Table 1. Spectral analysis (HF, LF and normalized HF), RMSSD and fetal stress index values before and after direct intravenous administration of 2.5 mg atropine.

The results are presented as median values (1^st–3^rd quartiles). A Wilcoxon test was used for analysis. Statistical significance was set as p <0.05.

	Before	%CV before	After	%CV after	p	Effect size
HF	52.9(37.2–75)	33.4	25.4(21.1–39.1)	30.2	0.043	1.13
LF	22.3(16–31.1)	35.2	18.1(14–41.8)	51.1	0.398	0.35
HF/(HF+LF)	0.68(0.61–0.78)	11.6	0.53(0.47–0.65)	18.3	0.018	0.92
RMSSD	8.7(6.3–9.2)	49.3	4(3–6.5)	37.6	0.018	1.13
FSI	57.3(52.4–61.2)	9.9	40.4(36–46.2)	17.3	0.018	1.49

HF = high frequency; LF = low frequency,

RMSSD = root mean square of the successive differences;