BACKGROUND: Short inter-pregnancy or birth interval is associated with an increased risk of adverse perinatal outcomes. However, some emerging evidence questions this association and there are also inconsistencies among the existing findings. This study aimed to systematically review the evidence regarding the effect of short inter-pregnancy or birth intervals on adverse perinatal outcomes in the Asia-Pacific region.
METHODS: A comprehensive search of five databases was conducted targeting studies published between 2000 to 2023. Studies that reported on short inter-pregnancy or birth interval and examined adverse perinatal outcomes, such as low birthweight (LBW) preterm birth (PTB), small for gestational age (SGA), and neonatal mortality were included and appraised for methodological quality using the Joanna Briggs Institute critical appraisal tools. Three reviewers independently screened the studies and performed data extraction. Narrative synthesis and meta-analyses were conducted to summarise the key findings.
RESULTS: A total of 41 studies that fulfilled the inclusion criteria were included. A short-interpregnancy interval was associated with an increased risk of low birthweight (odds ratio [OR] = 1.65; 95%CI:1.39, 1.95), preterm birth (OR = 1.50; 95%CI: 1.35, 1.66), and small for gestational age (OR = 1.24; 95%CI:1.09, 1.41). We also found elevated odds of early neonatal mortality (OR = 1.91; 95%CI: 1.11, 3.29) and neonatal mortality (OR = 1.78; 95%CI: 1.25, 2.55) among women with short birth intervals.
CONCLUSIONS: This review indicates that both short inter-pregnancy and birth interval increased the risk of adverse perinatal outcomes. This underscores the importance of advocating for and implementing strategies to promote optimal pregnancy and birth spacing to reduce the occurrence of adverse perinatal outcomes. Reproductive health policies and programs need to be further strengthened and promote access to comprehensive family planning services and increase awareness about the importance of optimal pregnancy and birth spacing.

UNASSIGNED: Short birth interval is associated with an increased risk of adverse health outcomes for mothers and children. Despite this, there is a lack of comprehensive evidence on short birth interval in the Asia-Pacific region. Thus, this study aimed to synthesise evidence related to the definition, classification, prevalence, and predictors of short birth interval in the Asia-Pacific region.
UNASSIGNED: Five databases (MEDLINE, Scopus, Cumulative Index to Nursing and Allied Health Literature, Maternity and Infant Care, and Web of Science) were searched for studies published between September 2000 and May 2023 (the last search was conducted for all databases in May 2023). We included original studies published in English that reported on short birth interval in the Asia-Pacific region. Studies that combined birth interval with birth order, used multi-country data and were published as conference abstracts and commentaries were excluded. Three independent reviewers screened the articles for relevancy, and two reviewers performed the data extraction and quality assessment. The risk of bias was assessed using the Joanna Briggs Institute critical appraisal tool. The findings were both qualitatively and quantitatively synthesised and presented.
UNASSIGNED: A total of 140 studies met the inclusion criteria for this review. About 58% (n = 82) of the studies defined short birth interval, while 42% (n = 58) did not. Out of 82 studies, nearly half (n = 39) measured a birth-to-birth interval, 37 studies measured a birth-to-pregnancy, four measured a pregnancy-to-pregnancy, and two studies measured a pregnancy loss-to-conception. Approximately 39% (n = 55) and 6% (n = 8) of studies classified short birth intervals as <24 months and <33 months, respectively. Most of the included studies were cross-sectional, and about two-thirds had either medium or high risk of bias. The pooled prevalence of short birth interval was 33.8% (95% confidence interval (CI) = 23.0-44.6, I2 = 99.9%, P < 0.01) among the studies that used the World Health Organization definition.
UNASSIGNED: This review\'s findings highlighted significant variations in the definition, measurement, classification, and reported prevalence of short birth interval across the included studies. Future research is needed to harmonise the definition and classification of short birth interval to ensure consistency and comparability across studies and facilitate the development of targeted interventions and policies.
UNASSIGNED: PROSPERO CRD42023426975.

