Table 1.

Sample characteristics.

Author	Country	N		Age M (SD)		Marital Status N; %		Educational Level N; %		Weeks Pregnant M (SD)
		EG	CG	EG	CG	EG	CG	EG	CG	EG	CG
[64]	USA	18	7	30.5 (4.05)		Married or cohabitating 20; 83%		Graduate or post-graduate 25; 100%		n/r	n/r
[65]	Norway	678	664	31 (4.6)	31.1 (4.5)	n/r	n/r	≤high school 100, 14.7% 1–3 years of university 189, 27.9% ≥4–5 years college or university 389, 57.4%	≤high school 107, 16.1% 1–3 years of university 183, 27.6% ≥4–5 years college or university 374, 56.3%	n/r	n/r
[66]	USA	46	45	28.91 (4.25)	29.16 (4.11)	n/r	n/r	n/r	n/r	n/r	n/r
[67]	Australia	36	41	31.69 (4.44)	31.54 (3.63)	In a relationship 10; 28% Separated or divorced 1; 3% Married 23; 64% Single 2; 6%	In a relationship 4; 10% Separated or divorced 0; 0% Married 36; 88% Single 1; 2%	<high-school 3; 8% Trace certificate/Diploma 8; 22% Undergraduate degree 17; 47% Post-graduate degree 8; 22%	<high-school 1; 2% Trace certificate/Diploma 4; 10% Undergraduate degree 29; 71% Post-graduate degree 7; 17%	20.54 (6.01)	22.63 (5.76)
[68] #	Ireland	32	14	33.81(2.53)		In a relationship 4; 11.1% Married 32; 88.9%		n/r	n/r	16.15 (2.88)
[69]	China	84	84	30.27 (3.8)	29.55 (4.21)	Married 167; 100%		n/r	n/r	13.81 * (na)	14.41 * (na)
[70]	China	62	61	31.31 (4.97)	30.98 (3.91)	n/r	n/r	≤high-school 5; 8.1% Some college 19; 30.6% Undergraduate degree 31; 50% ≥Post-graduate degree 7; 11.3%	≤high-school 11; 18% Some college 15; 24.6% Undergraduate degree 27; 44.3% ≥Post-graduate degree 8; 13.1%	25.52 (1.84)	26.33 (3.45)

Note. EG = experimental group; CG = control group; n/r = not reported; na = not available; # data refer only to participants who had completed the intervention; * in the original study the data were reported as days, while here they were calculated and reported as weeks by dividing them by 7.