Number & Rate of Live Births by Interpregnancy Interval and by Year,
City Of Detroit Health Department,
Michigan 1989-2023

Year	Multiparous Mothers	Interpregnancy Interval
		Short IPI		IPI of 12-35 Months		IPI of 36 Months and over
		Number	Rate	Number	Rate	Number	Rate
1989	8,787	2,080	236.7	3,254	370.3	3,453	393.0
1990	8,546	2,312	270.5	3,123	365.4	3,111	364.0
1991	5,846	1,708	292.2	2,050	350.7	2,088	357.2
1992	5,326	1,493	280.3	2,037	382.5	1,796	337.2
1993	11,978	3,361	280.6	4,678	390.5	3,939	328.9
1994	11,035	2,862	259.4	4,158	376.8	4,015	363.8
1995	9,505	2,132	224.3	3,716	391.0	3,657	384.7
1996	9,031	1,794	198.6	3,579	396.3	3,658	405.0
1997	9,269	1,832	197.6	3,457	373.0	3,980	429.4
1998	8,946	1,673	187.0	3,198	357.5	4,075	455.5
1999	8,594	1,583	184.2	3,084	358.9	3,927	456.9
2000	8,890	1,653	185.9	3,191	358.9	4,046	455.1
2001	8,669	1,604	185.0	3,125	360.5	3,940	454.5
2002	7,954	1,457	183.2	2,871	361.0	3,626	455.9
2003	7,806	1,419	181.8	2,788	357.2	3,599	461.1
2004	7,331	1,338	182.5	2,676	365.0	3,317	452.5
2005	7,137	1,405	196.9	2,483	347.9	3,249	455.2
2006	7,245	1,392	192.1	2,556	352.8	3,297	455.1
2007	6,379	1,264	198.2	2,251	352.9	2,864	449.0
2008	5,714	1,110	194.3	2,065	361.4	2,539	444.3
2009	5,555	1,102	198.4	1,904	342.8	2,549	458.9
2010	5,666	1,126	198.7	2,043	360.6	2,497	440.7
2011	5,689	1,150	202.1	1,980	348.0	2,559	449.8
2012	5,535	1,081	195.3	2,028	366.4	2,426	438.3
2013	5,583	1,079	193.3	2,024	362.5	2,480	444.2
2014	5,602	1,115	199.0	1,974	352.4	2,513	448.6
2015	5,902	1,160	196.5	2,096	355.1	2,646	448.3
2016	5,781	1,123	194.3	2,031	351.3	2,627	454.4
2017	5,917	1,097	185.4	2,134	360.7	2,686	453.9
2018	5,885	1,148	195.1	2,074	352.4	2,663	452.5
2019	5,825	1,147	196.9	2,005	344.2	2,673	458.9
2020	5,435	1,059	194.8	1,876	345.2	2,500	460.0
2021	4,966	900	181.2	1,723	347.0	2,343	471.8
2022	4,799	858	178.8	1,669	347.8	2,272	473.4
2023	4,226	774	183.2	1,427	337.7	2,025	479.2

Notes:

Rates are per 1,000 multiparous mothers.

Inter-pregnancy Interval (IPI) is the time in months between the date of last menstrual period of current pregnancy and the date of previous live birth among multiparous mothers. (This definition of IPI is sometimes called the "birth-to-birth interval, minus 9 months.")

Short IPI

The IPI is less than 12 months.

Source: 1989 Michigan Birth Certificate Registry;1990-2023 Geocoded Michigan Birth Certificate Registries.
Division for Vital Records & Health Statistics, Michigan Department of Health & Human Services