Table 4.

Mediation analysis with Pregnancy-Induced Hypertension as mediator.

Fertility Group	Total Effect				Direct Effect				Indirect Effect				%Mediation
	LPTB		EPTB		LPTB		EPTB		LPTB		EPTB		LPTB	EPTB
	OR	95% CI	OR	95% CI	OR	95% CI	OR	95% CI	OR	95% CI	OR	95% CI
Fertile	ref		ref		ref		ref		ref		ref
ART
All ART	1.40	1.30–1.50 ‡	1.52	1.34–1.70 ‡	1.36	1.26–1.46 ‡	1.45	1.28–1.62 ‡	1.03	1.02–1.04 ‡	1.04	1.03–1.06 ‡	9.36 ‡	12.43 ‡
Fresh	1.39	1.28–1.51 ‡	1.46	1.27–1.65 ‡	1.38	1.26–1.49 ‡	1.44	1.25–1.62 ‡	1.01	1.00–1.02 ‡	1.02	1.01–1.03 ‡	4.09†	5.65†
Frozen	1.42	1.21–1.62 ‡	1.58	1.22–1.94 ‡	1.31	1.12–1.49 ‡	1.39	1.08–1.70 ‡	1.08	1.06–1.10 ‡	1.14	1.11–1.17 ‡	25.94 ‡	32.64 ‡
Autologous egg	1.37	1.26–1.47 ‡	1.47	1.29–1.65 ‡	1.34	1.24–1.44 ‡	1.42	1.25–1.60 ‡	1.02	1.01–1.03 ‡	1.03	1.02–1.05 ‡	7.29 ‡	10.06 ‡
Donor egg	1.77	1.38–2.16 ‡	1.74	1.14–2.33 ‡	1.58	1.23–1.92 ‡	1.48	0.97–1.98 ‡	1.12	1.09–1.15 ‡	1.17	1.12–1.23 ‡	24.54 ‡	34.98 ‡
ICSI	1.42	1.26–1.58 ‡	1.39	1.13–1.64 ‡	1.39	1.23–1.55 ‡	1.34	1.09–1.59 ‡	1.02	1.01–1.03 ‡	1.04	1.02–1.05 ‡	7.32 ‡	12.18 ‡
No ICSI	1.36	1.21–1.50 ‡	1.47	1.22–1.72 ‡	1.35	1.21–1.49 ‡	1.46	1.21–1.71 ‡	1.01	1.00–1.01 ‡	1.01	0.99–1.02 ‡	1.88	1.95

LPTB = Late preterm birth; EPTB = Early preterm birth; OR = odds ratio; 95% CI = 95% confidence interval; ‡ = significant at p < 0.001.