The reason why amniotic fluid cannot be replenished

As the pregnancy time gradually increases, the amniotic fluid in the uterus will gradually increase. The amount of amniotic fluid directly affects whether the baby can develop well. The quality of the amniotic fluid is also very important. Sometimes the amniotic fluid cannot be replenished. There are many reasons for this situation, such as placental abnormalities, some medical problems of the pregnant woman herself, etc. Let's take a look at this aspect.

1. Reasons why amniotic fluid cannot be replenished

1. Fetal malformation

For example, congenital renal agenesis, renal dysplasia, ureteral or urethral stenosis and other malformations in the fetus may lead to oliguria or anuria and cause oligohydramnios.

2. Post-term pregnancy

In post-term pregnancy, the placenta functions poorly, perfusion is insufficient, and the fetus becomes dehydrated, resulting in low amniotic fluid. Some scholars also believe that in overdue pregnancy, the fetus is overmature, its renal tubules are more sensitive to antidiuretic hormone, and the low urine volume leads to oligohydramnios. The incidence of oligohydramnios caused by post-term pregnancy is as high as 20% to 30%.

3. Intrauterine growth retardation

Oligohydramnios is one of the characteristics of intrauterine growth retardation. Chronic hypoxia causes redistribution of fetal blood circulation, mainly supplying the brain and heart, while renal blood flow decreases and fetal urine production decreases, resulting in oligohydramnios.

4. Amniotic membrane lesions

Electron microscopic observations found that the amniotic epithelial layer becomes thinner when the amniotic fluid is too low, the epithelial cells atrophy, the microvilli are short and thick, the tips are swollen, the number is small, there is squamous metaplasia, the rough inner reticular and Golgi complex in the cells are also reduced, and the desmosomes and hemidesmosomes between the epithelial cells and the basement membrane are reduced. It is believed that some unexplained oligohydramnios may be related to lesions of the amniotic membrane itself.

2. Treatment principles for oligohydramnios in pregnant women

1. In the early or middle stages of pregnancy, if too little amniotic fluid is found, it is advisable to terminate the pregnancy from the perspective of eugenics.

2. During the 28th to 35th week of pregnancy, if too little amniotic fluid is found but B-ultrasound does not reveal any obvious fetal malformations, treatment is given to improve placental circulation and intra-amniotic fluid infusion to increase the amount of amniotic fluid in the uterus.

3. If oligohydramnios is found in pregnancy of more than 35 weeks, and the amount of amniotic fluid does not increase after treatment, the pregnancy should be terminated after excluding fetal malformation. The delivery process should be closely observed. If intrauterine distress occurs, oxygen should be given. If vaginal delivery cannot be completed in a short period of time, cesarean section should be performed to end the delivery.

This article introduces in detail the specific causes of oligohydramnios and the treatment principles that should be adopted for oligohydramnios. If you are a pregnant woman who finds that you have too little amniotic fluid, then you'd better carefully refer to the contents of this article to find out the cause of your low amniotic fluid so that you can prescribe the right medicine for treatment.