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Ultrasonic cross sectional fetal study correlated with fetal weight and skin fold thickness
178
Letters to the Editor
Ultrasonic cross sectional fetal study correlated with fetal weight and skin fold thickness To the Editor
April 15th, 1993
Most of the currently used sonographic techniques for estimating fetal weight involves measurements of head, abdomen and femur length. An objective study of thigh circumference, midarm circumference and liver size has been done in this study of 50 pregnant women for predicting I.U.G.R. This prospective study was done at Kasturba Hospital, Manipal, India. The patients studied were between 19 and 32 years old. Gestational age was estimated from good accordance between menstrual period and crown rump length or early B.P.D. before 14 weeks. The three ultrasound measurements done at 28, 32 and/after 36 weeks included standardized measurements, i.e. B.P.D., femur length, abdominal circumference and thigh circumference. The thigh circumference was measured according to the technique of Deter et al. The long axis of femur was first screened, and the transducer was then rotated 90” to obtain a cross-sectional profile of the middle of the thigh at a position so that the bone profile was as round as possible and the boundary of the thigh profile was well defined. The two maximum diameters were measured from outer to outer margin perpendicular to each other. Circumference was determined by the formula (Dl + D2) x 1.57. Delivery occurred within 2 weeks prior to or later than the predicted date of delivery either by spontaneous labor or cesarean section. Neonates were all beyond 36 weeks as per Dubowitz scoring. Skin fold thickness was measured within 48 h of birth with a Harpenden’s caliper. Skin fold thickness at biceps, quadriceps, flanks and subcapular regions were recorded. Measurements were evaluated based on the regression coefficient R and its statistical significance (P > 0.5) from zero, as determined using the t-test. The regression analysis of thigh circumference with abdominal circumference was highly significant P < 0.001. The correlation of thigh circumference and gestational age by Dubowitz scoring was statistically significant. The thigh skin fold thickness corKeywords: Estimated fetal weight; Ultrasonography cumference; Neonatal skin fold thickness. 0020-7293/93/$06.00 0 1993 International Federation Printed and Published in Ireland
of Gynecology
thigh cir-
and Obstetrics
related with thigh circumference measurements by ultrasound at 36 weeks of gestation. Measurements of thigh circumference provides a potentially straightforward method of assessing the deposition of muscle and fat in the growing fetus. The difference of 4% between the ultrasound and the anatomical measurements was found in a study done by Deter et al. and was comparable to its relationship to menstrual age [ 11.Thigh circumference appears to be linearly related to menstrual age in our study as well as studies done by Deter et al., Jeantry P et al. and Vintzileous et al. [l-4]. Our study demonstrated the sensitivity of 47% and specificity of 50% in detecting IUGR by thigh circumference. To conclude, thigh circumference, midarm circumference and liver size increase linearly as BPD, FL and AC and gestational age. The correlation is highly significant between them and abdominal circumference, showing that the cross sectional studies resemble each other. U.R. Rao K. Rao G. Selvan
Dept. of Obstetrics & Gynecology Kasturba Hospital Manipal 576119 India
References Deter RL, Warder A, Duncan G, Hadlock FP: Evaluation of foetal thigh circumference measurement - a comparative ultrasound and anatomical study. J Clin Ultrasound 14: 99, 1986. Deter RL, Warder A, Rossawik IK, Duncan G, Hadlock FP: Fetal thigh circumference - A Critical evaluation of its relationship to menstrual age. J Clinical Ultrasound 14: 105, 1986. Jeanty P, Romero A, Hobvbins JC: Fetal limb volume, A new parameter to assess fetal growth and nutrition. J UItrasound Medicine 4: 273, 1985. Vintzileous MA, Neckles S, Campbele WA, Andreoli WJ, Kaplan MG, Nochimson JD: Fetal liver ultrasound measurements during normal pregnancy Obstet. Gynaecol r%(4): 477, 1985. Correspondence to: U.R. Rao Dept. of Obst. & Gynaecology Kasturba Hospital Manipal 376119 India
