Background: Mathematical modeling and establishing the relationship between gestational age and biometric parameter is an important method of studying biological growth pattern of foetuses. The alterations seen in growth mechanism are the basis of further investigation for foetal growth aberrations.

Materials and Methods: In a hypothetical setting, we have studied Bipariteal Diameter (BPD) at various gestational ages from 12 to 40 weeks of gestation at 6 different intervals. The scatter diagram of these values has been plotted using Microsoft Excel 2010 suite.

Results: Using the trend-line future of excel graph, we have determined the relationship between gestational age and biometric parameter in question and extrapolated this equation to obtain the BPD values from 12th to 40th week of gestation at 1 week interval.

Discussion: Ideally whenever one has to construct intrauterine growth pattern using ultrasound, the patient is supposed to report for scan at specific interval. However in clinical practice, it is difficult to give scheduled appointment because of several constraints. Hence establishing a method which is independent of these factors to obtain growth curves has been possible using spread sheet program.

Conclusion: A detailed methodology to obtain intrauterine growth curve has been explained. This will further facilitate research to establish customised growth curve to serve for the local population.