Interpregnancy interval, air pollution, and the risk of low birth weight: a retrospective study in China.

BACKGROUND: Both interpregnancy intervals (IPI) and environmental factors might contribute to low birth weight (LBW). However, the extent to which air pollution influences the effect of IPIs on LBW remains unclear. We aimed to investigate whether IPI and air pollution jointly affect LBW. METHODS: A retrospective cohort study was designed in this study. The data of birth records was collected from the Jiangsu Maternal Child Information System, covering January 2020 to June 2021 in Nantong city, China. IPI was defined as the duration between the delivery date for last live birth and date of LMP for the subsequent birth. The maternal exposure to ambient air pollutants during pregnancy-including particulate matter (PM) with an aerodynamic diameter of ≤ 2.5 µm (PM2.5), PM10, ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2) and carbon monoxide (CO)-was estimated using a hybrid kriging-LUR-RF model. A novel air pollution score was proposed, assessing combined exposure to five pollutants (excluding CO) by summing their concentrations, weighted by LBW regression coefficients. Multivariate logistic regression models were used to estimate the effects of IPI, air pollution and their interactions on LBW. Relative excess risk due to interaction (RERI), attributable proportion of interaction (AP) and synergy index (S) were utilized to assess the additive interaction. RESULTS: Among 10, 512 singleton live births, the LBW rate was 3.7%. The IPI-LBW risk curve exhibited an L-shaped pattern. The odds ratios (ORs) for LBW for each interquartile range increase in PM2.5, PM10, O3 and the air pollution score were 1.16 (95% CI: 1.01-1.32), 1.30 (1.06-1.59), 1.22 (1.06-1.41), and 1.32 (1.10-1.60) during the entire pregnancy, respectively. An additive interaction between IPI and PM2.5 was noted during the first trimester. Compared to records with normal IPI and low PM2.5 exposure, those with short IPI and high PM2.5 exposure had the highest risk of LBW (relative risk = 3.53, 95% CI: 1.85-6.49, first trimester). CONCLUSION: The study demonstrates a synergistic effect of interpregnancy interval and air pollution on LBW, indicating that rational birth spacing and air pollution control can jointly improve LBW outcomes.

Interpregnancy interval and adverse perinatal outcomes: A within-individual comparative method.

Background and Aim: Previously observed associations between interpregnancy interval (IPI) and perinatal outcomes using a between-individual method may be confounded by unmeasured maternal factors. This study aims to examine the association between IPI and adverse perinatal outcomes using within-individual comparative analyses. Methods: We studied 10,647 individuals from the National Institute of Child Health and Human Development Consecutive Pregnancies Study in Utah with ≥3 liveborn singleton pregnancies. We matched two IPIs per individual and used conditional logistic regression to examine the association between IPI and adverse perinatal outcomes, including preterm birth (PTB, <37 weeks' gestation), small-for-gestational-age (SGA, <10th percentile of sex-specific birthweight for gestational age), low birthweight (LBW, <2,500 g), and neonatal intensive care unit (NICU) admission. Point and 95% confidence interval (CI) estimates were adjusted for factors that vary across pregnancies within individuals. Results: CIs did not unequivocally support either an increase or a decrease in the odds of PTB (adjusted odds ratio [aOR]: 1.31, 95% CI: 0.87, 1.96), SGA (aOR: 0.81, 95% CI: 0.51, 1.28), LBW (aOR: 1.59, 95% CI: 0.90, 2.80), or NICU admission (aOR: 0.96, 95% CI: 0.66, 1.40) for an IPI <6 months compared to 18-23-months IPI (reference), and neither did the CIs for the aOR of IPIs of 6-11 and 12-18 months compared to the reference. In contrast, an IPI ≥24 months was associated with increased odds of LBW (aOR: 1.66, 95% CI: 1.03, 2.66 for 24-29 months; aOR: 2.27, 95% CI: 1.21, 4.29 for 30-35 months; and aOR: 2.09, 95% CI: 1.17, 3.72 for ≥36 months). Conclusions: Using a within-individual comparative method, we did not find evidence that a short IPI compared to the recommended IPI of 18-23 months was associated with increased odds of PTB, SGA, LBW, and NICU admission. IPI ≥ 24 months was associated with increased odds of delivering an LBW infant.

Association between interpregnancy interval and adverse perinatal outcomes among subsequent twin pregnancies: a nationwide population-based study.

