The adjectives postterm, prolonged, postdates, and postmature are often loosely used
interchangeably to describe pregnancies that have exceeded a duration considered to be theupper
limit of normal.
Prolonged Pregnancy or postterm pregnancy is one that has lasted longer than 42 weeks or 294
days beyond the first day of the last menstrual period, and it is the preferred expression for an
extended pregnancy.
Post datism is pregnancy lasting beyond the estimated due date at 40 weeks.
Postmature is reserved for the pathologic syndrome in which the fetus experiencesplacental
insufficiency and resultant IUGR. Representing 20% cases of prolonged pregnancyand is associated
with:
1. Meconium-stained amniotic fluid
2. Oligohydramnios
3. Fetal distress
4. Evidence of loss of subcutaneous fat and
5. Dry, cracked skin Reflecting placental insufficiency
INCIDENCE
Using the definition of 294 days, the incidence of postterm pregnancy is 1-10 %. This ratehas
declined because of improved pregnancy dating accuracy and earlier intervention.
ADVERSE MATERNAL AND PERINATAL OUTCOMES ASSOCIATED WITH
🔹
POSTTERMPREGNANCY:
maternal:
- fetal macrosomia
- oligohydramnios
- preeeclampsia
- cesarean delivery
- labor dystocia
DEFINITION - fetal jeopardy
Currently, the American College of Obstetricians and Gynecologists (2021a) and the - shoulder dystocia
Societyfor Maternal-Fetal Medicine (2020) recommend defining FGR as either an EFW - postpartum hemorrhage
<10thpercentile for gestational age or an AC <10th percentile for gestational age - forceps delivery
FGR should be differentiated from SGA, which is a postnatal designation based onbirthweight - perneaal laceration
percentile.
-Importantly, as many as 70 percent of SGA new borns are not pathologically growth restricted.
Indeed, such children have normal outcomes and are thought to be appropriately grown when
🔹 perinatal:
-stillbirth
maternal ethnic group, parity, weight, and height are considered - postmaturity syndrome
- NICU admission
- meconium aspiration
- neonatal convulsions
- hypoxic-ischemic encephalopathy
- birth injuries
- infection
- childhood obesity
🔹
ETIOLOGIC FACTORS
🔹 The most frequent cause is an error in dating.
ETIOLOGIES OF INTRAUTERINE GROWTH RESTRICTION
PROLONGED PREGNANCY 🔹
🔹
When truly exists, the cause usually is unknown.
prepregnancy body mass index ≥25 and nulliparity significantly associated
prior postterm pregnancy are the most common identifiable risk factors (biologically
(POSTTERM PREGNANCY)
Conditions that result in fetal growth restriction broadly consist of
maternal,uterine,placental,and fetal disorders.
-These conditions result in growth delay by affecting nutrient and oxygen delivery to the
🔹
determined).
🔹 Male sex also has been associated.
Genetic predisposition may play a role . if a mother and daughter had a prolonged pregnancy,
placenta (maternal causes), nutrient and oxygen transfer across the placenta (placental the risk for the daughter to have a subsequent postterm pregnancy was significantly increased.
causes), and fetal nutrient uptake or regulation of growth processes (fetal causes).
-In clinical practice, there may be considerable overlap between the conditions that
determine manifestation, progression, and outcome.
🔹
Maternal, not paternal, genes influence prolonged pregnancy.
Rarely, it may be associated with placental sulfatase deficiency, adrenal hypoplasia or fetal
anencephaly.
DIAGNOSTIC TOOLS IN FETAL GROWTH RESTRICTION 🔹
INTERVENTIONS THAT DECREASE THE RATE OF POSTTERM PREGNANCY
🔹 Accurate dating on the basis of ultrasonography performed early in pregnancy.
🔹
The diagnosis of SGA would rely on biometric tests:
🔹 1. Ultrasound biometry
Breast and nipple stimulationat term have not been shown to affect the incidence ofpostterm
2. Biophysical tests
I.Diagnosis by ultrasound examination:
🔹
pregnancy.
