What Is Oligohydramnios?
Oligohydramnios refers to the amniotic fluid volume less than required for gestational age. It is typically diagnosed by ultrasound testing and may be described qualitatively. Example: amniotic fluid index ≤5cm, particular deepest pocket ≤2cm.
Oligohydramnios may be idiopathic or have a maternal, fetal, or placental reason. The fetal prognosis depends on different factors, including the underlying causes, the severity, and the gestational age at which oligohydramnios happens. Because enough volume of amniotic fluid is critical to regular fetal movement and lung development and for cushioning the fetus and umbilical cord from the uterine compression, pregnancies hampered by the oligohydramnios from any cause are at chance for fetal deformation, pulmonary hypoplasia, and umbilical cord compression.
Oligohydramnios is correlated with an increased risk for fetal or neonatal death, which may be linked to the underlying cause of the reduced amniotic fluid volume or sequelae of the reduced amniotic fluid volume.
What Causes Oligohydramnios?
Oligohydramnios can happen any time during pregnancy but are most generally diagnosed in the third trimester. Oligohydramnios is typically generated by the following:
Placental issues
If the placenta is not giving enough nutrients for the baby, then the baby may stop recycling fluid, hence lowering the amniotic fluid.
Birth defects
Certain birth injuries cause problems in the fetal urinary tract and kidneys, leading to inadequate urine production.
Premature rupture of membrane PROM:
When the water breaks before labor starts.
Leaking of amniotic fluid
A tear in the membrane can begin a gush or a trickle of amniotic fluid to leak.
Post-date pregnancy
A pregnancy that runs past 42 weeks is at risk of oligohydramnios because the amniotic fluid can be reduced by half after this time. moreover, in one study of 3050 uncomplicated pregnancies with singleton fetuses that 11% of them showed oligohydramnios.
Maternal problems
Maternal conditions, such as diabetes dehydration, hypertension, and preeclampsia have an impact on amniotic fluid levels.
Diagnosis
Oligohydramnios is an investigation made via ultrasound examination. Therefore, the clinical assessment of the patient is focused on establishing any underlying condition:
- History: Ask about symptoms of leaking fluid and feeling wet all the time.
- Examination: Mark the symphysis fundal height. Conduct a speculum examination.
- Ultrasound: Evaluate for liquor volume, structural abnormalities, renal agenesis, and obstructive uropathy. Mark the size of the fetal. Small babies can result from placental insufficiency, which also induces oligohydramnios. There may also be an increase in the pulsatility index of the umbilical artery doppler in placental insufficiency.
- Karyotyping: Especially in cases of early and unexplained oligohydramnios.
When recognizing rupture of the membrane as a cause for oligohydramnios, a bedside test can be conducted to detect the presence of IGFBP-1 in the vagina. This protein is found in the amniotic fluid, and if recognized, is strongly suggestive of membrane rupture. The test is particularly helpful if the investigation is unclear.
Managing Oligohydramnios Throughout Pregnancy
There is no long-term approach for oligohydramnios. However, a few things can temporarily rise amniotic fluid levels:
Oral Intake Of Fluids
Some medical experts may advise women to stay hydrated if they have oligohydramnios. Oral hydration is most modest, but in some cases, intravenous hydration may be required.
Installation Of Saline Solution Into The Amniotic Sac During Labor
During amnioinfusion, doctors use an intraamniotic catheter to join more liquid to the amniotic fluid. This may assist pad the umbilical cord, reducing the uncertainties of umbilical cord compression, which could cut off oxygen movement to the baby.
Investigational Therapies
Certain investigational therapies are applied to increase amniotic fluid, including tissue sealants, a sequence of hydration and DDAVP, and other methods.
It is significant to note, however, that the above techniques, if strong is temporary. They do not operate the underlying cause of the oligohydramnios. In many cases, the situation can indicate issues with uteroplacental circulation. In a situation where the baby’s passage may be compromised, the baby may need to be delivered in series to receive medical treatment.
Prognosis
Oligohydramnios in the second trimester brings a poor prognosis. In the majority of these events, there is premature rupture of membranes, following premature delivery and pulmonary hypoplasia which can produce significant respiratory distress at birth. When oligohydramnios is connected with placental insufficiency, there is likewise a higher rate of preterm delivery. These cases will carry a poorer prediction than that of a normally grown fetus. Amniotic fluid also enables the fetus to move its limbs in utero. Without this, the fetus can produce severe muscle contractures which may begin to disability physiotherapy after birth.
