Effect of nausea and vomiting during pregnancy on mother-to-infant bonding and the mediation effect of postpartum depression: the Japan Environment and Children’s Study

Table 3 Mediation effect of NVP on MIBS-J score through EPDS score in mediation analysis

Relative total effects (NVP → MIBS-J score)
	Crude model　β (95%CI)	Adjusted model　β (95%CI)
No NVP	0 (reference)	0 (reference)
Mild NVP	0.013 (-0.015, 0.073)	0.014 (-0.014, 0.079)
Moderate NVP	0.002 (-0.042, 0.051)	-0.003 (-0.057, 0.042)
Severe NVP	-0.025 (-0.116, 0.002)	-0.063 (-0.207, -0.081)
Relative direct effects (NVP → MIBS-J score)
	Crude model　β (95%CI)	Adjusted model　β (95%CI)
No NVP	0 (reference)	0 (reference)
Mild NVP	-0.017 (-0.081, -0.001)	-0.008 (-0.062, 0.027)
Moderate NVP	-0.031 (-0.116, -0.028)	-0.023 (-0.101, -0.006)
Severe NVP	-0.083 (-0.246, -0.134)	-0.091 (-0.268, -0.147)
Relative indirect effects (NVP → EPDS score → MIBS-J score)
	Crude model　β (BC 95%CI)	Adjusted model　β (BC 95%CI)
No NVP	0 (reference)	0 (reference)
Mild NVP	0.030 (0.024, 0.036)	0.022 (0.016, 0.027)
Moderate NVP	0.033 (0.027, 0.040)	0.020 (0.015, 0.026)
Severe NVP	0.058 (0.049, 0.067)	0.028 (0.020, 0.035)

The model was adjusted for maternal age, marital status, feelings about the pregnancy, parity, multiple births, psychological distress (the Kessler Psychological Distress Scale (K6)), maternal and paternal educational level, maternal and paternal smoking, maternal alcohol intake, annual household income, partner’s verbal or physical abuse, and infant’s sex
NVP nausea and vomiting during pregnancy, MIBS-J score the Japanese version of the Mother-to-Infant Bonding Scale score at one year after delivery, EPDS score Edinburgh Postnatal Depression Scale score, β standardized path coefficient, 95% CI 95% confidence interval, BC 95% CI bias-corrected bootstrap 95% confidence interval

ISSN: 1471-2393