Comparison of actual and ultrasound estimated second trimester gestational length in in-vitro fertilized pregnancies.
OBJECTIVE
To compare actual and calculated gestational age in pregnancies conceived by in-vitro fertilisation.


METHODS
In 36 healthy women conceiving by in-vitro fertilisation an equation described for use in a Nordic population was used for calculating gestational age from the biparietal diameter and femur length at a routine 18-19 week scan. This was compared to actual gestational length estimated from the day between oocyte retrieval and embryo transfer.


RESULTS
The mean difference amounted to -0.86 days with a standard deviation of 2.86 days, a range of -5 to +6 days and a 95% confidence interval -0.11 to 1.83 (t = 1.806, df = 35, p = 0.8). Correlation between the two methods was highly significant.


CONCLUSIONS
The equation used allows prediction of term with sufficient accuracy for general use in our population.
Geirsson
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Department of Obstetrics and Gynecology, National University Hospital, Reykjavik, Iceland.
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D000886:Anthropometry; D005260:Female; D005307:Fertilization in Vitro; D005333:Fetus / Q000033:anatomy & histology*; D006801:Humans; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012016:Reference Values; D016216:Ultrasonography, Prenatal