POLYHYDRAMNIOS & OLIGOHYDRAMNIOS

1. POLYHYDRAMNIOS & OLIGOHYDRAMNIOS PRESENTER: JOY WILLIAMS 16TH NOV 2009

2. INTRODUCTION • The amniotic fluid(AF) that’s bathes the fetus is necessary for its growth and development. • It cushions the fetus from physical trauma, permits lung growth and provides barrier against infection. • The fetus is surrounded by AF everywhere except at its attachment with the umbilical cord. • AF is largely derieved from fetal urine & fetal lung secretion although an additional contribution to AF comes from amniotic membrane secretions.

3. The composition of amniotic fluid is heterogenous consisting of proteins (albumins & globulins), lipids (phospholipids, cholesterol & lecithin) carbohydrates (predominantly glucose), inorganic salts, and cells derived from fetal epithelium, amniotic membrane, & dermal fibroblasts. This latter cell type grows well in culture and is frequently used for karyotyping.

4. The volume of the amniotic fluid varies according to the gestational age of the fetus. The amniotic fluid index (AFl) is a qualitative ultrasonic assessment of liquor volume that is a summation of the deepest vertical pool depth in each of 4 gradrants surrounding the fetus.

5. AMNIOTIC FLUID VOLUME • 8wks: 15ml, volume increases 10ml/wk • 17wks: 250ml, increases at 50ml/wk • 28-35wks: ~750-1000ml • 42wks: <500ml

6. INCIDENCE • USA oligohydramnios occurs in 4% and polyhydrmnios occurs in 1% of pregnancies • Preterm labour and delivery occurs in approximately 26% of mothers with polyhydramnios. Other complications include PROM, abruptio, malpresentation, CS delivery and PPH • In 1990 20% of cases of polyhydramnios involved associated fetal anomalies, including problems of the GI system 40%, CNS 26%, cardiovascular 22% or genitourinary system 13%. Among these cases multiple gestations occurred in 7.5%, 5% were due to maternal diabetes, and the remaining 8.5% were due to other causes.

7. The mortality rate in oligohydramnios is high. The lack of amniotic fluid allows compression of the fetal abdomen, which limits movement of its diaphragm. In addition to chest wall fixation, the lack of amniotic fluid flowing in and out of the fetal lung leads to pulmonary hypoplasia. Is also associated with meconium staining of the amniotic fluid, fetal heart conduction abnormalities, umbilical cord compression, poor tolerance of labor, lower apgar scores and fetal acidosis. In cases of IUGR, the degree of oligohydrmnios is often proportional to growth restriction, is frequently reflective of the extent of placental dysfuntion and is associated with a corresponding increase in the perinatal mortality rate. In twin gestation with twin-twin transfusion, polyhydramnios may occur in the recipient twin, and oligohydramnios may occur in the donor. This complication is associated with high morbidity and mortality rates. MORTALITY

8. POLYHYDRAMNIOS Definition:abnormally high level of AF; i.e AFI >95th centile for gestation.

9. Incidence: 0.4-1.5% of pregnancies TYPES -Acute: is an excess fluid accumulation more quickly & its occurs earlier in pregnancy. -Chronic: excess fluid that accumulates gradually & it is only noticed after the 30th wk of preg.

10. AETIOLOGY 1.MATERNAL -Diabetes -Pre-eclampsia -Heart failure 2.PLACENTAL -Chorioangioma -Arterio-venous fistula

11. 3.FETAL -Multiple gestation -Oesophageal atresia/ tracheo-oesophageal fistula -Duodenal atresia -Neuromuscular fetal condition -Anencephaly -Spina bifida 4.IDIOPATHIC

12. Clinical Presentation • History of increasing abdominal distension beyond gestational age • Maternal discomfort, dyspnea, dyspepsia, leg edema • Abdomen may be tense and tender • Fetal poles will be hard to palpate • SFH greater than the gestational age • Fluid thrill elicited on percussion • Fetal abnormalities include neonatal macrosomia, fetal or neonatal hydrops with anasarca, ascites, pleural or pericardial effusions, and GI tract obstruction • Congenital hip dislocation, clubfoot, and limb reduction defect • Abnormalities in fetal movemen • FHS are muffled