Letters to the Editor
Ultrasonic cross sectional fetal study correlated with fetal weight and skin fold thickness To the Editor
April 15th, 1993
Most of the currently used sonographic techniques for estimating fetal weight involves measurements of head, abdomen and femur length. An objective study of thigh circumference, midarm circumference and liver size has been done in this study of 50 pregnant women for predicting I.U.G.R. This prospective study was done at Kasturba Hospital, Manipal, India. The patients studied were between 19 and 32 years old. Gestational age was estimated from good accordance between menstrual period and crown rump length or early B.P.D. before 14 weeks. The three ultrasound measurements done at 28, 32 and/after 36 weeks included standardized measurements, i.e. B.P.D., femur length, abdominal circumference and thigh circumference. The thigh circumference was measured according to the technique of Deter et al. The long axis of femur was first screened, and the transducer was then rotated 90” to obtain a cross-sectional profile of the middle of the thigh at a position so that the bone profile was as round as possible and the boundary of the thigh profile was well defined. The two maximum diameters were measured from outer to outer margin perpendicular to each other. Circumference was determined by the formula (Dl + D2) x 1.57. Delivery occurred within 2 weeks prior to or later than the predicted date of delivery either by spontaneous labor or cesarean section. Neonates were all beyond 36 weeks as per Dubowitz scoring. Skin fold thickness was measured within 48 h of birth with a Harpenden’s caliper. Skin fold thickness at biceps, quadriceps, flanks and subcapular regions were recorded. Measurements were evaluated based on the regression coefficient R and its statistical significance (P > 0.5) from zero, as determined using the t-test. The regression analysis of thigh circumference with abdominal circumference was highly significant P < 0.001. The correlation of thigh circumference and gestational age by Dubowitz scoring was statistically significant. The thigh skin fold thickness corKeywords: Estimated fetal weight; Ultrasonography cumference; Neonatal skin fold thickness. 0020-7293/93/$06.00 0 1993 International Federation Printed and Published in Ireland
of Gynecology
thigh cir-
and Obstetrics
related with thigh circumference measurements by ultrasound at 36 weeks of gestation. Measurements of thigh circumference provides a potentially straightforward method of assessing the deposition of muscle and fat in the growing fetus. The difference of 4% between the ultrasound and the anatomical measurements was found in a study done by Deter et al. and was comparable to its relationship to menstrual age [ 11.Thigh circumference appears to be linearly related to menstrual age in our study as well as studies done by Deter et al., Jeantry P et al. and Vintzileous et al. [l-4]. Our study demonstrated the sensitivity of 47% and specificity of 50% in detecting IUGR by thigh circumference. To conclude, thigh circumference, midarm circumference and liver size increase linearly as BPD, FL and AC and gestational age. The correlation is highly significant between them and abdominal circumference, showing that the cross sectional studies resemble each other. U.R. Rao K. Rao G. Selvan
Dept. of Obstetrics & Gynecology Kasturba Hospital Manipal 576119 India
References Deter RL, Warder A, Duncan G, Hadlock FP: Evaluation of foetal thigh circumference measurement - a comparative ultrasound and anatomical study. J Clin Ultrasound 14: 99, 1986. Deter RL, Warder A, Rossawik IK, Duncan G, Hadlock FP: Fetal thigh circumference - A Critical evaluation of its relationship to menstrual age. J Clinical Ultrasound 14: 105, 1986. Jeanty P, Romero A, Hobvbins JC: Fetal limb volume, A new parameter to assess fetal growth and nutrition. J UItrasound Medicine 4: 273, 1985. Vintzileous MA, Neckles S, Campbele WA, Andreoli WJ, Kaplan MG, Nochimson JD: Fetal liver ultrasound measurements during normal pregnancy Obstet. Gynaecol r%(4): 477, 1985. Correspondence to: U.R. Rao Dept. of Obst. & Gynaecology Kasturba Hospital Manipal 376119 India