Cailey What causes low amniotic fluid in pregnant women?
There are many possible reasons for low amniotic fluid, such as fetus malformations, fetal urinary system disease , as well as decreased placental function and other conditions, will cause less amniotic fluid. Another reason for low amniotic fluid is delayed fetal development. Therefore, we must first find out what causes low amniotic fluid in pregnant women and observe whether the fetal development is normal. Generally, the causes of low amniotic fluid in pregnant women are as follows:
What is the reason for low amniotic fluid in pregnant women 1: Fetal malformation
For example, fetal congenital renal absence, renal hypoplasia, ureteral or urethral stricture and other malformations lead to oliguria or anuria, causing oligohydramnios.
What are the reasons for low amniotic fluid in pregnant women 2: expired pregnancy
In postterm pregnancy, the placental function decreases, the perfusion is insufficient, and the fetus becomes dehydrated, resulting in low amniotic fluid. Some scholars also believe that in postterm pregnancy, the fetus is overly mature and its renal tubules are more sensitive to antidiuretic hormone, resulting in low urine output leading to oligohydramnios. The incidence of oligohydramnios caused by post-term pregnancy is 20% to 30%.
What is the reason for low amniotic fluid in pregnant women 3: Intrauterine growth retardation (IUGR)
Oligohydramnios is one of the characteristics of intrauterine growth retardation. Chronic hypoxia causes fetal blood circulation to be redistributed, mainly supplying the brain and heart, while renal blood flow decreases and fetal urine production decreases, leading to oligohydramnios.
What is the reason for low amniotic fluid in pregnant women 4: amniotic membrane disease
Electron microscopic observation found that the amniotic epithelial layer became thinner during oligohydramnios, epithelial cells atrophied, microvilli were short and thick, with swollen tips and a small number. There was squamous epithelial metaplasia. The rough inner meshwork and Golgi complex in the cells were also reduced, and the desmosomes and hemidesmosomes between the epithelial cells and the basement membrane were reduced. It is believed that some unexplained oligohydramnios may be related to lesions of the amniotic membrane itself.
