A first look at the effects of long inter-pregnancy interval and advanced maternal age on perinatal outcomes: A retrospective cohort study

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.

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.

Interactions between long interpregnancy interval and advanced maternal age on neonatal outcomes

BACKGROUND

After the implementation of the universal two-child policy in China, it was more frequent to have long interpregnancy intervals (IPIs) and advanced maternal age. However, the interactions between long IPIs and advanced maternal age on neonatal outcomes are unknown.

METHODS

The study subjects of this historical cohort study were multiparas with singleton live births between October 1st, 2015, and October 31st, 2020. IPI was defined as the interval between delivery and conception of the subsequent pregnancy. Logistic regression models were used to calculate adjusted odds ratios (aORs) and 95% confidence intervals (CIs) of the risks of preterm birth (PTB), low birth weight (LBW), small for gestation age, and 1-min Apgar score ≤ 7 in different IPI groups. Relative excess risk due to interaction (RERI) was used to evaluate the additive interaction between long IPIs and advanced maternal age.

RESULTS

Compared with the 24 ≤ IPI ≤ 59 months group, the long IPI group (IPI ≥ 60 months) was associated with a higher risk of PTB (aOR, 1.27; 95% CI: 1.07-1.50), LBW (aOR, 1.32; 95% CI 1.08-1.61), and one-minute Apgar score ≤ 7 (aOR, 1.46; 95% CI 1.07-1.98). Negative additive interactions (all RERIs < 0) existed between long IPIs and advanced maternal age for these neonatal outcomes. Meanwhile, IPI < 12 months was also associated with PTB (aOR, 1.51; 95% CI 1.13-2.01), LBW (aOR, 1.50; 95% CI 1.09-2.07), and 1-min Apgar score ≤ 7 (aOR, 1.93; 95% CI 1.23-3.04).

CONCLUSIONS

Both short and long IPIs are associated with an increased risk of adverse neonatal outcomes. Appropriate IPI should be recommended to women planning to become pregnant again. In addition, better antenatal care might be taken to balance the inferiority of advanced maternal age and to improve neonatal outcomes.

Birth spacing and risk of adverse pregnancy and birth outcomes: A systematic review and dose-response meta-analysis

INTRODUCTION

The association between extreme birth spacing and adverse outcomes is controversial, and available evidence is fragmented into different classifications of birth spacing.

MATERIAL AND METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Short interpregnancy interval can lead to adverse pregnancy outcomes: A meta-analysis

BACKGROUND

The evidence of some previous papers was insufficient in studying the causal association between interpregnancy interval (IPI) and adverse pregnancy outcomes. In addition, more literature have been updated worldwide during the last 10 years.

METHODS

English and Chinese articles published from January 1980 to August 2021 in the databases of PubMed, Cochrane Library, Ovid, Embase, China Biology Medicine disc (CBM), and China National Knowledge Infrastructure (CNKI) were searched. Then following the inclusion and exclusion criteria, we screened the articles. Utilizing the Newcastle-Ottawa Scale (NOS), we evaluated the quality of the included articles. The literature information extraction table was set up in Excel, and the meta-analysis was performed with Stata 16.0 software (Texas, USA).

RESULTS

A total of 41 articles were included in the meta-analysis, and NOS scores were four to eight. The short IPI after delivery was the risk factor of preterm birth (pooled odds ratio 1.49, 95% confidence interval 1.42-1.57), very preterm birth (pooled OR: 1.82, 95% CI: 1.55-2.14), low birth weight (pooled OR: 1.33, 95% CI: 1.24-1.43), and small for gestational age (pooled OR: 1.14, 95% CI: 1.07-1.21), offspring death (pooled OR: 1.60, 95% CI: 1.51-1.69), NICU (pooled OR: 1.26, 95% CI: 1.01-1.57), and congenital abnormality (pooled OR: 1.10, 95% CI: 1.05-1.16), while was not the risk factor of gestational hypertension (pooled OR: 0.95, 95% CI: 0.93-0.98) or gestational diabetes (pooled OR: 1.06, 95% CI: 0.93-1.20).

CONCLUSION

Short IPI (IPI < 6 months) can lead to adverse perinatal outcomes, while it is not a risk factor for gestational diabetes and gestational hypertension. Therefore, more high-quality studies covering more comprehensive indicators of maternal and perinatal pregnancy outcomes are needed to ameliorate the pregnancy policy for women of childbearing age.

