The effect of short interpregnancy interval on birthweight and other pregnancy outcomes in Enugu, Southeast Nigeria

Short birth interval in the Asia-Pacific region: A systematic review and meta-analysis

Background

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.

Methods

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.

Results

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.

Conclusions

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.

Registration

PROSPERO CRD42023426975.

Spatial distribution of short birth interval and associated factors among reproductive age women in Ethiopia: spatial and multilevel analysis of 2019 Ethiopian mini demographic and health survey

BACKGROUND

Short Birth Interval negatively affects the health of both mothers and children in developing countries. Studies conducted in Ethiopia on the spatial variation and determinants of individual and community-level factors about short birth intervals were limited. Thus, this study was intended to assess the spatial variation of the short birth interval and its determinants in Ethiopia.

METHODS

This study is a secondary analysis of the Ethiopian Demographic and Health Survey (mini EDHS 2019). A total of 1784 reproductive-age women were included in the analysis. The global spatial autocorrelation (Global Moran's I) and the Getis-Ord statistics tool were used to detect the presence of clustering and the high/low hotspot areas of SBI respectively. Ordinary kriging was used to interpolate short birth intervals, and spatial scan statistics were employed to identify spatial clusters with high and low SBI. A multilevel multivariable model was used to identify predictors of a short birth interval.

RESULTS

The prevalence of SBI was 62.89% (95%CI: 59.3, 69.7) in Ethiopia. High clustering of SBI was observed in all parts of Somali, in Afar (zones 1, 3, 4, &5), Oromia (Guje, Bale, & West Harerge), and northern Tigray. The most likely significant primary cluster was observed in the Somali region. Women who lived in the primary cluster were 24% more likely to have a short birth interval than those who lived outside the window. In the multilevel mixed-effect analysis age 25-34 [(AOR = 0.40, 95% CI: 0.35, 0.45)], 35-49 [(AOR = 0.44, 95% CI: 0.38, 0.51)], Muslim religion follower [(AOR = 3.5, 95% CI: 2.7, 4.69)], no formal education [(AOR = 0.5, 95% CI: 0.37, 0.70)], primary education[(AOR = 0.4, 95%CI: 0.28, 0.53)], and secondary education [(AOR = 0.3, 95% CI: 0.24, 0.48)], middle [(AOR: 1.3, 95% CI: 1.2, 1.52)], rich wealth status [(AOR: 1.4, 95% CI: 1.3, 1.68)], female sex children [(AOR: 1.2, 95% CI: 1.09, 1.42)], and two or fewer ideal number of children [(AOR = 0.2, 95% CI: 0.25, 0.32)] were found to be significant predictors of SBI.

CONCLUSION

Overall, SBI was high and significantly clustered across the region of Ethiopia. Age, religion, education, wealth status, the sex of the indexed child, and the ideal number of children were found to be significantly associated with short birth intervals. Hence, the government should design a health promotion strategy and public health awareness in the identified hotspot areas of SBI and should scale up family planning and the wealth status of reproductive-age women.

Relationship between Birth Order and Postnatal Growth until 4 Years of Age: The Japan Environment and Children’s Study

Later-borns tend to be shorter than first-borns in childhood and adulthood. However, large-scale prospective studies examining growth during infancy according to birth order are limited. We aimed to investigate the relationship between birth order and growth during the first 4 years of life in a Japanese prospective birth cohort study. A total of 26,249 full-term singleton births were targeted. General linear and multivariable logistic regression models were performed and adjusted for birth weight, parents’ heights, maternal age at delivery, gestational weight gain, maternal smoking and alcohol drinking status during pregnancy, household income, breastfeeding status, and Study Areas. The multivariate adjusted mean length Z-scores in “first-borns having no sibling”, “first-borns having siblings”, “second-borns”, and “third-borns or more” were −0.026, −0.013, 0.136, and 0.120 at birth and −0.324, −0.330, −0.466, and −0.569 at 10 months, respectively. Results similar to those at 10 months were observed at 1.5, 3, and 4 years. The adjusted odds ratios (95% confidence intervals) of short stature at 4 years in “first-borns having siblings”, “second-borns”, and “third-borns or more” were 1.08 (0.84–1.39), 1.36 (1.13–1.62), and 1.50 (1.20–1.88), respectively, versus “first-borns having no sibling”. Birth order was significantly associated with postnatal growth and may be a factor predisposing to short stature in early childhood.

Birth weight and gestational age distributions in a rural Kenyan population

BACKGROUND

With the increased availability of access to prenatal ultrasound in low/middle-income countries, there is opportunity to better characterize the association between fetal growth and birth weight across global settings. This is important, as fetal growth curves and birthweight charts are often used as proxy health indicators. As part of a randomized control trial, in which ultrasonography was utilized to establish accurate gestational age of pregnancies, we explored the association between gestational age and birthweight among a cohort in Western Kenya, then compared our results to data reported by the INTERGROWTH-21st study.

