This document discusses fundal size discrepancies including being smaller or larger than dates. Being smaller than dates can be due to fetal issues like growth restriction or demise, or maternal issues like a wrong date. Differentials are investigated by ultrasound. Being larger than dates can be due to multiple pregnancies, macrosomia, or a wrong date. Oligohydramnios and polyhydramnios are also discussed, including their definitions, causes, investigations, complications and management. Intrauterine growth restriction is explained in detail with causes, investigations and complications.

1. FUNDAL SIZE DISCREPANCY
1 Smaller than date
Larger than date
Oligohydramnios
Intrauterine growth restriction (IUGR)
Polyhydramnios

2. REFERENCE
1. http://www.scribd.com/doc/38032808/Obstetric-Highlights-Elma
2. Oxford’s O&G
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3. SMALLER THAN DATE
 Short case
 Findings?
 Differentials
i. Fetal: Fetal demise, IUGR, missed miscarriage, transverse lie,
molar pregnancy
ii. Maternal: Wrong date, oligohydramnios*
 Investigated by USG
i. Fetal: Cardiac motion, fetal biometry (BPD, HC, AC, FL)
ii. Amniotic fluid: AFI <8 cm
iii. Placental: Texture, appearance
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4.  Management
 Manage the underlying problem (s) identified
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5. LARGER THAN DATE
 Short case
 Findings?
 Differentials
i. Fetal: Multiple pregnancy, macrosomia, molar pregnancy,
hydrops fetalis
ii. Maternal: Wrong date, pelvic masses, polyhydramnios*
 Investigated by USG
i. Fetal: # of fetus (es), fetal biometry (BPD, HC, AC, FL)
ii. Amniotic fluid: AFI >22 cm
iii. Placental: Texture, appearance
iv. Uterine: Leiomyomas
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6.  Management
 Manage the underlying problem (s) identified
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7. AMNIOTIC FLUID’S PHYSIOLOGY
 Amniotic fluids after 20w largely = to fetal urine
 Volume depends on fetal urine production, fetal
swallowing & absorption
 Normal volume varies with gestation
 Highest on 24th – 36th w
 Measured by USG
 1 deepest vertical pool
 Adding up deepest pools of all 4 quadrants = AFI
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8. OLIGOHYDRAMNIOS
 Formula: 2, 8
 Oligohydramnios means reduced amniotic fluid volume
measured as single deepest pool <2 cm or AFI <8 cm
 Differentials
1. Leakage of amniotic fluid
i. SROM; be it either PROM or PPROM
2. Reduced fetal urine production
i. IUGR
ii. Renal failure or abnormalities
iii. Post date pregnancy
3. Obstruction to fetal urine output
i. PUV 8

9.  Investigations
i. Speculum examination for ruptured membranes
ii. If suspected SROM; FBC, CRP, vaginal swab
iii. Fetal USG, including Doppler
iv. Calculate corrected POG
 Complications
1. Related to cause
i. PPROM leads to possible chorioamnionitis, preterm labour and
delivery
ii. IUGR increases fetal & neonatal morbidity and mortality
2. Related to reduced volume
i. Lung hypoplasia if occurs <22w
ii. Limbs abnormalities, eg, talipes (if prolonged)
iii. Oligohydramnios <22w has very poor prognosis 9

10.  Management
i. PROM: Induce labour (SVD) unless CS is indicated for another
reason
ii. PPROM: Monitor signs of infection*, steroids (Dexamethasone
best given at 28-34w), prophylactic oral Erythromycin (10 mg
QID x 10 days), daily CTGs
iii. IUGR: Manage according to umbilical artery Doppler & CTG
findings
iv. Renal tract abnormalities: Refer fetal medicine centre
v. Apparently isolated oligohydramnios: Reconsider cause,
intervention is not usual if Dopplers are normal
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11. IUGR
 Optimal fetal growth needs healthy mother, well-f(x)
placenta and the absence of pathology
 Analogous to failure to thrive (FTT) in children
 IUGR = pathologically small fetus
 Types
 Symmetric
 Entire body is proportionately small, early onset IUGR, chromosomal
abnormalities
 Asymmetric
 ‘Head-sparing effect’, normal HC, small AC and thin limbs, placental
insufficiency
 Causes? 11

