TABLE 2—

Crude Risk Factors for Inadequacy of Prenatal Care Use, Ribeirão Preto, Brazil, 1978–1979 and 1994

	1978–1979 (n = 4859)			1994 (n = 2204)
	No.	Inadequate Use, %	Crude Risk Ratio (95% Confidence Interval)	No.	Inadequate Use, %	Crude Risk Ratio (95% Confidence Interval)
Maternal age, y
< 20	656	59.0	1.39 (1.29, 1.49)	386	29.8	1.99 (1.65, 2.42)
20–34	3826	42.5	1.00	1607	14.9	1.00
≤ 35	373	49.9	1.17 (1.05, 1.31)	209	13.9	0.93 (0.65, 1.33)
Not known	4	0
Parity
1	1825	37.5	0.81 (0.75, 0.87)	948	14.0	0.78 (0.64, 0.96)
2–4	2513	46.5	1.00	1142	18.0	1.00
≥ 5	508	67.3	1.45 (1.34, 1.56)	111	40.5	2.26 (1.75, 2.92)
Not known	13	0
Marital status
Married	4075	40.2	1.00	1392	8.9	1.00
Cohabiting	486	71.4	1.78 (1.66, 1.90)	527	36.8	4.13 (3.37, 5.06)
Single	297	72.7	1.81 (1.67, 1.96)	254	24.8	2.78 (2.12, 3.66)
Not known	1	31
Maternal education, y
≤ 4	1085	63.8	2.62 (2.25, 3.07)	264	39.4	15.07 (7.48, 30.35)
5–11	3228	42.5	1.75 (1.50, 2.04)	1497	16.3	6.23 (3.12, 12.47)
≥ 12	535	24.3	1.00	306	2.6	1.00
Not known	11	137
Type of insurance
Private	332	26.2	1.00	874	2.5	1.00
Public	4317	47.7	1.82 (1.52, 2.19)	1290	27.9	11.09 (7.27, 16.91)
Not known	210	40
Maternal smoking
No	3424	42.9	1.00	1749	14.0	1.00
Yes	1406	50.8	1.18 (1.11, 1.26)	453	30.5	2.17 (1.81, 2.61)
Not known	29	2

Note. Subjects with missing information about gestational age and prenatal care were excluded from this analysis.