Association between Maternal Factors, Preterm Birth, and Low Birth Weight of Chilean Singletons

There has been an increase in preterm (PT) births in Western countries in recent years, which is associated with low-birthweight (LBW) children. The aim of this study was to determine the association between maternal factors and PT and LBW Chilean newborns. Methods: This was an analytical cross-sectional study of a national sample of 903,847 newborns and their mothers. The newborn gestational age, birth weight, maternal age, marital status, education, employment situation, and residence were analyzed. A multivariate logistic regression model was applied (α = 0.05) (STATA v.15). The prevalence was 6.8% and 5.0% for PT and LBW, respectively. The probability of the newborns being PT and LBW was 1.18 and 1.22 times if their mothers had <12 years of education and 1.38 and 1.29 times if the mothers were ≥35 years old, respectively. Mothers with <12 years education and ≥35 years were risk factors for PT and LBW newborns. Maternal educational attainment was a protective factor for the Chilean newborns, and a maternal age ≥35 years was a risk factor for PT and LBW.

The mediation role of psychological capital between family relationship and antenatal depressive symptoms among women with advanced maternal age: a cross sectional study

Background

Due to changes in family policy in China, pregnancy at advanced age (30 years old or above) is prevalent. Advanced maternal age is known to be related to a variety of negative health outcomes, including antenatal depression. Family relationship quality might be an important factor for antenatal depressive symptoms among Chinese women with advanced maternal age. However, the underlying mechanisms in which family relationship quality can affect antenatal depressive symptoms among this population and how positive psychological capital (PsyCap) intervenes in this impact are not clear.

Objectives

To describe the prevalence and demographic characteristics of antenatal depressive symptoms among Chinese pregnant women with advanced maternal age, and to explore the mediation effect of PsyCap in the associations between family relationship quality and antenatal depressive symptoms.

Methods

We conducted a cross-sectional survey at a tertiary hospital in China. A total of 192 women with maternal age of 30 years or older completed the questionnaires. Data on antenatal depressive symptoms, PsyCap, family relationship quality and demographic characteristics were collected. The multiple mediation models in SPSS’s PROCESS macro were used to test whether PsyCap mediated the relationship between family relationship quality and antenatal depressive symptoms.

Results

Approximately 28.6% of participants had antenatal depressive symptoms and 6.8% reported poor family relationship quality. Participants with higher education (p = .02) and better family relationship quality (p = .00) were less likely to have antenatal depressive symptoms. PsyCap collectively (β = 1.14, p < .05), or more specifically resilience (β = 0.61, p < .05) significantly mediated the relationship between poor family relationship quality and antenatal depressive symptoms.

Discussion

The relationship between family relationship quality and antenatal depressive symptoms can be mediated by PsyCap collectively or via resilience specifically. It is important to screen antenatal depressive symptoms among pregnant women with advanced age, especially those who have poor family relationship quality. Counseling and psychotherapy initiatives for resilience-enhancing training for pregnant women at advanced age may provide a promising target to break the link between poor family relationship quality and antenatal depressive symptoms.

Determinants of Poor Sleep Quality During the COVID-19 Pandemic Among Women Attending Antenatal Care Services at the Health Facilities of Debre Berhan Town, Ethiopia: An Institutional-Based Cross-Sectional Study

BACKGROUND

Women's ability to get sleep can be affected by pregnancy-related hormonal changes or other external stressful situations like the coronavirus disease 2019 (COVID-19).

OBJECTIVE

The objective of this study was to assess the proportion of poor sleep quality during the COVID-19 pandemic and its determinants among pregnant women attending antenatal care (ANC) services.

METHODS

An institutional-based cross-sectional study was conducted among 423 women attending ANC services at the health facilities in Debre Berhan Town, Ethiopia, from May to June 2020. A systematic random sampling technique was used to select the required samples. The tool consisted of questions that assessed (1) socio-demographic characteristics, obstetric and health care service-related characteristics; and media exposure to get information regarding COVID-19 infection; (2) To assess sleep quality; the Pittsburgh Sleep Quality Index (PSQI) was applied. And a global score of >5 indicates poor sleep quality, and a global score of ≤5 indicates good sleep quality.

RESULT

The overall prevalence of poor sleep quality was 62.8%, and was associated with pregnant women aged ≥46 years (AOR = 4.27), being in the third trimester (AOR = 2.51), being multigravida (AOR = 2.72), and having co-morbidity (AOR = 3.57).

CONCLUSION

The prevalence of poor sleep quality among pregnant women during the pandemic was found to be high. Advanced maternal age, third trimester pregnancy, being multigravida, and having comorbidity were determinants of poor sleep quality among pregnant women during the COVID-19 pandemic.