Sweeping of the membranes at term: Membrane sweeping or stripping is an age-old methodof
inducing labor that is still in common use. This intervention results in a local increase in
Ultrasound examination early in pregnancy is accurate in establishing the estimated date of pregnancy confinement (EDC) and may sometimes identify prostaglandin production and is believed to hasten the onset of labor. The intervention had no
genetic or congenital causes of IUGR pregnancy. significant impact on mode of delivery or the incidence of maternal or neonatal infections.
Serial ultrasound examinations are important in documenting growth and excluding anomalies.
The fetal AC is related to hepatic glycogen storage and liver size, therefore correlating closely with the nutritional state. It is the singe best
measurement for the detection of IUGR. Its sensitivity is further enhanced by serial measurements at least 14 days apart. Because of its high sensitivity, MANAGEMENT
🔸
some type of abdominal measurement should be part of every sonographic growth evaluation.
🔸 The most important calculated ultrasound variable of fetal growth is the sonographically estimated fetal weight (EFW).
The regulation of AFV by the late second and third trimester is primarily dependent on fetalurine output, production of pulmonary fluid, and fetal
After completing 42 weeks, labor induction is recommended to help avoid the morbidity andmortality.
The decision focuses on whether labor induction is warranted or if expectant management with fetal
surveillance is best.
swallowing. Placental dysfunction andfetal hypoxemia both may result in decreased perfusion of the fetal kidneys with subsequentoliguria and Although most authors agree that induction of labor is indicated in women with an"inducible"uterine cervix,
decreasing AFV. there is lack of agreement as to the management of the patient whose cervix is deemed "unfavorable."
Two techniques are used that can provide important diagnosticand prognostic information. A 2-cm vertical pocket was considered normal, 1 to 2 Antenatal testing may be used in an attempt to observe the prolonged pregnancy safely while awaiting the
cmmarginal, and less than 1 cm decreased. Alternatively, AFV may be assessed by the sum ofvertical pockets from four quadrants of the uterine spontaneous onset of labor or for ripening of the cervix prior to labor induction.
🔸
cavity. This four-quadrant amniotic fluidindex. (AFI) is compared with reference ranges that require knowledge of the gestational age.
The role of Doppler velocimetry in the management of fetal growth restriction is unique because it serves as a diagnostic as well as a monitoring
tool. With extreme increase in blood flow resistance, end-diastolic forward velocity may be absent (AEDV) or reversed(REDV).
Management options depend on:
1) Gestational age,
2) Absence/presence of maternal risk factors and/or
II.Biophysical Tests· 3) Evidence of fetal compromise, and
Not designed to predict size but predict fetal wellbeing. The presence of fetal welleing implies the absence of fetal acidaemia.· 4) Maternal preferences: Successful management depends on effective counseling of women and their full Algorithm for management of postterm pregnancy
Abnormal biophysical tests are more indicative of FGR than SGA.·All biophysical tests, including amniotic fluid volume (AFV), umbilical Doppler, CTG,
andbiophysical scoring, are poor at diagnosing a SGA fetus. 🔹
involvement in the decision making process.
Historically ,prolonged pregnancy has been managed in 2 ways , either by Inducing labor at41-42 weeks
SCREENING AND PREVENTION OF FETAL GROWTH RESTRICTION
🔹
gestation, or awaiting the onset of spontaneous labor, while monitoring thefetal wellbeing.
Routine induction of labor at 41 weeks:
Although postterm pregnancy is defined as a pregnancy of 42 weeks or more ofgestation,several large
Although treatment options in utero are limited, interventions that improve outcome exist. The various screening methods that have been proposed multicenter randomized studies reported favorable outcomes withroutine induction as early as the beginning o
🔹
include identification of riskfactors, as well as serum and ultrasound tests. 41 weeks of gestation.
