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,
Macomb County, Michigan 1989-2018
19895,357  947  176.82,540  474.11,870  349.1
19904,575  796  174.02,156  471.31,623  354.8
19912,438  431  176.81,179  483.6828  339.6
19921,331  236  177.3633  475.6462  347.1
19935,320  857  161.12,657  499.41,806  339.5
19945,414  913  168.62,618  483.61,883  347.8
19955,190  792  152.62,489  479.61,909  367.8
19965,328  835  156.72,572  482.71,921  360.5
19975,153  788  152.92,454  476.21,911  370.9
19985,087  784  154.12,418  475.31,885  370.6
19994,935  796  161.32,351  476.41,788  362.3
20005,306  863  162.62,541  478.91,902  358.5
20015,181  750  144.82,460  474.81,971  380.4
20025,053  812  160.72,397  474.41,844  364.9
20035,003  856  171.12,252  450.11,895  378.8
20044,936  845  171.22,266  459.11,825  369.7
20054,974  846  170.12,314  465.21,814  364.7
20065,351  923  172.52,432  454.51,996  373.0
20075,178  871  168.22,393  462.11,914  369.6
20084,872  846  173.62,235  458.71,791  367.6
20094,566  761  166.72,080  455.51,725  377.8
20104,551  645  141.72,089  459.01,817  399.3
20114,484  702  156.62,031  452.91,751  390.5
20124,589  720  156.92,023  440.81,846  402.3
20134,865  730  150.12,144  440.71,991  409.2
20144,938  835  169.12,135  432.41,968  398.5
20155,086  848  166.72,228  438.12,010  395.2
20165,196  800  154.02,332  448.82,064  397.2
20175,194  863  166.22,331  448.82,000  385.1
20185,089  829  162.92,283  448.61,977  388.5

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;1990-2018 Geocoded Michigan Birth Certificate Registries.
Division for Vital Records & Health Statistics, Michigan Department of Health & Human Services