What is the normal amniotic fluid index in the second trimester?

Women need regular prenatal checkups after pregnancy. All body indicators are within the normal range so as not to affect the development and growth of the fetus. The importance of amniotic fluid to the fetus is undeniable. Before the fetus is separated from the mother, it lives in the amniotic fluid. Therefore, no matter how much or how little, there will be certain safety risks. So what is the normal amniotic fluid index in the second trimester?

Fourth month (16 weeks); At 16 weeks of pregnancy, the fetus's hair, eyes, eyelashes, and nails begin to grow, and the vocal cords and taste buds have grown. The fetus is now about 18 cm long and weighs 113 g. Ultrasound examination showed: biparietal diameter: 3.28 - 3.6 cm, humerus: 1.75 - 2.0 cm, femur: 2.03 - 2.23 cm, chest circumference: 8.43 cm, abdominal circumference: 9.40 cm, amniotic fluid index: 10.5 cm.

Fifth month (20 weeks): At 5 months of pregnancy, the fetal movement begins to become stronger, the fetus has grown hair, can suck its thumb, and the organs in various parts of the body gradually grow. At this time, the fetus is about 25 cm long and weighs 224-500 grams. Ultrasound results: biparietal diameter: 4.47 - 5.0 cm, humerus: 2.57 - 2.97 cm, femur: 3.01 - 3.47 cm, chest circumference: 11.71 - 12.7 cm, abdominal circumference: 13.41 - 15.2 cm, amniotic fluid index: 12.4 - 14.7 cm.

Sixth month (24 weeks); At 24 weeks of pregnancy, the fetus' eyes can open and close, and can hear sounds inside the mother's body. The fetus' body is 29-30 cm long and weighs 680-1000 grams. B-ultrasound suggests; biparietal diameter: 5.73 - 6.07 cm, humerus: 3.72 - 4.3 cm, femur: 4.2 - 4.75 cm, chest circumference: 14.9 - 16.4 cm, abdominal circumference: 16.84 - 17.5 cm, amniotic fluid index: 14.3 - 15.9 cm.

Seventh month (28 weeks): At 28 weeks of pregnancy, the fetus gains weight rapidly, about double the weight at 24 weeks. The skin is red and slightly wrinkled. The weight is about 1150g - 1800g and the body length is 35 - 42cm. B-ultrasound showed; biparietal diameter: 6.64 - 7.01 cm, humerus: 4.39 cm, femur: 5.27 cm, chest circumference: 17.37 cm, abdominal circumference: 19.35 cm, amniotic fluid index: 15.2 - 17 cm.

In the above article, taking the amniotic fluid indicators of four, five, six and seven months as an example, we have introduced in detail what is considered a normal amniotic fluid index in the second trimester. We hope that this will be helpful to pregnant women. Once any abnormality is found in the amniotic fluid during the prenatal check-up, we still need to find ways to properly deal with it and ensure the normal development of the fetus at all times.