The diagnosis of oligohydramnios is made on the basis of monitoring the dynamics of the course of pregnancy and additional research methods:
Physical examination.
• There is a discrepancy between the size of the abdomen (circumference of the abdomen and the height of the fundus of the uterus) to the gestational age. With this pathology of amniotic fluid, the dimensions are much smaller than the accepted norms.
• A woman notes a decrease in the number of fetal movements, and in some cases, pain may also occur when the child moves.
• The fetal heartbeat is heard clearly, and parts of the fetus are well palpable due to the small amount of water. During childbirth, a flat fetal bladder is palpated.
Ultrasonography.
• Often, oligohydramnios is detected on ultrasound as an accidental finding.
• When determining the index of amniotic fluid and the height of the largest pocket of amniotic fluid, oligohydramnios is indicated by a decrease in its size to 1 cm or less. However, ultrasound to confirm oligohydramnios must be performed several times in a row for 1-3 months.
Lab tests.
• If a decrease in the amount of amniotic fluid is suspected, a woman is prescribed an examination for intrauterine infections (PCR): toxoplasmosis, cytomegalovirus, rubella, and others.
• Also shown is the determination of blood glucose levels, the level of markers of intrauterine fetal malformations (AFP and hCG), blood per group and Rh factor.
• According to indications (suspicion of chromosomal abnormalities), amniocentesis with karyotyping of fetal cells is prescribed.
Cardiotocography (CTG) and dopplerometry.
• Assess the condition of the fetus helps cardiotocography (assessment of heart contractions) and dopplerometry (assessment of blood flow in the fetus-umbilical cord-placenta system).