Effect of interpregnancy interval on outcomes of pregnancy after recurrent pregnancy loss

Effect of interpregnancy interval on the risk of gestational diabetes mellitus during a second pregnancy

BACKGROUND

Interpregnancy interval (IPI) is associated with the risk of GDM in a second pregnancy. However, an optimal IPI is still need to be determined based on the characteristics of the population. This study aimed to analyze the effect of interpregnancy interval (IPI) on the risk of gestational diabetes mellitus (GDM) in the Chinese population.

METHODS

We conducted a retrospective cohort study on female participants who had consecutive deliveries at Peking University Shenzhen Hospital from 2013 to 2021. The IPI was categorized into 7 groups and included into the multivariate logistic regression model with other confound factors. Analysis was also stratified based on age of first pregnancy, BMI, and history of GDM. Adjusted OR values (aOR) and 95% confidence intervals (CI) calculated. The regression coefficient of IPI months on GDM prediction risk was analyzed using a linear regression model.

RESULTS

A total of 2,392 participants were enrolled. The IPI of the GDM group was significantly greater than that of the non-GDM group (P < 0.05). Compared with the 18-24 months IPI category, participants with longer IPIs (24-36 months, 36-48 months, 48-60 months, and ≥ 60 months) had a higher risk of GDM (aOR:1.585, 2.381, 2.488, and 2.565; 95% CI: 1.021-2.462, 1.489-3.809, 1.441-4.298, and 1.294-5.087, respectively). For participants aged < 30 years or ≥ 30 years or without GDM history, all longer IPIs (≥ 36 months) were all significantly associated with the GDM risk in the second pregnancy (P < 0.05), while any shorter IPIs (< 18 months) was not significantly associated with GDM risk (P > 0.05). For participants with GDM history, IPI 12-18 months, 24-36 months, 36-48 months, and ≥ 60 months were all significantly associated with the GDM risk (aOR: 2.619, 3.747, 4.356, and 5.373; 95% CI: 1.074-6.386, 1.652-8.499, 1.724-11.005, and 1.078-26.793, respectively), and the slope value of linear regression (0.5161) was significantly higher compared to participants without a history of GDM (0.1891) (F = 284.168, P < 0.001).

CONCLUSIONS

Long IPI increases the risk of GDM in a second pregnancy, but this risk is independent of maternal age. The risk of developing GDM in a second pregnancy for women with GDM history is more significantly affected by IPI.

Association of interpregnancy interval and risk of adverse pregnancy outcomes in woman by different previous gestational ages

BACKGROUND

With an increasing proportion of multiparas, proper interpregnancy intervals (IPIs) are urgently needed. However, the association between IPIs and adverse perinatal outcomes has always been debated. This study aimed to explore the association between IPIs and adverse outcomes in different fertility policy periods and for different previous gestational ages.

METHODS

We used individual data from China's National Maternal Near Miss Surveillance System between 2014 and 2019. Multivariable Poisson models with restricted cubic splines were used. Each adverse outcome was analyzed separately in the overall model and stratified models. The stratified models included different categories of fertility policy periods (2014-2015, 2016-2017, and 2018-2019) and infant gestational age in previous pregnancy (<28 weeks, 28-36 weeks, and ≥37 weeks).

RESULTS

There were 781,731 pregnancies enrolled in this study. A short IPI (≤6 months) was associated with an increased risk of preterm birth (OR [95% CI]: 1.63 [1.55, 1.71] for vaginal delivery [VD] and 1.10 [1.03, 1.19] for cesarean section [CS]), low Apgar scores and small for gestational age (SGA), and a decreased risk of diabetes mellitus in pregnancy, preeclampsia or eclampsia, and gestational hypertension. A long IPI (≥60 months) was associated with an increased risk of preterm birth (OR [95% CI]: 1.18 [1.11, 1.26] for VD and 1.39 [1.32, 1.47] for CS), placenta previa, postpartum hemorrhage, diabetes mellitus in pregnancy, preeclampsia or eclampsia, and gestational hypertension. Fertility policy changes had little effect on the association of IPIs and adverse maternal and neonatal outcomes. The estimated risk of preterm birth, low Apgar scores, SGA, diabetes mellitus in pregnancy, and gestational hypertension was more profound among women with previous term births than among those with preterm births or pregnancy loss.

