Pregnancy - this is a very important period in the life of a woman.From pregnancy and delivery depends not only the health of the expectant mother, and child.Equally important during childbearing has qualitative and quantitative status of amniotic fluid or amniotic fluid.For their study used a variety of methods, including the method for determination of amniotic fluid index.To simplify the work of several of the doctor-diagnostician in ultrasound devices there are special programs for calculating the index of amniotic fluid and amniotic fluid standard table.It is for these data we can determine the pathology of amniotic fluid, such as oligohydramnios or polyhydramnios.
amniotic fluid or amniotic fluid is an aqueous medium in which the fetus develops.In the formation of amniotic fluid are many factors involved.These include: the urinary system of the fetus, amnion (water jacket or bag of waters), the skin of the fruit.
amount of amniotic fluid changes throughout pregnan
For example, a ten-term, its volume is equal to thirty milliliter of eighteen weeks, he has already reached four hundred milliliters, but by the end of pregnancy is one - one and a half liters.Functions of amniotic fluid are varied and numerous:
- amniotic fluid prevents the pressure from outside;
- amniotic fluid provide the optimum temperature for the life of the unborn child (about 37 degrees);
- creating an atmosphere of peace;
- amniotic fluid protects the fetus from infection;
- it in the amniotic fluid the fetus receives the full freedom of movement;
- amniotic fluid are involved in the formation of immunity Immunity - the types and characteristics of children in adult the child;
- amniotic fluid plays an important role in the generic process (cervix uteri).
Methods amniotic fluid
As noted above, there are methods of amniocentesis, for the calculation of their volumeand to explore the qualitative composition.These include:
- ultrasound waters and fruit;
- calculation of the index of amniotic fluid at special tables (to determine water scarcity or polyhydramnios);
- fetal cardiotocography (CTG);
- amnioscopy (inspection of water front, or membranes amnioscopy);
- amniocentesis (puncture of the amniotic sac and water sampling for analysis).
amniotic fluid index
amniotic fluid index is calculated to determine the amount of amniotic fluid.It can be defined as an objective way, and subjective.
- objective definition of AFI (amniotic fluid index)
diagnostician in the US by conducting a thorough scan of the uterus in transverse and longitudinal sections of notes the amount of amniotic fluid.For example, about polyhydramnios indicates an increased amount of water located between the anterior abdominal wall and the child.
- subjective definition AFI
In this case, also resorted to using ultrasound.The uterus is divided into four quadrants by lines perpendicular to each other (longitudinal line extends along the white line of the abdomen, and the transverse parallel navel).Each quadrant measured maximum upper pocket.The values of these pockets are formed, and the result is an index of amniotic fluid.
These tables amniotic fluid
data obtained by ultrasound compared with tables of amniotic fluid.Each unit has its own table of ultrasound.Example table:
first column of numbers represents the gestational age in weeks.The second and third are the lower and upper limit of normal AFI (in millimeters).
- 16: 73 - 201
- 17: 77 - 211
- 18: 80 - 220
- 19: 83 - 225
- 20: 86 - 230
- 21: 88 - 233
- 22: 89 - 235
- 23: 90 - 237
- 24: 90 - 238
- 25: 89 - 240
- 26: 89 - 242
- 27: 85 - 245
- 28: 86 - 249
- 29: 84 - 254
- 30: 82 - 258
- 31: 79 - 263
- 32: 77 - 269
- 33: 74 - 274
- 34: 72 - 278
- 35: 70 - 279
- 36: 68 - 279
- 37: 66 - 275
- 38: 65 - 269
- 39: 64 - 255
- 40: 63 - 240
- 41: 63 - 216
- 42: 63 - 192
For example, if within 24 weeksamniotic fluid index is 250 millimeters, this indicates polyhydramnios.And if the AFI in the same period is 156 millimeters - it says the normal amount of water.