Interpregnancy interval and subsequent perinatal risk of congenital heart disease in Guangzhou, Southern China: a retrospective cohort study, 2014-2019

BACKGROUND

The association between maternal interpregnancy interval (IPI) and congenital heart disease (CHD) in neonates remains inconclusive. This study aimed to examine the effect of maternal IPI on birth risk of CHD.

METHODS

Chinese women with two consecutive singleton deliveries in Guangzhou between January 2014 and December 2019 were selected as participants. Information on IPI and CHD was extracted from the Guangzhou Perinatal Health Care and Delivery Registry and the Guangzhou Birth Defects Surveillance Program. We stratified IPI into four categories: <24 months, 24-35 months, 36-59 months, and ≥60 months. A multivariate logistic regression model was used to examine the association between IPI and CHD. Subgroup analysis was also performed to assess whether the associations differed across top three CHD subtypes.

RESULTS

For 119,510 women enrolled in this study, the mean ages at two consecutive deliveries were 26.2 ± 3.8 and 28.8 ± 4.0 years, which yielded a median IPI of 51.2 (interquartile range, 32.1-77.2) months. Among them, 828 delivered infants with CHD during their second pregnancy. There was a J-shaped curve relationship between IPI and CHD with the lowest birth prevalence (5.33‰) at 24-35-month interval. Compared to women with an IPI of 24-35 months, those with an IPI ≥60 had an increased risk of delivering infants with CHD (adjusted odds ratio (OR), 1.41; 95% confidence interval (CI), 1.19-1.64). However, for those with an IPI <24 months (adjusted OR, 1.24; 95% CI, 0.97-1.51), IPI was statistically insignificant associated with the risk of delivering infants with CHD (p = .12). There were different patterns of associations for different CHD subtypes.

CONCLUSIONS

Longer maternal IPI (≥60 months) was associated with an increased risk of delivering infants with CHD in the Chinese population.

Association of Short and Long Interpregnancy Intervals with Adverse Birth Outcomes: Evidence from a Cross-Sectional Study in Northwest China

Purpose

To analyze the effects of a short interpregnancy interval (IPI) (<6 months) and a long IPI (>120 months) on neonatal adverse birth outcomes including low birth weight (LBW), small for gestational age (SGA), preterm birth (PTB), and birth defects in Shaanxi Province.

Patients and Methods

A stratified multistage random sampling method was used to recruit participants who gave birth between 2010 and 2013 in Shaanxi province. A self-designed questionnaire was used to collect the information of the participants. With the confounding factors controlled, the generalized linear model (GLM) was used to investigate the association between IPI and neonatal birth outcomes. The restricted cubic spline (RCS) function was used to evaluate the dose–response relationship between IPI and birth outcomes.

Results

A total of 13,231 women were included. The prevalence of LBW, SGA, PTB, and birth defects was 3.24%, 12.96%, 2.93%, and 2.12%, respectively. GLM showed that a short IPI (<6 months) was associated with a higher risk of SGA (RR=1.25, 95% CI: 1.04–1.52) and birth defects (RR=2.55, 95% CI: 1.45–4.47), and a long IPI (≥120 months) was associated with a higher risk of LBW (RR=1.54, 95% CI: 1.01–2.34) and PTB (RR=1.73, 95% CI: 1.08–2.76) than an IPI of 18–23 months. The RCS showed that LBW, SGA, and PTB demonstrated a j-shaped relationship with IPI (P for overall association < 0.001 for these three birth outcomes), and birth defects (P for overall association <0.001) had an inversely non-linear relationship with IPI.

Conclusion

Both short and long IPIs are associated with an increased risk of adverse birth outcomes.

Short and long interpregnancy interval and the risk for pediatric obstructive sleep apnea in the offspring

INTRODUCTION

Interpregnancy interval (IPI) is defined as the period between a live birth and the conception of a subsequent fetus. Both short (IPI < 6 months) and long IPI (IPI > 60 months) have been shown to increase the risk for adverse perinatal outcomes, some of which, are known risk factors for obstructive sleep apnea syndrome (OSAS) in the offspring.

AIMS

To study the association between IPI and risk for offspring OSAS, during a follow-up period of up to 18 years.

STUDY DESIGN

Population-based cohort.

SUBJECTS

In this population-based cohort analysis, all singleton live births, born to a mother with at least one previous birth occurring between 1991 and 2014, were included. Congenital malformations were excluded.

