September 28 30, 2018 · Amniotic Fluid –Too Little, Too Much – Bregand‐White Amniotic...
Transcript of September 28 30, 2018 · Amniotic Fluid –Too Little, Too Much – Bregand‐White Amniotic...
Course Director
September 28-30, 2018
Amniotic Fluid – Too Little, Too Much –Bregand‐White
Julia Bregand-White, MDUChicago Medicine
2018 University of Chicago Ultrasound SymposiumSeptember 29, 2018
Objectives Define normal amniotic fluid volume Describe methods of amniotic fluid volume assessment Review implications of abnormal amniotic fluid volume Review monitoring options in setting of abnormal
amniotic fluid volume
Disclosure I have no conflict of interest with respect to any of the
material presented in this lecture.
Amniotic Fluid – Too Little, Too Much –Bregand‐White
Amniotic fluid
Increased incidence of fetal and neonatal morbidity and
mortality whether
too much or
too little
Amniotic Fluid- function1. Lung development2. Allows fetal movements (muscles, bones, joints)3. Thermoregulation4. Protects against infection5. Protects fetus from trauma6. Protects cord from compression
Amniotic Fluid‐ regulation
Secretion from respiratory tract
Transport across skin <20w Fetal urine >20w Intramembranous flow
INFLOW
Amniotic Fluid – Too Little, Too Much –Bregand‐White
Amniotic Fluid‐ regulation
Fetal swallowing and reabsorption through GI tract
Transmembranous flow Transcervical (ruptured
membranes)
OUTFLOW
Amniotic Fluid‐ measurement Dye-determined amniotic fluid calculation Direct measurement at time of cesarean delivery Objective ultrasound assessment Subjective ultrasound assessment
Amniotic Fluid‐ volumeGestational age (weeks)
5th percentile 50th percentile 95th percentile
16 134 377 694
20 129 425 1986
24 129 469 3839
28 135 504 5016
34 157 538 3594
40 208 541 800
Sandlin AT, Ounpraseuth ST, Spencer HJ, et al: Amniotic fluid volume in normal singleton pregnancies: modeling with quantile regression. Arch Gynecol Obstet 289:967‐972, 2014
Amniotic Fluid – Too Little, Too Much –Bregand‐White
Amniotic Fluid‐ volume
RA Brace, EJ Wolf: Normal amniotic fluid volume changes throughout pregnancy. Am J Obstet Gynecol. 161:382‐388 1989
Amniotic Fluid‐ measurement Amniotic Fluid Index (AFI) 4 Quadrants: umbilicus
divides the upper and lower halves and the linea nigradivides the right and left halves
Patient supine Linear (or curvilinear)
transducer is placed along the maternal anterior abdominal wall and held perpendicularto the floor
Amniotic Fluid‐ measurement Oligohydramnios
Less than 5cm Only 1% of AFI in term
pregnancies are <7cm (Moore 1990)
Polyhydramnios Greater than 25cm Gestational age specific
Amniotic Fluid – Too Little, Too Much –Bregand‐White
Amniotic Fluid‐ measurement Maximum Vertical Pocket
(MVP; aka DVP, SDP) Largest single vertical
pocket of fluid that is at least 1 cm in width
Oligohydramnios <2cm
Severe <1cm
Polyhydramnios >8cm
Mild 8-12cm Severe >16cm
Amniotic Fluid‐ measurement 2D Pocket
Horizontal and vertical dimensions of the maximum vertical pocket
Multiply values together to obtain a single value, in cm2
Normal 15-50cm2
Amniotic Fluid‐ measurement
Subjective Assessment Visual interpretation
without ultrasound measurements
Amniotic Fluid – Too Little, Too Much –Bregand‐White
Amniotic Fluid‐ measurement
When in doubt, put color on…
Increased false positive oligohydramnios
EF Magann, SP Chauhan, S Barrilleaux, et al.: Ultrasound estimate of amniotic fluid volume: color Doppler overdiagnosis of oligohydramnios. Obstet Gyncol. 98:71‐74 2001
Amniotic Fluid‐ measurement Limitations
Excessive pressure Adipose tissue causing artificial echoes Fetal position
Not typically effected by Maternal positions Fetal movement Curvilinear or sector transducer
Amniotic Fluid‐ which is best?
