Table 1.
Baseline maternal and paternal characteristics compared by ongoing pregnancy or miscarriage. Odds ratios (OR) of miscarriage from uni- and multivariable logistic regression
| Overall | Ongoing | Miscarriage | p | OR | ||
|---|---|---|---|---|---|---|
| n | 203 | 166 | 37 | Univariable | Multivariable | |
| Maternal data | ||||||
| Age groups (years), n (%) | 0.06 | |||||
| < 30 | 120 (59) | 102 (61) | 18 (49) | – | ||
| 30–35 | 57 (28) | 47 (28) | 10 (27) | 1.2 (0.5–2.8, p = 0.67) | 1.7 (0.7–4.2, p = 0.26) | |
| > 35 | 26 (13) | 17 (10) | 9 (24) | 3.0 (1.1–7.7, p = 0.02) | 7.5 (2.3–26, p < 0.01) | |
| BMI (kg/m2), n (%) | 0.34 | |||||
| Underweight (< 18.5) | 5 (3) | 4 (2) | 1 (3) | – | ||
| Normal (18.5–24.9) | 120 (59) | 99 (60) | 21 (57) | 1.2 (0.1–8.5, p = 0.89) | 1.5 (0.1–12, p = 0.74) | |
| Pre-obese (25—29.9) | 56 (28) | 48 (29) | 8 (22) | 0.8 (0.3–1.8, p = 0.59) | 0.7 (0.3–1.7, p = 0.40) | |
| Obese (> 30) | 22 (11) | 15 (9) | 7 (19) | 2.2 (0.8–6.0, p = 0.13) | 3.4 (1.1–11, p = 0.03) | |
| Time to pregnancy (months), n (%) | 0.35 | |||||
| < 3 | 102 (50) | 81 (49) | 21 (57) | – | ||
| 3–6 | 42 (21) | 35 (21) | 7 (19) | 0.8 (0.3–1.9, p = 0.59) | ||
| 6–12 | 20 (10) | 15 (9) | 5 (14) | 1.3 (0.4–3.8, p = 0.66) | ||
| > 12 | 15 (7) | 15 (9) | 0 (0) | NA | ||
| Not planned | 24 (12) | 20 (12) | 4 (11) | 0.8 (0.2–2.3, p = 0.67) | ||
| Gravidity, n (%) | 0.87 | |||||
| 0 | 54 (27) | 43 (26) | 11 (30) | – | ||
| 1 | 66 (33) | 54 (33) | 12 (32) | 0.9 (0.4–2.2, p = 0.76) | 1.6 (0.5–5.4, p = 0.46) | |
| 2 + | 83 (41) | 69 (42) | 14 (38) | 0.8 (0.3–1.9, p = 0.60) | 2.6 (0.5–11, p = 0.22) | |
| Parity, n (%) | 0.59 | |||||
| 0 | 92 (45) | 73 (44) | 19 (51) | – | – | |
| 1 | 86 (42) | 71 (43) | 15 (41) | 0.8 (0.4–1.7, p = 0.59) | 0.5 (0.2–1.3, p = 0.14) | |
| 2 + | 25 (12) | 22 (13) | 3 (8) | 0.5 (0.1–1.7, p = 0.33) | 0.1 (0.01–0.6, p = 0.02) | |
| Previous miscarriages, n (%) | 0.46 | |||||
| 0 | 136 (67) | 108 (65) | 28 (76) | – | – | |
| 1 | 52 (26) | 45 (27) | 7 (19) | 0.6 (0.2–1.4, p = 0.27) | 0.5 (0.1–1.5, p = 0.20) | |
| 2 | 15 (7) | 13 (8) | 2 (5) | 0.6 (0.1–2.3, p = 0.51) | 0.2 (0.03–1.3, p = 0.12) | |
| Regular menstrual cycle, n (%) | 0.01 | |||||
| Yes | 165 (81) | 136 (82) | 29 (78) | – | ||
| No | 29 (14) | 26 (16) | 3 (8) | 0.5 (0.1–1.7, p = 0.34) | ||
| Unknown | 9 (4) | 4 (2) | 5 (14) | 5.9 (1.5–25, p = 0.01) | ||
| Previous PID, n (%) | 82 (40) | 69 (42) | 13 (35) | 0.59 | 0.8 (0.4–1.6, p = 0.47) | |
| Previous or prevalent chronic or psychiatric disease, n (%) | – | |||||
| 60 (30) | 50 (30) | 10 (27) | 0.86 | 0.9 (0.4–1.9, p = 0.71) | ||
| Last completed education, n (%) | 0.68 | |||||
| Grad. student (1–7 years) | 151 (74) | 123 (74) | 28 (76) | – | ||
| Grad. student studying | 25 (12) | 21 (13) | 4 (11) | 0.8 (0.2–2.4, p = 0.76) | ||
| Manual labor | 22 (11) | 17 (10) | 5 (14) | 1.3 (0.4–3.6, p = 0.64) | ||
