Number & Rate of Live Births by Interpregnancy Interval and by Year,
Michigan 1989-2022

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	72,706	14,046	193.2	33,254	457.4	25,406	349.4
1990	56,668	11,582	204.4	25,800	455.3	19,286	340.3
1991	42,993	9,223	214.5	19,267	448.1	14,503	337.3
1992	33,927	7,204	212.3	15,424	454.6	11,299	333.0
1993	78,460	15,930	203.0	36,511	465.3	26,019	331.6
1994	75,931	14,651	193.0	34,768	457.9	26,512	349.2
1995	72,682	12,952	178.2	33,451	460.2	26,279	361.6
1996	72,001	12,397	172.2	33,307	462.6	26,297	365.2
1997	73,124	12,609	172.4	33,224	454.4	27,291	373.2
1998	73,192	12,320	168.3	33,292	454.9	27,580	376.8
1999	71,707	11,979	167.1	32,654	455.4	27,074	377.6
2000	73,978	12,586	170.1	33,557	453.6	27,835	376.3
2001	73,370	12,141	165.5	33,535	457.1	27,694	377.5
2002	71,010	12,015	169.2	32,598	459.1	26,397	371.7
2003	70,682	12,346	174.7	32,194	455.5	26,142	369.9
2004	69,798	12,179	174.5	31,836	456.1	25,783	369.4
2005	69,035	12,257	177.5	31,245	452.6	25,533	369.9
2006	69,679	12,448	178.6	31,696	454.9	25,535	366.5
2007	67,750	12,253	180.9	30,820	454.9	24,677	364.2
2008	64,124	11,969	186.7	28,937	451.3	23,218	362.1
2009	62,003	11,106	179.1	28,358	457.4	22,539	363.5
2010	60,890	10,468	171.9	27,967	459.3	22,455	368.8
2011	60,929	10,425	171.1	27,593	452.9	22,911	376.0
2012	60,802	10,279	169.1	27,445	451.4	23,078	379.6
2013	62,125	10,415	167.6	27,957	450.0	23,753	382.3
2014	63,534	10,851	170.8	28,413	447.2	24,270	382.0
2015	65,134	11,144	171.1	29,212	448.5	24,778	380.4
2016	66,454	11,198	168.5	30,211	454.6	25,045	376.9
2017	65,046	10,863	167.0	29,626	455.5	24,557	377.5
2018	63,746	10,754	168.7	29,093	456.4	23,899	374.9
2019	62,507	10,432	166.9	28,215	451.4	23,860	381.7
2020	59,665	9,995	167.5	27,293	457.4	22,377	375.0
2021	59,976	10,039	167.4	27,914	465.4	22,023	367.2
2022	56,754	9,699	170.9	26,097	459.8	20,958	369.3

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;1990-2022 Geocoded Michigan Birth Certificate Registries.
Division for Vital Records & Health Statistics, Michigan Department of Health & Human Services