Skip to main content
. Author manuscript; available in PMC: 2019 May 1.
Published in final edited form as: Am J Obstet Gynecol. 2018 Feb 2;218(5):521.e1–521.e12. doi: 10.1016/j.ajog.2018.01.031

Table 2.

Statistics for Candidate Predictor Variables for Visit 1 (60 to 136 weeks’ gestation) and Visit 3 (220 to 296 weeks’ gestation): Numbers and Proportions of Participants with Sleep Disordered Breathing (SDB; AHI ≥5), Means by SDB Status, and Odds Ratios for Associations between Candidate Predictor Variables and SDB

Candidate predictor variables Visit 1
N = 3264
Visit 3
N = 2512
New Onset at Visit 3 N = 2258*

Descriptive
Statistic
Odds Ratio**
(95% CI)
Descriptive
Statistic
Odds Ratio**
(95% CI)
Descriptive Statistic Odds Ratio** (95% CI)
Total: n (%) SDB 115 (3.5) 207 (8.2) 132 (5.8)
Maternal age at Visit 1, in years
  Mean (standard deviation)
    SDB 29.7 (5.9) 1.7 (1.4, 2.0) 29.8 (5.5) 1.7 (1.5, 2.0) 29.8 (5.1) 1.8 (1.5, 2.1)
    no SDB 26.7 (5.6) reference 26.7 (5.3) reference 26.7 (5.3) reference
    P-value <.0001 <.0001 <.0001
  Category: n (%) SDB
    13–21 11 (1.6) 0.5 (0.2, 0.9) 13 (2.8) 0.3 (0.2, 0.5) 8 (1.9) 0.3 (0.1, 0.6)
    22–35 82 (3.5) reference 162 (8.6) reference 107 (6.3) reference
    >35 22 (10.0) 3.1 (1.9, 5.1) 32 (19.9) 2.6 (1.7, 4.0) 17 (12.6) 2.1 (1.2, 3.7)
    P-value <.0001 <.0001 <.0001
Maternal race: n (%) SDB
    White Non-Hispanic 66 (3.3) reference 124 (7.8) reference 83 (5.8) reference
    Black Non-Hispanic 22 (5.3) 1.6 (1.0, 2.6) 32 (11.1) 1.5 (1.0, 2.2) 17 (7.1) 1.2 (0.7, 2.1)
    Hispanic 15 (2.5) 0.7 (0.4, 1.3) 25 (5.9) 0.7 (0.5, 1.2) 17 (4.3) 0.7 (0.4, 1.2)
    Asian 6 (4.9) 1.5 (0.6, 3.5) 14 (15.2) 2.1 (1.2, 3.9) 9 (10.7) 1.9 (0.9, 4.0)
    Other 6 (3.8) 1.2 (0.5, 2.7) 12 (10.1) 1.3 (0.7, 2.5) 6 (5.6) 1.0 (0.4, 2.3)
    P-value 0.1738 0.0126 0.2131
Education status reported at Visit 1: n (%) SDB
    Less than high school 8 (3.6) reference 8 (5.3) reference 3 (2.3) reference
    Completed high school or GED 18 (4.4) 1.2 (0.5, 2.9) 17 (6.2) 1.2 (0.5, 2.8) 8 (3.3) 1.4 (0.4, 5.5)
    Some college 28 (4.1) 1.1 (0.5, 2.5) 36 (7.0) 1.3 (0.6, 2.9) 23 (4.9) 2.2 (0.6, 7.4)
    Associate or technical degree 19 (5.3) 1.5 (0.6, 3.5) 39 (13.9) 2.9 (1.3, 6.3) 24 (9.6) 4.5 (1.3, 15.3)
    Completed college 24 (2.6) 0.7 (0.3, 1.6) 66 (8.7) 1.7 (0.8, 3.6) 45 (6.6) 3.0 (0.9, 9.8)
