Table 4.
Obstetric and perinatal outcomes in the intention-to-treat population. Values are number (percentage) unless stated otherwise
| Blastocyst stage group (n=603) | Cleavage stage group (n=599) | Absolute difference (95% CI) | Risk ratio (95% CI) | |
|---|---|---|---|---|
| Cumulative results | ||||
| Induced abortion | 2 (0.3) | 4 (0.7) | −0.3 (−1.1 to 0.5) | 0.49 (0.09 to 2.20) |
| Stillbirth or intrauterine death | 0 | 1 (0.2) | NA | NA |
| Neonatal death | 0 | 0 | NA | NA |
| Perinatal death | 0 | 0 | NA | NA |
| Live births | n=355 | n=350 | ||
| Mean (SD) gestational age at delivery (weeks)* | 38.3 (2.8) | 38.7 (2.7) | −0.4 (−15.4 to 14.6) | NA |
| Mean (SD) birth weight (g)* | 3359 (596) | 3382 (571) | −23.2 (−11.2 to 65.1) | NA |
| Small for gestational age (<10 centile)* | 28 (8.0) | 31 (9.2) | −1.2 (−5.4 to 3.1) | 0.87 (0.54 to 1.43) |
| Large for gestational age (>90 centile)* | 28 (8.0) | 30 (8.8) | −0.9 (−5.0 to 3.3) | 0.90 (0.56 to 1.48) |
| Low birth weight (<2500 g)* | 26 (7.5) | 21 (6.2) | 1.2 (−2.5 to 5.0) | 1.20 (0.69 to 2.09) |
| Very low birthweight (<1500 g)* | 3 (0.9) | 3 (0.9) | −0.0 (−1.4 to 1.4) | 0.97 (0.20 to 4.76) |
| Preterm birth (gestation)*: | ||||
| <32 weeks | 3 (0.9) | 4 (1.2) | −0.3 (−1.8 to 1.2) | 0.73 (0.16 to 3.23) |
| 32-<37 weeks | 31 (8.9) | 16 (4.7) | 4.2 (0.5 to 7.9) | 1.87 (1.05 to 3.34) |
| Girls/boys*† | 165/181 (47.7) | 170/167 (50.4) | −2.8 (−10.3 to 4.7) | 0.94 (0.81 to 1.10) |
| Caesarean delivery* | 84 (24.1) | 81 (24.0) | 0.1 (−6.3 to 6.5) | 1.00 (0.77 to 1.31) |
| No of major congenital anomalies | 4 (1.1) | 4 (1.2) | −0.0 (−1.6 to 1.5) | 0.97 (0.25 to 3.87) |
| Twin deliveries | ||||
| Overall | 7 (2.0) | 9 (2.6) | −0.6 (−2.8 to 1.6) | 0.75 (0.29 to 2.01) |
| From SET‡ | 1 (0.3) | 2 (0.6) | −0.3 (−1.3 to 0.7) | 0.49 (0.04 to 5.37) |
| From DET | 6 (1.7) | 7 (2.0) | −0.3 (−2.3 to 1.7) | 0.83 (0.28 to 2.46) |
| From natural conception | 0 | 0 | NA | NA |
CI=confidence interval; DET=double embryo transfer; NA=not applicable; SD=standard deviation; SET=single embryo transfer.
*
Singleton pregnancies.
†
Data were missing for sex in two liveborn babies in blastocyst stage group.
‡
One intrauterine death occurred at 21 weeks.