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,
Allegan County Health Department,
Michigan 1989-2022
1989801  148  184.8398  496.9255  318.4
1990691  144  208.4334  483.4213  308.2
1991584  128  219.2288  493.2168  287.7
1992593  114  192.2305  514.3174  293.4
1993792  144  181.8392  494.9256  323.2
1994829  150  180.9417  503.0262  316.0
1995788  128  162.4389  493.7271  343.9
1996796  135  169.6364  457.3297  373.1
1997835  147  176.0398  476.6290  347.3
1998831  141  169.7401  482.6289  347.8
1999837  135  161.3406  485.1296  353.6
2000842  148  175.8416  494.1278  330.2
2001864  137  158.6434  502.3293  339.1
2002882  150  170.1433  490.9299  339.0
2003862  135  156.6427  495.4300  348.0
2004853  137  160.6422  494.7294  344.7
2005864  143  165.5421  487.3300  347.2
2006937  150  160.1468  499.5319  340.4
2007861  178  206.7405  470.4278  322.9
2008834  155  185.9407  488.0272  326.1
2009807  150  185.9416  515.5241  298.6
2010763  134  175.6378  495.4251  329.0
2011741  155  209.2361  487.2225  303.6
2012763  147  192.7372  487.5244  319.8
2013766  128  167.1374  488.3264  344.6
2014855  152  177.8410  479.5293  342.7
2015892  148  165.9439  492.2305  341.9
2016883  152  172.1434  491.5297  336.4
2017851  147  172.7427  501.8277  325.5
2018893  152  170.2451  505.0290  324.7
2019787  142  180.4409  519.7236  299.9
2020770  129  167.5380  493.5261  339.0
2021771  122  158.2415  538.3234  303.5
2022771  144  186.8395  512.3232  300.9

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