Definition: A fetal weight of more than4.5 kg at term or fetal birth weight > 90percentile for the gestationalage..
CausesGenetic or constitutional:obese women tend to givebirth to macrosomic babies.Diabetes and prediabetes.Post-date (postmaturity).Multiparity: The first baby is about 100 gmsmaller than the next.Hydrops foetalis.
Macrosomia and diabetes¼ th of insulin dependentmothers have MacrosomicinfantsExcess growth happens in 3rdtrimester.GDM mothers have sameincidence of Macrosomic infantsas other diabetics
Definition !IUGR is defined as a fetus that has an estimatedweight that is less than the 10th percentile for it’sgestational ageAt term, the cutoff birth weight for IUGR is 2,500 g (5 lb, 8 oz)
Growth percentiles for fetal weightversus gestational age
Correlation of birth weight percentile toperinatal morbdity and mortalility
Is small for gestational age (SGA) thesame as IUGR?• IUGR is used synonymously with small forgestational age (SGA) but implies a pathologiccondition. EFW at or below 10th percentile is used toidentify fetuses at risk However a certain number of fetuses at orbelow the 10th percentile just may beconstitutionally small and not growthrestricted
IUGR VS SGAIUGR: fetus with birth weight <10thpercentile for gestational age due to pathologicprocess.SGA: fetus with birth weight <10thpercentile for gestational age in the absence ofpathologic process
1. Symmetrical growth restriction 20 % of IUGR Infants proportional decrease in all organs HC/AC ratio is normal Occurs in early pregnancy : Cellular hyperplasia Increase risk for long term neurodevelopmental dysfunction Due to Intrinsic factor Chromosomal abnormalities Congenital anomalies Intrauterine infection
2.Asymmetrical growth restriction 80% of IUGR Infants Increase HC/AC ratio : decrease in abdominal size Brain sparing effects Occurs in late pregnancy : cellular hypertrophy Risk for perinatal hypoxia, neonatal hypoglycemia Good prognosis Due to extrinsic factors : Uteroplacental insufficiency Maternal vascular disease: hypertension Multiple gestations Placental disease
3. Combined type Asymmetrical symmetrical Symmetrical asymmetricalMore morbidities and mortalitiesMore long term effects
Ponderal IndexUltrasound criteria for diagnosis of fetal malnutrition;Gestation age independent;Way of characterizing the relationship of height tomass for an individual.PI = 1000 xTypical values are 20 to 25.PI is normal in symmetric IUGR.PI is low in asymmetric IUGR.Mass (kgs)Height (cms)
Case #4Infant is delivered at 38weeks to mom whopresents with headachesand epigastric pain BW: 2.1 kg HC: 50th%tile Lt: 30th%tilePre-eclampsia/HELLP
Case # 5- What if?Mom with noprenatal caredeliversundiagnosed twinsat EGA 34 weeksDiscordant twins
Case # 6- What if?An infant isdelivered at 42weeks via c- sectiondue to NRHTs afterinductionPost dates- decreased subcutaneous fat- skin desquamation- wizened facies- large AF(diminished membranousbone formation)- meconium staining
Placental causes• Placental infarction• Placental abruption• Chorioangioma• Placenta previa , circumvallate placenta• Marginal or velamentous insertion of umbilical cord
IUGRSymmetric IUGR Asmmetric IUGRSmall symmetrically. Head is larger than abdomen.Ponderal index is normal. Ponderal index is low.Normal head-abdomen ratio. High head-abdomen ratio.Genetic, infections. Placental vascular insufficiency.Complicated neonatal course. Benign neonatal course ifcomplications are treated adequately.
History for risk factor– Teen age– High altitude– Socioeconomic factor– Smoking , Alcohol , Drugs– Previous IUGR pregnancy history– previous IUGR in family
Signs:Seldom elicited before 28 weeks of gestation:Failure of fetus and uterus to grow at the normal rate overa 4 week period;Uterine fundal height should be at least 2cm less thanexpected for the length of gestation;Poor maternal weight gain;Diminished fetal movements.
Physical examinationUterine fundal height Uterine fundus Pubic symphysis Simple, Safe, Inexpensive for screening Between 18 and 30 weeks, the uterine fundal height in centimeters coincides withweeks of gestation. If the measurement is more than 2 to 3 cm from theexpected height or < 1oth percentile from normal curve,inappropriate fetal growth may be suspected
Ultrasonic measurementInitial U/S at 16 to 20 weeks to establishgestational age and identify anomalies andrepeated at 32 to 34 weeks to evaluatefetal growth
Ultrasonography BiometryThe measurements most commonly used to measure andfollow fetal growth are:Biparietal DiameterFemur LengthHead CircumferenceAbdominal CircumferenceRatio :- Head circumference to the abdominal circumference (HC/AC).
