Uterus smaller than date Oligohydramnios & Intrauterine Growth Restriction (IUGR) M. Kamil
Amniotic fluid • Function • Physical space for fetal movement -> important for normal musculoskeletal development • Permits fetal swallowing • Important for GI tract development • Permits fetal breathing • Necessary for lung development • Prevent umbilical cord compression • Protect from trauma
Amniotic fluid evaluation • Component of fetal testing for 2nd and 3rd trimester sonogram. • Measurements 2 ways: • Single deepest vertical fluid pocket (nl 2 – 8 cm) • AFI - The sum of the deepest vertical pockets from each of four equal uterine quadrants (nl 5 – 24 cm)
Gestational-age-specific nomogram of AFI
Oligohydramnios • D efinition • AFI 5 cm (or < 5th percentile)/ • The absence of a fluid pocket 2-3 cm in depth/ • Fluid volume of less than 500 mL at 32 – 36 weeks. • Anhydramnios – No measurable pocket of amniotic fluid is identified
Clinical manifestation and diagnosis • U terine size < expected for gestational age • Performed ultrasound to assess AF volume • AFI 5 cm • Single deepest pocket of amniotic fluid 2 cm • Gestational age specific nomogram: < 2.5th percentile • A fluid volume of less than 500 mL at 32-36 weeks.
Evaluation •• T horough maternal history • Targeted physical examination • Ultrasound evaluation with fetal biometry and fetal anomalies • Fetal growth restriction • Aneuploidy - nuchal translucency • Placental abnormalities (abruption)
Management • Admission for investigation • Rule out ROM • Amniocentesis - > Karyotyping • Doppler ultrasound for fetal distress • Evidence of fetal distress- > immediate C-sec • If no fetal distress, induced and delivered via SVD • Send placenta for pathological examination
Complications of oligohydramnios • Early onset of oligohydramnios • Potter sequence syndrome • Limb deformities • Abdominal wall defects • Pulmonary hypoplasia • Cord compression
Intrauterine Growth Restriction (IUGR)
Intrauterine Growth Restriction (IUGR) • Introduction • Detection usually on routine U/S • Important for prenatal care • Confirming diagnosis • Determining the cause and severity of fetal growth restriction (FGR) • Counseling the parents • Closely monitor fetal growth and well-being • Determining the optimal time for route of delivery
IUGR VS SGA • Definition of IUGR: • A fetus or infant whose weight is less than the 10th percentile at a given GA as determined by U/S • Or Infants whose growth velocity < expected • SGA: An infant with a birth weight at the lower extreme of the normal birth weight distribution. • BW <10th % • BW < 2SD below the mean (3rd %)
Beckmann, C., Herbert, W., Laube, D., Ling, F., Smith, R., & American Col ege of Obstetricians Gynecologists. (2014). Obstetrics and gynecology (7th ed.).
Uterine fetal growth pattern Reethiya, L., & Rokeshwar, H.D., Doctrina Perpetua: Guides on Obstetrics. (2015).
Types of IUGR Reethiya, L., & Rokeshwar, H.D., Doctrina Perpetua: Guides on Obstetrics. (2015). P ondoral index: Ratio of BW to Length:
Causes and risk factors of FGR Beckmann, C., Herbert, W., Laube, D., Ling, F., Smith, R., & American College of Obstetricians Gynecologists. (2014). Obstetrics and gynecology (7th ed.).
Evaluation • Assess gestational age on early routine visit. • History to assess the risk factors. • Physical examination • Screening test – serial measurements of fundal height. • Fundal height should increase approx. 1cm/week between 20 and 36 weeks • Significant discrepancy of > 2 cm may indicate IUGR Ultrasound
Evaluation (Continued) • Investigation • CBC – Hb, WBC (possible infection) • TORCHES Screening • Look for dysmorphic features • Mother urine for substance/ meconium for substance • Blood sugar • Calcium • Bilirubin
Evaluation (Continued) • Ultrasound • To assess fetal size and growth. • Fetal biometry measurements and compare with standardized table • Biparietal diameter • Head circumference • Abdominal circumference (AC) – false negative < 10% • Femur length
Evaluation (Continued) • Direct studies • Invasive studies of the fetus. • Amniocentesis for fetal lung maturity • Fetal karyotyping and viral cultures and PCRs
Evaluation (Continued) • Doppler velocimetry • On fetal umbilical artery. • Measured by Systolic/ Diastolic ratio • Normal at term: 1.8 to 2.0
Doppler velocimetry (continued) • IUGR secondary to uteroplacental insufficiency • Show reversed end- dystolic flow • May suggest impending fetal demise
References • Beckmann, C., Herbert, W., Laube, D., Ling, F., Smith, R., & American College of Obstetricians Gynecologists. (2014). Obstetrics and gynecology (7th ed.). • http://www.stanfordchildrens.org/en/topic/default?id=amniocentesis-90- P02429 • Callahan, T., & Caughey, A. (2007). Blueprints obstetrics & gynecology (4th ed. / Tamara L. Callahan, Aaron B. Caughey. ed., Blueprints). Philadelphia ; London: Lippincott Williams & Wilkins. • Cunningham, F., & Williams, J. (2014). Williams obstetrics. (24th ed. / [edited by] F. Gary Cunningham et al. ed.). New York ; London: McGraw-Hill Medical.