Amnioscopy and amniocentesis

To examine the condition of the amniotic fluid, amnioscopy is used, which was described by Saling in 1962. Amnioscopy is a method for detecting meconium in the amniotic fluid by visually examining the lower pole of the amniotic sac.

An endoscope equipped with a conical obturator is inserted into the cervical canal to the lower pole of the fetal bladder. After removing the obturator, a light source is attached and the waters are examined through the amniotic membranes, determining the amount of anterior waters and the admixture of meconium. A special lighting device has been developed for endoscopic examinations in obstetric practice. The developed device allows for greater and uniform illumination, effective absorption of thermal rays and greater light output. When using the device, abundant anterior waters are visible, easily displacing, light or slightly opalescent. Small areas of cheesy grease are visible and the waters are usually milky white. With a large amount of anterior waters, they have a bluish tint. Some authors distinguish the color of the waters as "turbid" in fetal hypoxia.

[ 1 ], [ 2 ], [ 3 ], [ 4 ], [ 5 ], [ 6 ]

Amniotic fluid analysis during pregnancy

Amniotic fluid analysis during pregnancy or amniocentesis is performed to study the chromosome set of the future child in detail. If, as a result of previous analyses, there is a suspicion of a formed chromosomal pathology in the fetus. This analysis is not mandatory, the woman has the right to decide for herself whether to conduct it or not.

The analysis should be carried out at 15-20 weeks of pregnancy, the safest period is 16-17 weeks. Under ultrasound control, a puncture is carefully made and a small amount of amniotic fluid is collected. After that, the obtained sample is kept in a nutrient solution for several days and studied. The final result can be obtained after 21 days.

Complications from amniocentesis are extremely rare, but there are risks you should be aware of:

• In 0.5-1% of cases, labor may begin after the analysis.
• Despite the fact that the procedure is carried out under aseptic conditions, the possibility of inflammation exists.
• If a woman has a negative Rh factor and the fetus is positive, then vaccination is carried out to prevent the production of antibodies in the mother’s body.

Amniocentesis is a method by which amniotic fluid is aspirated from the amniotic cavity. Amniocentesis can expand the diagnostic capabilities of the fetus. Based on the study of amniotic fluid and the cells it contains, it is possible to determine the genetic risk and prevent the birth of a sick child.

Currently, more than 2,500 nosological forms of genetically determined diseases are known. Prenatal diagnostics are justified and advisable in the following cases:

• there is a possibility of having a child with a severe hereditary disease, the treatment of which is impossible or ineffective;
• the risk of having a sick child is higher than the risk of complications after using prenatal diagnostic methods;
• There is an accurate test for prenatal diagnosis, and there is a laboratory equipped with the necessary equipment.

[ 7 ], [ 8 ], [ 9 ], [ 10 ], [ 11 ]

Indications for amniocentesis

The main indications for prenatal diagnostics are:

• the presence of structural rearrangement of chromosomes, especially translocations and inversions in one of the parents;
• the woman is over 40 years old (and according to some researchers, over 35 years old);
• heterozygous state in both parents for autosomal recessive diseases or only in the mother for X-linked defects;
• the presence of a disease with an autosomal dominant type of inheritance in parents;
• the previous birth of a child with congenital defects.

Technique of amniocentesis

During transabdominal amniocentesis, the placenta, umbilical cord, and fetus can be easily damaged. After careful asepsis and determining the location of the placenta and fetus, the amniocentesis site is selected and, under local anesthesia (0.25% novocaine solution), after emptying the bladder, amniocentesis is performed 4 cm below the navel and 2 cm to the right or left (suprapubic access). Transvaginal amniocentesis can also be used both before and after 20 weeks of pregnancy.