Changes in fetal and neonatal mortality during 40 years by offspring sex: a national registry-based study in Norway

Table 4 Absolute change (per 1000) and relative change in fetal mortality rates by sex of child for different pregnancy periods

	23-28 weeks				29-36 weeks				≥ 37 weeks
	Absolute change		Relative change		Absolute change		Relative change		Absolute change		Relative change
	Coefficient	95% CI	Coefficient	95% CI	Coefficient	95% CI	Coefficient	95% CI	Coefficient	95% CI	Coefficient	95% CI
Boy	1.146	1.046, 1.247	1.184	0.997, 1.407	3.847	3.680, 4.013	1.102	1.000, 1.214	4.105	3.930, 4.280	1.062	0.969, 1.164
Girl	0.982	0.879, 1.086	1.000		3.441	3.270, 3.612	1.000		3.943	3.763, 4.123	1.000
Boy * (Year - 1967)	−0.019	−0.024, −0.015	0.975	0.969, 0.981	−0.089	−0.096, −0.081	0.959	0.955, 0.962	−0.099	−0.107, −0.091	0.955	0.951, 0.959
Girl * (Year - 1967)	−0.014	−0.019, −0.009	0.980	0.974, 0.987	−0.082	−0.090, −0.075	0.955	0.951, 0.959	−0.089	−0.098, −0.081	0.960	0.956, 0.963
Test for equal average trends for boys and girls:	p = 0.131		p = 0.142		p = 0.274		p = 0.242		p = 0.119		p = 0.081
N	1,974,811				1,973,314				1,969,216

Non-immigrants in Norway, 1967–2005. Linear probability and logistic regression analyses. Pregnancies with gestational length >22 weeks.

ISSN: 1471-2393