    Degree work beyond college 18 (2.7) 0.7 (0.3, 1.7) 41 (7.7) 1.5 (0.7, 3.2) 29 (6.0) 2.7 (0.8, 9.1)
    P-value 0.1459 0.0067 0.0227
Smoked during 3 months before became pregnant: n (%) SDB
    Yes 30 (5.3) 1.7 (1.1, 2.6) 48 (11.7) 1.6 (1.1, 2.3) 28 (8.0) 1.5 (1.0, 2.3)
    No 85 (3.2) reference 159 (7.6) reference 104 (5.5) reference
    P-value 0.0120 0.0064 0.0685
Chronic hypertension: n (%) SDB
    Yes 9 (12.9) 4.2 (2.0, 8.6) 18 (31.6) 5.5 (3.1, 9.8) 11 (24.4) 5.5 (2.7, 11.1)
    No 105 (3.4) reference 188 (7.8) reference 121 (5.6) reference
    P-value 0.0001 <.0001 <.0001
Hypothyroidism: n (%) SDB
    Yes 11 (6.4) 1.9 (1.0, 3.7) 22 (16.2) 2.3 (1.4, 3.7) 14 (11.8) 2.3 (1.3, 4.1)
    No 101 (3.4) reference 178 (7.7) reference 114 (5.5) reference
    P-value 0.0443 0.0007 0.0058
Family history*** of diabetes: n (%) SDB
    Yes 42 (6.0) 2.1 (1.4, 3.2) 62 (11.4) 1.7 (1.2, 2.3) 36 (7.6) 1.5 (1.0, 2.2)
    No 70 (2.9) reference 137 (7.2) reference 90 (5.2) reference
    P-value 0.0001 0.0018 0.0480
Family history*** of heart disease: n (%) SDB
    Yes 20 (7.7) 2.3 (1.4, 3.8) 26 (12.1) 1.6 (1.0, 2.5) 13 (7.3) 1.3 (0.7, 2.3)
    No 69 (3.5) reference 124 (8.0) reference 81 (5.8) reference
    P-value 0.0015 0.0452 0.4298
Family history*** of hypertension: n (%) SDB
    Yes 53 (5.2) 1.8 (1.2, 2.9) 87 (10.8) 1.7 (1.2, 2.4) 56 (7.8) 1.8 (1.2, 2.8)
    No 35 (2.9) reference 62 (6.6) reference 37 (4.4) reference
    P-value 0.0058 0.0018 0.0051
BMI at Visit 1, in kg/m2
  Mean (standard deviation)
    SDB 36.7 (8.3) 2.9 (2.5, 3.4) 33.4 (7.6) 2.5 (2.2, 2.8) 31.1 (6.2) 2.0 (1.7, 2.2)
    no SDB 26.0 (6.0) reference 25.8 (5.8) reference 25.7 (5.8) reference
    P-value <.0001 <.0001 <.0001
  Category: n (%) SDB
    <25 8 (0.5) reference 28 (2.1) reference 24 (2.0) reference
    25 to <30 12 (1.5) 3.2 (1.3, 7.8) 41 (6.9) 3.4 (2.1, 5.6) 35 (6.4) 3.5 (2.0, 5.9)
    30 to <35 33 (8.7) 20.0 (9.2, 43.7) 60 (19.3) 11.0 (6.9, 17.6) 38 (14.6) 8.6 (5.0, 14.6)
    ≥35 60 (17.2) 43.7 (20.7, 92.2) 76 (28.9) 18.7 (11.8, 29.6) 34 (16.8) 10.1 (5.9, 17.5)
    P-value <.0001 <.0001 <.0001
BMI at Visit 3, in kg/m2
  Mean (standard deviation)
    SDB -- -- 35.7 (6.7) 2.5 (2.2, 2.8) 33.9 (6.0) 2.0 (1.8, 2.3)
    no SDB -- -- 28.6 (5.7) reference 28.5 (5.7) reference
    P-value -- -- <.0001 <.0001
  Category: n (%) SDB
    <25 -- -- 8 (1.2) reference 7 (1.2) reference