MATERIALS AND METHODS

Hospitalizations of the offspring due to OSAS diagnosis up to 18 years of age, were evaluated according to IPI length. Intermediate IPI (6-60 months) was considered as the reference. A Kaplan-Meier survival curve and a Cox hazards regression model were used to compare the incidence of OSAS between the groups, and to adjust for confounding variables.

RESULTS

The study population included 144,397 deliveries, of which 13.1% (n = 18,947) were followed by short IPI, 7.9% (n = 11,438) and 79.0% (n = 114,012) were followed by long and intermediate IPI, respectively. OSAS hospitalization rates were significantly higher among the long IPI group compared to intermediate and short IPIs (0.9%; 0.7% and 0.6%, respectively, p = .001). The association between long IPI and offspring pediatric OSAS remained significant after controlling for preterm delivery, maternal diabetes, and smoking, and mode of delivery, (adjusted HR = 1.45; 95% CI, 1.17-1.80).

CONCLUSIONS

Children born following long IPI are at increased risk for pediatric OSAS.

Short interpregnancy interval and low birth weight births in India: Evidence from National Family Health Survey 2015-16

Evidence on the effect of interpregnancy interval (IPI) on low birth weight (LBW) births is limited in developing countries including India. Our study aims to examine association between IPI and LBW births in India. We used data from the fourth round of the National Family Health Survey (NFHS-4) conducted in 2015–16 with a representative sample of 52,825 most recent births for examining the association between IPI and LBW. IPI is defined as the gap between the first month in which the index pregnancy was reported in the reproductive calendar (referred to as the month of conception) and the month of pregnancy outcome (including live births and terminations) of preceding pregnancy. Reproductive calendar data were used to estimate IPI. Association between IPI and LBW were examined using multivariable binary logistic regressions. Seventeen percent of the births in our sample were LBW, and more than half (57.6%) of these were accompanied with IPI less than 18 months. Prevalence of LBW births was highest among mother's who had IPI less than six months (19.4%). Regression results, adjusted for control variables, indicate that the risk of LBW was significantly higher among births whose mothers had IPI less than six months (odds ratio: 1.19, 95% CI:1.05-1.36) compared with those whose mothers had IPI between 18 and 23 months. This study provides additional evidence on the association between short IPI (<6 months) and LBW births in India. Promoting spacing methods of family planning is an option that India may consider for increasing the IPI and thereby reducing LBW births. Ensuring recommended iron and folic acid tablets/equivalent syrup and TT injections for every pregnant woman may offset the adverse consequences of shorter IPI.

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12% of the LBW births were accompanied with IPI <6 months, 20% between 6 and 11 months, and 25% between 12 and 17 months.

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The risk of LBW births is higher among mothers having an IPI of <6 months compared with mothers having an IPI of 18–23 months.

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Promoting spacing methods of family planning may consider for increasing the IPI and thereby reducing LBW births in India.

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Promoting recommended TT injections and iron-folic acid supplements may offset the adverse consequences of short IPI.

Interpregnancy interval and the risk for recurrence of placental mediated pregnancy complications

Objective The aim of this study was to investigate the effect of short or long interpregnancy interval (IPI) with placental mediated pregnancy complications after already complicated first delivery. Methods We performed a retrospective cohort analysis of all women with singleton pregnancies who delivered their first three consecutive deliveries in one university-affiliated medical center (1994-2013). Placental mediated complications included placental abruption, small for gestational age, preeclampsia, gestational hypertension, or preterm delivery. Following first complicated delivery, IPI was compared stratified by second delivery outcome. Following two complicated deliveries, IPI was compared stratified by third delivery outcome. IPI was evaluated as continuous or categorical variable (>18, 18-60, >60 months). Related samples Cochrans' Q test and Mann-Whitney analysis were used as appropriate. Results Overall, 4310 women entered analysis. Of them, 18.3%, 10.5%, and 9.3% had complicated first, second, and third delivery, consecutively. Evaluated continuously, longer IPI, but not short IPI, was associated with higher rates of complicated second delivery. Stratified to categories, IPI had no effect on recurrent complications evaluated separately or as composite. Conclusion Our results suggest that long IPI may increase risk for placental mediated pregnancy complications. Further studies are needed to evaluate this effect.