13. DIAGNOSIS • Clinical: size > dates • USS: 10cm per pockets; AFI > 25 • Delivery: >2000ml fluid

14. EVALUATION • Maternal blood: eg. Diabetes screen, AFP,TORCH • Ultrasound -twin congenital anomalies, hydrops -fetal urine production -confirm diagnosis AFI>24cm • AF: AFP,chromosome • Placental biopsy

15. TREATMENT 1.Treatment of aetiology 2.Bed rest 3.Amniocentesis: is to relief maternal distress. 1500ml is removed gradually(500ml/hr) thru drainage or rapidly(50ml/min)thru suction. 4.?Diuretics, low Na diet 5.Antepartum monitoring 6.Indomethacin

16.     Indomethacin therapy: Mechanism: lung liquid production or fetal urine production, & absorption fluid movement across fetal membranes Dose: 1.5-3 mg/kg per day. Complications:constriction of fetal ductus arteriosus. .

17. DIFFERENTIAL DIAGNOSIS 1.     Twins 2.     Ovarian cyst 3.     Full bladder 4.     Hydatiform mole .

18. COMPLICATION -Uterine overdistention Maternal respiratory compromise Premature labor PROM -Abruption -Cord prolapse Fetal malpresentation PPH -Fetal congenital malformation -Fetal macrosomia

19. OLIGOHYDRAMNIOS Definition: inadequate volume of AF,ie.AFI<5th centile for gestation.

20. INCIDENCE • 8.2-37.8% pregnancies -8.2% of antenatal patients(50% post-term) -37.8% of patients in labor(50% ROM)

21. AETIOLOGY • Fetal: • 1. Spontaneous rupture of the membranes • 2. IUGR • 3. Post-term pregnancy • 4. Congenital anomaliesof the urinary tract: renal aplasia, obstuction • 5. Twin-twin transfusion

22. B. Maternal: 1.     Uteroplacental insufficiency 2.     Drugs: Prostaglandin synthetase inhibitors, ACEI , NSAIDs 3.     Placental abruption C. Idiopathic

23. Clinical Presentation • History of clear fluid leaking from vagina • Fetal poles may be very obviously felt and hard • SFH small for dates uterus • Marked deformation of the fetus including external compression with a flattened facies and epicanthal folds, hypertelorism, low set ears, a mongoloid slant of the palpebral fissure, a crease below the lower lip and micrognathia. • Bowed legs, clubbed feet • Single umbilical artery • Small for gestational age • Death from severe respiratory insufficiency • FHS heard.

24. DIAGNOSIS • Clinical: size < date • USS: AFI< 5 • Delivery: scanty fluid, meconium

25. EVALUATION • Maternal medical illness; hypertension, medication • Ultrasound: congenital anomalies, IUGR

26. TREATMENT Second trimester: Transabdominal amnioinfusion: 200ml -Injection of indigo carmine -Amniocentesis for chromosome Third trimester: -Moderate; bed rest, hydration, antenatal monitoring -Severe: delivery, fetal monitoring, amnioinfusion

27. AMNIOINFUSION TECHNIQUE • Ultrasound assessment: optional • Insert catheter • Protocol # 1 -10ml/min * 60min, then 3ml/min monitor interuterine pressure drain fluid if increased tone and fetal distress

28. Protocol # 2 -250ml at 10-20ml/min, until AFI>8cm Repeat as necessary

29. COMPLICATION OF OLIGOHYDRAMNIOS • IUGR • Fetal distress • Operative deliveries • Congenital anomalies • Meconium aspiration

30. PROGNOSIS • The prognosis for both polyhydramnios & oligohydramnios depends on the cause. If excess or reduced AF is the result of an underlying fetal abnormality, the nature of that abnormality will determine the prognosis.

31. PREVENTION • In order to prevent polyhydramnio or oligohydramnio, it would be necessary to prevent the underlying cause. • Good control of maternal diabetes • The prevention of infection transmittable from mother to fetcs.

32. THANKS!!!!!!!