CONCLUSION

For pregnant women with shorter or longer IPIs, more targeted health care measures during pregnancy should be formulated according to infant gestational age in previous pregnancy.

Interpregnancy interval after a miscarriage and obstetric outcomes in the subsequent pregnancy in a low-income setting, Nigeria: A cohort study

Objectives:

The aim of this study was to determine and compare the occurrence of adverse pregnancy outcomes in a cohort of pregnant women with interpregnancy interval of < and ⩾6 months (short and normal interpregnancy interval, respectively) following a spontaneous miscarriage in their last pregnancies.

Methods:

This was a cohort study that involved pregnant women with a spontaneous pregnancy loss in their last pregnancies. They were recruited at a gestational age of 13–15 weeks and followed up to determine the obstetric and foetal outcomes of their pregnancies at four tertiary hospitals in Nigeria from July 2018 to September 2019. Data collected were analysed using SPSS version 26.0. A Chi-square and multivariate logistic regression analysis were done, and a p-value of less than 0.05 was assumed to be statistically significant.

Results:

A total of 705 participants were studied, out of which 448 (63.5%) and 257 (36.5%) of the participants had short and normal interpregnancy interval after a spontaneous miscarriage. Over 80% of the participants had first-trimester pregnancy losses and were managed with manual vacuum aspiration in 73.3% of the cases. The majority, 87.5% for the normal interpregnancy interval cohort and 86.4% for the short interpregnancy interval cohort, had live births, while 8.5% and 10.1% of the women in the normal and short interpregnancy interval cohorts, respectively, had repeat miscarriages. There was no statistical difference in the occurrence of live births and repeat miscarriages between both cohorts (p > 0.05). There was no increased risk of occurrence of adverse foetomaternal outcomes in both groups (p > 0.05). Multivariate logistic regression analysis showed that there was no statistical difference in the occurrence adverse foetomaternal outcomes between the studied cohorts (p > 0.05).

Conclusion:

There was no significant difference in the occurrence of adverse maternal and foetal outcomes in the cohorts of mothers with short and normal interpregnancy interval following miscarriages in their last previous pregnancies.

The effects of a postmiscarriage menstrual period prior to reconceiving

BACKGROUND

The optimal interpregnancy interval after a single pregnancy loss is controversial. It is common obstetrical practice to recommend that women who have had a miscarriage in the first trimester of pregnancy should wait for 1 or more menstrual cycles before attempting to conceive again.

OBJECTIVE

This study aimed to assess whether conception before the first menstrual period after a spontaneous pregnancy loss is associated with a risk of repeat miscarriage or adverse perinatal outcomes.

STUDY DESIGN

This retrospective cohort study included 107 women who had a spontaneous miscarriage in the first trimester of pregnancy followed by a subsequent pregnancy with an interpregnancy interval of <12 weeks. All miscarriages had ended in either spontaneous expulsion of the products of conception or medical or surgical evacuation of the uterus. The perinatal outcome measures of 57 women who conceived after the first menstrual period following a spontaneous miscarriage were compared with perinatal outcome measures of 50 women who conceived before the first menstrual period following a spontaneous miscarriage. The primary outcome was rate of pregnancy loss, and the secondary outcomes were gestational age at delivery and birthweight.

RESULTS

The rate of recurrent miscarriage was 10.4% for women who conceived before the first menstrual period following a spontaneous miscarriage and 15.8% for those who conceived after (P=.604). There were no differences in the gestational age at delivery (38.9 vs 38.7 weeks; P=.66) or the birthweight (3347±173 vs 3412±156 g; P=.5) between the 2 groups. Other outcomes, such as mode of delivery and 5-minute Apgar score, were also similar for both groups. A multiple logistic regression analysis confirmed that conception before the first menstrual period following a spontaneous miscarriage was not associated with a higher incidence of subsequent miscarriage (odds ratio, 1.74; P=.46) or any other untoward outcome.