Early menarche is associated with insulin resistance in advanced maternal age before delivery

Purpose: With the wide implementation of the universal two-child policy in China, the number of pregnant women in advanced maternal age (AMA) will increase gradually. We aimed to assess the association between age at menarche (AAM) and insulin resistance (IR) before delivery in AMA. Methods: A total of 80 pregnant women in AMA were consecutively enrolled before delivery in Zhongda hospital. Pregnant women were stratified into early menarche group and late menarche group according to the age of regular menstruation (about 13 years). At delivery, serum glucose and lipid levels were measured. IR was calculated by the method of homeostasis model assessment 2(HOMA2). Results: The fasting blood insulin (17.68(9.72-36.71) and 10.35(7.76-15.10), respectively; p = .006) and HOMA-IR (2.08(1.18-4.37) and 1.24(0.89-1.78), respectively; p = .005) were higher in early menarche group than in late menarche group. AAM was inversely associated with HOMA-IR in AMA (r= -0.27, p = .014). In the multivariable analysis, AAM in late menarche group was negatively related to the level of HOMA-IR compared to those in early menarche group (β= -2.275, p≤.0001). Conclusions: Taken together, our findings suggest that AAM was inversely associated with HOMA-IR in AMA. Furthermore, pregnant women in AMA with early menarche might have higher HOMA-IR levels than those with late menarche. Clinical trial registration: Chinese Clinical Trial Registry (No. ChiCTR-RRC-16008714), retrospectively registered.

Associations of maternal ambient temperature exposures during pregnancy with the risk of preterm birth and the effect modification of birth order during the new baby boom: A birth cohort study in Guangzhou, China

Maternal exposures to ambient temperatures during pregnancy may increase the preterm birth (PTB) risk; however, which periods have stronger effects remain controversial. The effects of temperature exposure on PTB in first- and second-born neonate groups may be different during the new baby boom that has followed the Two-child Policy in China. We examined a birth cohort of 4928 pregnant women beginning in 2016 in Guangzhou, China. An inverse distance weighted method was used to estimate the temperature exposure at each individual residential address. A distribution lag non-linear model incorporating a Cox proportional hazard model was employed to estimate the effects of temperature exposure on PTB and test the effects modification of birth order related to the new baby boom. A total of 4101 pregnant women were included, of which 234 (5.7%) experienced PTB. Compared with the mean temperature (23.0 °C), we found a significantly higher risks of PTB associated with high temperatures (i.e, 30 °C [95th centile]) from the 4th to 8th, and 22nd to 27th gestational weeks. A peak effect was found during the 6th week (HR = 1.79, 95% CI: 1.26, 2.54) and 24th week (HR = 1.83, 95% CI: 1.27, 2.62). The risks of PTB were reduced for low temperatures (i.e. 14 °C [5th centile] versus 23.0 °C) from the 2nd to 10th and 20th to 26th gestational weeks, and the negative peak effect was found during the 4th week (HR = 0.43, 95% CI: 0.26, 0.72) and 23rd week (HR = 0.59, 95% CI: 0.43, 0.83). Stratification analyses showed that significant effects of 30 °C versus 23 °C on PTB were observed during the 4th to 8th weeks in the second-born neonate, and the peak effect was found in the 6th week (HR = 2.13, 95% CI: 1.31, 3.47). However, we did not find significant effects of 30 °C during the same weeks in the first-born neonate group. Maternal exposures to higher temperatures during pregnancy may increase the risk of PTB, and lower temperatures may decrease the risk of PTB. Stronger effects of temperature exposures during the first trimester on PTB risk were found among the second-born neonates than among the first-born neonates.

The relationship between vitamin D and insulin resistance before delivery in advanced maternal age

BACKGROUND

With the widely implementation of universal two-child policy, the number of pregnant women in advanced maternal age (AMA) will increase gradually. We aimed to assess the association of vitamin D levels and insulin resistance (IR) during the late pregnancy in AMA.

METHODS

A total of 80 pregnant women were consecutively enrolled in the cross-sectional study before delivery from the August 2016 to June 2017 at the department of gynecology and obstetrics in the hospital of ZhongDa, affiliated to Southeast University. At delivery, serum 25(OH) D and metabolism parameters including glucose and lipid levels were measured. IR was calculated by the method of homeostasis model assessment 2(HOMA2).

RESULTS

Pregnant women in AMA with vitamin D deficiency have higher fasting insulin (14.70(8.76-34.65) and 10.89(7.15-16.12), respectively, P = 0.031) and HOMA-IR indices (1.78(1.07-4.14) and 1.30(0.83-1.89), respectively, P = 0.024) than those with vitamin D non-deficiency. Serum 25(OH) D levels were inversely associated with HOMA-IR indices (r = - 0.25, P = 0.025). In multivariable analysis for adjusting confounder factors, vitamin D non-deficiency was also negatively correlated with HOMA-IR compared to vitamin D deficiency (β = - 1.289, P = 0.026).