12. Maternal causes Placental insufficiency Fetal causes
1. Chronic diseases 1. Abnormal trophoblastic 1. Genetic abnormalities
i. HPT invasion i. Trisomy 13, 18 or
ii. Cardiac disease i. Pre eclampsia 21
iii. CKD ii. Placenta accreta ii. Turner’s
2. Substance abuse 2. Infarction syndrome
i. Alcohol 3. Abruptio placenta iii. Triploidy
ii. Recreational drug 4. Palcental location 2. Congenital
use i. Placenta previa abnormalities
3. Smoking 5. Tumors i. Cardiac; TOF, TGA
4. Autoimmune diseases i. Chorioangiomas ii. Gastroschisis
i. Antiphospholipid (placental 3. Congenital infection
Ab syndrome hemangiomas) i. CMV
5. Genetic disorder 6. Abnormal umbilical ii. Rubella
i. Phenylketonuria cord or cord insertion iii. Toxoplasmosis
6. Poor nutrition i. 2 vessels cord 4. Multiple pregnancy
7. Low socio-economic
status #MOST COMMON
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13.  Investigations
i. Fetal biometry (BP, HC, AC, FL)
ii. Fetal USG, including Doppler
iii. CTGs
 Management
 Early identification and intensive fetal monitoring are the
keys to managing IUGR. The aim is to continue the
pregnancy safely as long as possible, thereby decreasing
prematurity, but deliver before fetus becomes
excessively compromised.
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14.  Complications
i. Meconium aspiration
ii. Intrapartum fetal distress and asphyxia
iii. Emergency CS
iv. Necrotizing enterocolitis
v. Hypoglycemia
vi. Hypocalcemia
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15. POLYHYDRAMNIOS
 Formula: 8, 22
 Polyhydramnios means increased amniotic fluid volume
measured as single deepest pool >8 cm or AFI >22 cm
 Differentials
1. Increased fetal urine production
i. Maternal diabetes (chronic DM, GDM)
ii. TTTS
iii. Hydops fetalis
2. Inability to swallow or absorb amniotic fluid
i. GIT obstruction: Duodenal atresia, tracheo-esophageal fistula
ii. Neurological/muscular: Anencephaly, myotonic dystrophy
iii. Facial obstruction 15
3. Idiopathic (usually mild)

16.  Investigations
i. Fetal USG
ii. MGTT to exclude maternal diabetes
 Complications
i. Maternal discomfort because of abdominal distension
ii. Malpresentation
iii. Preterm delivery
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17.  Management
i. AFI >40 cm: Severe, usually a/w fetal abnormality,
amnioreduction (drainage of excess fluid by a needle), NSAIDs
ii. Fetal abnormality: Refer fetal medicine centre
iii. TTTS: Refer to fetal medicine centre, laser ablation of placental
anastomoses
iv. Preterm: Assess delivery risk (cervical scan), consider steroids
v. Unstable/transverse lie: Admit, CS if labour ensues with
abnormal lie
vi. DM/GDM: Control maternal blood sugar accordingly*
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18. ABDOMINAL FINDINGS?
Oligohydramnios Polyhydramnios
1. Smaller than date 1. Grossly distended,
2. Easily palpable fetal shining abdomen
parts 2. Fullness over the flanks
3. Loud fetal heart 3. Larger than date
sounds 4. Hardly palpable fetal
parts
5. Abnormal lie
6. Muffled fetal heart
sounds
7. Positive fluid thrill
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19. THANKS, ALLAHUA’LAM. 
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