CONCLUSION

Conception shortly after a spontaneous miscarriage without waiting for at least the first postmiscarriage menstrual period is not associated with adverse maternal or neonatal outcomes compared with those of women with similar interpregnancy intervals who conceived after their next menstrual period.

Pregnancy intervals after stillbirth, neonatal death and spontaneous abortion and the risk of an adverse outcome in the next pregnancy in rural Bangladesh

Background

Studies have revealed associations between preceding short and long birth-to-birth or birth-to-pregnancy intervals and poor pregnancy outcomes. Most of these studies, however, have examined the effect of intervals that began with live births. Using data from Bangladesh, we examined the effect of inter-outcome intervals (IOI) starting with a non-live birth or neonatal death, on outcomes in the next pregnancy. Pregnancy spacing behaviors in rural northeast Bangladesh have changed little since 2004.

Methods

We analyzed pregnancy histories for married women aged 15-49 years who had outcomes between 2000 and 2006 in Sylhet, Bangladesh. We examined the effects of the preceding outcome and the IOI length on the risk of stillbirth, neonatal death and spontaneous abortion using multinomial logistic regression models.

Results

Data included 64,897 pregnancy outcomes from 33,495 mothers. Inter-outcome intervals of 27-50 months and live births were baseline comparators. Stillbirths followed by IOI’s <=6 months, 7-14 months or overall <=14 months had increased risks for spontaneous abortion with adjusted relative risk ratios (aRRR) and 95% confidence intervals = 29.6 (8.09, 108.26), 1.84 (0.84, 4.02) and 2.53 (1.19, 5.36), respectively. Stillbirths followed by IOIs 7-14 months had aRRR 2.00 (1.39, 2.88) for stillbirths.

Neonatal deaths followed by IOIs <=6 months had aRRR 28.2 (8.59, 92.63) for spontaneous abortion. Neonatal deaths followed by IOIs 7-14 and 15-26 months had aRRRs 3.08 (1.82, 5.22) and 2.32 (1.38, 3.91), respectively, for stillbirths; and aRRRs 2.81 (2.06, 3.84) and 1.70 (1.24, 3.84), respectively, for neonatal deaths.

Spontaneous abortions followed by IOIs <=6 months and 7-14 months had, respectively, aRRRs 23.21 (10.34, 52.13) and 1.80 (0.98, 3.33) for spontaneous abortion.

Conclusion

In rural northeast Bangladesh, short inter-outcome intervals after stillbirth, neonatal death and spontaneous abortion were associated with a high risk of a similar outcome in the next pregnancy. These findings are aligned with other studies from Bangladesh. Two studies from similar settings have found benefits of waiting six months before conceiving again, suggesting that incorporating this advice into programs should be considered. Further research is warranted to confirm these findings.

Electronic supplementary material

The online version of this article (10.1186/s12884-019-2203-0) contains supplementary material, which is available to authorized users.

Interpregnancy Interval After Pregnancy Loss and Risk of Repeat Miscarriage

OBJECTIVE

To assess whether interpregnancy interval length after a pregnancy loss is associated with risk of repeat miscarriage.

METHODS

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.

RESULTS

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.

CONCLUSION

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

BACKGROUND

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.

OBJECTIVE AND RATIONALE

Our aim was to determine if a short IPI (<6 months) following miscarriage is associated with adverse outcomes in the next pregnancy.

SEARCH METHODS

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.

OUTCOMES

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.

WIDER IMPLICATIONS

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.

Inter-pregnancy interval and adverse outcomes: Evidence for an additional risk in health disparate populations

OBJECTIVE

Short interpregnancy interval (IPI), <18 months between pregnancies, is a potential cause of adverse delivery and birth outcomes, and may be a particular issue among those with other risks. Our goal was to examine IPI and delivery/infant complications in Tennessee.

METHODS

Birth certificate/vital records data included 101,912 women with a previous delivery. IPI groups (<6, 6-12, 12-18, 18-60 months) were compared on outcomes.

