Table 4 Reference values for GSD, YSD, CRL and HR in previous studies and the present study
Author | Studied population | Inclusion criteria | Scanning method | Gestational days 45 55 65 | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
GSD mm | CRL mm | YSD mm | HR bpm | GSD mm | CRL mm | YSD mm | HR bpm | GSD mm | CRL mm | YSD mm | HR bpm | ||||
Robinson and Fleming, 1975 [7] (n = 334) | Spontaneous | No information about outcome | TA | – | 6.1 | – | – | – | 13.8 | – | – | – | 24.2 | – | – |
Lindsay et al., [21] 1992 (n = 327) | Spontaneous | Pregnancy continued ≥ 27 weeks | TV | – | – | 2.7 | – | – | – | 3.1 | – | – | – | 3.5 | – |
Grisolia et al., [22] 1993 (n = 248) | Spontaneous | Normal live birth | TV/TA | 14.0 | 7.0 | – | – | 26.0 | 15.0 | – | – | 38.0 | 25.0 | – | – |
Britten et al., [23] 1994 (n = 361) | Assisted reproduction | Normal live birth | TV | – | – | – | 123.3 | – | – | – | 163.0 | – | – | – | – |
Yapar et al., [24] 1995 (n = 1331) | No information | No information about outcome | TV | – | – | – | 128.2 | – | – | – | 161.6 | – | – | – | 175.1 |
Coulam et al. [25] 1996 (n = 361) | Assisted reproduction | Normal live birth | TV | 16.0 | 5.5 | – | 123.0 | 29.0 | 15.3 | – | 163.0 | – | – | – | – |
Tannirandorn et al., [2] 2000 (n = 547) | Spontaneous | Normal live birth | TV | – | – | – | 147.4 | – | – | – | 163.9 | – | – | – | 172.7 |
McLennan et al., [26] 2008 (n = 396) | Mixed spontaneous + assisted | Pregnancy continued ≥ 20 weeks | TV/TA | – | 7.0 | – | – | – | 15.0 | – | – | – | 26.0 | – | – |
Papaioannou et al. [5] 2010 (n = 4698) | Mixed (spontaneous 97.9% + assisted 2.1%) | Normal live birth | TV | 17.4 | 5.4 | 3.6 | 120.0 | 27.3 | 14.0 | 4.2 | 156.0 | 37.3 | 24.6 | 4.8 | 174.0 |
Our study 9 (n = 30,416) | Assisted reproduction | Normal live birth | TV | 19.0 | 3.4 | 3.7 | 117.0 | 29.0 | 13.6 | 4.5 | 159.0 | 40.0 | 24.0 | 5.0 | 176.0 |