Disorders of the amniotic fluid

3. Disorders of the amniotic fluid

4. Normal amniotic fluid increases in amount throughout pregnancy • - at 38 weeks- 1 L. • -it diminishes to approximately 800 mL at term. • Amniotic fluid is not static. • - the water of which it is largely composed changes every hour and the solutes change about every 3 hrs

5. *There are two chief abnormalities of amniotic fluid: • -hydramnios (or polyhydramnios) • -oligohydramnios

6. Hydramnios: • -The amount of liquor around the fetus is called (the amniotic fluid volume (AFV). • -could be known by ultrasound scanning. • -measuring the liquor in each of four quadrants around the fetus named an amniotic fluid index (AFI). • Hydramnios is said to be excessive amount of amniotic fluid ,AFI is above the 95th centile for gestational age

7. Causes and predisposing factor: • in many cases the cause is unknown. • • esophageal atresia • • open neural tube defect • • multiple pregnancy, monozygotic twins(identical twin) • • maternal diabetes mellitus • • rarely, with Rhesus isoimmunization • • chorioangioma, tumour of the placenta • • an encephalic fetus.

8. Types • 1-Chronic hydramnios • It is the most common type. • gradual in onset • usually starting from about the 30th week of pregnancy.

9. 2-Acute hydramnios • This is very rare. • It usually occurs at about 20 weeks • comes suddenly. • The uterus reaches the xiphisternum in about 3 or 4 days. • It is frequently associated with monozygotic twins or severe fetal abnormality.

10. Clinical presentation : • breathlessness and discomfort. • have severe abdominal pain (acute form ). • exacerbation of symptoms associated with pregnancy such as indigestion, heartburn and constipation. • Edema • varicosities of the vulva and lower limbs

11. Abdominal examination • On inspection: • the uterus is larger than expected for the period of gestation • globular in shape. • The abdominal skin appears stretched and shiny • marked striae gravidarum • clear appearance of superficial blood vessels.

12. On palpation: • the uterus tense . • it is difficult to feel the fetal parts • the fetus may be balloted between the two hands. • A fluid thrill may be elicited by placing a hand on one side of the abdomen and tapping the other side with the fingers

13. A wave of fluid will move across from the side that is tapped and this is felt by the opposite examining hand. • It may be helpful to measure the abdominal girth ,particularly in cases of acute hydramnios, in order to observe the rate of increase. • Auscultation of the fetal heart can be difficult . • Ultrasonic scanning is used to

14. 1- confirm the diagnosis of hydramnios • 2 – calculate the DP, AFV and AFI, and therefore the severity of the hydramnios • 3-may reveal a multiple pregnancy or fetal abnormality. • X-ray examination is not often performed.

15. .Complications • • maternal ureteric obstruction • • increased fetal mobility leading to unstable lie and malpresentation • • cord presentation and prolapse • • pre-labour (and often preterm) rupture of the membranes • • placental abruption when the membranes rupture • • pre-term labour • • a higher incidence of pre-eclampsia • • increased incidence of caesarean section • • postpartum haemorrhage • • raised perinatal mortality rate.

16. Management • The aim of managing this condition is: • to relieve maternal symptoms • prolonging of pregnancy it if safe. • Management :depond on • - the condition of the woman and fetus • -the cause of hydromnous • -degree of the hydramnios • -the stage of pregnancy

17. 1-The woman may be admitted to a consultant obstetric unit. • 2-The cause of the condition should be determined • 3-fetal karyotyping may be indicated. • 4-Diabetes mellitus will be managed • . N.B: The presence of fetal abnormality will be taken into consideration in choosing the mode and timing of birth. • If gross abnormality is present, labour may be induced. • if the fetus is suffering from an operable condition such as esophageal atresia, transfer will be arranged to a neonatal surgical unit

18. Mild case of hydromnious: • . She should be encouraged to get adequate rest • -if she is working it may be helpful to discuss maternity leave • - assess nature of her job and the stress • -if the hydramnios is found to be idiopathic, in mild asymptomatic cases, she can be reassured that fetal outcome is likely to be good. • -Regular ultrasound scans will reveal whether or not the hydramnios is progressive. • - Many cases of idiopathic hydramnios resolve spontaneously as pregnancy progresses.