Maternal History: Intrauterine Growth Restriction (IUGR) A recent review in the Cochrane Library concluded that routine induction in low-risk pregnancies at or after
🔹
A history of poor pregnancy outcome is clearly correlated with the subsequent delivey of agrowth-restricted infant. Fetal growth restriction (FGR) 41weeks' gestation is associated with reduction in perinatal mortality,and no increase in therate of instrumental
Maternal Serum Analytes: or cesarean delivery.
At least four hormone/protein markers measured in the maternal sera during the early second trimester are associated with subsequent IUGR. These
🔹
🔸
include serum estriol, human placental lactogen, human chorionic gonadotrophin and alpha-fetoprotein. Antepartum Fetal Surveillance
An elevated maternal serum alpha-fetoprotein or human chorionic gonadotropin level in the second trimester are considered as markers of It is widely believed that fetal surveillance may be used in an attempt to observe theprolonged pregnancy
🔹
abnormal placentation and have been associated with an increased risk for IUGR. safely while awaiting either the spontaneous onset of labor or spontaneous ripening of the cervix before
Clinical Examination: elective induction. The perinatal mortality is significantly increased beginning at 41 weeks' gestation and
From the early second trimester on, each antenatal visit includes the measurement of thedistance between the maternal uterine fundus and the possibly even earlier.
symphysis pubis. After 20weeks'gestation, the normal symphyseal-fundal height in centimeters approximates theweeks of gestation after allowances The optimal gestational age for the initiation of fetal testing has not been established, it would seem prudent
for maternal height and fetal station; a lag of the symphyseal-fundal height of 4 cm or more suggests growth restriction. Although the measurement to initiate fetal testing no later than 41 weeks of gestation.
of the symphyseal-fundal height is a poor screening tool for the detection of IUGR, the accuracy of subsequent ultrasound prediction of IUGR is The condition ofthe fetus can change quickly and thus,monitoring should be at frequent intervals,twice-
🔹
enhanced if there is aclinical suspicion of IUGR based on a lagging fundal height. weekly testing of patients at risk for fetal distress was superior to weekly testing. The implicit assumption in
Maternal Doppler Velocimetry: the expectant management strategy is that the presence of anabnormal fetal test (such as oligohydramnios,
Abnormal uterine artery flow velocity wave forms are a manifestation of delayed trophoblastinvasion that are highly associated with gestational low biophysical profile score, or spontaneousfetal heart rate decelerations) represents a change in fetal status
hypertensive disorders, IUGR and fetaldemise. that requires interventionin the form of prompt delivery.
Therefore, Doppler velocimetry of the uterine arteries has been examined for its usefulness in predicting pregnancies destined to produce a growth-
restricted fetus. It is found that in women with hypertensive disorders, the presence of an elevated uterine artery systolic/diastolic (S/D) ratio (>2.6) 🔹 MANAGEMENT DURING LABOR AND DELIVERY
Labor is a particularly dangerous time for the postterm fetus. Thus, women whose pregnancies are known or
and diastolic notching increased the risk for IUGR and stillbirth.
A uterine artery Doppler resistance profile that is high, persistently notched, orboth,identifies women at high-risk for preeclampsia and IUGR when suspected to be postterm ideally come to the hospital as soon as they suspect labor.
performed between 22and 23weeks' gestation While being evaluated for active labor, fetal heart rate and uterine contractions are monitored electronically
for variations consistent with fetal compromise. Consider amniotomy to diagnose thick meconium.
PREVENTIVE STRATEGIES
🔹
Because many causes of IUGR are nonpreventable, few interventions have proved effective for prevention.
Smoking is the single most common preventable cause of IUGR, women who quit smoking at 7months' gestation have newborns with higher mean
birth weights than do women who smoke throughout the pregnancy. Women who quit smoking before 16 weeks' gestation are not at any increased
by fatema okoff PHYSIOLOGY OF FETAL GROWTH
🔹
risk for an IUGR infant.
