The causes of oligohydramnios during pregnancy are usually due to the abnormal development of the villi of the aquatic membrane or a violation of their ability to produce a sufficient amount of amniotic fluid. In the latter case, the triggering factor for oligohydramnios can be the penetration of infection, metabolic diseases, congenital malformations of the fetus. Experts often associate the pathogenesis of oligohydramnios during pregnancy with the insufficient ability of the chorion to produce OPV, which can be provoked by various negative circumstances that affect the body of the expectant mother.
The most common cause of oligohydramnios during pregnancy is congenital malformations of the fetus. In most cases, the pathology is diagnosed after the 20th week of embryogenesis, combined with anomalies in the development of the kidneys and facial skull. Intrauterine infections that have penetrated to the fetal membranes from the genital organs of a woman are capable of causing oligohydramnios during pregnancy. Other viral and bacterial pathologies are also dangerous, in particular, influenza and SARS after conception. The pathogen circulating in the mother's blood freely penetrates through the veins of the umbilical cord to the chorion and provokes a violation of the production of OPV.
A fairly common cause of oligohydramnios during pregnancy is a violation of metabolic processes in the patient's body. That is why women with diabetes and obesity are at risk. In this case, oligohydramnios during pregnancy is observed already in the first trimester. This condition can also be provoked by concomitant diseases of internal organs - pathologies of the urinary tract, cardiovascular system, and kidneys. The risk of developing oligohydramnios during pregnancy increases with multiple pregnancies. In most cases, it is due to the increased need of babies for nutrients.
Oligohydramnios during pregnancy can also occur in the pathology of the placenta, in particular, if there is a violation of blood flow, uneven blood flow to its individual parts. The risk increases with abnormal attachment, in case of premature detachment of the placenta or its aging, with malformations of the placenta. The risk group for the occurrence of oligohydramnios during pregnancy includes women who are prone to the use of alcohol, nicotine, and psychotropic substances. The danger is present when working in hazardous industries. Therefore, in order to reduce the likelihood of the formation of oligohydramnios, the impact of these factors on the body should be avoided.