RESUMO
The cross sectional study was to determine the curve for umbilical cord cross section area with respect to fetal age in primi and multi gravida separately using sonography. Methods: 100 uneventful pregnancies of second and third trimester were studied. SPSS, v17, IBM, Chicago, were used for statistical analysis and polynomial regression equations were calculated. Results: The regression equation of umbilical cord cross section area to Gestational Age: y = -3.143 + 0.286 x – 0.004 x2 ,(R2 0.512, p value <0.001) in primigravida . For multigravida cord cross section area to Gestational Age : )y= -1.992 + 0.192 x – 0.002 x2 , (R2 0.563, p value <0.001), where x is fetal age in weeks, y is cord cross section area in cm2 . Conclusion: The cord cross section area increased significantly with fetal age upto 32 weeks, thereafter a plateau was seen in primigravida. No plateau was observed in multigravida.