular diseases cause reduced utero-placental blood flow
Pregnancy induced hypertension Pre eclampsia caused by abnormal trophoblatic invasion of spiral arterioles ultimately causes luminal narrowing and give rise to poor blood flow Pregnancy induced hypertension
Pre eclampsia caused by abnormal trophoblatic invasion of spiral arterioles ultimately causes luminal narrowing and give rise to poor blood flow
Cyanotic heart disease / pulmonary disease Causes poor fetal oxygenation due to chronic hypoxia Cyanotic heart disease / pulmonary disease
Causes poor fetal oxygenation due to chronic hypoxia
Use of teratogenic drugs Anticonvulsants, coumarins , cocaine cause poor fetal weight gain Use of teratogenic drugs
Anticonvulsants, coumarins , cocaine cause poor fetal weight gain

Clinicals - Examination

Fact Explanation
Abdominal palpation - symphisio fundal height Abdominal palpation has a sensitivity of 30% for detecting SGA (smaal for gestational age) fetuses. The symphysis-fundal distance has a sensitivity of 27–86% and specificity of 80–93% for detecting SGA Abdominal palpation - symphisio fundal height
Abdominal palpation has a sensitivity of 30% for detecting SGA (smaal for gestational age) fetuses. The symphysis-fundal distance has a sensitivity of 27–86% and specificity of 80–93% for detecting SGA
Low body mass index Poor maternal nutrition is an identified cause of fetal growth restriction Low body mass index
Poor maternal nutrition is an identified cause of fetal growth restriction
High blood pressure Pre eclampsia can cause fetal growth restriction.Diagnostic criteria for preeclampsia are systolic blood pressure of 140 mmHg or more or a diastolic blood pressure of 90 mm Hg or more on two occasions at least six hours apart High blood pressure
Pre eclampsia can cause fetal growth restriction.Diagnostic criteria for preeclampsia are systolic blood pressure of 140 mmHg or more or a diastolic blood pressure of 90 mm Hg or more on two occasions at least six hours apart
Fetal heart rate Heard with a pinard. Fetal tachycardia occurs with compromise of fetal blood flow Fetal heart rate
Heard with a pinard. Fetal tachycardia occurs with compromise of fetal blood flow