METHODS

This study was conducted in 8 geographical clusters across 3 counties in Western Kenya. Eligible subjects were nulliparous women carrying singleton pregnancies. An early ultrasound was performed between 6 + 0/7 and 13 + 6/7 weeks gestational age. At birth, infants were weighed on platform scales provided either by the study team (community births), or the Government of Kenya (public health facilities). The 10th, 25th, median, 75th, and 90th BW percentiles for 36 to 42 weeks gestation were determined; resulting percentile points were plotted, and curves determined using a cubic spline technique. A signed rank test was used to quantify the comparison of the percentiles generated in the rural Kenyan sample with those of the INTERGROWTH-21st study.

RESULTS

A total of 1291 infants (of 1408 pregnant women randomized) were included. Ninety-three infants did not have a measured birth weight. The majority of these were due to miscarriage (n = 49) or stillbirth (n = 27). No significant differences were found between subjects who were lost to follow-up. Signed rank comparisons of the observed median of the Western Kenya data at 10th, 50th, and 90th birthweight percentiles, as compared to medians reported in the INTERGROWTH-21st distributions, revealed close alignment between the two datasets, with significant differences at 36 and 37 weeks. Limitations of the current study include small sample size, and detection of potential digit preference bias.

CONCLUSIONS

A comparison of birthweight percentiles by gestational age estimation, among a sample of infants from rural Kenya, revealed slight differences as compared to those from the global population (INTERGROWTH-21st).

TRIAL REGISTRATION

This is a single site sub-study of data collected in conjunction with the Aspirin Supplementation for Pregnancy Indicated Risk Reduction In Nulliparas (ASPIRIN) Trial, which is listed at  ClinicalTrials.gov ,  NCT02409680 (07/04/2015).

Association of Interpregnancy Interval With Adverse Birth Outcomes

IMPORTANCE

Many studies have reported an association of interpregnancy interval (IPI) between 2 consecutive births with adverse birth outcomes in low- and middle-income countries. However, most of these studies ignore the implications of some unmeasured confounders.

OBJECTIVE

To explore the association of IPI with adverse perinatal outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This large-scale cohort study used the Guangdong Provincial Women and Children Health Information System in Guangdong Province, China, to obtain birth data recorded between January 1, 2014, and December 31, 2020. Matched-sibling design was used. The final cohort included first-born and second-born sibling pairs delivered by mothers who were permanent residents of Guangdong Province.

EXPOSURES

The exposure variable was IPI, which was categorized as follows: less than 6, 6 to 11, 12 to 17, 18 to 23, 24 to 29, 30 to 35, and 36 or more months.

MAIN OUTCOMES AND MEASURES

The outcome variables were adverse birth outcomes: preterm birth (PTB, gestational age <37 weeks), low birth weight (LBW, <2500 g), and small for gestational age (SGA). Adjusted odds ratio (OR) and interaction odds ratio (IOR) associated with IPI were calculated.

RESULTS

The study consisted of 725 392 sibling pairs of multiparous mothers. Among these mothers, 718 111 (99.0%) were aged 20 to 34 years, and 715 583 (98.7%) were of Han Chinese ethnicity. Unmatched analysis showed that a short IPI of less than 6 months was associated with higher risks of PTB (adjusted OR, 1.96; 95% CI, 1.87-2.06), LBW (adjusted OR, 1.88; 95% CI, 1.79-1.98), and SGA (adjusted OR, 1.34; 95% CI, 1.30-1.38) compared with an IPI of 18 to 23 months. These associations were attenuated in the matched-sibling analysis. An association of short IPI (<6 months) with PTB (adjusted IOR, 1.40; 95% CI, 1.30-1.51), LBW (adjusted IOR, 1.30; 95% CI, 1.21-1.40), and SGA (adjusted IOR, 1.16; 95% CI, 1.11-1.22) remained in the matched analysis. For IPI of 36 months or more, the odds of PTB (adjusted OR, 1.08; 95% CI, 1.03-1.14) and LBW (adjusted OR, 1.13; 95% CI, 1.07-1.19) in the unmatched analysis were also greater than the reference interval (18-23 months), but not for SGA (adjusted OR, 0.96; 95% CI, 0.93-0.99). Associations between a long IPI (≥36 months) and PTB (adjusted IOR, 1.10; 95% CI, 1.02-1.19) and LBW (adjusted IOR, 1.16; 95% CI, 1.07-1.26) remained through the sibling comparisons.

CONCLUSIONS AND RELEVANCE

Results of this study indicated that mothers with a short (<6 months) or long (≥36 months) IPI had greater odds of adverse birth outcomes. The findings may inform family planning policies and guide individuals and families who are planning for another pregnancy in China.