| Elementary school | 5 (3) | 5 (3) | 0 (0) | NA | ||
| Self-attained physical health (1–5), n (%) | 0.19 | |||||
| Level 5 (best) | 40 (20) | 37 (22) | 3 (8) | – | ||
| Level 4 | 124 (61) | 97 (58) | 27 (73) | 3.4 (1.1–15, p = 0.05) | ||
| Level 3 | 32 (16) | 27 (16) | 5 (14) | 2.3 (0.5–12, p = 0.29) | ||
| Level 2 | 7 (3) | 5 (3) | 2 (5) | 4.9 (0.6–38, p = 0.12) | ||
| Physical activity per week (hours), n (%) | 0.52 | |||||
| 1–3 | 50 (25) | 43 (26) | 7 (19) | – | ||
| 4–6 | 75 (37) | 62 (37) | 13 (35) | 1.3 (0.5–3.7, p = 0.62) | ||
| 7 + | 78 (38) | 61 (37) | 17 (46) | 1.7 (0.7–4.8, p = 0.27) | ||
| Smoking, n (%) | 0.60 | |||||
| Never | 117 (58) | 92 (55) | 25 (68) | – | ||
| Previously | 31 (15) | 27 (16) | 4 (11) | 0.6 (0.2–1.6, p = 0.30) | ||
| Stoppeda | 41 (20) | 35 (21) | 6 (16) | 0.6 (0.2–1.6, p = 0.35) | ||
| Current | 14 (7) | 12 (7) | 2 (5) | 0.6 (0.1–2.4, p = 0.54) | ||
| Alcohol, n (%) | 0.10 | |||||
| None 6 months prior | 66 (33) | 54 (33) | 12 (32) | – | ||
| Stoppedb | 136 (67) | 112 (68) | 24 (65) | 1.0 (0.5–2.1, p = 0.93) | ||
| Current | 1 (1) | 0 (0) | 1 (3) | NA | ||
| Paternal datac | ||||||
| Age groups, n (%) | 0.01 | |||||
| < 30 | 71 (35) | 58 (35) | 13 (35) | – | ||
| 30–35 | 72 (36) | 65 (39) | 7 (19) | 0.5 (0.2–1.3, p = 0.14) | ||
| > 35 | 55 (27) | 35 (23) | 17 (46) | 2.0 (0.9–4.7, p = 0.10) | ||
| Age difference | 0.32 | |||||
| ± 5 years | 151 (74) | 126 (76) | 25 (68) | – | ||
| Father + 10 years | 16 (8) | 11 (7) | 5 (14) | 2.3 (0.7–7.0, p = 0.15) | ||
| Father + 5–10 years | 29 (14) | 23 (14) | 6 (16) | 1.3 (0.5–3.4, p = 0.59) | ||
| Mother + 5 years | 2 (1) | 1 (1) | 1 (3) | 5.0 (0.2–130, p = 0.26) | ||
| Self-attained physical health (1–5), n (%) | 0.57 | |||||
| Level 5 (best) | 44 (22) | 39 (24) | 5 (14) | – | ||
| Level 4 | 98 (48) | 78 (47) | 20 (54) | 2.0 (0.7–6.4, p = 0.20) | ||
| Level 3 | 46 (23) | 36 (22) | 10 (27) | 2.2 (0.7–7.5, p = 0.19) | ||
| Level 2 | 8 (4) | 6 (4) | 2 (5) | 2.6 (0.3–15, p = 0.31) | ||
| Level 1 | 2 (1) | 2 (1) | 0 (0) | NA | ||
| Physical activity per week (hours), n (%) | 0.35 | |||||
| 1–3 | 54 (27) | 43 (26) | 11 (30) | – | ||
| 4–6 | 68 (34) | 59 (36) | 9 (24) | 0.6 (0.2–1.6, p = 0.29) | ||
| 7 + | 76 (37) | 59 (36) | 17 (46) | 1.1 (0.5–2.7, p = 0.78) | ||
| Smoking, n (%) | 0.60 | |||||
| Never | 120 (59) | 99 (60) | 21 (57) | – | ||
| Previously | 22 (11) | 16 (10) | 6 (16) | 1.8 (0.6–4.9, p = 0.29) | ||
| Stoppeda | 11 (5) | 10 (6) | 1 (3) | 0.5 (0.03–2.7, p = 0.48) | ||
| Current | 50 (25) | 41 (25) | 9 (24) | 1.0 (0.4–2.4, p = 0.94) | ||
| Alcohol, n (%) | 0.51 | |||||
| No | 43 (21) | 36 (22) | 7 (19) | – | ||
| Yes | 155 (76) | 125 (75) | 30 (81) | 1.2 (0.5–3.3, p = 0.65) | ||
Students t-test, chi2-test or Mann–Whitney U-test, as appropriate
BMI body-mass index, PID pelvic inflammatory disease
aStopped 6 months before pregnancy
bStopped at pregnancy start
c5 fathers declined to participate