Clinical Edge

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Unintended Pregnancy & Interpregnancy Interval

Contraception; ePub 2018 Mar 1; Ahrens, et al

Unintended pregnancies are associated with shorter interpregnancy interval (IPI) across the reproductive age spectrum, a recent study found. Using data from the National Survey of Family Growth, researchers estimated the percentage of pregnancies that were unintended among IPI groups (<6, 6-11, 12-17, 18-23, >24 months) by maternal age at last live birth (15-19, 20-24, 25-29, 30-44 years). They found:

  • ∼40% of pregnancies were unintended and 36% followed an IPI <18 months.
  • The percentage of pregnancies that were unintended decreased as IPI increased within each maternal age group.


Ahrens KA, Thoma M, Copen C, et al. Unintended pregnancy and interpregnancy interval by maternal age, National Survey of Family Growth. [Published online ahead of print March 1, 2018]. Contraception. doi:10.1016/j.contraception.2018.02.013.