Anat Cell Biol.  2019 Dec;52(4):478-485. 10.5115/acb.19.094.

Screening of the growth of thymus of human fetuses

• Asghar A
• Asad MR
• Naaz S
• Rani M

• KMID: 2466702
• DOI: http://doi.org/10.5115/acb.19.094

Abstract

The thymus is a lymphoepithelial organ, and its morphometry is commonly utilized for surveillance of the immunological status of fetus and neonates. Many studies showed that fetal thymus size is used as a prognostic indicator for pregnancy-related disorders such as eclampsia, preterm labor, and gestational diabetes. The study aims to establish reference ranges of the normal fetal thymus size between 12 and 40 weeks of gestational age (GA). The study was conducted on 89 fetuses. They were dissected to capture the morphometry of thymus: transverse diameter, perimeter, and weight. Considering these parameters were dependent variables of GA and gestational weight (GW). Their relationship was studied by a multiple regression model. The best fit models in predicting thymic dimensions as a function of GA and GW were determined using regression analysis. Mean transverse diameter, perimeter, and thymus weight was 33.45±2.91 mm, 125.72±55.4 mm, and 3.078±3.06 g, respectively. They were increased throughout pregnancy as GA and GW advanced. The regression equation for a transverse diameter of the thymus as a function of GA was (0.303×GA-4.885, R²=0.8196) and for the perimeter of the thymus was (1.0212×GA-15.24, R²=0.8666). Reference ranges and baseline data of the normal fetal thymic dimensions between 12 and 40 weeks of GA have been established.

Keyword

Gestational age; Perimeter; Transverse diameter; Thymus weight; Ultrasound

MeSH Terms

Diabetes, Gestational
Eclampsia
Female
Fetus*
Gestational Age
Humans*
Infant, Newborn
Mass Screening*
Obstetric Labor, Premature
Pregnancy
Reference Values
Thymus Gland*
Ultrasonography

Figure

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  Fig. 1 (A) Methodology for study of growth pattern of thymus. (B) Measurement of Transverse diameter in dissected thymus by Digital Vernier Caliper. (C) Measurement of perimeter and area by taking impression on graph paper.

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  Fig. 2 Multiple regression analysis of transverse diameter with gestational age and weight (A) and perimeter with gestational age and weight (B).

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  Fig. 3 Multiple regression analysis of thymus weight with gestational age and weight (A) and thymus weight with transverse diameter and perimeter of thymus (B).

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