interpregnancy

Interpregnancy interval (IPI) refers to the period between the end of one pregnancy and the conception of the next. It is typically measured from the date of delivery to the estimated date of conception of the subsequent pregnancy, and can also be approximated by using the delivery date and the gestational age of the next pregnancy. The concept is used in obstetrics and public health to understand how spacing between pregnancies affects maternal and child outcomes.

Short IPI, often defined as less than about 18 months, has consistently been associated with higher risks of preterm birth, low birth weight, small-for-gestational-age infants, and perinatal death. Some studies also link short intervals to increased maternal anemia and postpartum complications. Long IPI, such as several years between pregnancies, shows more variable associations; risks may be elevated in women who are older or who have underlying fertility problems, but the evidence is less uniform than for short intervals.

Guidelines on optimal spacing vary by organization and individual health status. Many public health recommendations emphasize aiming for an interpregnancy interval of roughly 18 to 24 months after a live birth to reduce adverse outcomes. After a miscarriage or abortion, guidance is more individualized and often less restrictive, depending on maternal health and fertility desires. Contraception, breastfeeding patterns, and overall maternal health influence IPI and can be addressed through postpartum care and family planning services.