Table III.
Crude and adjusted OR (95% CI) for cervical insufficiency by maternal characteristic among singleton live births, US 2005 Natality file.
| Variable | Crude OR | Adjusted OR* | Adjusted OR** |
|---|---|---|---|
| Race (ref = White) | |||
| Black | 2.66 (2.43–2.90) | 2.45 (2.22–2.71) | 2.18 (2.02–2.36) |
| Asian/Pacific Islander | 1.10 (0.90–1.34) | 0.96 (0.79–1.18) | 0.97 (0.81–1.16) |
| American Indian/Alaskan Native | 1.16 (0.79–1.70) | 1.62 (1.10–2.37) | 1.02 (0.75–1.38) |
| Pregnancy terminations (ref = 0) | |||
| 1 | 2.80 (2.53–3.12) | 2.49 (2.23–2.77) | 1.71 (1.57–1.85) |
| 2 | 6.03 (5.30–6.87) | 4.66 (4.07–5.33) | 2.86 (2.60–3.16) |
| 3 | 12.12 (10.26–14.32) | 8.07 (6.77–9.61) | 3.55 (3.10–4.06) |
| 4+ | 20.76 (17.31–24.91) | 12.36 (10.19–15.00) | 5.96 (5.24–6.78) |
| Mother's age | 1.06 (1.06–1.07) | 1.03 (1.03–1.04) | 1.02 (1.02–1.03) |
| Marital status: not married versus married | 0.87 (0.80–0.95) | 0.89 (0.80–0.99) | 0.80 (0.73–0.87) |
| Alcohol use | 0.41 (0.18–0.91) | 0.37 (0.17–0.84) | 1.00 (0.69–1.44) |
| History of diabetes | 3.04 (2.63–3.53) | 1.69 (1.45–1.98) | 1.30 (1.15–1.47) |
| Pregnancy-induced hypertension | 1.19 (1.01–1.41) | 1.02 (0.86–1.21) | 0.90 (0.76–1.06) |
| Anemia in pregnancy | 1.55 (1.22–1.96) | 1.38 (1.08–1.75) | 1.25 (1.05–1.49) |
| Genital herpes | 1.88 (1.41–2.51) | 1.25 (0.93–1.68) | 1.57 (1.25–1.96) |
| Renal disease | 2.26 (1.40–3.64) | 2.21 (1.36–3.59) | 1.61 (1.10–2.35) |
| Hydramnios/oligohydramnios | 1.97 (1.58–2.47) | 1.48 (1.18–1.86) | 1.39 (1.13–1.71) |
| Mother's education level (ref = college) | |||
| Some High school or less | 0.58 (0.50–0.66) | 0.93 (0.79–1.08) | 0.66 (0.59–0.74) |
| High school graduate | 0.90 (0.82–0.99) | 1.05 (0.95–1.17) | 0.86 (0.80–0.94) |
| Prenatal care adequacy (ref = adequate) | |||
| Inadequate | 1.04 (0.87–1.26) | 1.00 (0.82–1.21) | 0.70 (0.59–0.82) |
| Intermediate | 0.93 (0.78–1.10) | 0.88 (0.73–1.05) | 0.80 (0.70–0.92) |
| Adequate plus | 3.41 (3.09–3.76) | 2.91 (2.64–3.22) | 2.57 (2.38–2.78) |
| Weight gain during pregnancy | 0.97 (0.96–0.97) | 0.97 (0.97–0.98) | 0.99 (0.99–0.99) |
| Previous preterm birth | 8.16 (7.49–8.89) | ||
| Live births now living (ref = three or more) | |||
| 0 | 4.18 (3.48–5.02) | ||
| 1 | 1.77 (1.60–1.97) | ||
| 2 | 1.38 (1.24–1.55) | ||
| Live births now dead (ref = 0) | |||
| One | 4.90 (4.38–5.48) | ||
| Two or more | 5.69 (4.69–6.90) | ||
*Primiparous-only model; Hosmer and Lemeshow Goodness-of-fit test: P-value = 0.18.
**Model with multiparous women. Cervical insufficiency is reported on the 1989 Revision of the US Certificate of Live Birth but not on the 2003 revised version. Thus, analysis data set is only from States that report data based on the 1989 Revision of the US Certificate of Live Birth.