amniotic fluid

Polyhydromnios & Oligohydromnios

2015-2016

Deepest vertical pocket (DVP): it's performed by assessing a pocket of maximal depth of amniotic fluid on ultrasound which is free of umbilical cord & fetal parts.

DVP between 2-8 cm...normal.

< 2 cm..... oligohydromnios.
> 8 cm..... polyhydromnios.

Amniotic fluid index (AFI): It's an index for fetal well-being & it's apart of biophysical profile. To determine AFI, we use 4 quadrant technique, when the deepest vertical length of each pocket of fluid is measured in each quadrant & summing them.

AFI between 8-18 is...normal

< 5...oligohydromnios
> 20-24...polyhydromnios

A

Clinical assessment of amniotic fluid volume depend essentially on non invasive method such as ultrasound. These include;


1-the deepest vertical pool (DVP)
2-amniotic fluid index (AFI)

Oligohydromnios

Oligohydromnios is a condition in pregnancy characterized by;
a deficiency of amniotic fluid, it is defined as AFV < 5th percentile for gestation,
AFI < 5 or DVP < 2cm.

Causes

1-preterm premature rupture of membrane
2-placental insufficiency
3-congenital fetal anomalies.
4-prolonged pregnancy or post-term.
5-maternal drugs as NSAID.
6-maternal complications as hypertension, dehydration, preeclampsia.

HISTORY

History of PPROM
post maturity
drugs intake
less fetal movement.


INVESTIGATIONS

1-Ultrasound examination

...May reveal IUGR or presence of structural anomalies in kidney
...Biophysical profile
...Exclusion of congenital anomalies.
...Degree of oligohydromnios.
2-Color doppler ultrasound of both uterine & umbilical circulation.
3-Fetal specimen for karyotyping & viral infection.

EXAMINATION

may reveal the presence of chronic hypertension or pre eclampsia.
small for date uterus.
Fetal pools may be very obviously felt , the uterus "full of fetus".
fetal malpresentation

TREATMENT

Depend on;
-Aetiology, Gestational age, Fetal status & Severity.
-bed rest
-maternal hydration to increase amniotic fluid volume
-amnioinfusion during labour to prevent umbilical cord compression in sever cases of oligohydromnios with serial USG to monitor growth, AFI, BPP.
-fetal surgery
-labour usually induced in the case of pregnancy at term or post date or in case of ROM.


Complications of oligohydromnios
Fetal risk

1-perinatal mortality

2-pulmonary hypoplasia
3-skeletal deformities. Potter syndrome .
4-prematurity.
5-fetal distress.

Maternal risk

1-increase the risk of CS due to fetal distress secondary to either IUGR, malformation or cord compression.
2-high rate of physician intervention.

Polyhydromnios

is an excess amount of amniotic fluid it's defined as AFV above 95th centile for gestational age, AFI> 20-24 or DVP of >8 cm
4Classification of severity

Mild....DVP=8-12 cm

Moderate.....DVP=12-15 cm
Severe......DVP=>15 cm.


Causes

1-Maternal

DM

2-Placental

Chorioangioma of placenta.

3-idiopathic.

4-Fetal
...Intestinal obstruction
...Esophageal compression .
...Impairment of swallowing due to CNS leasion as anencephally.
...Chromosomal abnormalities as trisomy 18
...Fetal polyuria
...Multiple gestation
...Cardiac failure due to fetal anaemia.
...Congenital infection
...Fetal hydrops


HISTORY

...A careful history, with attention to maternal symptoms, dis.such as DM or recent viral infection.
...abdomen is enlarged quickly & the fetus unusually mobile.
...dyspnoea & indigestion.
...In rare cases, there is abdominal pain & vomiting.
...sever abdominal swelling & discomfort.

EXAMINATION

...the abdomen will appear distended.
...large for date uterus.
...abdomen may be tense, tender & fetal pools hard to palpate.
...oedema of abdominal wall & vulva.
...the presentation is unstable.
...it may be difficult to hear fetal heart beat.

INVESTIGATIONS

1-Ultrasound scanning
2-Karyotype if there is structural abnormalities.
3-investigation to mother for DM.
4-screening for viral infection.


TREATMENT

1-Polyhydromnios without symptoms requires NO treatment.

2-treatment indicated when there is sever polyhydromnios.
a-when pregnancy remote from term & woman is in discomfort, options of treatment are;
1- medical treatment, (indomethacin).
2-amniocentesis
3-correction of underlying pathology
b-in case near term in which the woman is in serious discomfort , labour should be induced.

Intrapartum management

1-allow labour to progress & monitor progress of labour by partogram.
2-during labour, rupture of membrane done with slow release of liquor by controlled ARM to decrease risk of abruptio placenta.
3-check for cord prolapse when membrane ruptured.
4-active management of 3rd stage of labour as PPH can occur.

Complications of polyhydromnios

Fetal risks

1-perinatal mortality

2-hypoxia


Maternal risks

1-abdominal discomfort

2-spontaneous preterm labour
3-spontaneous rupture of membrane
4-malpresentation & unstable lie.
5-post partum haemorrhage
6-increase incidence of CS
7-higher incidence of pre-eclampsia

Assessment of oligohydromnios

Assessment of polyhydromnios

Potter syndrome