In 2019, the number of children exposed to intrauterine hyperglycemia reached 20.4 million according to the IDF atlas. The main manifestation of the effect of maternal glucose on the fetus is a complex of pathological changes — diabetic fetopathy (DF). Fetus ultrasound examination (U/S) is one of the main tools for diagnosing DF. Early and timely ultrasound diagnosis of DF improves perinatal outcomes and is possible as early as 21 weeks of gestation. The lack of a single ultrasound regulation for patients with GDM and uniform ultrasound fetal-metric percentile scales leads to late diagnosis of DF and late insulin therapy prescription.
OBJECTIVE
To compare the effectiveness of various ultrasound fetal-metric percentile scales for early detection of fetal macrosomia as the initial sign of DF in patients with GDM.
MATERIAL AND METHODS
The study included 70 pregnant women with newly diagnosed hyperglycemia (not meeting the criteria for manifest diabetes mellitus (MDM)). Group I — 24 pregnant women with hyperglycemia detected before 24 weeks. Group II — 46 pregnant women with hyperglycemia diagnosed during the period from 24 to 28 weeks. Across pregnancy dynamic ultrasound examinations were performed; once every 3 weeks according to the standard method recommended by the ISUOG. The weight and height parameters of all children were analyzed using the intergrowth-21 project newborn calculator, and 22 fetuses were identified whose birth weight exceeded 90 percentiles. Fetal-metric parameters of dynamic ultrasound examination were analyzed according to 4 normative percentile scales: Hadlock, Medvedev M.V.et al., project INTERGROWTH-21, internal normative scale of Moscow Regional Research Institute of Obstetrics and Gynecology. For a subgroup of fetuses with macrosomia (n=22) the number of times each of the scales reached the 75th percentile first was calculated.
RESULTS
We compared 4 percentile scales: 1. F. Hadlock et al, 2. The INTERGROWTH-21 project, 3. M.V. Medvedev et E.V. Yudina, 4. Internal standards of the Moscow Regional Research Institute of Obstetrics and Gynecology (L.M. Titchenko, M.A. Belousov) When comparing pairs, there are trends towards a statistical difference between the INTERGROWTH-21 scale and the Hadlock scale (p=0.036) as well as a difference between the INTERGROWTH-21 scale and Medvedev et al. (p=0.061). Thus, according to our study, the INTERGROWTH-21 scale has the highest sensitivity (91%) in determining fetal macrosomia but it has the lowest specificity of 50%. To predict the formation of fetal macrosomia the gestational age at which the fetal abdominal circumference exceeded the 75th percentile was not statistically significant.
CONCLUSION
The percentile assessment of fetuses in patients with hyperglycemia newly diagnosed in pregnancy according to the percentile scale of the INTERGROWTH-21 project allows earlier than other scales to form a risk group for fetal macrosomia that can contribute to the early diagnosis of DF and the timely insulin therapy prescription regardless of the type of maternal hyperglycemia.
