Obstetrics and Gynecology - A.M. Gromova 2000

Modern methods of fetal condition assessment
Ultrasound examination

Ultrasound refers to elastic wave oscillations with frequencies exceeding 20 kHz. Ultrasonic waves have The ability to reflect off boundaries between media with contrasting acoustic properties.

It is generally considered that Ultrasound Examination during Pregnancy has no adverse effects on the fetus. In an uncomplicated pregnancy, ultrasound scans are performed three times: at 12–13 weeks, 15–17 weeks, and 22–24 weeks. Ultrasound screening enables Prenatal Diagnosis of fetal malformations, Central Nervous system pathologies (hydrocephaly, microcephaly, anencephaly, encephalocele, Spina bifida), cardiopulmonary abnormalities (Congenital Heart defects, chest cysts, pleural effusion), gastrointestinal tract disorders (ascites, diaphragmatic hernia, duodenal atresia, etc.), renal abnormalities (Polycystic Kidney Disease, Hydronephrosis-hydroureter, renal agenesis), and allows for fetometry (measuring the biparietal diameter, Femur length, abdominal and chest circumference). Furthermore, it records fetal heart rate and breathing movements, diagnoses multiple pregnancies and abnormal pregnancy development, determines the thickness, Location, and maturity grade of the Placenta, identifies Placenta Previa or abruption, and assesses the Amniotic Fluid volume. Ultrasound guidance is also used for invasive Procedures such as amniocentesis, chorionic villus sampling, cordocentesis, intrauterine transfusion, and cystic lesion drainage.

The Introduction of ultrasonic Diagnostics into obstetric practice, which enabled the measurement of Blood FLOW IN major fetal vessels, has made it possible to functionally assess Circulation in the placental villous tree (dopplerometry). These studies help predict The Development of fetal growth restriction. Additionally, ultrasound makes it possible to evaluate placental development (maturity grade), which plays a crucial role in fetal development.

According to Grannum's Classification, there are 4 grades of placental maturity: Grade 0 is characterized by a homogeneous tissue texture with a well-defined, smooth chorionic plate and a non-differentiated basal layer; Grade I features a wavy chorionic plate and small, scattered echogenic inclusions within the parenchyma; Grade II shows indentations of the chorionic plate that do not reach the basal layer, alongside echogenic inclusions; Grade III is defined by chorionic plate indentations extending down to the basal membrane, with dense echogenic inclusions in the parenchyma that occasionally cast acoustic shadows.

Under physiological conditions, each stage of pregnancy corresponds to a specific grade of placental maturity: Grade 0 is typical up to 30 weeks of gestation; Grade I spans from 31 to 36 weeks; Grade II ranges from 33 to 38 weeks; and Grade III corresponds to 37 to 42 weeks of pregnancy.

Any deviation from the physiological process of placental maturation is considered an indicator of chronic fetal compromise.