    25 to <30 -- -- 37 (3.9) 3.2 (1.5, 6.9) 31 (3.5) 3.1 (1.3, 7.0)
    30 to <35 -- -- 54 (12.2) 11.0 (5.2, 23.4) 39 (10.0) 9.5 (4.2, 21.5)
    ≥35 -- -- 103 (25.3) 26.9 (13.0, 56.0) 54 (16.5) 16.8 (7.5, 37.4)
    P-value -- -- <.0001 <.0001
Neck circumference at Visit 1, in cm
  Mean (standard deviation)
    SDB 36.8 (4.6) 2.8 (2.3, 3.3) 35.5 (3.9) 2.3 (2.0, 2.6) 34.6 (2.7) 1.8 (1.6, 2.2)
    no SDB 32.8 (2.8) reference 32.7 (2.8) reference 32.6 (2.7) reference
    P-value <.0001 <.0001 <.0001
  Category: n (%) SDB
    <34 23 (1.1) reference 62 (3.8) reference 50 (3.3) reference
    34 to 36.5 32 (4.6) 4.3 (2.5, 7.5) 73 (13.6) 4.0 (2.8, 5.7) 50 (10.6) 3.5 (2.3, 5.2)
    >36.5 56 (16.7) 18.1 (11.0, 29.8) 65 (25.8) 8.8 (6.0, 12.9) 27 (13.9) 4.7 (2.9, 7.8)
    P-value <.0001 <.0001 <.0001
Systolic blood pressure at Visit 1, in mm Hg
  Mean (standard deviation)
    SDB 116.5 (13.3) 1.9 (1.6, 2.3) 115.0 (11.8) 1.8 (1.6, 2.1) 114.0 (11.3) 1.7 (1.4, 2.0)
    no SDB 108.8 (10.5) reference 108.5 (10.4) reference 108.5 (10.4) reference
    P-value <.0001 <.0001 <.0001
  Category: n (%) SDB
    <140 107 (3.4) reference 197 (8.0) reference 126 (5.7) reference
    ≥140 5 (26.3) 10.3 (3.6, 29.1) 6 (42.9) 8.6 (3.0, 25.1) 4 (36.4) 9.5 (2.7, 32.8)
    P-value <.0001 <.0001 0.0004
Systolic blood pressure at Visit 3, in mm Hg
  Mean (standard deviation)
    SDB -- -- 116.6 (11.7) 1.8 (1.5, 2.0) 115.4 (10.8) 1.6 (1.4, 1.9)
    no SDB -- -- 110.2 (10.6) reference 110.1 (10.6) reference
    P-value -- -- <.0001 <.0001
  Category: n (%) SDB
    <140 -- -- 201 (8.2) reference 131 (5.9) reference
    ≥140 -- -- 4 (25.0) 3.8 (1.2, 11.7) 1 (8.3) 1.5 (0.2, 11.3)
    P-value -- -- 0.0230 0.7224
Frequent snoring**** in 4 weeks before Visit 1: n (%) SDB
    Yes 35 (8.6) 3.9 (2.5, 6.2) 64 (20.2) 4.0 (2.8, 5.7) 39 (14.3) 3.6 (2.3, 5.5)
    No 43 (2.3) reference 87 (5.9) reference 59 (4.4) reference
    P-value <.0001 <.0001 <.0001
Frequent snoring**** in 4 weeks before Visit 3: n (%) SDB
    Yes -- -- 106 (22.5) 6.5 (4.6, 9.2) 67 (16.8) 6.1 (4.0, 9.2)
    No -- -- 58 (4.3) reference 40 (3.2) reference
    P-value -- -- <.0001 <.0001
*

Participants with AHI <5 at V1.

**

Odds ratios for continuous predictors are computed by logistic regression for a 1-standard deviation difference.

***

Father, mother, brother, sister, half-brother or half-sister.

****

Snoring ≥3 days per week