BACKGROUND: The existing evidence on the association between interpregnancy interval (IPI) and pregnancy outcomes primarily focuses on singleton pregnancies, with limited research on twin pregnancies. OBJECTIVE: This study aimed to investigate the association between IPI and adverse perinatal outcomes in twin pregnancies. STUDY DESIGN: This population-based, retrospective cohort study analyzed data from the National Center for Health Statistics in the United States between 2016 and 2020. We included multiparous women aged 18 to 45 years with live-born twins without congenital anomalies, born between 26 and 42 weeks of gestation. Poisson regression models, adjusted for potential confounders, were used to evaluate the associations between IPI and adverse outcomes, including preterm birth (PTB) <36 weeks, small for gestational age (SGA), neonatal intensive care unit (NICU) admission, neonatal composite morbidity, and infant death. Missing data on covariates were managed using multiple imputations. Dose-response analyses were performed using the restricted cubic splines (RCS) approach. Subgroup analyses were stratified by maternal age, parity, and combination of neonatal sex. Sensitivity analyses were conducted using complete data and excluding pregnancies with intervening events during the IPI. RESULTS: A total of 143,014 twin pregnancies were included in the analysis. Compared to the referent group (IPI of 18-23 months), an IPI of less than 6 months was associated with an increased risk of PTB<36 weeks (RR, 1.21; 95% confidence interval [95% CI]: 1.17-1.25), SGA (RR, 1.11; 95% CI: 1.03-1.18), neonatal composite morbidity (RR, 1.19; 95% CI: 1.12-1.27), NICU admission (RR, 1.18; 95% CI: 1.14-1.22), and infant death (RR, 1.29; 95% CI: 1.05-1.60). An IPI of 5 years or more was associated with an increased risk of PTB<36 weeks (RR, 1.18; 95% CI: 1.15-1.21), SGA (RR, 1.24; 95% CI: 1.18-1.30), neonatal composite morbidity (RR, 1.10; 95% CI: 1.05-1.15), and NICU admission (RR, 1.14; 95% CI: 1.11-1.17). The dose-response analyses showed that these outcomes had U-shaped or J-shaped associations with IPI. The associations between IPI and the outcomes slightly differed by advanced maternal age, parity, and combination of neonatal sex. The sensitivity analyses yielded similar results to the main findings. CONCLUSION: Extreme IPI, less than 6 months or more than 5 years, was associated with adverse outcomes in twin pregnancies. IPI could be used as a predictor for risk stratification in high-risk twin pregnancies.

Interpregnancy interval following missed abortion and the risk for preterm birth.

OBJECTIVE: Short inter-pregnancy interval (IPI) of <18 months following a live birth, has been associated with adverse pregnancy outcome. This study aimed to evaluate whether a short IPI following a medically treated missed abortion (MA) poses similar perinatal risks in a subsequent pregnancy. STUDY DESIGN: The retrospective analysis included patients with history of an MA at up to 10 weeks of gestation, treated with misoprostol (pgE1) only, and with a documented subsequent live pregnancy (2010-2022). 1110 Patients were allocated into two groups: IPI ≤18 months and IPI >18 months. The primary outcome was the risk for a spontaneous preterm birth (PTB) <37 weeks of gestation in the consecutive pregnancy. Secondary outcomes included maternal and neonatal adverse outcomes. Statistical analysis was performed using the Statistical Program for Social Sciences for Windows version 26 (SPSS Inc, Chicago, IL). RESULTS: The cohort included 1,110 patients: 430 (38.74 %) patients with IPI <18 months and 680 (61.26 %) patients with IPI >18 months. The characteristics of the two groups were not significantly different. The rates of spontaneous PTB <37 and <34 weeks of gestation were significantly higher in the short vs. long IPI cohort (16.28 % vs. 7.06 % and 6.74 % vs. 5.0 %, respectively, p < 0.05). These patients also had a higher risk for Cesarean delivery (31.63 % vs. 23.34 %, p = 0.005) and postpartum hemorrhage (4.42 % vs. 2.06 %, p = 0.029) compared to patients with IPI >18 months. The observed differences remained statistically significant even after adjusting for potential confounding variables using multiple regression analysis. No other significant differences in neonatal or maternal outcomes were noted. CONCLUSION: Short IPI (≤18 months) following a medical treatment MA may be associated with an increased risk of PTB, Cesarean delivery and PPH.

Does reversible postpartum contraception reduce the risk of pregnancy condition recurrence? A longitudinal claims-based study from Maine.

