Gestational age in pregnancies conceived after in vitro fertilization: a comparison between age assessed from oocyte retrieval, crown‐rump length and biparietal diameter

Abstract

Objective To compare gestational age (GA)

Changes in Neurotrophin Levels in Umbilical Cord Blood From Infants With Different Gestational Ages and Clinical Conditions

“…The SGA status was defined as birth weights Ͻ10 centiles (25). The gestational age was derived by antenatal ultrasound when done between 13 and 24 wk using Campbell dating standard (26), crown-rump length, or the femur length (27,28). The Ballard score (29,30) was used when ultrasound estimation was not available (31).…”

Ultrasound Evaluation of the First Trimester

“…Several tables and formulas have been published to determine gestational age from CRL. 8,9,54 One of the earliest publications appeared in 1975. 8 Despite the major advances in ultrasound technology since that time, assessment of numerous CRL tables using the gold standard of pregnancies with highly accurate dating based on in vitro fertilization 55 shows that the difference between the various tables is generally no more than 3 days.…”

Morphological and functional evaluation of normal and abnormal fetal growth by ultrasonography

“…This is partly because the fetus is flexed, especially after 12 weeks, and also because individual variability becomes larger. On the other hand, gestational age variation estimated from a BPD of 35-60 mm (corresponding to 15-22 weeks) was 8.4 days (2SD) [2]. At around 14 weeks, there is no difference in the range estimated by CRL and BPD measurements.…”

“…This is because CRL measurement during this period shows the least amount of difference between fetuses compared with other parameters such as BPD, FL or AC [2]. Ultrasound determination of fetal CRL in the first trimester of pregnancy was introduced by Robinson [3].…”

“…There is a steady Campbell and Wilkin [10] ln EFW = -4.564 ? 0.282(AC) -0.00331(AC) 2 Warsof et al [12] Log 10 increase in growth velocity of 220 g/week until 34 weeks and a steady decline of 154 g/week thereafter until 40 weeks [22]. This tendency is confirmed by populationbased data from California in [1970][1971][1972][1973][1974][1975][1976], showing that the median growth rate for singletons reaches a maximum of nearly 250 g/week at 33 weeks and declines to approximately 75 g/week at 40 weeks [23].…”