Low-dose aspirin has been extensively evaluated as a possible preventive agent forimproving placental vascular development by virtue of its
inhibitory action on plateletaggregation. Consideration should be given to hospitalized bed rest, which has the advantages of positive enforcement
The ability to reach an optimal birth weight results from the interaction between the fetal growth potential, the health of the
fetus, the capacity of the mother to supply adequate substrates required and the ability of the placenta to transport these
substrates to the fetus.
🔹
of rest and facilitation of daily fetal testing
Corticosteroids are a universally available antenatal therapeutic option that positively affects outcome by enhancing lung maturation and
preventing intraventricular hemorrhage,administration of a complete 48-hour course of antenatal steroids to anygrowth restricted fetus when
The fetus requires several substrates for normal growth; the most important areoxygen,glucose and amino acids. Any
persistent decrease in the availability of any of thesesubstrates will limit the ability of the fetus to reach its growth potential.
Small For Gestational Age (SGA) -Persistent and severe substrate deficiency may threaten the ability of the fetus to survive.
delivery is anticipated before 34 weeks' gestation, if this can be safely accomplished.
Intrauterine Growth Restriction (IUGR)
REGULATION OF FETAL GROWTH
THE TIMING OF DELIVERY Human fetal growth is characterized by sequential patterns of tissue and organ growth,differentiation, and maturation.
In the absence of definitive fetal therapy, proper timing of delivery is often the criticalmanagement issue wvhen dealing with the growth-restricted Fetal growth has been divided into three phases. The initial phase of hyperplasia occurs inthe first 16 weeks and is
fetus. In principle, the decisionfor delivery always weighs fetal risks against risks that can be anticipated as a result of preterm delivery. characterized by a rapid increase in cell number.
The risks of prematurity are of primary concern and make the management of the preterm growth restricted fetus particularly challenging The second phase,which extends up to 32 weeks' gestation, includes both cellular hyperplasia andhypertrophy. After
32weeks,fetal growth is by cellular hypertrophy, and it is during this phasethat most fetaI fat and glycogen are accumulated.
DELIVERY
Because a large proportion of growth-restricted infants suffer intrapartum asphyxia,intrapartum management demands continuous FHR monitoring.
Cesarean delvery without a trial of labor is indicated when the risks of vaginal delivery are unacceptable to the mother and fetus.
These circumstances include prelabor evidence offetal acidemia,spontaneous late decelerations, or late decelerations with minimal uterine activity. In
addition, absent and reversed end-diastolic flow in the umbilical artery isassociated with a high incidence of fetal intolerance of labor, thus cesarean
delivery is often required and should be considered for these severely growth restricted fetuses.
In the instance of less abnormal fetal testing typically in the setting of a more advanced gestational age, selection of the route of delivery is based on
the difficulty anticipated in inducing labor,the Bishop score, and AFV. During labor, a tracing without late decelerations is predictive of a good
outcome in casescomplicated by IUGR. However, with late decelerations, the incidence of asphyxia ingrowth-restricted infants is far greater than in
normally grown infants.
🔹
COMPLICATIONS
Despite significant advances in availability and delivery of perinatal and neonatalservices,there remains a significant increased
🔹
risk of adverse outcome in IUGR pregnancies.
Among affected pregnancies, the risks of morbidity and mortality increase proportionately with the severity of growth
restriction, and inversely with the gestational age at which IUGR is detected.
🔹
The severity of complications may be related to the underlying etiology of IUGR.
Other neonatal complications seen more frequently among growth-restricted fetuses than appropriately grown fetuses of
similar gestational ages include intrapartum fetaldistress,neonatal asphyxia, meconium aspiration, polycythemia, electrolyte and
🔹
metabolicabnormalities such as hypoglycemia and hypocalcemia,jaundice and hyperbilirubinemia,andhypothermia.
