| Table 3. Multiple pregnancy rate according to woman’s age category. RLA 1998-2008 | |||||||||||
| Clinical pregnancies according to gestational order in women aged ≤34 years old | |||||||||||
| 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | |
| n | 1,568 | 1,843 | 1,815 | 2,276 | 2,431 | 2,659 | 2,895 | 3,127 | 3,434 | 3,853 | 3,946 |
| Gestational order (%) | |||||||||||
| Singleton | 66% | 65% | 66% | 66% | 66% | 68% | 69% | 71% | 72% | 72% | 73% |
| Twin | 23% | 23% | 26% | 24% | 25% | 26% | 25% | 24% | 24% | 24% | 22% |
| ≥Triplet | 10% | 11% | 9% | 9% | 9% | 8% | 7% | 6% | 5% | 5% | 6% |
| Clinical pregnancies according to gestational order in women aged 35 to 39 years old | |||||||||||
| 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | |
| n | 869 | 944 | 963 | 1,272 | 1,439 | 1,531 | 1,840 | 1,982 | 2,268 | 2,674 | 2,819 |
| Gestational order (%) | |||||||||||
| Singleton | 75% | 76% | 73% | 72% | 71% | 72% | 73% | 74% | 80% | 80% | 79% |
| Twin | 19% | 19% | 21% | 21% | 21% | 22% | 20% | 22% | 18% | 17% | 18% |
| ≥Triplet | 6% | 6% | 6% | 7% | 7% | 5% | 7% | 4% | 3% | 3% | 2% |
| Clinical pregnancies according to gestational order in women aged ≥40 years old | |||||||||||
| 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | |
| n | 197 | 226 | 248 | 315 | 448 | 437 | 504 | 681 | 604 | 720 | 751 |
| Gestational order (%) | |||||||||||
| Singleton | 82% | 84% | 79% | 83% | 78% | 75% | 79% | 81% | 85% | 88% | 87% |
| Twin | 14% | 14% | 18% | 14% | 18% | 18% | 16% | 16% | 14% | 10% | 11% |
| ≥Triplet | 4% | 2% | 3% | 3% | 5% | 7% | 5% | 4% | 2% | 2% | 1% |
Numbers may not add up to 100% due to rounding.