CONCLUSIONS

Taken together, our findings suggest that serum 25(OH) D levels were inversely associated with HOMA-IR in AMA. Furthermore, pregnant women in AMA with vitamin D deficiency might have higher HOMA-IR levels than those with vitamin D non-deficiency.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (No. ChiCTR-RRC-16008714). retrospectively registered.

Long interpregnancy interval and adverse perinatal outcomes: A retrospective cohort study

We conducted a retrospective cohort study of 9,552 women experiencing their second delivery between 2014 and 2016 at the International Peace Maternity and Child Health Hospital to investigate the association between the interpregnancy interval (IPI) and adverse perinatal outcomes. With the 12-23-mon IPI as the reference category, logistic regression analyzes were used to examine associations between different IPIs (<12, 12-23, 24-59, 60-119, and ≥120 mon) and perinatal outcomes (gestational diabetes mellitus, premature membrane rupture, gestational hypertension, preterm birth, low birth weight, and macrosomia). Compared with the 12-23-mon IPI category, women with longer IPIs had a higher risk of adverse perinatal outcomes, and those with an IPI ≥120 mon had the highest risk of gestational diabetes mellitus and premature membrane rupture (adjusted odds ratio (OR) 1.76, 95% confidence interval (CI) 1.32-2.35 and adjusted OR 2.03, 95% CI 1.53-2.67, respectively). These results indicate that a longer IPI is associated with a higher risk of adverse perinatal outcomes and an IPI of ≥120 mon appears to be independently associated with a higher risk of gestational diabetes mellitus and premature membrane rupture.

Examining internal migration effects on short versus long interbirth intervals in Cotonou, Benin Republic

Background

The literature on migration-fertility relationship uses various measures of fertility, such as fertility rates, actual fertility and family size preferences. This study introduces a different measure—interbirth intervals over women’s reproductive years—to examine how internal migration is associated with short interbirth intervals (less than 24 months) and long interbirth intervals (greater than 60 months) in Cotonou, the largest city of Benin Republic.

Methods

The paper uses primary data on 2852 live births to 1659 women aged 15–49 years from the 2018 Fertility and Migration Survey in Cotonou. Competing-risks models were fitted for the analysis.

Results

Nineteen percent of live births were of short interbirth intervals and 16% were of long interbirth intervals. The prevalence of short interbirth intervals was higher among migrants who spent less than 5 years in Cotonou (29%) than among non-migrants (19%) and earlier migrants (18%). Non-migrants had the highest proportion of long interbirth intervals (19%). Within the first 5 years following the migration to Cotonou, migrants had higher subhazard ratio (SHR) of short interbirth intervals (SHR: 1.71, 95% CI: 1.33–2.21) and lower SHR of long interbirth intervals (SHR: 0.64, 95% CI: 0.47–0.87) than non-migrants. This association holds after controlling for socioeconomic characteristics—but with a slightly reduced gap between migrants who spent less than 5 years in Cotonou and non-migrants. Afterwards and irrespective of women’s socioeconomic backgrounds, migrants who spent 5 or more years in Cotonou and non-migrants had similar risks of short and long interbirth intervals. Finally, from 5 years of stay in Cotonou, migrants for reasons other than school or job were less likely to experience short interbirth intervals (SHR: 0.65, 95% CI: 0.46–0.98 for migrants who spent 5–10 years in Cotonou, and SHR: 0.74, 95% CI: 0.54–1.02 for migrants who spent more than 10 years in Cotonou) than non-migrants.

Conclusion

Family planning programmes should mainly target migrants in the early years after their arrival in Cotonou. Moreover, non-migrants need to be sensitised on the adverse health outcomes of long interbirth intervals.

Role of Maternal Nutrition in the Health Outcomes of Mothers and Their Children: A Retrospective Analysis

BACKGROUND Low nutrition status of mothers plays an important role in increasing the prevalence of poor pregnancy outcomes. Poor pregnancy outcomes are the most common in the Guangzhou region of China. The objective of the study was to evaluate the role of maternal nutrition in the improvement of health outcomes for mothers and their children in the Guangzhou region of China. MATERIAL AND METHODS In this study, pregnancy medical records of women were analyzed. Data related to questionnaires which had been provided during hospital stays for nutritional consumption were gathered. Demographic characteristics and health outcomes of mothers and their children were recorded. Correlations of health outcomes with maternal nutrition were tested with respect to Z-scores at 95% confidence level. RESULTS Based on the health outcomes of mothers and their children, the study divided participants into 2 groups. The first group was mothers and their children with good health outcomes (live births with weighing ≥2.5 kg; the GHO group, n=130) and the second group was mothers and their children with poor health outcomes (miscarriage or premature birth with weighing less than 2.5 kg; the PHO group, n=70). These results showed positive correlation between financial status of the mother (salaried, P<0.001), maternal body mass index (P=0.001), maternal nutrition (P<0.001), maternal education (in years, P<0.001), and maternal age (P=0.004)) with health outcomes of mothers and their children. CONCLUSIONS The financial status of the mother, maternal nutrition, maternal age, and maternal education were the key determinants for predicting health outcomes of mothers and their children.

