Table 2.
The incidences of adverse fetal outcomes reported in the literature
| Study period | Number of cases (controls) | Preterm delivery (< 37 wk) | Abnormal CTG (timing) | Apgar score ≤ 7 (min) | Meconium staining of amniotic fluid | PPH (> 500 mL) | References |
| 1951-1983 | 100 (156) | 38% | - | - | - | 7% | [12] |
| 38% U | |||||||
| 1963-1976 | 42 (42) | 39% | - | - | - | 19% | [4] |
| 39% S | |||||||
| 1965-1974 | 56 | 36% | 14% (NS) | - | 27% | 9% | [38] |
| 36% S | 8 B | NS | |||||
| 1971-1972 | 116 (116) | - | 19% (labour) | 7% (1) | 28% | - | [13] |
| 3% LD | 3% (5) | 7% < 37 wk | |||||
| 16% B or T | 21% > 37 wk | ||||||
| 1971-1974 | 100 (100) | - | - | 10% (1) | 12% | - | [23] |
| 8% (5) | NS | ||||||
| 1975-1984 | 83 | 44% | - | - | 45% | - | [46] |
| 44% S | 10% < 37 wk | ||||||
| 35% > 37 wk | |||||||
| 1979-1981 | 18 | - | - | - | 58.30% | 22% | [39] |
| NS | |||||||
| 1980–1981 | 117 | - | 14% (antepartum) | 10% (NS) | 16.20% | - | [48] |
| 4% (labour) | NS | ||||||
| 1988-1990 | 320 (320) | 19% | 12.8% (NS) | 8% (1) | 38% | - | [18] |
| 12% S | 2% (5) | 13% < 37 wk | |||||
| 7% I | 25% > 37 wk | ||||||
| 1988-1995 | 79 (792) | 14% | 2% (NS) | None | 44% | - | [57] |
| 14% S | 2% B | NS | |||||
| 1989-1995 | 50 | 60% | - | - | - | 2% | [56] |
| 60% U | |||||||
| 1989-1997 | 206 | 27% | - | 1% (5) | 21% | - | [20] |
| 4% S | 5% < 37 wk | ||||||
| 23% I | 16% > 37 wk | ||||||
| 1990-1996 | 91 (16, 818) | 14% | 20% (labour) | 8% (1) | 15% | - | [11] |
| 14% U | 2% (5) | NS | |||||
| 1999-2001 | 70 | 17% | - | - | 14% | 17% | [30] |
| 6% S | 4% < 37 wk | ||||||
| 11% I | 10% > 37 wk | ||||||
| 1999-2002 | 690 (44, 792) | 12% | 7%3 | 7%3 | 25% | - | [25] |
| 12% U | |||||||
| 1999-20031 | 352 | 38% | - | - | - | - | [31] |
| 16% S | |||||||
| 22% I | |||||||
| 2000-2007 | 122 | 4% | - | 8% (1) | 13% | 7% | [49] |
| 4% S | 2% (5) | ||||||
| 2003-2005 | 8 | 50% | - | - | 62% | - | [14] |
| 50% U | NS |
S: Spontaneous preterm labour; I: Iatrogenic preterm labour; U: Unspecified preterm labour; NS: Not specified; B: Bradycardia; T: Tachycardia; LD: Late decelerations; PPH: Post-partum hemorrhage; -: Not reported.
1
Cases were recruited between 1999 and 2003, but the affected pregnancies had occurred from 1986;
2
Controls in this study had a history of stillbirth in a previous pregnancy;
3
Glantz et al[25] report findings of asphyxial events (defined as operative delivery due to abnormal CTG, post-partum umbilical artery pH < 7.05 or Apgar score < 7 at 5 min).