IUGR is also associated with increased risk of long-term negative effects on cognitivefunction as well as cerebral palsy and
other neurological deficiencies.
interchangeably to describe pregnancies that have exceeded a duration considered to be theupper
limit of normal.
Prolonged Pregnancy or postterm pregnancy is one that has lasted longer than 42 weeks or 294
days beyond the first day of the last menstrual period, and it is the preferred expression for an
extended pregnancy.
Post datism is pregnancy lasting beyond the estimated due date at 40 weeks.
Postmature is reserved for the pathologic syndrome in which the fetus experiencesplacental
insufficiency and resultant IUGR. Representing 20% cases of prolonged pregnancyand is associated
with:
1. Meconium-stained amniotic fluid
2. Oligohydramnios
3. Fetal distress
4. Evidence of loss of subcutaneous fat and
5. Dry, cracked skin Reflecting placental insufficiency
INCIDENCE
Using the definition of 294 days, the incidence of postterm pregnancy is 1-10 %. This ratehas
declined because of improved pregnancy dating accuracy and earlier intervention.
ADVERSE MATERNAL AND PERINATAL OUTCOMES ASSOCIATED WITH
🔹
POSTTERMPREGNANCY:
maternal:
- fetal macrosomia
- oligohydramnios
- preeeclampsia
- cesarean delivery
- labor dystocia
DEFINITION - fetal jeopardy
Currently, the American College of Obstetricians and Gynecologists (2021a) and the - shoulder dystocia
Societyfor Maternal-Fetal Medicine (2020) recommend defining FGR as either an EFW - postpartum hemorrhage
<10thpercentile for gestational age or an AC <10th percentile for gestational age - forceps delivery
FGR should be differentiated from SGA, which is a postnatal designation based onbirthweight - perneaal laceration
percentile.
-Importantly, as many as 70 percent of SGA new borns are not pathologically growth restricted.
Indeed, such children have normal outcomes and are thought to be appropriately grown when
🔹 perinatal:
-stillbirth
maternal ethnic group, parity, weight, and height are considered - postmaturity syndrome
- NICU admission
- meconium aspiration
- neonatal convulsions
- hypoxic-ischemic encephalopathy
- birth injuries
- infection
- childhood obesity
🔹
ETIOLOGIC FACTORS
🔹 The most frequent cause is an error in dating.
ETIOLOGIES OF INTRAUTERINE GROWTH RESTRICTION
PROLONGED PREGNANCY 🔹
🔹
When truly exists, the cause usually is unknown.
prepregnancy body mass index ≥25 and nulliparity significantly associated
prior postterm pregnancy are the most common identifiable risk factors (biologically
(POSTTERM PREGNANCY)
Conditions that result in fetal growth restriction broadly consist of
maternal,uterine,placental,and fetal disorders.
-These conditions result in growth delay by affecting nutrient and oxygen delivery to the
🔹
determined).
🔹 Male sex also has been associated.
Genetic predisposition may play a role . if a mother and daughter had a prolonged pregnancy,
placenta (maternal causes), nutrient and oxygen transfer across the placenta (placental the risk for the daughter to have a subsequent postterm pregnancy was significantly increased.
causes), and fetal nutrient uptake or regulation of growth processes (fetal causes).
-In clinical practice, there may be considerable overlap between the conditions that
determine manifestation, progression, and outcome.
🔹
Maternal, not paternal, genes influence prolonged pregnancy.
Rarely, it may be associated with placental sulfatase deficiency, adrenal hypoplasia or fetal
anencephaly.
DIAGNOSTIC TOOLS IN FETAL GROWTH RESTRICTION 🔹
INTERVENTIONS THAT DECREASE THE RATE OF POSTTERM PREGNANCY
🔹 Accurate dating on the basis of ultrasonography performed early in pregnancy.
🔹
The diagnosis of SGA would rely on biometric tests:
🔹 1. Ultrasound biometry
Breast and nipple stimulationat term have not been shown to affect the incidence ofpostterm
2. Biophysical tests
I.Diagnosis by ultrasound examination:
🔹
pregnancy.
