OLIGOHYDRAMNIOS

PHYSIOLOGY OF AMNIOTIC FLUID

Amniotic fluid volume 8 weeks : 15 ml,increases 10 ml/wk 17 wks :250 ml ,increases 50 ml/wk 28-38 wks :750-1000ml (decreases after 34 wks) 42 wks<500ml

FUNCTIONS OF AMNIOTIC FLUID Shock absorber – protects from external trauma. Protects cord from compression. Permits fetal movements – development of musculoskeletal system, prevents adhesions. Swallowing of AF enhances growth & development of GIT. AF volume maintains AF pressure – reduces loss of lung liquid – pulmonary development. Maintenance of fetal body temperature. Some fetal nutrition, water supply. Bacteriostatic properties – decreases potential for infection

Definition It is an extremely rare condition where the liquor amnii is deficient in amount to the extent of less than 200ml at term.(D.C.Dutta) Sonographically, it is defined when the maximum vertical pool of liquor is less than 2cm or when amniotic fluid index(AFI)is less than 5cm.

INCIDENCE 0.5 – 5%

Etiology Fetal chromosomal anomalies Intrauterine infection Drugs-PG inhibitors, ACE inhibiters Renal agenesis or obstruction of the urinary tract of the fetus preventing micturition IUGR associated with placental insufficiency Amnion nodosum-Failure of secretion by the cells of amnion covering the placenta. Post-maturity Early rupture of fetal membrane

FETAL MATERNAL DRUGS PLACENTAL IDIOPATHIC PROM (50%) CHROMOSOMAL ANOMALIES CONGENITAL ANOMALIES IUGR IUFD POSTTERM PREGNANCY MATERNAL PREECLAMPSIA APLA SYNDROME CHRONIC HTN DRUGS PG SYNTHETASE INHIBITORS ACE INHIBITORS IDIOPATHIC PLACENTAL CHRONIC ABRUPTION CVS

Diagnosis Uterine size is much smaller than the period of amenorrhea Less fetal movements The uterus is “full of fetus” because of scanty liquor Malpresentation (breech) is common Evidences of intrauterine growth retardation of the fetus Sonographic diagnosis is made when largest liquor pool is less than 2cm.Ultrasound visualization is done following amnio infusion of 300 ml of warm saline solution. Visualization of normal filling and emptying of fetal bladder essentially rules out urinary tract abnormality. Oligohydramnios with fetal symmetric growth retardation is associated with increased chromosomal abnormality.

Diagnosis SIGNS Uterus – small for date Feels full of fetus SYMPTOMS NO SPECIFIC SYMPTOMS H/O leaking p/v Post term s/o preeclampsia Drugs Less fetal movements SIGNS Uterus – small for date Feels full of fetus Malpresentations IUGR

USG AFI <5 cm (5-8 borderline)

Complications Abortion Fetal: Abortion Deformity due to intra-amniotic adhesions or due to compression Fetal pulmonary hypoplasia Cord compression High fetal mortality Potter’s syndrom Malpresentations Foetal distress-low apgar

Maternal : Prolonged labor due to inertia Increased operative interference due to malpresentation. The sum effect may lead to increased maternal morbidity. Increased operative intervention

Management DEPENDS UPON AETIOLOGY GESTATIONAL AGE SEVERITY FETAL STATUS & WELL BEING

Determine Etiology R/O PROM, h/o medical illness TARGETED USG FOR ANOMALIES R/O IUGR ,IUFD when suspected Amniocentesis if chromosomal anomalies suspected – early symmetric IUGR Tests for APLA Syndrome , if suspect

Management Patient will be admitted to the hospital Do ultra sound If renal agenesis is not present ,placental Function tests should perform In order to prevent compression deformities and hypo plastic lung disease amnio infusion with normal saline or ringer’s lactate may be performed. Induce labor because of placental insufficiency

Epidural anesthesia may be indicated to reduce the painful uterine contractions Continuous fetal monitoring to prevent fetal hypoxia due to cord compression or placental insufficiency

Treatment ADEQUATE REST – decreases dehydration HYDRATION – Oral/IV Hypotonic fluids(2 Lit/d) temporary increase helpful during labour, USG SERIAL USG – Monitor growth, AFI, BPP INDUCTION OF LABOUR/ LSCS Lung maturity attained Lethal malformation Fetal jeopardy Severe IUGR Severe oligohydramnios

Amnio infusion AMNIOINFUSION INDICATIONS 1.Diagnostic 2.Prophylactic 3.Therapeutic Decreases cord compression Dilutes meconium

There appears to be no advantage of prophylactic amnioinfusion over therapeutic amnioinfusion carried out only when fetal heart rate decelerations or thick meconium-staining of the liquor occur.

TREATMENT ACC. TO CAUSE Drug induced – OMIT DRUG PROM – INDUCTION PPROM – Antibiotics, steroid – Induction FETAL SURGERY VESICO AMNIOTIC SHUNT- Laser photocoagulation for TTTS

Nursing diagnosis Anxiety related to the outcome Inadequate knowledge related to the condition Potential for maternal and fetal complications

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