Korean Circ J.  2009 Oct;39(10):414-417. 10.4070/kcj.2009.39.10.414.

Perinatal Changes in Size of the Fetal Great Arteries

• Kim HS
• Hong YM
• Sohn S
• Choi JY

• KMID: 2028921
• DOI: http://doi.org/10.4070/kcj.2009.39.10.414

Abstract

BACKGROUND AND OBJECTIVES
At birth, the fetal circulation must immediately adapt to extrauterine life. Our goal was to evaluate perinatal changes in the size of the aorta (Ao) and pulmonary artery (PA), and to investigate factors influencing these changes. SUBJECTS AND METHODS: Aortic and PA diameters were measured by echocardiography in 50 healthy term babies one day before and 4 to 5 days after birth. RESULTS: Compared with prenatal measurements, the Ao increased (from 7.4+/-0.6 mm to 8.4+/-0.6 mm, p<0.01) and the PA decreased (from 9.5+/-0.8 mm to 8.7+/-0.8 mm, p<0.01) in size after birth. The Ao/PA ratio increased from 0.78+/-0.07 before birth to 0.97+/-0.08 after birth (p<0.01), but there was no significant difference in the sum of the diameters of the great arteries between pre- and postnatal measurements. Postnatal increases in aortic size correlated negatively with prenatal aortic diameter (r=-0.37, p<0.05), but was not related to body weight. According to multiple regression analysis, significant variables for predicting perinatal changes in size of the Ao and PA were the prenatal Ao/PA ratio and the prenatal PA diameter, respectively. CONCLUSION: Despite a difference existing in prenatal diameters between Ao and PA, circulatory changes at birth make the great artery sizes equal, and do so regardless of body weight.

Keyword

Aorta; Pulmonary artery; Fetus; Echocardiography

MeSH Terms

Aorta
Arteries
Body Weight
Echocardiography
Fetus
Parturition
Pulmonary Artery

Figure

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  Fig. 1 Postnatally, the diameter of the aorta (Ao) increases and that of the pulmonary artery (PA) decreases compared with measurements before birth.

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  Fig. 2 The Ao/PA diameter ratio increases from 0.78±0.07 before birth to 0.97±0.08 after birth (p<0.01), but there is no significant difference in the sum of the Ao and PA diameters before and after birth. Ao: aorta, PA: pulmonary artery.

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  Fig. 3 The postnatal increase in the diameter of the aorta (Ao) is related to the prenatal aortic diameter (A) and is not related to body weight (B).

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  Fig. 4 Postnatal decreases in pulmonary artery (PA) diameter correlate positively with prenatal PA diameter (A) and negatively with body weight (B).

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  Fig. 5 Postnatal diameter of the aorta (Ao) correlates with the sum of prenatal Ao and pulmonary artery (PA) diameters.

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