Postdate pregnancy is a pregnancy that pasts more than forty weeks. This can be dangerous for the mother, fetus, and newborn. By knowing the most appropriate ultrasound criteria in predicting the probability of postdate pregnancy, its complications can be reduced by taking timely measures. Therefore, the present study was conducted with the aim of determining the relationship between ultrasound criteria in determining the age of postdate fetuses. This cross-sectional study (descriptive-analytical type) was done in Kermanshah Imam Reza Hospital on 33 pregnant women that, according to LMP and first-trimester ultrasound, pregnancy age was more than 40 weeks. Gestational age was calculated by various ultrasound criteria, including head circumference measurement (HC), Abdominal Circumference (AC), Biparietal Diameter (BPD), femur length (FL), and Transcerebellar Diameter (TCD). The findings were compared with calculated age by LMP. Data were analyzed by SPSS16 software. Correlation rate of pregnancy age based on LMP with FL (R=0.576, P<0.001), AC (R=0.208, P=0.245), BPD (R= -0.200, P=0.264), HC (R= -0.211, P=0.238) and TCD were (R=0.111, P=0.538). The pregnancy age correlation rate based on LMP with ultrasound criteria in general was (R=0.140, P=0.436). There was a direct relationship between gestational age based on LMP with FL, AC, TCD and inversely related to BPD and HC. Among the sonographic criteria, only the FL criterion was significantly correlated with LMP. In general, the correlation between gestational age based on LMP and ultrasound was not statistically significant.
Can biparietal diameter-to-femur length ratio be a useful sonographic marker for screening thanatophoric dysplasia since the first trimester? A literature review of case reports and a retrospective study based on 10,293 routine fetal biometry measurements
