Chapter 11: Disorders of Amnionic Fluid

Question 1

Amniotic fluid volume increase

Answer 1

30 mL at 10 weeks
200 mL by 16 weeks
800 mL by the mid-third trimester

Question 2

Amniotic fluid composition

Answer 2

98% water

Question 3

Abnormally decreased fluid volume

Answer 3

Oligohydrmanios

Question 4

Abnormally increased fluid volume

Answer 4

hydramnios or polyhydramnios

Question 5

(First half of pregnancy) Transfer of water and other small molecules

across amnion

Answer 5

transmembranous flow

Question 6

(First half of pregnancy) Transfer of water and other small molecules

across the fetal vessels on placental surface

Answer 6

intramembranous flow

Question 7

(First half of pregnancy) Transfer of water and other small molecules

across fetal skin

Answer 7

transcutaneous flow

until keratinisation at 22 to 25 weeks

Question 8

Fetal urine produc­tion begin

Answer 8

8 and 1 1 weeks’ gestation

Question 9

when does lethal renal abnormalities manifests

Answer 9

after 1 8 weeks

Question 10

Fetal urine osmolality

Answer 10

equal to amniotic fluid

hypotonic to maternal and fetal plasma

Question 11

Amniotic fluid volume regulation late pregnancy

Fetal urination

Answer 11

production

Question 12

Amniotic fluid volume regulation late pregnancy

Fetal swallowing

Answer 12

Resorption

Question 13

Amniotic fluid volume regulation late pregnancy

Fetal lung fluid secretion

Answer 13

Production

Question 14

Amniotic fluid volume regulation late pregnancy

intramembranous flow across the fetal vessels on placental surface

Answer 14

Resorption

Question 15

Amniotic fluid volume regulation late pregnancy

transmembranous flow across amniotic membrane

Answer 15

Resorption

Question 16

Measurement: dye dilution

Answer 16

aminohippurate

Question 17

Mean value (22-39 wks)

Answer 17

750ml

Question 18

Normal Single deepest pocket

Answer 18

> 2cm

<8cm

Question 19

Normal AFI

Answer 19

> 5cm

<25 cm

Question 20

Mild Hydramnios

Answer 20

AFI 25 to 29.9 cm

SDP 8 to 9.9 cm

Question 21

Moderate Hydramnios

Answer 21

AFI 30 to 34.9 cm

SDP 10 to 11.9 cm

Question 22

Severe

Answer 22

AFI 35 cm or more

SDP 12 cm or more

Question 23

Etiology of hydramnios

Answer 23

• fetal anomalies:
  structural abnormalities or genetic syndromes , and diabetes
• Con­genital infection: cytomegalovirus, toxoplas­mosis, syphilis, and parvovirus
• red blood cell alloimmunization
• placental chorioangioma
  -hydrops fetalies

Question 24

Pathophysiology: hydramnios with diabetes

Answer 24

maternal hyperglycemia causes fetal hypergly­cemia, with resulting fetal osmotic diuresis into the amniotic fluid compartment

Question 25

Diagnostic criteria for twin-twin transfusion syn­drome (TTTS)

Answer 25

Monochorionic ges­tations, hydramnios of one sac and oligohydramnios of the other

Question 26

Hydramnios complication

Answer 26

Maternal -uterine Distention - Dyspnea and orthopne - Edema - lower extremities, vulva, and abdominal wall - placental abruption, uterine dysfunction during labor, and postpartum hemorrhage fetal -membrane rupture or therapeutic amnioreduction

Question 27

Oligohydramnios ethology

Answer 27

- fetal abnormality - placental abnormality su􏰀ciently severe —> impair perfusion - Rule out ruptured membrane

Question 28

Oligohydramnios Congenital anomalies (renal)

Answer 28

bilateral renal agenesis bilateral multicystic dysplastic kidney unilateral renal agenesis with contralateral multicystic dysplastic kidney infantile form of autosomal recessive poycystic kidney dis­ease

Question 29

Oligohydramnios Congenital anomalies (genitourinary)

Answer 29

persistent cloaca and sireno­ melia

Question 30

Drugs causing oligohydramnios

Answer 30

ACEi ARBs ``` Effects: fetal hypotension renal hypoperfusion renal ischemia anuric renal failure ``` NSAIDs Effects: acute and chronic renal insu􏰀ciency Fetal skull bone hypoplasia and limb contrac­tures

Question 31

Oligohydramnious outcome

Answer 31

stillbirth preterm birth heart rate pattern abnormalities growth restriction

Question 32

Oligohydramnios management

Answer 32

close fetal surveillance | maternal hydration