Investigations - Diagnosis

Fact Explanation
Ultra sound scan - dating scan Accurate dating in early pregnancy is essential for making the diagnosis of IUGR (intra uterine growth retardation). The usual qualifier for reliable dating and establishment of an accurate gestational age is a certain date for the last menstrual period in a woman with regular cycles or assessment of gestational age by an ultrasound examination performed no later than the 20th gestational week, when the margin of error is seven to 10 days Ultra sound scan - dating scan
Accurate dating in early pregnancy is essential for making the diagnosis of IUGR (intra uterine growth retardation). The usual qualifier for reliable dating and establishment of an accurate gestational age is a certain date for the last menstrual period in a woman with regular cycles or assessment of gestational age by an ultrasound examination performed no later than the 20th gestational week, when the margin of error is seven to 10 days
Ultra sound scan - fetal anatomy Fetal anatomical estimations are an important indicator of IUGR.
1st trimester - crown rump length
2nd trimester - biparietal diameter, head circumference, abdominal circumference, femur length.
Ultrasound determination of head circumference, biparietal diameter, femur length, and abdominal circumference can be used to derive an EFW (estimated fetal weight). When fetal growth can be followed by serial estimates of fetal weight, a diagnosis of IUGR may be established from falling percentiles in a chart of EFW plot against gestational age
Ultra sound scan - fetal anatomy
Fetal anatomical estimations are an important indicator of IUGR.
1st trimester - crown rump length
2nd trimester - biparietal diameter, head circumference, abdominal circumference, femur length.
Ultrasound determination of head circumference, biparietal diameter, femur length, and abdominal circumference can be used to derive an EFW (estimated fetal weight). When fetal growth can be followed by serial estimates of fetal weight, a diagnosis of IUGR may be established from falling percentiles in a chart of EFW plot against gestational age
Ultra sound scan - amniotic fluid assessment The assessment of amniotic fluid is an integral part of any ultrasound examination of fetal growth. Amniotic fluid
volume can be reported either as the maximum vertical pocket, or the four-quadrant AFI (amniotic fluid index).
Low amniotic fluid volume may reasonably be defined after 37 weeks as an AFI < 5 cm or as a maximum vertical pocket < 2 cm.
The combination of IUGR and polyhydramnios (AFI > 25 cm) suggests non-placental fetal causes
Ultra sound scan - amniotic fluid assessment
The assessment of amniotic fluid is an integral part of any ultrasound examination of fetal growth. Amniotic fluid
volume can be reported either as the maximum vertical pocket, or the four-quadrant AFI (amniotic fluid index).
Low amniotic fluid volume may reasonably be defined after 37 weeks as an AFI < 5 cm or as a maximum vertical pocket < 2 cm.
The combination of IUGR and polyhydramnios (AFI > 25 cm) suggests non-placental fetal causes
Non-Stress Test This is one of the first tests used in the surveillance of IUGR fetuses and the simplest to perform. The physician uses a heart rate monitor to determine changes in the fetal heart rate with fetal movement. If the heart rate increases more than 15 beats for more than 15 seconds, this is considered to be a reactive test. If the heart rate does not accelerate, remains flat, or decreases, then this is an abnormal test. The problem with this test is that it changes late in the course of the disease and does not identify a fetus with IUGR. When patients are diagnosed with IUGR and require continuous monitoring, the fetal heart rate tracing may be useful in detecting fetal distress Non-Stress Test
This is one of the first tests used in the surveillance of IUGR fetuses and the simplest to perform. The physician uses a heart rate monitor to determine changes in the fetal heart rate with fetal movement. If the heart rate increases more than 15 beats for more than 15 seconds, this is considered to be a reactive test. If the heart rate does not accelerate, remains flat, or decreases, then this is an abnormal test. The problem with this test is that it changes late in the course of the disease and does not identify a fetus with IUGR. When patients are diagnosed with IUGR and require continuous monitoring, the fetal heart rate tracing may be useful in detecting fetal distress