RESULTS

Thirty-nine percent of the deliveries had IPI <18 months, 9% were <6 months, rates 11% and 27% higher than nationally. Women with IPI <18 months were younger, lower educated with lower income, had higher BMIs, and were more likely to be unmarried, smokers, and have begun prenatal care later (p < .001). In adjusted analyses, IPI <18 months predicted elevated risk for precipitous labor, low-birth weight, preterm delivery, NICU admission, and infant mortality, with effects strongest for IPI <6 months. Finally, risks related to IPI <6 months were substantially higher for the lowest income women.

CONCLUSIONS

Rates of less than optimal IPI were high in this population already experiencing significant maternal-child health disparities, with short IPI a particular risk factor for poor outcomes for the most disadvantaged women, suggesting yet another precursor for adverse birth outcomes in those already most at risk.

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

OBJECTIVE

To compare time to pregnancy and live birth among couples with varying intervals of pregnancy loss date to subsequent trying to conceive date.

METHODS

In this secondary analysis of the Effects of Aspirin in Gestation and Reproduction trial, 1,083 women aged 18-40 years with one to two prior early losses and whose last pregnancy outcome was a nonectopic or nonmolar loss were included. Participants were actively followed for up to six menstrual cycles and, for women achieving pregnancy, until pregnancy outcome. We calculated intervals as start of trying to conceive date minus pregnancy loss date. Time to pregnancy was defined as start of trying to conceive until subsequent conception. Discrete Cox models, accounting for left truncation and right censoring, estimated fecundability odds ratios (ORs) adjusting for age, race, body mass index, education, and subfertility. Although intervals were assessed prior to randomization and thus reasoned to have no relation with treatment assignment, additional adjustment for treatment was evaluated given that low-dose aspirin was previously shown to be predictive of time to pregnancy.

RESULTS

Couples with a 0-3-month interval (n=765 [76.7%]) compared with a greater than 3-month (n=233 [23.4%]) interval were more likely to achieve live birth (53.2% compared with 36.1%) with a significantly shorter time to pregnancy leading to live birth (median [interquartile range] five cycles [three, eight], adjusted fecundability OR 1.71 [95% confidence interval 1.30-2.25]). Additionally adjusting for low-dose aspirin treatment did not appreciably alter estimates.

CONCLUSION

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

The effect of a very short interpregnancy interval and pregnancy outcomes following a previous pregnancy loss

OBJECTIVE

We sought to assess the relationship between a short interpregnancy interval (IPI) following a pregnancy loss and subsequent live birth and pregnancy outcomes.

STUDY DESIGN

A secondary analysis of women enrolled in the Effects of Aspirin in Gestation and Reproduction trial with a human chorionic gonadotropin-positive pregnancy test and whose last reproductive outcome was a loss were included in this analysis (n = 677). IPI was defined as the time between last pregnancy loss and last menstrual period of the current pregnancy and categorized by 3-month intervals. Pregnancy outcomes include live birth, pregnancy loss, and any pregnancy complications. These were compared between IPI groups using multivariate relative risk estimation by Poisson regression.

RESULTS

Demographic characteristics were similar between IPI groups. The mean gestational age of prior pregnancy loss was 8.6 ± 2.8 weeks. The overall live birth rate was 76.5%, with similar live birth rates between those with IPI ≤3 months as compared to IPI >3 months (adjusted relative risk [aRR], 1.07; 95% confidence interval [CI], 0.98-1.16). Rates were also similar for periimplantation loss (aRR, 0.95; 95% CI, 0.51-1.80), clinically confirmed loss (aRR, 0.75; 95% CI, 0.51-1.10), and any pregnancy complication (aRR, 0.88; 95% CI, 0.71-1.09) for those with IPI ≤3 months as compared to IPI >3 months.

CONCLUSION

Live birth rates and adverse pregnancy outcomes, including pregnancy loss, were not associated with a very short IPI after a prior pregnancy loss. The traditional recommendation to wait at least 3 months after a pregnancy loss before attempting a new pregnancy may not be warranted.