Sweeping of the membranes at term: Membrane sweeping or stripping is an age-old methodof
inducing labor that is still in common use. This intervention results in a local increase in
Ultrasound examination early in pregnancy is accurate in establishing the estimated date of pregnancy confinement (EDC) and may sometimes identify prostaglandin production and is believed to hasten the onset of labor. The intervention had no
genetic or congenital causes of IUGR pregnancy. significant impact on mode of delivery or the incidence of maternal or neonatal infections.
Serial ultrasound examinations are important in documenting growth and excluding anomalies.
The fetal AC is related to hepatic glycogen storage and liver size, therefore correlating closely with the nutritional state. It is the singe best
measurement for the detection of IUGR. Its sensitivity is further enhanced by serial measurements at least 14 days apart. Because of its high sensitivity, MANAGEMENT
🔸
some type of abdominal measurement should be part of every sonographic growth evaluation.
🔸 The most important calculated ultrasound variable of fetal growth is the sonographically estimated fetal weight (EFW).
The regulation of AFV by the late second and third trimester is primarily dependent on fetalurine output, production of pulmonary fluid, and fetal
After completing 42 weeks, labor induction is recommended to help avoid the morbidity andmortality.
The decision focuses on whether labor induction is warranted or if expectant management with fetal
surveillance is best.
swallowing. Placental dysfunction andfetal hypoxemia both may result in decreased perfusion of the fetal kidneys with subsequentoliguria and Although most authors agree that induction of labor is indicated in women with an"inducible"uterine cervix,
decreasing AFV. there is lack of agreement as to the management of the patient whose cervix is deemed "unfavorable."
Two techniques are used that can provide important diagnosticand prognostic information. A 2-cm vertical pocket was considered normal, 1 to 2 Antenatal testing may be used in an attempt to observe the prolonged pregnancy safely while awaiting the
cmmarginal, and less than 1 cm decreased. Alternatively, AFV may be assessed by the sum ofvertical pockets from four quadrants of the uterine spontaneous onset of labor or for ripening of the cervix prior to labor induction.
🔸
cavity. This four-quadrant amniotic fluidindex. (AFI) is compared with reference ranges that require knowledge of the gestational age.
The role of Doppler velocimetry in the management of fetal growth restriction is unique because it serves as a diagnostic as well as a monitoring
tool. With extreme increase in blood flow resistance, end-diastolic forward velocity may be absent (AEDV) or reversed(REDV).
Management options depend on:
1) Gestational age,
2) Absence/presence of maternal risk factors and/or
II.Biophysical Tests· 3) Evidence of fetal compromise, and
Not designed to predict size but predict fetal wellbeing. The presence of fetal welleing implies the absence of fetal acidaemia.· 4) Maternal preferences: Successful management depends on effective counseling of women and their full Algorithm for management of postterm pregnancy
Abnormal biophysical tests are more indicative of FGR than SGA.·All biophysical tests, including amniotic fluid volume (AFV), umbilical Doppler, CTG,
andbiophysical scoring, are poor at diagnosing a SGA fetus. 🔹
involvement in the decision making process.
Historically ,prolonged pregnancy has been managed in 2 ways , either by Inducing labor at41-42 weeks
SCREENING AND PREVENTION OF FETAL GROWTH RESTRICTION
🔹
gestation, or awaiting the onset of spontaneous labor, while monitoring thefetal wellbeing.
Routine induction of labor at 41 weeks:
Although postterm pregnancy is defined as a pregnancy of 42 weeks or more ofgestation,several large
Although treatment options in utero are limited, interventions that improve outcome exist. The various screening methods that have been proposed multicenter randomized studies reported favorable outcomes withroutine induction as early as the beginning o
🔹
include identification of riskfactors, as well as serum and ultrasound tests. 41 weeks of gestation.
