What should pregnant women do if they have too little amniotic fluid? Amnioinfusion accurately "replenishes water" to help the fetus grow healthily

Recently, the obstetrics department of Yiyang Central Hospital admitted a 33-week pregnant woman, Ms. Xu, who had too little amniotic fluid. After symptomatic supportive treatment such as fluid infusion, Ms. Xu's amniotic fluid index did not improve significantly. After repeated discussions, the obstetrics director Liu Jiandi suggested that the patient undergo amnioinfusion to supplement the amniotic fluid.

On January 9, Cao Wei, deputy director of the obstetrics and gynecology department, and Sun Liang, the attending physician, were fully informed of the conversation and related preparations. Under the guidance of B-ultrasound performed by Chen Feng, director of the Ultrasound Department, and Han Dong, deputy director, Cao Wei began to perform amnioinfusion on Ms. Xu.

Before the operation, Ms. Xu's amniotic fluid index was 30mm. After 400ml of warm saline was injected, the amniotic fluid index was re-measured to 98mm. Ms. Xu was in good general condition after the operation, with good fetal heart rate and fetal movement, no abdominal pain, abdominal distension, vaginal bleeding or discharge, and the fetal heart rate monitoring was reactive.

What is amnioinfusion?

Oligohydramnios is the main cause of adverse perinatal outcomes. Oligohydramnios causes excessive flexion and compression of the fetus, leading to musculoskeletal deformities; the lack of an "acoustic window" makes it difficult to diagnose fetal malformations by ultrasound; during labor, the uterus contracts, and the umbilical cord and placenta are directly compressed between the uterine wall and the fetus, affecting the blood and oxygen supply to the fetus, resulting in repeated variable decelerations, meconium-stained amniotic fluid, and fetal distress, which in turn increases the cesarean section rate and perinatal mortality rate.

When ultrasound indicates that the fetus has too little amniotic fluid (AFV < 3cm or AFI < 7cm) or no amniotic fluid, excluding related contraindications, amniocentesis can be performed under ultrasound guidance. After confirming that the puncture needle is in the amniotic cavity, amniocentesis is performed with a perfusion solution that has been preheated to 37°C (usually 0.9% sodium chloride solution or Ringer's solution). The total perfusion volume is generally 250-700ml, so that AFV reaches a normal level (5-7cm). Re-examination 5-7 days after surgery, if AFV < 3cm or AFI < 7cm, amniocentesis can be repeated.

The usual treatment method is intravenous infusion, but it often has little effect. The application of amnioinfusion technology has solved the above problems. By infusing fluid into the amniotic cavity, the amount of amniotic fluid is increased, the amount of amniotic fluid is normalized, the excessive flexion and pressure of the fetus are relieved, and the detection rate of fetal malformations by ultrasound is improved; at the same time, the protective effect of amniotic fluid on the fetus is restored, the intrauterine environment of the fetus is improved, the pressure on the umbilical cord is relieved, the incidence of abnormal fetal heart rate, cesarean section rate, and perinatal mortality rate are reduced, and the incidence of neonatal aspiration pneumonia is reduced.

For fetal malformation and oligohydramnios who require induced labor, transabdominal amnioinfusion and ethacridine lactate can be performed to assist in induced labor, which is beneficial to the diffusion of the induction drug in the amniotic cavity, while shortening the labor process and reducing the pain of the person being induced.

Hunan Medical Chat Special Author: Cao Wei from Yiyang Central Hospital

Follow @湖南医聊 to get more health science information!

(Edited by YT)