Child malnutrition remains a significant concern in the Asia-Pacific region, with short birth intervals recognised as a potential risk factor. However, evidence of this association is inconclusive. This study aimed to systematically review the existing evidence and assess the summary effects of short birth interval on child malnutrition in the Asia-Pacific region. Five electronic databases were searched in May 2023 to identify relevant studies reporting the association between short birth interval and child malnutrition, including stunting, wasting, underweight, anaemia and overall malnutrition, in Asia-Pacific region between September 2000 and May 2023. Fixed-effects or random-effects meta-analysis was performed to estimate the summary effects of short birth interval on child malnutrition. Out of 56 studies meeting the inclusion criteria, 48 were included in quantitative synthesis through meta-analysis. We found a slightly higher likelihood of stunting (n = 25, odds ratio [OR] = 1.13; 95% confidence interval [CI]: 0.97-1.32) and overall malnutrition (n = 3, OR = 2.42; 95% CI: 0.88-6.65) among children born in short birth intervals compared to those with nonshort intervals, although the effect was not statistically significant. However, caution is warranted due to identified heterogeneity across studies. Subgroup analysis demonstrated significant effects of short birth intervals on child malnutrition in national-level studies and studies with larger sample sizes. These findings underscore short birth intervals as a significant contributor to child malnutrition in the Asia-Pacific region. Implementing effective policies and programs is vital to alleviate this burden, ultimately reducing child malnutrition and associated adverse outcomes, including child mortality.

Short birth interval (SBI) has been linked to an increased risk of adverse maternal, perinatal, infant and child health outcomes. However, the prevalence and maternal and child health impacts of SBI in the Asia-Pacific region have not been well understood. This study aims to identify and summarise the existing evidence on SBI including its definition, measurement prevalence, determinants and association with adverse maternal and child health outcomes in the Asia-Pacific region.
Five databases (MEDLINE, Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Maternity and Infant Care, and Web of Science (WoS)) will be systematically searched from September 2000 up to May 2023. Data will be extracted, charted, synthesised and summarised based on the outcomes measured, and where appropriate, meta-analysis will be performed. The risk of bias will be assessed using Joanna Briggs Institute quality appraisal. Grading of Recommendation Assessment, Development and Evaluation framework will be used to evaluate the quality of cumulative evidence from the included studies.
This review does not require ethics approval. Findings will be disseminated through peer-reviewed publications, policy briefs and conference presentations.
A protocol will be registered on PROSPERO for each separate outcome before performing the review.Cite Now.

Although the risk of autism spectrum disorder (ASD) has been reported to be associated with interpregnancy intervals (IPIs), their association remains debatable due to inconsistent findings in existing studies. Therefore, the present study aimed to explore their association. PubMed, Embase, Web of Science, and the Cochrane Library were systematically retrieved up to May 25, 2022. An updated search was performed on May 25, 2023, to encompass recent studies. The quality of the included studies was assessed using the Newcastle-Ottawa Scale (NOS). Our primary outcome measures were expressed as adjusted odds ratios (ORs). Given various control measures for IPI and diverse IPI thresholds in the included studies, a Bayesian network meta-analysis was performed. Eight studies were included, involving 24,865 children with ASD and 2,890,289 children without ASD. Compared to an IPI of 24 to 35 months, various IPIs were significantly associated with a higher risk of ASD (IPIs < 6 months: OR = 1.63, 95% CI 1.53-1.74, n = 5; IPIs of 6-11 months: OR = 1.50, 95% CI 1.42-1.59, n = 4; IPIs of 12-23 months: OR = 1.19, 95% CI 1.12-1.23, n = 10; IPIs of 36-59 months: OR = 0.96, 95% CI 0.94-0.99, n = 2; IPIs of 60-119 months: OR = 1.15, 95% CI 1.10-1.20, n = 4; IPIs > 120 months: OR = 1.57, 95% CI 1.43-1.72, n = 4). After adjusting confounding variables, our analysis delineated a U-shaped restricted cubic spline curve, underscoring that both substantially short (< 24 months) and excessively long IPIs (> 72 months) are significantly correlated with an increased risk of ASD.  Conclusion: Our analysis indicates that both shorter and longer IPIs might predispose children to a higher risk of ASD. Optimal childbearing health and neurodevelopmental outcomes appear to be associated with a moderate IPI, specifically between 36 and 60 months. What is Known: • An association between autism spectrum disorder (ASD) and interpregnancy intervals (IPIs) has been speculated in some reports. • This association remains debatable due to inconsistent findings in available studies. What is New: • Our study delineated a U-shaped restricted cubic spline curve, suggesting that both shorter and longer IPIs predispose children to a higher risk of ASD. • Optimal childbearing health and neurodevelopmental outcomes appear to be associated with a moderate IPI, specifically between 36 and 60 months.

