National guidelines – recommendations for pregnancy dating | Unit follows guidelines | Unit does not follow guidelines | Missing information | |||
---|---|---|---|---|---|---|
(n) | (%) | (n) | (%) | (n) | (%) | |
First trimester-based (11–14 weeks), if performed | 11 | 28.9 | 26 | 68.5 | 1 | 2.6 |
CRL-based, if 11 weeks + 0 days to 12 weeks + 2 days | 11 | 28.9 | 24 | 63.2 | 3 | 7.9 |
BPD-based, if 12 weeks + 3 days to 22 weeks + 5 days | 34 | 89.5 | 3 | 7.9 | 1 | 2.6 |
Based on size of largest fetus in multiple pregnancies | 37 | 97.4 | 0 | 0.0 | 1 | 2.6 |
Based on days since embryo transfer + number of cultivation days + 14 days in ART pregnancies | 30 | 78.9 | 1 | 2.6 | 7a | 18.5 |