Dye determined is as good as direct measurement at time of cesarean delivery
Thanks but no thanks!
EF Magann, NS Whitworth, JC Files, et al.: Dye‐dilution techniques using aminohippurate sodium: do they accurately reflect amniotic fluid volume?. J MaternFetal Neonatal Med 11:167‐170 2002
Amniotic Fluid – Too Little, Too Much –Bregand‐White
Amniotic Fluid‐ which is best? AFI and MVP reliably identify normal AFV Not as accurate when fluid is abnormal1
No difference in subjective vs objective assessment2
A normal AFV varies during gestation and depends on the population being investigated
1‐ SP Chauhan, EF Magann, JC Morrison, et al.: Ultrasonographic assessment of amniotic fluid does not reflect actual amniotic fluid volume. Am J Obstet Gynecol. 177:291‐296 19972‐Magann, SP Chauhan, NS Whitworth, et al.: Subjective versus objective evaluation of amniotic fluid volume of pregnancies of less than 24 weeks’ gestation: how can we be accurate?. J Ultrasound Med. 20:191‐195 2001
Amniotic Fluid‐ which is best? Cochrane Review 2008
5 RCT: 3226 women
No superior method to prevent poor peripartumoutcomes NICU admission
Umbilical artery pH <7.1
AFI associated with more Oligohydramnios
Inductions of labor
C/S for FHR abnormalities
Diagnosis of Oligohydramnios
Rate of Induction of Labor
AF Nabhan, YA Abdelmoula: Amniotic fluid index versus single deepest vertical pocket as a screening test for preventing adverse pregnancy outcome. Cochrane Database Syst Rev.
Amniotic Fluid‐ which is best? MVP was the better measurement because the use of the AFI increased the diagnosis of oligohydramnios and labor inductions without improvement in peripartum outcomes
AF Nabhan, YA Abdelmoula: Amniotic fluid index versus single deepest vertical pocket as a screening test for preventing adverse pregnancy outcome. Cochrane Database Syst Rev.
Amniotic Fluid – Too Little, Too Much –Bregand‐White
too little
Oligohydramnios‐ definition Too little
AFV <200 (500cc) AFI < 5cm MVP <2cm 2D pocket <15cm2
Oligohydramnios- outcomesSeverity of Oligo Oligo vs normal
Perinatal mortality: Normal fluid (2cm<MVP<8cm)
1.97/1000
Marginal fluid (MVP 1-2cm) 37.7/1000
Low fluid (MVP <1cm) 109.4/1000
NO difference in perinatal outcomes Cesarean delivery for fetal
labor intolerance Umbilical cord arterial pH of
less than 7 NICU admissions Seizures in the first 24 hours
after delivery Neonatal death
Amniotic Fluid – Too Little, Too Much –Bregand‐White
Oligohydramnios- etiologyProduction vs Obstruction vs Loss
Prerenal Placental insufficiency Fetal demise Maternal hypovolemia
Renal Renal agenesis Cystic dysplastic kidneys Maternal medications- ACE-I, ARB, NSAID
Postrenal Bilateral UPJ obstruction Posterior urethral valves Ruptured membranes
Rule out ruptured membranes!
