Background: Maternal and fetal complications following the macrosomia are of utmost importance. The present study was carried out with the aim of determining the prevalence of fetal macrosomia and post-term delivery and multiparity as its risk factors in Kashan in 1999-2000.

Materials and Methods: It was an analytical study. During the first phase the prevalence of macrosomia was determined during a two-year period (1999-2001), then, the second phase was conducted on 110 infants with macrosomia (Case group) and 110 without macrosomia (Control). Groups were matched according to the sex, BMI, level of education, prenatal care, mother’s nationality and age. A questionnaire was used for data collection, then the role of post-term delivery (>40 weeks) and multiparity was determined.

Results: Macrosomia was found in 3.04% of the infants. Post-term delivery was reported in 45.5% and 61.8% of the control and case group, respectively (P<0.02). The mean parity was 2.39±1.34 and 2.54±1.37 in the control and case group, respectively (NS).

Conclusion: The prevalence of macrosomia is not high in Kashan. Post-term delivery has increased the rate of macrosomia, however, multiparity has no statistically significant association. Further studies are highly recommended.