Investigations - Management

Fact Explanation
Umbilical artery doppler studies Indicate the blood flow in umbilical artery.
When oligohydramnios is found and
IUGR (intra uterine growth restriction) is suspected from fetal biometry, umbilical cord artery Doppler studies are indicated. As placental insufficiency worsens,
diastolic flow progressively decreases.
Absent or reversed end-diastolic velocities are mostly found in early-onset IUGR
Umbilical artery doppler studies
Indicate the blood flow in umbilical artery.
When oligohydramnios is found and
IUGR (intra uterine growth restriction) is suspected from fetal biometry, umbilical cord artery Doppler studies are indicated. As placental insufficiency worsens,
diastolic flow progressively decreases.
Absent or reversed end-diastolic velocities are mostly found in early-onset IUGR
middle cerebral artery (MCA) doppler studies Indicate the blood flow in middle cerebral artery.
Longitudinal studies on deteriorating early-onset IUGR fetuses have reported that the pulsatility index in the MCA progressively
becomes abnormal.
In late-onset IUGR, there is observational evidence that MCA vasodilatation is associated with adverse outcome independently of the umbilical artery
middle cerebral artery (MCA) doppler studies
Indicate the blood flow in middle cerebral artery.
Longitudinal studies on deteriorating early-onset IUGR fetuses have reported that the pulsatility index in the MCA progressively
becomes abnormal.
In late-onset IUGR, there is observational evidence that MCA vasodilatation is associated with adverse outcome independently of the umbilical artery
fetal biophysical profile (BPP) The fetal biophysical profile (BPP) is a group of measurements that includes the amniotic fluid volume, fetal tone, fetal movements, fetal breathing movements, and fetal heart rate monitoring (NST). When normal, each parameter receives two points, for a maximum total of ten points.
The BPP is usually performed to lower the false positive rate of the NST; however, the BPP has a false positive rate ranging from 75% for a score of six to 20% for a score of zero. The main advantages of the BPP test are the direct assessment of fetal behavior and the technical ease in performing the test. The disadvantages are the performance time required (at least 30 minutes), the dependence on visual interpretation of the NST, and the indirect provision of information regarding fetal cardiovascular status and perfusion.
If evaluation of the AFI reveals oligohydramnios, this calls for further evaluation irrespective of the overall score
fetal biophysical profile (BPP)
The fetal biophysical profile (BPP) is a group of measurements that includes the amniotic fluid volume, fetal tone, fetal movements, fetal breathing movements, and fetal heart rate monitoring (NST). When normal, each parameter receives two points, for a maximum total of ten points.
The BPP is usually performed to lower the false positive rate of the NST; however, the BPP has a false positive rate ranging from 75% for a score of six to 20% for a score of zero. The main advantages of the BPP test are the direct assessment of fetal behavior and the technical ease in performing the test. The disadvantages are the performance time required (at least 30 minutes), the dependence on visual interpretation of the NST, and the indirect provision of information regarding fetal cardiovascular status and perfusion.
If evaluation of the AFI reveals oligohydramnios, this calls for further evaluation irrespective of the overall score
Venous doppler Reflects fetal cardiac function.
Predictive of adverse perinatal outcome.
Blood flow should always be antegrade.
Absent or reversed flow is always abnormal.
Venous doppler
Reflects fetal cardiac function.
Predictive of adverse perinatal outcome.
Blood flow should always be antegrade.
Absent or reversed flow is always abnormal.
Oral glucose tolerance test Important to detect gestational diabetes, as this can cause fetal growth restriction.
Diagnostic values :
1 hour blood glucose level ≥180 mg/dl (10 mmol/L)
2 hour blood glucose level ≥155 mg/dl (8.6 mmol/L)
Oral glucose tolerance test
Important to detect gestational diabetes, as this can cause fetal growth restriction.
Diagnostic values :
1 hour blood glucose level ≥180 mg/dl (10 mmol/L)
2 hour blood glucose level ≥155 mg/dl (8.6 mmol/L)
Protein in urine To detect pre eclampsia, as it can cause fetal growth restriction.
pre eclampsia: proteinuria (>300 mg of protein in a 24-hour urine sample)
Protein in urine
To detect pre eclampsia, as it can cause fetal growth restriction.
pre eclampsia: proteinuria (>300 mg of protein in a 24-hour urine sample)
Growth curves The most widely used definition of IUGR (intra uterine growth restriction) is a fetus whose estimated weight is below the 10th percentile for its gestational age.
(Estimated fetal weight is plot against the gestational age )
IUGR is usually classified as symmetric and asymmetric. Symmetric growth restriction implies a fetus whose entire body is proportionally small.
A fetus with asymmetric IUGR has a normal head dimension but a small abdominal circumference (due to decreased liver size)(plotting the abdominal circumference and the head circumference against gestational age in the same chart)
Growth curves
The most widely used definition of IUGR (intra uterine growth restriction) is a fetus whose estimated weight is below the 10th percentile for its gestational age.
(Estimated fetal weight is plot against the gestational age )
IUGR is usually classified as symmetric and asymmetric. Symmetric growth restriction implies a fetus whose entire body is proportionally small.
A fetus with asymmetric IUGR has a normal head dimension but a small abdominal circumference (due to decreased liver size)(plotting the abdominal circumference and the head circumference against gestational age in the same chart)
Bio chemical markers ( eg: hCG , alpha fetoprotein) In the first trimester an unexplained low, pregnancy associated plasma protein A or hCG has an increased risk of intra uterine growth restriction (IUGR). In the second trimester,
an unexplained elevation of serum alpha a-fetoprotein, hCG, or inhibin-A
is also associated with these adverse
outcomes
Bio chemical markers ( eg: hCG , alpha fetoprotein)
In the first trimester an unexplained low, pregnancy associated plasma protein A or hCG has an increased risk of intra uterine growth restriction (IUGR). In the second trimester,
an unexplained elevation of serum alpha a-fetoprotein, hCG, or inhibin-A
is also associated with these adverse
outcomes