Amniotic Fluid IndexMild IUGR – Normal amniotic fluidSevere IUGR – Oligohydramnios (AFI is ≤ 5)Incidence 40%On ultrasonography - a pocket of fluid < 1cm is diagnosedas oligohydramnios.
The amniotic fluid index is obtained by summing thelargest cord-free vertical pocket in each of the fourquadrants of an equally divided uterus.
Abnormal umbilical artery Doppler velocimetryA. Normal velocimetry patternwith an S/D ratio of <30.B. The diastolic velocityapproaching zero reflectsincreased placental vascularresistance.C. During diastole, arterialflow is reversed (negativeS/D ratio), which is anominous sign that mayprecede fetal demise– characterized by absent or reversed end-diastolicflow– associated with fetal growth restriction
An IUGR infant is at risk forHypothermia?Hypoglycemia?OrHypocalcemia?decreased subcutaneous fat, increasedsurface- volume ratio, decreased heatproductiondecreased glycogen stores/glycogenolysis/ gluconeogenesisincreased metabolic ratedeficient catecholamine releaseAssociated with perinatal stress, asphyxia,prematurity
ManagementPrepregnancy: to prevent it by identifying risk factors andtreat as necessary (e.g. improve nutrition intake, stopsmoking or alcohol, ASA in APA syndrome, and Heparin inthrombophilias)Antepartum: identify risk factors that can be changed.Fetal surveillance by ultrasound (BPP) and fetal heartmonitoring (Non-Stress Test). To decide on timing and modeof delivery.
Growth restriction near term Prompt delivery Recommend delivery at 34 weeks or beyond ifthere is clinically significant oligohydramnios
Growth restriction remote from term No specific treatment If diagnosed in prior to 34 weeks, and amnionicfluid volume and fetal surveillance are normal Observation is recommendedscreening fortoxoplasmosis,herpes,rubella,CMV and others Specific treatment(causes of IUGR) andsupportive care If severe IUGR or bad obstetric conditions Terminate pregnancy should be considered
IUGR- OutcomeNeurodevelopment etiology and adverse event dependent lower intelligence, learning/ behavioraldisorders, neurologic handicaps symmetric, chromosomal disorders, congenitalinfections--- poorer outcome school performance influenced by social class
CaseSW a16 years old G1 P0+0 presented early for prenatalcarePMH: NonePSH: NoneAllergies: NoneMedications: Prenatal vitaminsSocial Hx: + Tobacco 1ppd x > 5 years, No illicit drug use• B average in high school and good support system• Lives in Denver, HIGH ALTITUDE• Poor nutrition
She followed up regularly and had an uncomplicated1st trimester…..• At 18 weeks fundal height measured 17 cm• At 22 weeks fundal height measured 20 cm• At 24 weeks fundal height measured 21 cmAt this point I am worried about IUGR with thissluggish growth.Although we do not use fundal height to diagnoseIUGR, it can be a clue to a developing problem.•A fundal height that lags by more than 3 cm or isincreasing in disparity with the gestational agemay signal IUGR.• A lag of 4 cm or more certainly suggests growthrestriction.• The size of the uterus should be assessed at eachprenatal visit.
So now we have increasing concernover her poor fundal height. Whatother risk factors for IUGR does AMYhave?A) TeenB) Poor nutritionC) Poor abdominal girth growthD) High altitudeE) SmokerF)All of the aboveANSWER F
Maternal weight GainDecreased maternal weight gain is arelatively insensitive sign of IUGR baby…
Risk Factors of IUGRWith all these risk factors, poor weight gain,and an inadequate fundal height…What would you do to further evaluate forpotential IUGR?1)Consult OB now2) Get an ultrasound3) Do an NST4) Continue to watch one more weekANSWER 2
The result of 32 wks USComments:a single intrauterine pregnancy. No obvious fetal anatomicabnormalities were seen. Not all malformations of the abovementioned organ systems can be detected by ultrasound.There is an overall growth lag of two weeks, with the headand abdomen lagging three weeks.Amniotic fluid is lower limits of normal measuring 8.5 cm . S/Dratio is slightly elevated. She declined amniocentesis.Recommend follow up growth in three weeks. Thisappointment was scheduled today
History of Present Illness• That was her ultrasound at 24 weeks. You repeat it at 27weeks: 3 week growth lag and AFI 8.5• Repeat US at 30 weeks: normal growth since last US – 15day lag; AFI 10.5• Repeat US at 32 weeks: EFW 9% AFI 5.9Is this IUGR? What do you do now?