The association between extreme birth spacing and adverse outcomes is controversial, and available evidence is fragmented into different classifications of birth spacing.
We conducted a systematic review of observational studies to evaluate the association between birth spacing (i.e., interpregnancy interval and interoutcome interval) and adverse outcomes (i.e., pregnancy complications, adverse birth outcomes). Pooled odds ratios (ORs) with 95% confidence intervals (CI) were calculated using a random-effects model, and the dose-response relationships were evaluated using generalized least squares trend estimation.
A total of 129 studies involving 46 874 843 pregnancies were included. In the general population, compared with an interpregnancy interval of 18-23 months, extreme intervals (<6 months and ≥ 60 months) were associated with an increased risk of adverse outcomes, including preterm birth, small for gestational age, low birthweight, fetal death, birth defects, early neonatal death, and premature rupture of fetal membranes (pooled OR range: 1.08-1.56; p < 0.05). The dose-response analyses further confirmed these J-shaped relationships (pnon-linear  < 0.001-0.009). Long interpregnancy interval was only associated with an increased risk of preeclampsia and gestational diabetes (pnon-linear  < 0.005 and pnon-linear  < 0.001, respectively). Similar associations were observed between interoutcome interval and risk of low birthweight and preterm birth (pnon-linear  < 0.001). Moreover, interoutcome interval of ≥60 months was associated with an increased risk of cesarean delivery (pooled OR 1.72, 95% CI 1.04-2.83). For pregnancies following preterm births, an interpregnancy interval of 9 months was not associated with an increased risk of preterm birth, according to dose-response analyses (pnon-linear  = 0.008). Based on limited evidence, we did not observe significant associations between interpregnancy interval or interoutcome interval after pregnancy losses and risk of small for gestational age, fetal death, miscarriage, or preeclampsia (pooled OR range: 0.76-1.21; p > 0.05).
Extreme birth spacing has extensive adverse effects on maternal and infant health. In the general population, interpregnancy interval of 18-23 months may be associated with potential benefits for both mothers and infants. For women with previous preterm birth, the optimal birth spacing may be 9 months.

UNASSIGNED: Eight databases, PubMed, CINAHL, Web of Science, Embase, PsycINFO, Cochrane Library, Popline, and Maternity and Infant Care, were searched, covering the period of January 2000 to January 2022. Studies that had examined the association between SBI and any form of child mortality were included. The findings of the included studies were summarized through fixed-effects or random-effects meta-analysis and the model was selected based on the heterogeneity index.
UNASSIGNED: A total of 51 studies were included. Of them, 19 were conducted in Ethiopia, 10 in Nigeria and 7 in Bangladesh. Significant higher likelihoods of stillbirth (odds ratio (OR) = 2.11; 95% confidence interval (CI) = 1.32-3.38), early neonatal mortality (OR = 1.58; 95% CI = 1.04-2.41), perinatal mortality (OR = 1.71; 95% CI = 1.32-2.21), neonatal mortality (OR = 1.85; 95% CI = 1.68-2.04), post-neonatal mortality (OR = 3.01; 95% CI = 1.43-6.33), infant mortality (OR = 1.92; 95% CI = 1.77-2.07), child mortality (OR = 1.67; 95% CI = 1.27-2.19) and under-five mortality (OR = 1.95; 95% CI = 1.56-2.44) were found among babies born in short birth intervals than those who born in normal intervals.
UNASSIGNED: SBI significantly increases the risk of child mortality in LMICs. Programmes to reduce pregnancies in short intervals need to be expanded and strengthened. Reproductive health interventions aimed at reducing child mortality should include proper counselling on family planning, distribution of appropriate contraceptives and increased awareness of the adverse effects of SBI on maternal and child health.

Closely spaced birth increases the risk of adverse maternal and child health outcomes. In Ethiopia, the prevalence of short birth spacing was highly variable across studies. Besides, contraceptive use, educational status, and duration of breastfeeding were frequently mentioned factors affecting short birth spacing. Therefore, this meta-analysis aimed to estimate the pooled prevalence of short birth spacing and its association with contraceptive use, educational status, and duration of breastfeeding among reproductive-age women in Ethiopia.
International databases: Google Scholar, PubMed, CINAHL, Cochrane library, HINARI, and Global Health were searched systematically to identify articles reporting the prevalence of short birth spacing and its association with contraceptive use, educational status, and duration of breastfeeding among reproductive-age women in Ethiopia. The data were analyzed by STATA/SE version-14 statistical software. The random-effect model was used to estimate the pooled prevalence of short birth spacing and the log odds ratio was used to determine the association. Moreover, egger\'s test and I-squared statistics were used to assess publication bias and heterogeneity respectively.
After reviewing 511 research articles, a total of nine articles with 5,682 study participants were included in this meta-analysis. The pooled prevalence of short birth spacing in Ethiopia was 46.9% [95% CI: (34.7, 59.1)]. Significant heterogeneity was observed between studies (I2 = 98.4, p <0.001). Not using contraceptives [OR = 3.87, 95% CI: (2.29, 6.53)] and duration of breastfeeding < 24 months [OR = 16.9, 95%CI: (2.69, 106.47)] had a significant association with short birth spacing.
Although a minimum inter-pregnancy interval of two years was recommended by the World Health Organization (WHO), significant numbers of women still practiced short birth spacing in Ethiopia. Duration of breastfeeding and non-use of contraceptives were factors significantly associated with short birth spacing. So, efforts should be made to improve breastfeeding practice and contraceptive utilization among women in Ethiopia.