Management - Supportive

Fact Explanation
Patient education Risk to the baby:
Increased risk for cesarean delivery
Increased risk for hypoxia (lack of oxygen when the baby is born)
Increased risk for meconium aspiration, which is when the baby swallows part of the first bowel movement. This can cause the alveoli to be over distended, a pneumothorax to occur, and/or the baby can develop bacterial pneumonia.
Hypoglycemia (low blood sugar)
Polycythemia (increased number of red blood cells)
Hyperviscosity (decreased blood flow due to an increased number of red blood cells)
Increased risk for motor and neurological disabilities
Patient education
Risk to the baby:
Increased risk for cesarean delivery
Increased risk for hypoxia (lack of oxygen when the baby is born)
Increased risk for meconium aspiration, which is when the baby swallows part of the first bowel movement. This can cause the alveoli to be over distended, a pneumothorax to occur, and/or the baby can develop bacterial pneumonia.
Hypoglycemia (low blood sugar)
Polycythemia (increased number of red blood cells)
Hyperviscosity (decreased blood flow due to an increased number of red blood cells)
Increased risk for motor and neurological disabilities
General measures Treatment of maternal disease, cessation of substance abuse, good nutrition and institution of bed rest General measures
Treatment of maternal disease, cessation of substance abuse, good nutrition and institution of bed rest

Management - Specific

Fact Explanation
Asprin ( anti platelet therapy ) The use of low-dose asprin therapy in populations at high risk, such as those with abnormal uterine artery Doppler studies, is controversial.
Recommended to start at early pregnancy - before 20th gestational week ( placental development occurs at this gestational age )
Asprin ( anti platelet therapy )
The use of low-dose asprin therapy in populations at high risk, such as those with abnormal uterine artery Doppler studies, is controversial.
Recommended to start at early pregnancy - before 20th gestational week ( placental development occurs at this gestational age )
Antenatal steroids Antenatal steroids are prescribed to promote fetal lung maturity, if the fetus is below 34-35 weeks Antenatal steroids
Antenatal steroids are prescribed to promote fetal lung maturity, if the fetus is below 34-35 weeks
Magnesium sulfate MgSO4 during the first trimester may also be beneficial.
MAGPIE trial showed that magnesium sulphate halves the relative risk of eclampsia, without appearing to have substantive harmful effects on either the mother or the baby in the short term
Also, Magnesium deficiency might be one of the causes of IUGR, and magnesium sulfate treatment was effective
Magnesium sulfate
MgSO4 during the first trimester may also be beneficial.
MAGPIE trial showed that magnesium sulphate halves the relative risk of eclampsia, without appearing to have substantive harmful effects on either the mother or the baby in the short term
Also, Magnesium deficiency might be one of the causes of IUGR, and magnesium sulfate treatment was effective
Timing of delivery If isolated IUGR: deliver at 38 0/7 to 39 6/7 weeks. If IUGR with additional risk factors
eg oligohydramnios, abnormal Doppler,
maternal risk factors or co-morbidities, aim tp deliver between 34 0/7 – 37 6/7 weeks
Timing of delivery
If isolated IUGR: deliver at 38 0/7 to 39 6/7 weeks. If IUGR with additional risk factors
eg oligohydramnios, abnormal Doppler,
maternal risk factors or co-morbidities, aim tp deliver between 34 0/7 – 37 6/7 weeks
Mode of delivery IUGR is not a contraindication for induction of labour or vaginal delivery unless there are other contraindications (eg: cephalo pelvic disproportion ). Continuous fetal monitoring (use of cardiotocography) during labour is necessary. Low-threshold for caesarean section.
If umbilical artery doppler studies show absent or reversed end diastolic volume, delivery by caesarean section is recommended
Mode of delivery
IUGR is not a contraindication for induction of labour or vaginal delivery unless there are other contraindications (eg: cephalo pelvic disproportion ). Continuous fetal monitoring (use of cardiotocography) during labour is necessary. Low-threshold for caesarean section.
If umbilical artery doppler studies show absent or reversed end diastolic volume, delivery by caesarean section is recommended
Intra partum management Uteroplacental insufficiency may be
exacerbated by labour,
Higher risk of cesarean section,
Close monitoring in labor is indicated
Intra partum management
Uteroplacental insufficiency may be
exacerbated by labour,
Higher risk of cesarean section,
Close monitoring in labor is indicated

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