Oligohydramnios (oligohydramnios) is the pathology of amniotic fluid, when during a full-term pregnancy there is a decrease in their number to 500 ml or less. According to various data, such a pathology occurs in 0.3-5.5 cases of all births.
Causes
The reasons leading to a decrease in the volume of amniotic fluid are divided into several large groups:
Caused by congenital anomalies in the development of the fetus.
• These include various malformations of the urinary system of the fetus (absence or sharp narrowing of the urethra, narrowing of the ureters, absence of kidneys, polycystic kidney disease, underdeveloped valves of the urethra).
Caused by fetal pathology.
• intrauterine infection of the fetus (cytomegalovirus, chlamydia, mycoplasma and other infections),
• oligohydramnios can also be caused by intrauterine growth retardation (IUGR) or chromosomal abnormalities (Down syndrome, Marfan syndrome).
Causes due to chronic extragenital diseases of a woman.
• pathology of the cardiovascular system (arterial hypertension, thrombophlebitis, cardiovascular insufficiency),
• chronic kidney disease (pyelonephritis, glomerulonephritis),
• preeclampsia and systemic diseases (systemic lupus erythematosus, rheumatoid arthritis and rheumatism, and others).
Excess weight and diabetes can also provoke the development of oligohydramnios. Dehydration (dehydration of the body) of a woman with diarrhea, vomiting, poisoning. Chronic nicotine intoxication.
Causes due to the pathology of the placenta.
• fetoplacental insufficiency,
• numerous infarcts of the placenta,
• malformations of the placenta,
• premature maturation of the placenta.
Other reasons.
• intrauterine fetal death,
• delayed pregnancy,
• multiple pregnancy,
• leakage of amniotic fluid.
Oligohydramnios due to long-term use of certain drugs (prostaglandin synthesis inhibitors: indomethacin, naproxen). Also isolated idiopathic or oligohydramnios with an unidentified cause.