Table 3.
Pregnancy characteristics and outcome of spontaneous and assisted conceived monochorionic twins
| Monochorionic twins | ||||
|---|---|---|---|---|
| Spontaneous conception (n = 223) | Assisted conception (n =29) | p‐value | OR (95% CI) | |
| Maternal age, years (mean ± SD) | 31.4 ± 4.8 | 33.7 ± 3.1 | <0.001 | |
| Age ≥35 years, n (%) | 53 (23.7) | 24 (41.4) | 0.004 | 4.4 (2.3–8.5) |
| Parity, n (median, range) | 0 (0–8) | 0 (0–3) | 0.002 | |
| Nulliparous, n (%) | 95 (42.7) | 23 (79.3) | <0.001 | 7.5 (3.6–15.5) |
| Imminent preterm labor, n (%) | 42 (18.8) | 4 (13.8) | 0.353 | |
| Hypertensive disorders, n (%) | 31 (13.9) | 7 (24.1) | 0.040 | 2.0 (1.0–3.8) |
| Pregnancy‐induced and pre‐existing hypertension, n (%) | 17 (7.6) | 3 (10.3) | 0.467 | |
| Preeclampsia, n (%) | 17 (7.6) | 4 (13.9) | 0.108 | |
| Diabetes, n (%) | 5 (2.2) | 3 (10.3) | 0.001 | 5.0 (1.8–14.4) |
| Cesarean section, n (%) | 104 (47.2) | 15 (54.4) | 0.305 | |
| Elective CS, n (%) | 48 (21.7) | 7 (22.4) | 0.901 | |
| Emergency CS, n (%) | 56 (25.3) | 9 (31.6) | ||
| n = 446 fetuses | n = 58 fetuses | |||
| Gestational age, weeks (median, range) | 36+4 (20+2–40+4) | 36+3 (23+0–37+2) | 0.971 | |
| <32 weeks, n (%) | 60 (13.4) | 8 (13.8) | 0.938 | |
| 32–37 weeks, n (%) | 212 (47.4) | 26 (44.8) | 0.709 | |
| ≥37 weeks, n (%) | 174 (39.1) | 24 (41.4) | 0.744 | |
| Birthweight, grams (mean ± SD) | 2268 ± 610 | 2133 ± 681 | 0.118 | |
| SGA, n (%) | 63 (14.1) | 10 (17.2) | 0.526 | |
| Low birthweight, n (%) | 275 (61.5) | 40 (69.0) | 0.271 | |
| Very low birthweight, n (%) | 53 (11.9) | 11 (19.0) | 0.126 | |
| Mortality | ||||
| IUFD, n (%) | 11 (2.5) | 1 (1.7) | 0.729 | |
| Early NND, n (%) | 13 (2.9) | 2 (3.4) | 0.820 | |
| Late NND, n (%) | 0 | 2 (3.4) | <0.001 | N/C |
| Neonatal morbiditya | ||||
| RDS, n (%) | 35 (7.8) | 11 (19.0) | 0.006 | 2.8 (5.3–2.8) |
| IVH, n (%) | 13 (2.9) | 2 (3.4) | 0.820 | |
| NEC, n (%) | 8 (1.8) | 5 (8.6) | 0.002 | 5.2 (1.6–16.4) |
| Sepsis, n (%) | 36 (8.1) | 3 (5.2) | 0.439 | |
| Major neonatal morbidity, n (%)a | 64 (14.3) | 14 (24.1) | 0.052 | |
| Admission to NICU, n (%)a | 102 (22.8) | 16 (27.6) | 0.420 | |
Abbreviations: CI, confidence interval; CS, cesarean section; IUFD, intrauterine fetal death; IVH, intraventricular hemorrhage; NEC, necrotizing enterocolitis; NICU, neonatal intensive care unit; NND, neonatal death; OR, odds ratio; RDS, respiratory distress syndrome; SGA, small for gestational age.
a
Excluding intrauterine fetal deaths.