Table 1.

Comparison of the demographic characteristics of the RPL study populations

	Total, n = 563	Primary RPL n = 335	Secondary RPL n = 228	p
Maternal age (y)	29.2 ± 6.0 (17–56; 29)	27.1 ± 5.5 (17–56; 26)	32.2 ± 5.5 (19–44; 32)	0.0002
Paternal age (y)	31.8 ± 6.9 (19–60; 31)	30.1 ± 6.7 (19–60; 29)	34.3 ± 6.4 (21–54; 34)	0.08
Gestational age (weeks)	9.6 ± 2.8 (3.1–22; 9.3)	9.5 ± 2.6 (3.1–18; 9.1)	9.8 ± 3.0 (3.4–22; 9.3)	0.85
No. of pregnancies	4.0 ± 2.3 (2–21; 3)	3.0 ± 1.4 (2–12; 3)	5.3 ± 2.6 (3–21; 5)	0.007
No. of miscarriages	2.7 ± 1.2 (2–12; 2)	2.6 ± 1.2 (2–12; 2)	2.7 ± 1.1 (2–9; 2)	0.56

Mean ± standard deviation (minimum and maximum values; median); gestational ages were calculated based on the last menstrual period; p was calculated by comparing the primary and secondary RPL