Oligohydramnios- evaluation After you’ve ruled out ruptured membranes… History and physical looking for risk factors for utero-
placental insufficiency Chronic kidney disease Chronic hypertension Placental abruption
Targeted ultrasound Fetal anomalies Fetal growth Fetal well-being
Amniotic Fluid – Too Little, Too Much –Bregand‐White
Oligohydramnios- management Dependent on etiology
Renal agenesis- options counseling Medication exposure- stop offending agent Dehydration- hydration
Increased antenatal testing Weekly assessment of AFV: consider NST, BPP Fetal growth monitoring: US every 3-4 weeks
Delivery timing Oligohydramnios at term is generally considered an
indication for delivery
TOO MUCH
Polyhydramnios- definition Complicates 0.2-2% of pregnancies
Stratified by Severity Mild: AFI 25-30cm SDV 8-11cm Moderate: AFI 30-35cm SDV 2-15cm Severe: AFI >35.1cm SDV >16cm
Amniotic Fluid – Too Little, Too Much –Bregand‐White
Polyhydramnios- etiology Idiopathic (aka I have no idea)
50-60% of cases Congenital anomalies and genetic disorders
8-45% Maternal diabetes
5-26% Multiple gestations
8-10% Fetal anemia
1-11% Other- hydrops, Bartter syndrome, viral infections
Polyhydramnios- etiology Severity implicates likelihood of finding fetal anomaly
Mild: 17% Moderate: 72% Severe: 86%
N Damato, RA Filly, RB Goldstein, et al.: Frequency of fetal anomalies in sonographically detected polyhydramnios. J Ultrasound Med. 12 (1):11‐15 1993
Polyhydramnios- etiology Congenital anomalies
Central nervous system 28% Anencephaly, holoprosencephaly,
spina bifida
Cardiac 22% High output cardiac failure (fetal
anemia, fetal/placental tumors)
Gastrointestinal malformation 14% Small bowel atresia or
obstruction
Other Facial/neck tumors, cleft lip/palate
MS Nobile de Santis, T Radaelli, E Taricco, et al.: Excess of amniotic fluid: pathophysiology, correlated diseases and clinical management. Acta Biomed. 75 (Suppl 1):53‐55 2004
Amniotic Fluid – Too Little, Too Much –Bregand‐White
Polyhydramnios- implications Risk of aneuploidy
10% poly + anomaly Trisomies 21, 18, 13
1% if poly alone
Severe persistent poly in the 2nd and 3rd trimesters is associated with a higher incidence of aneuploidy Warrants amniocentesis
A Golan, I Worman, J Sagi, et al.: Persistence of polyhydramnios during pregnancy: its significance and correlation with maternal and fetal complications. Gynecol Obstet Invest. 37:18‐20 1994
Polyhydramnios- evaluation History and physical looking for risk factors for associated
conditions Pre-gestational or gestational diabetes
Lab Maternal antibody screen, diabetic screen TORCH, parvovirus
Targeted ultrasound Fetal anomalies Fetal growth Fetal echo Fetal well-being Consider amniocentesis- genetic and infectious
MFM Consultation
Polyhydramnios- adverse outcomes Preterm labor Maternal respiratory distress Malpresentation Placental abruption Cord prolapse Postpartum hemorrhage
Perinatal mortality odds ratio 5.5
E Maymon, F Ghezzi, I Shoham‐Vardi, et al.: Isolated hydramnios at term gestation and the occurrence of peripartum complications. Eur J Obstet GynecolReprod Biol. 77:157‐161 1998
Amniotic Fluid – Too Little, Too Much –Bregand‐White
Polyhydramnios- management Antenatal testing
Consider antenatal testing with AFV assessment at least weekly Multidisciplinary team approach
In setting of severe persistent polyhydramnios where risk fo aneuploidy and/or fetal anomaly are high
MFM, NICU, genetic counselors, pediatric surgeons, pediatric cardiologist, SW
Interventions Amniocentesis- large volume reduction Indomethacin- 2.2-3mg/kg/day for short course prior to 32w
Delivery timing Consider delivery at 39w in the setting of mild poly, appropriate antenatal
testing and minimal maternal symptoms Consider delivery earlier if severe poly or uncontrolled maternal
symptoms
Thank you!