Preterm Birth: A Prominent Risk Factor for Low Apgar Scores

Table 4

Risk factors for preterm birth before 32 weeks of gestation. Analyses performed by univariate and multivariate logistic regression.

Parameter	Total	32 weeks		Univariate logistic regression			Multivariate logistic regression
			(%)	OR	95% conf. int.		OR	95% conf. int.
Age (years)
≤26	5386	96	1.78	1.00			1.00
27–30	5975	47	0.79	0.92	0.82–1.03		0.98	0.84–1.16
31–33	4341	54	1.24	0.84	0.68–1.05		0.97	0.70–1.34
≥34	4915	63	1.28	0.78	0.56–1.08	0.135	0.95	0.59–1.54	0.84
Height (cms)
≥175	1800	18	1.00	1.00
159–174	14992	99	0.66	1.11	0.77–1.59
≤158	2084	23	1.10	1.22	0.59–2.54	0.588	—	—	—
BMI (kg/m^2)
<25	11359	80	0.70	1.00
25–29.9	4862	39	0.80	1.09	0.87–1.38
≥30	2319	19	0.82	1.19	0.75–1.89	0.448	—	—	—
Smoking
No	15784	108	0.68	1.00			1.00
Yes	3236	34	1.05	1.54	1.05–2.27	0.029	1.61	1.07–2.41	0.022
Thyroid disease
No	18379	131	0.71	1.00			1.00
Yes	550	10	1.82	2.58	1.35–4.93	0.004	2.32	1.17–4.57	0.015
Type 1 diabetes mellitus
No	18823	134	0.71	1.00
Yes	140	1	0.71	1.00	0.16–6.28	0.997	—	—	—
Inflammatory bowel disease
No	18762	194	1.03	1.00
Yes	138	3	2.17	2.12	0.67–6.71	0.201	—	—	—
Epilepsy
No	18798	137	0.73	1.00			1.00
Yes	158	4	2.53	3.54	1.29–9.67	0.014	3.14	1.13–8.78	0.029
Parity
0	8418	82	0.97	1.00			1.00
≥1	10602	60	0.57	0.58	0.41–0.81	0.001	0.68	0.47–0.98	0.036
Previous cesarean section
No	17796	132	0.74	1.00
Yes	1224	10	0.82	1.10	0.58–2.10	0.768	—	—	—
Multiple pregnancy
No	20314	216	1.06	1.00			1.00
Yes	303	44	14.52	15.8	11.2–22.3	<0.001	15	10–24	<0.001
Preeclampsia
No	20067	214	1.07	1.00			1.00
Yes	550	46	8.36	8.47	6.09–11.78	<0.001	5.48	3.39–8.86	<0.001