Hydramnios/ Oligohydramnios

Question 1

Amniotic Fluid

Answer 1

• clear liquid that surrounds the fetus in the uterus
• clear, straw-colored substance
• odorless
• fetus’s urine makes up most of the amniotic fluid after about 20 weeks of pregnancy
• about 500ml enter and leave the amniotic sac per hour
  ○ Gradual increase up to 36 weeks to around 600-1000 ml then decrease after that
  ■ 500 ml – 18 weeks
  ■ 800 ml – 34 weeks
  ■ 600 ml – at term pregnancy up to 14 weeks

Question 2

Amniotic Fluid Purpose

Answer 2

• development of fetal lungs
• protect fetus from infection
• develop muscle and bones
• prevents umbilical cord from being compressed (for nutrients)
• helps digestive and respiratory system to develop
• regulate fetal body temperature
• protect fetus from mother’s movements (fall or sudden blow)

Question 3

Amniotic Fluid Purpose

Answer 3

• development of fetal lungs
• protect fetus from infection
• develop muscle and bones
• prevents umbilical cord from being compressed (for nutrients)
• helps digestive and respiratory system to develop
• regulate fetal body temperature
• protect fetus from mother’s movements (fall or sudden blow)

Question 4

Amniotic Fluid Clinical Importance

Answer 4

1. screening for fetal malformation (serum alpha-fetoprotein)
2. assessment of fetal well-being (amniotic fluid index; usually done during sonography/ ultrasound)
3. assessment of fetal lung maturity (L/S ratio)
   ○ Lecithin Myelin
   ○ 2:0 to 2.5
4. diagnosis and follow-up of labor
5. diagnosis of PROM (ferning test)
   ○ Nitrazine paper test
   ○ Blue = prom
   ○ Yellow = urine

Question 5

Amniotic Fluid Volume Assessment

Answer 5

• fundal height measurement is unreliable
• objective assessment is done through ultrasonography
  ○ deepest vertical pool
  ○ amniotic fluid index (AFI) or single maximal vertical pocket (MVP)

OLIGOHYDRAMNIOS
POLYHYDRAMNIOS

Question 6

Polyhydramnios

Answer 6

• increased amniotic fluid volume relative to AOG
• excess fluid volume of 2000 mL and/ or AFI above 24 cm

Question 7

Polyhydramnios Complications

Answer 7

• fetal malpresentation: breech
• premature rupture of membranes (too wide, overstretch)
• preterm birth
• prolapsed cord (umbilical cord slips down first than the baby)

Question 8

Polyhydramnios Etiology

Answer 8

1. fetal anomalies (20%)
2. placental abnormalities
3. maternal causes (30%)

Question 9

Polyhydramnios Etiology (Fetal Anomalies)

Answer 9

1. anencephaly
2. open spina bifida
3. esophageal atresia
4. hydrops fetalis (baby cannot manage fluid inside body)

Question 10

Polyhydramnios Etiology (Placental Abnormalities)

Answer 10

1. chorioangioma (tumor grows in placenta, increased blood vessels that compresses umbilical vessel)

Question 11

Polyhydramnios Etiology (Maternal Causes)

Answer 11

1. diabetes mellitus (increased risk for hyperglycemia, increases fetal sugar and fetal diuresis)
2. pregnancy induced hypertension (edema formation due to placental implantation problems)

Question 12

Polyhydramnios Assessment

Answer 12

1. discrepancy between fundal height and AOG
2. rapid growth of uterus
3. shortness of breath (diaphragm pressure)
4. discomfort in abdomen
5. lower extremity varicosities
6. uterine contractions due to overstretching of uterus
7. weight gain (2 lbs/ week = 2nd trimester; 1 lb/ week = 3rd trimester)

Question 13

Polyhydramnios Medical Management

Answer 13

1. amniocentesis
2. tocolytic therapy

Question 14

Amniocentesis

Answer 14

• prenatal diagnostic test
• small amount of amniotic fluid is removed to determine genetic abnormality
• artificial rupture of the membrane to reduce fluid and pressure
• transiently effective
• done daily to be effective
• watch out for risk for infection

Question 15

Tocolytic Therapy

Answer 15

prostaglandin synthesis inhibitor (Indomethacin) = noninvasive treatment = decrease amniotic fluid volume by decreasing fetal urinary output but may cause premature closure of the fetal ductus arteriosus

Question 16

Oligohydramnios

Answer 16

• decreased amniotic fluid relative to AOG
• less than normal amniotic fluid volume of 500 ml or an AFI below 5 cm
• may cause miscarriage, stillbirth, malpresentation or preterm birth

Question 17

Oligohydramnios Etiology

Answer 17

• actual cause = unknown

can be seen in some cases of:
1. postmaturity (beyond 40 weeks; IUGR because of placental insufficiency and sometimes in fetal conditions such as in the kidneys)
2. IUGR
3. fetal conditions with renal malformations (renal atresia, dysplastic kidneys, obstructive lesion of urinary tract)

Question 18

Oligohydramnios Assessment

Answer 18

1. uterus fails to meet expected growth rate
2. complaints of fluid leaking from vagina
3. malpresentation: breech
4. less fetal movement (less amniotic movement)

Question 19

Oligohydramnios Complications

Answer 19

1. fetal pulmonary hypoplasia
2. cord compression
3. fetal adhesions
4. potter syndrome

Question 20

Potter Syndrome

Answer 20

• rare condition
• characteristics developed when there is decreased amount of amniotic fluid
• small pressure can cause physical features abnormalities

Question 21

Oligohydramnios Nursing Diagnoses

Answer 21

1. impaired gas exchange related to cord compression
2. fear related to unknown outcome of the pregnancy
3. risk for maternal and fetal injury

Question 22

Oligohydramnios Therapeutic Management

Answer 22

• evaluate fetus for signs of postmaturity, congenical anomalies, and respiratory difficulty
• provide comfort measures in bedding and perineal care
• amnioinfusion

Question 23

Amnioinfusion

Answer 23

• goal of transabdominal amnioinfusion: keep amniotic fluid at normal volume to avoid complications for the mother and fetus
• assess mother’s vs and contraction status, monitor FHR