Risk factors and potential protective factors of pregnancy-induced hypertension in China: A cross-sectional study

A cross-sectional study was conducted to the reported factors and assesses possible protective factors for pregnancy-induced hypertension (PIH) in China. The data of pregnant women who delivered between October 2016 and September 2017 were collected from a birth registry. The primary outcome was the occurrence of PIH. Secondary outcomes were delivery before 34 gestational weeks and other adverse obstetric outcomes of PIH. Among the 99 535 women enrolled, 5731 women (5.8%) developed PIH. BMI had a positive correlation with the primary and two secondary outcomes (adjusted OR = 2.05, 2.56, 1.87, respectively, for overweight; adjusted OR = 4.44, 3.90, and 2.63, respectively, for obesity). Otherwise, calcium supplementation during pregnancy was a potential protective factor for those outcomes (adjusted OR = 0.87, 0.14, and 0.44, respectively). These results provide a basis for PIH prevention strategy in the Chinese public health sector. Calcium supplementation and lowering the BMI might have the potential benefit on reducing the prevalence of PIH in selected women.

Risk of adverse pregnancy outcomes associated with short and long birth intervals in Bangladesh: evidence from six Bangladesh Demographic and Health Surveys, 1996-2014

OBJECTIVE

To examine the effect of short (<36 months) and long (≥60 months) birth intervals on adverse pregnancy outcomes in Bangladesh.

DESIGN, SETTING AND PARTICIPANTS

We analysed data from six Bangladesh Demographic and Health Surveys (1996-1997, 1999-2000, 2004, 2007, 2011 and 2014). We included all singleton non-first live births, most recently born to mothers within 5 years preceding each survey (n=21 382). We defined birth interval according to previous research which suggests that a birth interval between 36 and 59 months is the most ideal interval. Bivariate and multivariable analyses were conducted to obtain the crude and adjusted ORs (aOR) respectively to assess the odds of first-day neonatal death, early neonatal death and small birth size for both short (<36 months) and long (≥60 months) spacing between births.

MAIN OUTCOME MEASURES

First-day neonatal death, early neonatal death and small birth size.

RESULTS

In the multivariable analysis, compared with births spaced 36-59 months, infants with a birth interval of <36 months had increased odds of first-day neonatal death (aOR: 2.11, 95% CI: 1.17 to 3.78) and early neonatal death (aOR: 1.58, 95% CI: 1.13 to 2.22). Compared with births spaced 36-59 months, infants with a birth interval of ≥60 months had increased odds of first-day neonatal death (aOR: 2.02, 95% CI: 1.10 to 3.73) and small birth size (aOR: 1.17, 95% CI: 1.02 to 1.34). When there was a history of any previous pregnancy loss, there was an increase in the odds of first-day and early neonatal death for both short and long birth intervals, although it was not significant.

CONCLUSIONS

Birth intervals shorter than 36 months and longer than 59 months are associated with increased odds of adverse pregnancy outcomes. Care-providers, programme managers and policymakers could focus on promoting an optimal birth interval between 36 and 59 months in postpartum family planning.

Advanced Maternal Age and the Future Health of the Offspring

OBJECTIVE

We aimed to evaluate the association between advanced maternal age and the long-term health of the offspring.

METHODS

In this population-based cohort study, hospitalizations of offspring up to the age of 18 years were compared according to maternal age. The incidence of long-term hospitalizations of the offspring due to cardiovascular, endocrine, neurological, hematological, respiratory and gastro-intestinal morbidities was evaluated. Deliveries occurred between the years 1991 and 2014 in a tertiary medical center. Kaplan-Meier survival curves were used to compare cumulative morbidity incidence. Cox regression models were performed to control for confounders.

RESULTS

During the study period, 202,709 deliveries were included, of which 26,287 (12.9%) were in women aged 35-39 years, and 6,718 (3.3%) in women aged 40-50 years. Children born to older mothers did not have a significantly different cumulative incidence of long-term pediatric morbidities evaluated, as compared with the comparison group, using Kaplan-Meier survival analyses. In the Cox regression analyses, advanced maternal age did not exhibit an independent association with long-term morbidities of the offspring.