Maternal History: Intrauterine Growth Restriction (IUGR) A recent review in the Cochrane Library concluded that routine induction in low-risk pregnancies at or after
🔹
A history of poor pregnancy outcome is clearly correlated with the subsequent delivey of agrowth-restricted infant. Fetal growth restriction (FGR) 41weeks' gestation is associated with reduction in perinatal mortality,and no increase in therate of instrumental
Maternal Serum Analytes: or cesarean delivery.
At least four hormone/protein markers measured in the maternal sera during the early second trimester are associated with subsequent IUGR. These
🔹
🔸
include serum estriol, human placental lactogen, human chorionic gonadotrophin and alpha-fetoprotein. Antepartum Fetal Surveillance
An elevated maternal serum alpha-fetoprotein or human chorionic gonadotropin level in the second trimester are considered as markers of It is widely believed that fetal surveillance may be used in an attempt to observe theprolonged pregnancy
🔹
abnormal placentation and have been associated with an increased risk for IUGR. safely while awaiting either the spontaneous onset of labor or spontaneous ripening of the cervix before
Clinical Examination: elective induction. The perinatal mortality is significantly increased beginning at 41 weeks' gestation and
From the early second trimester on, each antenatal visit includes the measurement of thedistance between the maternal uterine fundus and the possibly even earlier.
symphysis pubis. After 20weeks'gestation, the normal symphyseal-fundal height in centimeters approximates theweeks of gestation after allowances The optimal gestational age for the initiation of fetal testing has not been established, it would seem prudent
for maternal height and fetal station; a lag of the symphyseal-fundal height of 4 cm or more suggests growth restriction. Although the measurement to initiate fetal testing no later than 41 weeks of gestation.
of the symphyseal-fundal height is a poor screening tool for the detection of IUGR, the accuracy of subsequent ultrasound prediction of IUGR is The condition ofthe fetus can change quickly and thus,monitoring should be at frequent intervals,twice-
🔹
enhanced if there is aclinical suspicion of IUGR based on a lagging fundal height. weekly testing of patients at risk for fetal distress was superior to weekly testing. The implicit assumption in
Maternal Doppler Velocimetry: the expectant management strategy is that the presence of anabnormal fetal test (such as oligohydramnios,
Abnormal uterine artery flow velocity wave forms are a manifestation of delayed trophoblastinvasion that are highly associated with gestational low biophysical profile score, or spontaneousfetal heart rate decelerations) represents a change in fetal status
hypertensive disorders, IUGR and fetaldemise. that requires interventionin the form of prompt delivery.
Therefore, Doppler velocimetry of the uterine arteries has been examined for its usefulness in predicting pregnancies destined to produce a growth-
restricted fetus. It is found that in women with hypertensive disorders, the presence of an elevated uterine artery systolic/diastolic (S/D) ratio (>2.6) 🔹 MANAGEMENT DURING LABOR AND DELIVERY
Labor is a particularly dangerous time for the postterm fetus. Thus, women whose pregnancies are known or
and diastolic notching increased the risk for IUGR and stillbirth.
A uterine artery Doppler resistance profile that is high, persistently notched, orboth,identifies women at high-risk for preeclampsia and IUGR when suspected to be postterm ideally come to the hospital as soon as they suspect labor.
performed between 22and 23weeks' gestation While being evaluated for active labor, fetal heart rate and uterine contractions are monitored electronically
for variations consistent with fetal compromise. Consider amniotomy to diagnose thick meconium.
PREVENTIVE STRATEGIES
🔹
Because many causes of IUGR are nonpreventable, few interventions have proved effective for prevention.
Smoking is the single most common preventable cause of IUGR, women who quit smoking at 7months' gestation have newborns with higher mean
birth weights than do women who smoke throughout the pregnancy. Women who quit smoking before 16 weeks' gestation are not at any increased
by fatema okoff PHYSIOLOGY OF FETAL GROWTH
🔹
risk for an IUGR infant.