She has an overall 3 week lag and anEGW 12% at 32 weeks. Is this IUGR?A) Yes ,any growth lag is IUGRB)Yes any EFW<l15% is IUGRC)No ,too early to diagnose IUGRD) No, IUGR is EGW overall lag 4 weeksANSWER C
IUGR is usually not detectable before 32-34 weeks(maximal fetal growth). But it must be suspectedearlierSigns rarelyoccur before 28weeks ofgestation
What is Intrauterine GrowthRestriction (IUGR)?A fetus with IUGR often has an estimated fetal weight associatedwith which of the following?A) Abdominal circumference is below 5th percentileB) Abdominal circumference is below the 2.5th percentileC) Less than the 5th percentile for its gestational ageD) Less than the 10th percentile for its gestational ageANSWER D
What is one of the pathologicMaternal/Placental causes forIUGR?A.Gestational DiabetesB.HypertensionC.ObesityD.Hyperemesis GravidarumANSWER B
Which of the following is not apathologic FETAL cause for IUGR?D)CMV infectionC)Congenital heartdiseaseB)Cleft lip/palateA)Trisomy 21ANSWER B
Does SW have symmetrical orasymmetrical IUGR?A)AsymmetricalB) SymmetricalAnswer B
Comments of the ultrasound at 32 weeks.It reads:A complete detailed scan of a single intrauterine pregnancy wasperformed. Noobvious fetal anatomic abnormalities were seen. Not allmalformations of theabove mentioned organ systems can be detected by ultrasound.There is an overallgrowth lag of two weeks, with the head and abdomen laggingthree weeks. Amnioticfluid is lower limits of normal measuring 5.9 cm . S/D ratio isslightlyelevated.
How else can IUGR be diagnosed in additionto a <10% weight for gestational age?A) USB) Inadequate Maternal Weight gainC) Non-reassuring NSTD) Fundal HeightANSWER A
So SW has had a 32 wk US withEFW 10% and AFI 6.9.What is your next step?A)Repeat USin8 weeksB)No furtherUS neededC)Repeat USin4 weeksD)TransfertoOBANS C
Yes! Correct Answer:Repeat US in 3-4 weeksRepeat US at 35 weeks:Comments:A repeat ultrasound of this single intrauterine pregnancy was performed.EFW is in the less than 10th percentile in growth.Amniotic fluid is within normal limits for this gestation.Umbilical artery dopplers performed and S/D ratio isnormal.Recommendations include:1. follow up ultrasound in 1 week for AFI and dopplers2. follow-up ultrasound in 2 weeks for growth3. NST testing twice weekly.
SW is in your office to review the results. Youexplain the results and schedule her for anultrasound next week and the week after.Any other advice for her?Click for advice1. Rest as much as possible-she does not work and is out of school.2. Perform daily kick counts.3. She will need weekly visits with biweekly NSTs.She asks you: “Why so manyultrasounds?” What do you tell her?
You tell her:“Ultrasound measurement of the fetus is the goldstandard for assessing fetal growth.”AND“We need to follow the amount of fluid around the baby aswell. If it is too low, we will need to deliver your babyearly.”Click here.Click here next
When should we (Family Practice)Transfer care to the Obstetricians? A)Whenever you are unsure oruncomfortable with the situation B)Definite need for C-Section C)Worsening fetal status D)Severe/worsening Maternal Disease E)Unsure of IUGR etiology F)All of the aboveAnswer F
Which of the following may we see afterthe birth of a baby with IUGR?A) Decreased oxygen levelsB) Meconium aspirationC) HypoglycemiaD) Difficulty maintaining normal body temperatureE) PolycythemiaF) StillbirthG) All of the AboveANSWER G
Case Close• SW remained on the family practice service because sheremained stable and her biweekly BPP and NST werereassuring.• In the 36th week, she was found to haveoligohydramnios by US AFI = 3.2 along with IUGREFW < 10%• Pt was at this time transferred to OB for care.• She was already known to them because we consultedthem at the first signs of IUGR.• Amniocentesis was done to ensure fetal lung maturityand she was induced soon there after.• Patient vaginally delivered a baby with Down’sSyndrome• No other complications at birth