Table 4.

Small-for-Gestational-Age Singletons According to Parental Infertility and Treatment

			Reference: Group A			Reference: Group B
	No. of singletons	No. of small-for-gestational-age (%)	Crude OR (95% CI)	Adjusted OR* (95% CI)	Adjusted OR† (95% CI)	Crude OR (95% CI)	Adjusted OR* (95% CI)	Adjusted OR† (95% CI)
Group A:
Fertile couples	50614	2200 (4.3)	1.00 Ref	1.00 Ref	1.00 Ref
Group B:
Infertile couples conceiving naturally	5722	345 (6.0)	1.41 (1.26–1.59)	1.33 (1.18–1.50)	1.24 (1.10–1.40)	1.00 Ref	1.00 Ref	1.00 Ref
Group C:
Infertile couples receiving treatment	4271	304 (7.1)	1.69 (1.49–1.91)	1.78 (1.56–2.02)	1.40 (1.23–1.60)	1.19 (1.02–1.40)	1.31 (1.11–1.54)	1.14 (0.96–1.35)
ICSI	396	30 (7.6)	1.80 (1.24–2.62)	1.94 (1.33–2.82)	1.40 (0.96–2.05)	1.28 (0.87–1.88)	1.43 (0.97–2.12)	1.14 (0.77–1.70)
IVF	1474	93 (6.3)	1.48 (1.20–1.84)	1.58 (1.27–1.96)	1.17 (0.94–1.46)	1.05 (0.83–1.33)	1.16 (0.91–1.48)	0.95 (0.74–1.22)
IUI	1322	103 (7.8)	1.86 (1.51–2.28)	1.96 (1.59–2.41)	1.57 (1.27–1.94)	1.32 (1.05–1.66)	1.45 (1.15–1.83)	1.27 (1.00–1.61)
HT	1079	78 (7.2)	1.71 (1.36–2.17)	1.75 (1.39–2.22)	1.52 (1.20–1.93)	1.21 (0.94–1.57)	1.31 (1.01–1.69)	1.22 (0.94–1.58)

Logistic regression; OR: odd ratios; CI: confidence interval; ICSI: intracytoplasmic sperm injection; IVF: in vitro fertilization; IUI: intrauterine insemination; HT: hormonal treatment.

^*Adjusted for maternal age, and smoking.

^†Adjusted for maternal age, smoking, and parity.