YearMultiparous MothersInterpregnancy Interval
Short IPIIPI of 12-35 MonthsIPI of 36 Months and over
NumberRateNumberRateNumberRate
Number & Rate of Live Births by Interpregnancy Interval and by Year,
Hillsdale County, Michigan 1989-2022
1989373  83  222.5161  431.6129  345.8
1990314  70  222.9134  426.8110  350.3
1991316  79  250.0133  420.9104  329.1
1992272  73  268.4119  437.580  294.1
1993336  66  196.4156  464.3114  339.3
1994319  55  172.4151  473.4113  354.2
1995334  61  182.6156  467.1117  350.3
1996299  51  170.6139  464.9109  364.5
1997315  49  155.6135  428.6131  415.9
1998304  63  207.2131  430.9110  361.8
1999333  57  171.2145  435.4131  393.4
2000371  72  194.1175  471.7124  334.2
2001340  59  173.5155  455.9126  370.6
2002370  66  178.4178  481.1126  340.5
2003325  68  209.2150  461.5107  329.2
2004379  74  195.3181  477.6124  327.2
2005358  72  201.1168  469.3118  329.6
2006353  74  209.6160  453.3119  337.1
2007387  95  245.5170  439.3122  315.2
2008356  84  236.0155  435.4117  328.7
2009332  78  234.9160  481.994  283.1
2010345  69  200.0175  507.2101  292.8
2011306  70  228.8139  454.297  317.0
2012289  62  214.5126  436.0101  349.5
2013341  68  199.4156  457.5117  343.1
2014345  79  229.0163  472.5103  298.6
2015308  67  217.5156  506.585  276.0
2016370  97  262.2155  418.9118  318.9
2017342  77  225.1174  508.891  266.1
2018331  76  229.6154  465.3101  305.1
2019304  62  203.9149  490.193  305.9
2020301  64  212.6161  534.976  252.5
2021316  58  183.5148  468.4110  348.1
2022247  52  210.5114  461.581  327.9
        

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