CONCLUSION

Despite the association of advanced maternal age with adverse maternal and immediate neonatal outcomes, there does not seem to be an association with the long-term morbidity of the offspring.

Does previous cesarean section influence neonatal birth weight? A path analysis in China

BACKGROUND

Since the One-child Policy was revised to a Two-child policy in 2013, the number of pregnancies with previous cesarean section suddenly increased in China. The aim of this study was to test if a previous cesarean section influenced the neonatal birth weight under Chinese background.

METHODS

A retrospective study was conducted. Path analysis was used to test the hypothesized model for the association among previous cesarean section, placenta previa, gestational age and neonatal birth weight. Comparative fit index, the root-mean-square error of approximation and weighted root-mean-square residual were used to evaluate the model fit.

RESULTS

3466 electronic records for second pregnancies met the criteria; a modified model was established (the root-mean-square error of approximation=0.049, comparative fit index=0.992, weighted root-mean-square residual=0.960). The effects of previous cesarean section on neonatal birth weight were mediated via four paths. The direct effects (coefficient: 0.056) showed opposite signs compared to indirect effects (coefficient: -0.127) in this path analysis. It meant that the negative effects of the previous cesarean section were suppressed by other factors which bring positive effects.

CONCLUSION

This study showed that previous cesarean section had negative effects on neonatal birth weight with increasing incidence of placenta previa and preterm birth. But these effects were suppressed by other positive factors, such as maternal body mass index, just after the child policy updated in China.

A clinico-pathologic study of placenta percreta

OBJECTIVE

To review a single-center case series of placenta percreta and to evaluate risk factors and the impact of surgical techniques used in previous cesarean delivery.

METHODS

The present retrospective cohort study included pregnancies with placenta percreta managed between January 1, 2002, and March 31, 2017, at Saint Luc University Hospital, Brussels, Belgium. The data reviewed included demographics, outcomes, inter-pregnancy interval, and surgical techniques used for uterine closure in previous cesarean delivery. A cases series of non-accreta placenta previa was used as a control group.

RESULTS

There were 19 pregnancies included in the study. The most common ultrasonography signs in the study group were loss of the clear zone (14/17; 82%), placental lacunae (17/17; 100%), and subplacental hypervascularity (11/14; 79%). Median gravidity, parity, and number of previous cesarean deliveries were higher (P<0.05) and inter-pregnancy interval was longer (P<0.05) in the study group than the control group. There was no difference between the groups in the surgical techniques used for previous cesarean deliveries.

CONCLUSION

The prenatal ultrasonography diagnosis of placenta percreta is accurate and facilitates optimal management by a specialized multidisciplinary team. Multicenter studies are required to further evaluate the impact of the surgical techniques used for prior cesarean delivery on the risks of placenta percreta in subsequent pregnancies.

Determinants of sleep quality among pregnant women in China: a cross-sectional survey

PURPOSE

Sleep disturbances are common during pregnancy, yet few studies are currently available regarding the determinants of sleep quality among pregnant women in China. This study aimed to: (a) calculate the prevalence of sleep disorder during pregnancy, (b) examine the difference in sleep quality among three trimesters, and (c) identify determinants of sleep quality in pregnant women.

MATERIALS AND METHODS

This study was designed as a cross-sectional survey. Five hundred pregnant women were recruited at the outpatient department of obstetrics and gynecology of two teaching hospitals in central China. Five selfreport questionnaires were used for gathering data, including information of sample characteristics, sleep quality (Pittsburgh Sleep Quality Index (PSQI)), prenatal depression (the Edinburgh Postnatal Depression Scale (EPDS)), perceived stress (Perceived Stress Scale (PSS)), and perceived social support (Multidimensional Scale of Perceived Social Support (MSPSS)).

RESULTS

A total of 454 pregnant women participated in the study between September 2016 and April 2017. Eighty-seven percent pregnant women experienced sleep disorder (PSQI score >5). Poorer global sleep quality, subjective sleep quality, lower sleep efficiency and sleep disturbances were most prevalent during third trimester. The significant contributors to sleep quality for pregnant women were prenatal depression, maternal age, and gestational age.

CONCLUSIONS

Sleep disorder is very common in pregnant women from China. Depressive symptoms, increased maternal age, and gestational age are determinants of sleep quality. These determinants can assist healthcare professionals in preventative intervention.