Trying to conceive after a pregnancy loss: how long should couples wait?

Trying to Conceive After an Early Pregnancy Loss: An Assessment on How Long Couples Should Wait

Giovane R et al., 2016 · Obstetrics & Gynecology · Open Access

Our study supports the hypothesis that there is no physiologic evidence for delaying pregnancy attempt after an early loss.

412: The effect of very short interpregnancy interval on pregnancy outcomes after previous pregnancy loss

Wong L et al., 2014 · American Journal of Obstetrics and Gynecology ·

Interpregnancy Interval After Pregnancy Loss and Risk of Repeat Miscarriage

Sundermann AC et al., 2017 · Obstetrics and gynecology

To assess whether interpregnancy interval length after a pregnancy loss is associated with risk of repeat miscarriage. This analysis includes pregnant women participating in the Right From the Start (2000-2012) community-based prospective cohort study whose most recent pregnancy before enrollment ended in miscarriage. Interpregnancy interval was defined as the time between a prior miscarriage and the last menstrual period of the study pregnancy. Miscarriage was defined as pregnancy loss before 20 weeks of gestation. Cox proportional hazard models were used to estimate crude and adjusted hazard ratios and 95% CIs for the association between different interpregnancy interval lengths and miscarriage in the study pregnancy. Adjusted models included maternal age, race, parity, body mass index, and education. Among the 514 study participants who reported miscarriage as their most recent pregnancy outcome, 15.7% had a repeat miscarriage in the study pregnancy (n=81). Median maternal age was 30 years (interquartile range 27-34) and 55.6% of participants had at least one previous livebirth (n=286). When compared with women with interpregnancy intervals of 6-18 months (n=136), women with intervals of less than 3 months (n=124) had the lowest risk of repeat miscarriage (7.3% compared with 22.1%; adjusted hazard ratio 0.33, 95% CI 0.16-0.71). Neither maternal race nor parity modified the association. Attempting to conceive immediately was not associated with increased risk of miscarriage in the next pregnancy. An interpregnancy interval after pregnancy loss of less than 3 months is associated with the lowest risk of subsequent miscarriage. This implies counseling women to delay conception to reduce risk of miscarriage may not be warranted.

Interpregnancy interval following miscarriage and adverse pregnancy outcomes: systematic review and meta-analysis

Kangatharan C et al., 2017 · Human reproduction update

A short interpregnancy interval (IPI) following a delivery is believed to be associated with adverse outcomes in the next pregnancy. The optimum IPI following miscarriage is controversial. Based on a single large-scale study in Latin and South America, the World Health Organization recommends delaying pregnancy for 6 months after a miscarriage to achieve optimal outcomes in the next pregnancy. Our aim was to determine if a short IPI (<6 months) following miscarriage is associated with adverse outcomes in the next pregnancy. Studies were retrieved from MEDLINE, Embase and Pubmed, with no time and language restrictions. The search strategy used a combination of Medical Subject Headings terms for miscarriage, IPI and adverse outcomes. Bibliographies of the retrieved articles were also searched by hand. All studies including women with at least one miscarriage, comparing subsequent adverse pregnancy outcomes for IPIs of less than and more than 6 months were included. Two independent reviewers screened titles and abstracts for inclusion. Characteristics of the studies were extracted and quality assessed using Critical Appraisal Skills Programme criteria. A systematic review and meta-analysis were conducted to compare short (<6 months) versus long (>6 months) IPI following miscarriage in terms of risk of further miscarriage, preterm birth, stillbirth, pre-eclampsia and low birthweight babies in the subsequent pregnancy. Review Manager 5.3 was used for conducting meta-analyses. Sixteen studies including 1 043 840 women were included in the systematic review and data from 10 of these were included in one or more meta-analyses (977 972 women). With an IPI of less than 6 months, the overall risk of further miscarriage (Risk ratio (RR) 0.82 95% CI 0.78, 0.86) and preterm delivery (RR 0.79 95% CI 0.75, 0.83) were significantly reduced. The pooled risks of stillbirth (RR 0.88 95% CI 0.76, 1.02); low birthweight (RR 1.05 95% CI 0.48, 2.29) and pre-eclampsia (RR 0.95 95% CI 0.88, 1.02) were not affected by IPI. Similar findings were obtained in subgroup analyses when IPI of <6 months was compared with IPI of 6-12 months and >12 months. This is the first systematic review and meta-analysis providing clear evidence that an IPI of less than 6 months following miscarriage is not associated with adverse outcomes in the next pregnancy. This information may be used to revise current guidance.