Table 2.

Neonatal outcomes in the study groups compared with the reference group.

Outcome   n	Ref. group 26 870	ART 255	Anovulation 68	Endometriosis 49	Male factor 43	Tubal factor 38	PCOS 27	Unexplained 30
Preterm birth
%	6.3	12.7	13.4	18.6	9.8	10.5	14.8	6.7
P-value		<0.0001	<0.05	<0.005	NS	NS	NS	NS
OR		2.17	2.33	3.43	1.62	1.77	2.61	1.07
95% CI		1.48–3.17	1.15–4.71	1.59–7.42	0.58–4.53	0.63–4.99	0.90–7.57	0.26–4.51
AOR		2.12	2.07	3.25	1.80	1.71	2.85	1.06
95% CI		1.44–3.11	1.01–4.23	1.50–7.07	0.64–5.11	0.60–4.85	0.98–8.30	0.25–4.48
LBW
%	4.7	8.7	7.4	10.2	9.3	10.5	3.7	10.0
P-value		<0.005	NS	NS	NS	NS	NS	NS
OR		1.93	1.62	2.32	2.09	2.40	0.79	2.27
95% CI		1.24–3.00	0.65–4.04	0.92–5.86	0.75–5.87	0.85–6.79	0.11–5.79	0.69–7.49
AOR		1.83	1.35	2.13	2.27	2.33	0.87	2.18
95% CI		1.17–2.86	0.54–3.40	0.84–5.41	0.80–6.42	0.82–6.63	0.12–6.49	0.65–7.24
SGA
%	9.7	12.4	11.8	6.3	19.1	7.9	7.4	23.3
P-value		NS	NS	NS	NS	NS	NS	<0.05
OR		1.30	1.24	0.62	2.18	0.80	0.74	2.83
95% CI		0.90–1.90	0.59–2.59	0.19–1.20	1.01–4.72	0.24–2.59	0.18–3.14	1.21–6.59
AOR		1.08	1.02	0.49	1.78	0.69	0.78	2.29
95% CI		0.73–1.59	0.49–2.16	0.15–1.59	0.78–4.06	0.21–2.25	0.18–3.33	0.97–5.41
NICU admiss
%	9.5	16.6	14.7	18.4	20.9	15.8	18.5	10.0
P-value		<0.0005	NS	<0.05	<0.05	NS	NS	NS
OR		1.87	1.64	2.14	2.51	1.78	2.16	1.05
95% CI		1.34–2.60	0.84–3.21	1.04–4.01	1.20–5.24	0.74–4.26	0.82–5.70	0.32–3.48
AOR		1.64	1.32	1.78	2.49	1.62	1.98	0.92
95% CI		1.17–2.30	0.67–2.60	0.86–3.68	1.18–5.26	0.67–3.90	0.74–5.28	0.28–3.05

Preterm birth <37 gestational weeks, LBW: low birth weight (<2500 g), SGA: small for gestational age (fetal indexes < the 10th percentile adjusted for Finnish population), NICU: neonatal intensive care unit.

AOR: OR adjusted for age, parity, BMI, smoking, previous foetal deaths and miscarriages, chronic illness, and marital status.