Interpregnancy Interval after Miscarriage: Less than Six Months vs. Greater than Six Months

ABSTRACT

Background: After a woman experiences a pregnancy loss she often asks her clinician for recommendations on when to try conceiving again. Current recommendations to wait 6 or more months may not coincide with the woman’s reproductive desires. Several studies have looked at interpregnancy intervals following a live birth, but few have ventured to answer the clinical question of how long a woman should wait to conceive after a miscarriage.

Methods:  An exhaustive literature search using three databases was conducted with search terms: “interpregnancy interval,” “spontaneous abortion,” and “miscarriage.”  In addition bibliographies from several relevant background articles were used. Included were studies conducted on women with history of a spontaneous abortion at < 20 weeks of gestation who later became pregnant and evaluated interpregnancy intervals (IPI) with emphasis of IPI’s <6 months in comparison to IPI > 6 months. Studies needed to be based on humans and published in the English language. Exclusions were made for women whose preceding pregnancy resulted in live birth or if the study required recurrent spontaneous abortions (SABs).

Results: Three studies met inclusion and exclusion criteria and were included in this systematic review. One secondary review of a RCT assessed a population of 677 women who had a SAB then subsequently became pregnant found that live birth and complication outcomes were best in the 0-3 month IPI in comparison to longer IPI. A prospective cohort study that evaluated 4619 women who were nulliparous, had a SAB, and subsequently became pregnant found that women who conceived within 6 months after miscarriage had higher live birth outcomes with fewer complications. Another study with retrospective cohort design and a population of 30 937 Scottish women who had a SAB and subsequently became pregnant found that women with IPI <6 months had the highest live birth rate and lowest pregnancy complication rate.

Conclusion:  Decreasing interpregnancy interval to less than 6 months after spontaneous abortion is shown to be associated with a higher live birth rate and fewer complications. More research is needed to evaluate interpregnancy intervals less than 3 months in order to determine the benefit or risk of recommending a 0-3 month interpregnancy interval after miscarriage.

Keywords:  Interpregnancy interval, spontaneous abortion, miscarriage.

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REVIEWED STUDIES:

Wong LF, Schliep KC, Silver RM, et al. The effect of a very short interpregnancy interval and pregnancy outcomes following a previous pregnancy loss. Am J Obstet Gynecol. 2015;212:375.e1-375.11.

El Behery MM, Siam S, Seksaka MA, Ibrahim ZM. Reproductive performance in the next pregnancy for nulliparous women with history of first trimester spontaneous abortion. Arch Gynecol Obstet. 2013;288:939-944.

Love ER, Bhattacharya S, Smith NC, Bhattacharya S. Effect of interpregnancy interval on outcomes of pregnancy after miscarriage: retrospective analysis of hospital episode statistics in Scotland. BMJ. 2010;341:3967.

AUTHOR: Katie Volk is currently completing her second year in the School of PA Studies at Pacific University, Oregon.  She will graduate with an MS degree in August, 2016.