TABLE 4.
Summary table of fetal and neonatal outcomes for effect and heterogeneity: twin compared with singleton pregnancies after in vitro fertilization/intracytoplasmic sperm injection treatment.
| Outcome | Heterogeneity, I2 % (P value) | OR (95% CI) |
|---|---|---|
| Congenital anomaly | 0 (.84) | 1.1 (1.0–1.2) |
| Preterm birth rate (<37 wk) | 97 (<.01) | 8.3 (7.8–8.9) |
| Early preterm birth rate (<32 wk) | 88 (<.01) | 3.5 (3.1–3.9) |
| Very preterm birth rate (<28 wk) | 82 (<.01) | 5.5 (5.2–5.9) |
| Low birth weight (<2,500 g) | 89 (<.01) | 10.6 (9.9–11.4) |
| NICU/SCBU admission rate | 91 (<.01) | 6.5 (5.8–7.3) |
| Perinatal mortality rate | 0 (.49) | 2.4 (2.1–2.8) |
| Stillbirth rate | 36 (.09) | 2.2 (1.8–2.6) |
| Mean birth weight (g) | 95 (<.01) | −856 (880–832)a |
| Mean gestational age (wk) | 95 (<.01) | −2.9 (−3.0 to −2.8)a |
Note: CI = confidence interval; NICU = neonatal intensive care unit; OR = odds ratio; SCBU = special care baby unit.
a
Mean difference (95% CI).