Which fetal anomaly is associated with oligohydramnios

Fig 1 — Amniotic fluid centiles during pregnancy. Polyhydramnios is over the 95th centile, oligohydramnios is below the 5th centile. The volume of amniotic fluid increases steadily until 33 weeks of gestation. It plateaus from weeks, and then declines — with the volume of amniotic fluid at term approximately ml.

It is predominantly comprised of the fetal urine output , with small contributions from the placenta and some fetal secretions e. The fetus breathes and swallows the amniotic fluid. It gets processed, fills the bladder and is voided, and the cycle repeats.

Problems with any of the structures in this pathway can lead to either too much or too little fluid. Anything that reduces the production of urine, blocks output from the fetus, or a rupture of the membranes allowing amniotic fluid to leak can lead to oligohydramnios. The diagnosis of oligohydramnios is made via ultrasound examination. They have similar diagnostic accuracy, however AFI is more commonly used. Oligohydramnios is a diagnosis made via ultrasound examination.

Therefore, the clinical assessment of the patient is directed at establishing any underlying cause:. When considering ruptured membranes as a cause for oligohydramnios, a bedside test can be performed to detect the presence of IGFBP-1 insulin-like growth factor binding protein-1 in the vagina.

This protein is found in amniotic fluid, and if detected, is strongly suggestive of membrane rupture. The test is particularly useful if the diagnosis is unclear. Fig 2 — Ultrasound image of normal fetal kidney. In cases of oligohydramnios, the kidneys should be assessed. The management of oligohydramnios is largely dependent on the underlying cause. The two most common causes are rupture of the membranes and placental insufficiency.

If oligohydramnios is due to ruptured membranes, labour is likely to commence within hours in most pregnancies. In cases of preterm rupture of membranes i. A course of steroids should be given to aid fetal lung development, and antibiotics to reduce the risk of ascending infection. In women where oligohydramnios is caused by placental insufficiency , the timing of delivery depends on a number of factors:. Oligohydramnios in the second trimester carries a poor prognosis. In the majority of these cases, there is premature rupture of membranes which may or may not be associated with infection , with subsequent premature delivery and pulmonary hypoplasia — which can cause significant respiratory distress at birth.

When oligohydramnios is associated with placental insufficiency , there is also a higher rate of preterm deliveries usually through planned induction of labour. These cases will carry a poorer prognosis than that of a normally grown fetus. Amniotic fluid also allows the fetus move its limbs in utero exercise. Without this, the fetus can develop severe muscle contractures — which may lead to disability despite physiotherapy after birth. It plateaus from weeks, and then declines - with the volume of amniotic fluid at term approximately ml.

In uteroplacental insufficiency assessment of fetal growth and Doppler in the umbilical artery, ductus venosus and middle cerebral artery will help decide the best time for delivery. Delivery: Fetal urinary tract abnormalities: standard obstetric care and delivery. Rupture of the membranes: expectant management and vaginal delivery if cephalic presentation.

Uteroplacental insufficiency: cesarean section or vaginal delivery depending on gestational age, fetal size and degree of fetal compromise as defined by Doppler and or cardiotocography.

Too much amniotic fluid can cause the mother's uterus to become overdistended and may lead to preterm labor or premature rupture of membranes the amniotic sac. Hydramnios is also associated with birth defects in the fetus. When the amniotic sac ruptures, large amounts of fluid leaving the uterus may increase the risk of placental abruption early detachment of the placenta or umbilical cord prolapse when the cord falls down through the cervical opening where it may be compressed.

The following are the most common symptoms of hydramnios. However, each woman may experience symptoms differently. Symptoms may include:. The symptoms of hydramnios may resemble other medical conditions. Always consult your doctor for a diagnosis. In addition to a complete medical history and a physical examination, hydramnios is usually diagnosed with ultrasound a test using sound waves to create a picture of internal structures by measuring pockets of fluid to estimate the total volume.

In some cases, ultrasound is also helpful in finding a cause of hydramnios, such as multiple pregnancy or a birth defect. Amnioreduction--amniocentesis inserting a needle through the uterus and into the amniotic sac to remove some of the amniotic fluid; this procedure may need to be repeated. Delivery if complications endanger the well-being of the fetus or mother, then an early delivery may be necessary.

Oligohydramnios is a condition in which there is too little amniotic fluid around the fetus. It occurs in about 4 percent of all pregnancies. There are several causes of oligohydramnios. Generally, it is caused by conditions that prevent or reduce amniotic fluid production.

Factors that are associated with oligohydramnios include the following:. Amniotic fluid is important in the development of fetal organs, especially the lungs.