Table 1.

Comparison of fetal cardiac monitoring methods. The first column presents a four-point ordinal scale of medical equipment cost, from low ($) to extremely high ($ $ $ $). The horizontal line indicates when, during pregnancy, the technology can be used. The color of the line indicates the time required for training operators (green: low; blue: moderate; cyan: considerable; red: high; magenta: extreme). The thickness of the line indicates the relative evidence for the utility of each technology.

^*GA ≥ 24 weeks (Várady et al 2003).

^†GA ≥ 20 weeks (Peters et al 2001).

^‡GA ≥ 20 weeks (Peters et al 2001).

^§GA ≥ 20 weeks (Grivell et al 2015).

^¶GA ≥ 18 weeks (Sameni and Clifford 2010).

^∥Intrapartum (GA ≥ 36 weeks) (Norén et al 2006).

^**GA ≥ 20 weeks (World Health Organization 2016b).

^††GA ≥ 20 weeks (Peters et al 2001).