Low-dose aspirin has been extensively evaluated as a possible preventive agent forimproving placental vascular development by virtue of its
inhibitory action on plateletaggregation. Consideration should be given to hospitalized bed rest, which has the advantages of positive enforcement
The ability to reach an optimal birth weight results from the interaction between the fetal growth potential, the health of the
fetus, the capacity of the mother to supply adequate substrates required and the ability of the placenta to transport these
substrates to the fetus.
🔹
of rest and facilitation of daily fetal testing
Corticosteroids are a universally available antenatal therapeutic option that positively affects outcome by enhancing lung maturation and
preventing intraventricular hemorrhage,administration of a complete 48-hour course of antenatal steroids to anygrowth restricted fetus when
The fetus requires several substrates for normal growth; the most important areoxygen,glucose and amino acids. Any
persistent decrease in the availability of any of thesesubstrates will limit the ability of the fetus to reach its growth potential.
Small For Gestational Age (SGA) -Persistent and severe substrate deficiency may threaten the ability of the fetus to survive.
delivery is anticipated before 34 weeks' gestation, if this can be safely accomplished.
Intrauterine Growth Restriction (IUGR)
REGULATION OF FETAL GROWTH
THE TIMING OF DELIVERY Human fetal growth is characterized by sequential patterns of tissue and organ growth,differentiation, and maturation.
In the absence of definitive fetal therapy, proper timing of delivery is often the criticalmanagement issue wvhen dealing with the growth-restricted Fetal growth has been divided into three phases. The initial phase of hyperplasia occurs inthe first 16 weeks and is
fetus. In principle, the decisionfor delivery always weighs fetal risks against risks that can be anticipated as a result of preterm delivery. characterized by a rapid increase in cell number.
The risks of prematurity are of primary concern and make the management of the preterm growth restricted fetus particularly challenging The second phase,which extends up to 32 weeks' gestation, includes both cellular hyperplasia andhypertrophy. After
32weeks,fetal growth is by cellular hypertrophy, and it is during this phasethat most fetaI fat and glycogen are accumulated.
DELIVERY
Because a large proportion of growth-restricted infants suffer intrapartum asphyxia,intrapartum management demands continuous FHR monitoring.
Cesarean delvery without a trial of labor is indicated when the risks of vaginal delivery are unacceptable to the mother and fetus.
These circumstances include prelabor evidence offetal acidemia,spontaneous late decelerations, or late decelerations with minimal uterine activity. In
addition, absent and reversed end-diastolic flow in the umbilical artery isassociated with a high incidence of fetal intolerance of labor, thus cesarean
delivery is often required and should be considered for these severely growth restricted fetuses.
In the instance of less abnormal fetal testing typically in the setting of a more advanced gestational age, selection of the route of delivery is based on
the difficulty anticipated in inducing labor,the Bishop score, and AFV. During labor, a tracing without late decelerations is predictive of a good
outcome in casescomplicated by IUGR. However, with late decelerations, the incidence of asphyxia ingrowth-restricted infants is far greater than in
normally grown infants.
🔹
COMPLICATIONS
Despite significant advances in availability and delivery of perinatal and neonatalservices,there remains a significant increased
🔹
risk of adverse outcome in IUGR pregnancies.
Among affected pregnancies, the risks of morbidity and mortality increase proportionately with the severity of growth
restriction, and inversely with the gestational age at which IUGR is detected.
🔹
The severity of complications may be related to the underlying etiology of IUGR.
Other neonatal complications seen more frequently among growth-restricted fetuses than appropriately grown fetuses of
similar gestational ages include intrapartum fetaldistress,neonatal asphyxia, meconium aspiration, polycythemia, electrolyte and
🔹
metabolicabnormalities such as hypoglycemia and hypocalcemia,jaundice and hyperbilirubinemia,andhypothermia.
IUGR is also associated with increased risk of long-term negative effects on cognitivefunction as well as cerebral palsy and
other neurological deficiencies.