19. Management For a woman with symptomatic hydramnios,: • - an upright position will help to relieve any dyspnoea • -she may be given antacids to relieve heartburn and nausea. • -If the discomfort from the swollen abdomen is severe, therapeutic amniocentesis, or amnioreduction, may be considered.

20. Risk of this procedure : • infection may be introduced • the onset of labour initiated • a temporary relief . • accumulate fluid again • the procedure may need to be repeated.

21. Acute hydramnios managed by : • amnioreduction • a poor prognosis for the baby. • the fluid continues to increase at an alarming rate • the membranes rupture spontaneously • and the fetus or fetuses are born • grossly premature, in a river of amniotic fluid.

22. Administration of drugs such as indomethacin and sulindac reduce fetal urine production • -IOL in late pregnancy if the symptoms become worse. • - The lie must be corrected if it is not longitudinal • -the membranes will be ruptured cautiously, allowing the amniotic fluid to drain out slowly in order to • * avoid altering the lie • *to prevent cord prolapse. • * to avoid Placental abruption

23. -Labour is usually normal • -the midwife should be prepared for the possibility of postpartum haemorrhage. • -The baby should be carefully examined for abnormalities • -Check for the patency of the esophagus by passing a nasogastric tube.

24. Oligohydramnios: • -definition : is an abnormally small amount of amniotic fluid At term, it may be 300–500 mL or less.

25. Causes of oligohydromnious in the first half of pregnancy: • -renal agenesis (absence of kidneys) • - Potter's syndrome in which the baby also has pulmonary hypoplasia.

26. pregnancy before 37 weeks: • -fetal abnormality • - pre-term pre-labour rupture of the membranes • -the amniotic fluid fails to re-accumulate. • - The lack of amniotic fluid reduces the intrauterine space and over time will cause compression deformities.

27. characteristics of the baby • has a squashed-looking face, • flattening of the nose • micrognathia • a deformity of the jaw • talipes of the feet. • The skin is dry • leathery in appearance

28. -Oligohydramnios sometimes occurs in the post-term pregnancy has been linked to the development of placental insufficiency. • As placental function reduces, blood perfusion to the fetal organ systems including the kidneys also decrease . decrease fetal urine formation leads to oligohydramnios, as the major component of amniotic fluid is fetal urine.

29. Recognition • Abdominal examination : • the uterus appear smaller than expected for the period of gestation. • a reduction in fetal movements. • When the abdomen is palpated the uterus is small and compact and fetal parts are easily felt. • Breech presentation is possible. • Auscultation is normal.

30. -Ultrasonic scanning will enable differentiation of oligohydramnios from intrauterine growth restriction (although both may occur together where there is placental insufficiency). • -Renal abnormality may be visible on the scan. • - measurement of amniotic fluid and the AFI below the 5th centile

31. Management • -The woman may be admitted to hospital. • -If the ultrasound scan demonstrates renal agenesis the baby will not survive. • -if renal agenesis is not present then further investigations for the woman to check the possibility of pre-term rupture of the membranes. • - Placental function tests will also be performed. • When the cause of the oligohydramnios is not known

32. prophylactic amnioinfusion with normal saline, Ringer's lactate or 5% glucose may be performed in order to : • 1-prevent compression deformities • 2-avoid hypo plastic lung disease • 3- prolong the pregnancy.

33. Benefit of this procedure : • -resulted in lower caesarean section rates • -improved neonatal outcome for normal babies

34. Follow up(full term ) fetal surveillance bycardiotocography(CTG) amniotic fluid measurement by ultrasoundDoppler assessment of fetal and uteroplacental arteries maternal counting, recording and reporting of fetal movement was not effective in reducing stillbirths

35. -At any stage of pregnancy labour may intervene by IOL. • - Epidural analgesia may be indicated because uterine contractions are often unusually painful with this condition. • - Impairment of placental circulation or cord compression may result in fetal hypoxia and therefore continuous fetal heart rate monitoring is desirable

36. -At any stage of pregnancy labour may intervene by IOL. • - Epidural analgesia may be indicated because uterine contractions are often unusually painful with this condition. • - Impairment of placental circulation or cord compression may result in fetal hypoxia and therefore continuous fetal heart rate monitoring is desirable

37. - In rare cases the membranes may adhere to the fetus. • - if meconium is passed in utero it will be more concentrated and represent a greater danger to an asphyxiated baby during birth.

38. Thankyou