Hydramnios/ Oligohydramnios Flashcards
Amniotic Fluid
- 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
Amniotic Fluid Purpose
- 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)
Amniotic Fluid Purpose
- 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)
Amniotic Fluid Clinical Importance
- screening for fetal malformation (serum alpha-fetoprotein)
- assessment of fetal well-being (amniotic fluid index; usually done during sonography/ ultrasound)
- assessment of fetal lung maturity (L/S ratio)
○ Lecithin Myelin
○ 2:0 to 2.5 - diagnosis and follow-up of labor
- diagnosis of PROM (ferning test)
○ Nitrazine paper test
○ Blue = prom
○ Yellow = urine
Amniotic Fluid Volume Assessment
- 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
Polyhydramnios
- increased amniotic fluid volume relative to AOG
- excess fluid volume of 2000 mL and/ or AFI above 24 cm
Polyhydramnios Complications
- fetal malpresentation: breech
- premature rupture of membranes (too wide, overstretch)
- preterm birth
- prolapsed cord (umbilical cord slips down first than the baby)
Polyhydramnios Etiology
- fetal anomalies (20%)
- placental abnormalities
- maternal causes (30%)
Polyhydramnios Etiology (Fetal Anomalies)
- anencephaly
- open spina bifida
- esophageal atresia
- hydrops fetalis (baby cannot manage fluid inside body)
Polyhydramnios Etiology (Placental Abnormalities)
- chorioangioma (tumor grows in placenta, increased blood vessels that compresses umbilical vessel)
Polyhydramnios Etiology (Maternal Causes)
- diabetes mellitus (increased risk for hyperglycemia, increases fetal sugar and fetal diuresis)
- pregnancy induced hypertension (edema formation due to placental implantation problems)
Polyhydramnios Assessment
- discrepancy between fundal height and AOG
- rapid growth of uterus
- shortness of breath (diaphragm pressure)
- discomfort in abdomen
- lower extremity varicosities
- uterine contractions due to overstretching of uterus
- weight gain (2 lbs/ week = 2nd trimester; 1 lb/ week = 3rd trimester)
Polyhydramnios Medical Management
- amniocentesis
- tocolytic therapy
Amniocentesis
- 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
Tocolytic Therapy
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
Oligohydramnios
- 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
Oligohydramnios Etiology
- 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)
Oligohydramnios Assessment
- uterus fails to meet expected growth rate
- complaints of fluid leaking from vagina
- malpresentation: breech
- less fetal movement (less amniotic movement)
Oligohydramnios Complications
- fetal pulmonary hypoplasia
- cord compression
- fetal adhesions
- potter syndrome
Potter Syndrome
- rare condition
- characteristics developed when there is decreased amount of amniotic fluid
- small pressure can cause physical features abnormalities
Oligohydramnios Nursing Diagnoses
- impaired gas exchange related to cord compression
- fear related to unknown outcome of the pregnancy
- risk for maternal and fetal injury
Oligohydramnios Therapeutic Management
- evaluate fetus for signs of postmaturity, congenical anomalies, and respiratory difficulty
- provide comfort measures in bedding and perineal care
- amnioinfusion
Amnioinfusion
- 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
