Table 1.

Number of singleton and multiple maternities and rate per 1000 maternities by year of birth and rate ratio compared with 1997, England 1997–2008

	All maternities	Singleton maternities	Multiple maternities
			All multiples			Twins			Triplets and above
	N	N	N	Rate/1000	Rate ratio	N	Rate/1000	Rate ratio	N	Rate/1000	Rate ratio
1997	602 383	593 558	8825	14.7	1	8526	14.2	1	299	0.50	1
				14.3 to 15.0	–		13.9 to 14.5	–		0.44 to 0.56	–
1998	596 232	587 530	8702	14.6	1.00	8399	14.1	1.00	303	0.51	1.02
				14.3 to 14.9	0.97 to 1.03		13.8 to 14.4	0.97 to 1.03		0.45 to 0.57	0.87 to 1.20
1999	583 714	575 172	8542	14.6	1.00	8286	14.2	1.00	256	0.44	0.88
				14.3 to 14.9	0.97 to 1.03		13.9 to 14.5	0.97 to 1.03		0.39 to 0.50	0.75 to 1.04
2000	567 157	558 765	8392	14.8	1.01	8136	14.3	1.01	256	0.45	0.91
				14.5 to 15.1	0.98 to 1.04		14.0 to 14.7	0.98 to 1.04		0.40 to 0.51	0.77 to 1.07
2001	558 109	549 757	8352	15.0	1.02	8140	14.6	1.03	212	0.38	0.77
				14.6 to 15.3	0.99 to 1.05		14.3 to 14.9	1.00 to 1.06		0.33 to 0.43	0.64 to 0.91
2002	560 122	551 598	8524	15.2	1.04	8357	14.9	1.05	167	0.30	0.60
				14.9 to 15.5	1.01 to 1.07		14.6 to 15.2	1.02 to 1.09		0.26 to 0.35	0.50 to 0.73
2003	584 180	575 394	8786	15.0	1.03	8649	14.8	1.05	137	0.23	0.47
				14.7 to 15.4	1.00 to 1.06		14.5 to 15.1	1.02 to 1.08		0.20 to 0.28	0.39 to 0.58
2004	601 147	591 971	9176	15.3	1.04	9020	15.0	1.06	156	0.26	0.52
				15.0 to 15.6	1.01 to 1.07		14.7 to 15.3	1.03 to 1.09		0.22 to 0.30	0.43 to 0.63
2005	606 808	597 618	9190	15.1	1.03	9043	14.9	1.05	147	0.24	0.49
				14.8 to 15.5	1.00 to 1.06		14.6 to 15.2	1.02 to 1.08		0.21 to 0.28	0.40 to 0.59
2006	628 974	619 205	9769	15.5	1.06	9620	15.3	1.08	149	0.24	0.48
				15.2 to 15.8	1.03 to 1.09		15.0 to 15.6	1.05 to 1.11		0.20 to 0.28	0.39 to 0.58
2007	648 385	638 315	10 070	15.5	1.06	9935	15.3	1.08	135	0.21	0.42
				15.2 to 15.8	1.03 to 1.09		15.0 to 15.6	1.05 to 1.11		0.18 to 0.25	0.34 to 0.51
2008	665 426	655 058	10 368	15.6	1.06	10 199	15.3	1.08	169	0.25	0.51
				15.3 to 15.9	1.03 to 1.09		15.0 to 15.6	1.05 to 1.11		0.22 to 0.30	0.42 to 0.62