Polyhydramnios

Question 1

Define polyhydramnios

Answer 1

MVP >/= 8 cm or >/= 24 cm AFI

Question 2

What is mild vs moderate vs severe polyhydramnios?

Answer 2

Mild 24-29.9 cm
Moderate 30-34.9
Severe > 35 cm

(65-70%)DVP 8-11 cm
(20%)12-15 cm
(<15%) >/-= 16 cm

Question 3

What is the likelihood of aneuploidy with mild vs moderate vs severe polyhydramnios?

Answer 3

6-10% (mild), 10-15% (mod) and 20-40% (severe)

Question 4

What is the mechanism for polyhydramnios?

Answer 4

impaired fetal swallowing or overproduction of fetal urine due to high-output cardiac states, renal abnormality or osmotic fetal diuresis

Question 5

List some causes of polyhydramnios

Answer 5

Idiopathic (60-70%), fetal abnormalities (10%), maternal diabetes - GDM, fetal anomalies with disturbance in fetal swallowing (CNS abnormalities –cleft palate, micrognathia; abnormalities that compress the trachea –neck/mediastinal/lung masses, congenital high airway obstruction sequence, TEF, esophageal/duodenal atresia, meconium peritonitis, CDH, CCAM, GI obstruction and neurologic or muscular disorders – myotonic dystrophy), genetic syndromes (Charge, Noonan, Beckwith), congenital infections – PV, CMV, syphilis, high cardiac-output states - placental tumor – chorangioma (>/= 5 cm), sacrococcygeal teratoma, cardiac – Ebstein, TOF with abs pulmonary valve, cardiomyopathy, SVT and complete HB, fetal thyrotoxicosis, uteropelvic junction obstruction and alloimmunization

Question 6

List complications associated with polyhydramnios’s

Answer 6

maternal dyspnea, PTL/PTD, SGA infant, macrosomia (infants weighing >4000 grams), perinatal mortality, PPROM, abnormal fetal presentation, cord prolapse and PPH, bradycardia, chorioamnionitis, and IUFD

Question 7

How do you measure DVP/AFI?

Answer 7

DVP - US transducer held perpendicular to the floor while scanning in the sagittal plane (parallel to the long axis of the patient’s body) and the largest vertical pocked of AF is measured.

AFI – Uterus divided into 4 equally sized quadrants with depth measurement of single deepest fluid pocket in each quadrant and summed up.

  To be included in the sums, each pocket must be at least 1 cm, absent of umbilical cord loops

Question 8

How would you manage polyhydramnios?

Answer 8

Targeted US, growth, diabetes screen, allolimmunization screen, test for syphilis; consider repeat GDM screen

Detailed sono – growth, cardiac anatomy, placenta, fetal movement (neuro func), position of hands/feet (arthrogryposis syndromes), stomach size (atresia), face/palate anatomy, fetal neck, kidneys, lower spine and pelvis

Antenatal testing not required for sole indication of mild idiopathic polyhydramnios

weekly testing, serial growths

Amniocentesis with chromosomal microarray, Genetic counseling offered

Question 9

When do you deliver?

Answer 9

39 weeks

Question 10

What are treatment options?

Answer 10

amnioreduction considered with onset of severe maternal discomfort, dyspnea or both in the setting of severe polyhydramnios

 Indomethacin should not be given for sole purpose of decreasing amniotic fluid –showed an increased risk for IVH, periventricular leukomalacia and NEC.  

 Median volume removed is 1-2L 

 Historically, used passive gravitational drainage to a syringe manual aspiration technique with a 3-way tap, now we use a vacuum-assisted aspiration device 

 Benefit: prolongs pregnancy