According to the UNICEF, WHO and World Bank joint estimation, 1 in every 13 children suffered from wasting globally. The highest burden of undernutrition recorded in Asia and Africa. Wasting remains a considerable public health problem in Ethiopia despite the introduction of exhaustive nutritional programmes. As reported in the literature, the prevalence of wasting in Ethiopia has remained high over the last four decades. In Ethiopia, more than one-third of child deaths are associated with malnutrition. The current nutritional interventions implemented in Ethiopia need to be evidence based. For this purpose, systematic review is preferable as it can present a more reliable and precise estimate than individual studies. The aim of this review is to assess the pooled prevalence of wasting and its association with birth interval in Ethiopia.
Studies published after 20 January 2012 will be retrieved from databases, mainly PubMed/Medline, Scopus, Embase, CINAHL and HINARI. The articles retrieved from databases will be selected after reading the title, abstract and full text. Three reviewers will independently assess the quality of each study using both the Joanna Briggs Institute and Ottawa Scale critical appraisal checklists. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist will be used to maintain scientific strength. Funnel plots, Egger\'s test and Begg\'s test will be used to deal with publication bias, and I2, forest plots and Cochrane\'s Q square statistics will be used for heterogeneity. Potential causes of heterogeneity will be explored through sensitivity and subgroup analyses. Because heterogeneity among studies is inevitable, given the wide geographical area and variety of study designs, the Der-Simonian and Laird random-effects model will be used. The presence of a statistical association between birth interval and wasting will be declared if the p value is <0.05 with the 95% CI.
Ethical issues will not be applicable to this review and meta-analysis. This review and meta-analysis will report the pooled prevalence of wasting and its association with birth interval in Ethiopia. Effort will be made to publish the findings in a peer-reviewed journal such as the Ethiopian Journal of Health and Development, and the findings will be presented at national conferences. A hard copy will also be sent to Woldia University and Debre Berhan University.

BACKGROUND: Perinatal mortality remains a problem in Ethiopia. Findings of primary studies varied on level of perinatal mortality and its predictors including inter-pregnancy interval. The aim of this review was to estimate the pooled perinatal mortality rate, its trend overtime and verify the association with inter-pregnancy interval in Ethiopian context.
METHODS: Studies were accessed through the electronic web-based search strategies from PubMed, ScienceDirect, Hinari for health via Research4Life, Google and Advanced Google search, and retrieving via relevant references using a combination of medical subject headings (MeSH terms) and key words related with inter-pregnancy interval. R version 3.4.3 software was used for the meta-analysis. A forest plot and I2 test were done to assess heterogeneity. Sensitivity analysis and subgroup analysis were done to deal with heterogeneity. A weighted inverse variance random-effects model was applied to estimate pooled effect sizes. A funnel plot and Egger\'s regression test were done to check publication bias.
RESULTS: A total of 34 studies used to answer review questions (30 for perinatal mortality rate and its trend estimation from 1997 to 2019 and 8 for its relationship with inter-pregnancy interval). The pooled perinatal mortality rate was 51.3 per 1000 total births (95% CI: 40.8-62.8). The pooled stillbirth rate was 36.9 per 1000 births (95% CI: 27.3-47.8) and early neonatal mortality rate was 29.5 per 1000 live births (95% CI: 23.9-35.6). Increasing trend was seen in stillbirth rate (23.7 to 36.9 per 1000 births) while decreasing trend in early neonatal mortality rate (51 to 29.5 per 1000 live births). Slight reduction trend was observed in overall perinatal mortality rate (66 to 51.3 per 1000 births). An inter-pregnancy interval less than 15 months was found to be statistically significantly associated with perinatal mortality; pooled OR = 2.76 (95% CI: 2.1-3.62). Spacing pregnancy for at least 15 months was related with reducing perinatal mortality by 64% (95% CI: 52.38, 72.38%).
CONCLUSIONS: In Ethiopia, perinatal mortality rate remains high. Insignificant reduction trend was observed in overall perinatal mortality rate. Counseling couples about the importance of spacing pregnancy and intensifying long-acting contraceptive use will help in reducing perinatal mortality related to poor pregnancy spacing.