Table 6.

Odds ratios for women in the different age groups who had given birth following ART vs. spontaneous pregnancy^a

	Age group				All age groups
	≤39	40–44	≥45	≥40
	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)	OR (95% CI)
Civil status
Married/ cohabiting	Reference	Reference	Reference	Reference	Reference
Single status at registration	7.51 (5.35–10.53)	4.09 (3.46–4.83)	3.71 (2.28–6.04)	0.73 (3.24–4.29)	4.62 (4.02–5.33)
Parity
Primiparous	Reference	Reference	Reference	Reference	Reference
Multiparous	0.27 (0.25–0.30)	0.21 (0.20–0.23)	0.22 (0.16–0.30)	0.25 (0.24–0.27)	0.24 (0.22–0.25)
Twin
No	Reference	Reference	Reference	Reference	Reference
Yes	9.85 (8.58–11.30)	7.50 (6.87–9.20)	8.02 (5.21–12.35)	7.94 (7.22–8.72)	8.91 (8.06–9.82)
Age group
≤ 39	NA	NA	NA	NA	Reference
40–44	NA	NA	NA	NA	3.40 (3.57–4.05)
≥ 45	NA	NA	NA	NA	4.72 (4.05–5.50)
Gestational age
At term, 37–42 weeks	Reference	Reference	Reference	Reference	Reference
Post term, > 42 weeks	0.63 (0.23–1.72)	0.92 (0.49–1.75)	1.65 (0.19–14.31)	0.90 (0.54–1.50)	0.86 (0.51–1.44)
Preterm, 32–36 weeks	1.37 (1.14–1.65)	1.20 (1.00–1.43)	0.95 (0.55–1.66)	1.26 (1.12–1.43)	1.26 (1.12–1.43)
Very preterm, < 32 weeks	1.57 (0.93–2.64)	1.92 (1.15–3.19)	0.13 (0.02–0.93)	1.47 (1.03–2.10)	1.60 (1.11–2.29)
Birthweight
Normal birthweight, ≥2500 g	Reference	Reference	Reference	Reference	Reference
Low birthweight, 1500 g - 2499 g	1.01 (0.81–1.25)	0.90 (0.72–1.11)	1.62 (0.88–2.99)	1.02 (0.88–1.17)	0.98 (0.85–1.14)
Very low birthweight, < 1500 g	0.81 (0.56–1.45)	0.59 (0.34–1.02)	4.82 (0.67–34.83)	0.82 (0.56–1.20)	0.70 (0.47–1.04)
Size for gestational age
AGA1	Reference	Reference	Reference	Reference	Reference
SGA2	1.35 (0.97–1.88)	0.84 (0.64–1.10)	1.54 (0.69–3.42)	1.16 (0.96–1.42)	1.02 (0.83–1.24)
LGA3	1.27 (0.98–1.64)	1.08 (0.88–1.32)	1.70 (0.92–3.16)	1.22 (1.05–1.43)	1.17 (1.00–1.37)

^aAdjusting for all variables presented in Table 4

¹Appropriate for gestational age

²Small for gestational age

³Large for gestational age