PURPOSE: To estimate the effect of reversible postpartum contraception use on the risk of recurrent pregnancy condition in the subsequent pregnancy and if this effect was mediated through lengthening the interpregnancy interval (IPI). METHODS: We used data from the Maine Health Data Organization's Maine All Payer Claims dataset. Our study population was Maine women with a livebirth index pregnancy between 2007 and 2019 that was followed by a subsequent pregnancy starting within 60 months of index pregnancy delivery. We examined recurrence of three pregnancy conditions, separately, in groups that were not mutually exclusive: prenatal depression, hypertensive disorders of pregnancy (HDP), and gestational diabetes (GDM). Effective reversible postpartum contraception use was defined as any intrauterine device, implant, or moderately effective method (pills, patch, ring, injectable) initiated within 60 days of delivery. Short IPI was defined as ≤ 12 months. We used log-binomial regression models to estimate risk ratios and 95 % confidence intervals, adjusting for potential confounders. RESULTS: Approximately 41 % (11,448/28,056) of women initiated reversible contraception within 60 days of delivery, the prevalence of short IPI was 26 %, and the risk of pregnancy condition recurrence ranged from 38 % for HDP to 55 % for prenatal depression. Reversible contraception initiation within 60 days of delivery was not associated with recurrence of the pregnancy condition in the subsequent pregnancy (aRR ranged from 0.97 to 1.00); however, it was associated with lower risk of short IPI (aRR ranged from 0.67 to 0.74). CONCLUSION(S): Although initiation of postpartum reversible contraception within 60 days of delivery lengthens the IPI, our findings suggest that it does not reduce the risk of prenatal depression, HDP, or GDM recurrence. This indicates a missed opportunity for providing evidence-based healthcare and health interventions in the intrapartum period to reduce the risk of recurrence.

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.

Interpregnancy interval after vacuum delivery and subsequent perinatal outcomes.

OBJECTIVE: To evaluate whether a short interpregnancy interval (IPI) after vacuum extraction (VE), poses similar perinatal risks in a subsequent pregnancy. METHODS: This was a retrospective, single-center cohort study between 2011 and 2021. Nulliparous women with term, singleton VE deliveries and with known pregnancy outcomes in their subsequent pregnancy were eligible for inclusion in the study. Each woman was allocated into one of two groups based on the IPI, <18 months and between 18 and 60 months. The primary outcome was the risk of spontaneous preterm birth (PTB) <37 weeks in the consecutive birth. RESULTS: We included 1094 pregnancies: 212 (19.4%) with IPI <18 months and 882 (80.6%) with IPI between 18 and 60 months following the previous VE delivery. The VE characteristics were comparable between the groups. Young maternal age was a risk factor for a short IPI (28.0 ± 4.8 vs 30.3 ± 4 years, P < 0.01). Spontaneous PTB <37 weeks was significantly higher in the IPI <18 months group with 18-60 months (7.1% vs 2.6%, P = 0.002). Polynomial regression analysis also confirmed a significantly increased risk of preterm birth <37 weeks (P < 0.01). Short IPI <18 months was also associated with an increase in the risk of low birthweight <2500 g (6.1% vs 2.8%, P = 0.02) and admission to the neonatal intensive care unit (6.1% vs 2.6%, P = 0.013). The incidence of recurrent VE, albeit significant (2.3% vs 4.9%, P = 0.049), was low in both groups. No differences were noted in any of the other secondary outcomes. CONCLUSION: Short IPI (<18 months) following term VE delivery is associated with higher neonatal risks, particularly PTB, in the subsequent pregnancy. These findings are particularly important when counseling women planning an optimal IPI.

The association between postpartum depressive symptoms and contraception.

BACKGROUND: Postpartum depression affects 10% to 20% of birthing people and is associated with changes in healthcare use. Little is known about the association between postpartum depressive symptoms and choice to use contraception; however, both untreated or undertreated depression and short interpregnancy intervals pose substantial perinatal health risks. OBJECTIVE: This study aimed to evaluate whether postpartum depressive symptoms are associated with changes in decisions to use any method of contraception. STUDY DESIGN: This retrospective cohort study included birthing people who delivered between 2017 and 2022 and were referred to a collaborative care program for mental healthcare. Through this program, birthing people with mental health conditions have access to specialized perinatal mental healthcare and prospective symptom monitoring via a patient registry. Postpartum depressive symptoms are assessed via the Patient Health Questionnaire-9, and scores were stratified by severity according to clinical cutoffs. Contraceptive method choice was determined by documentation in the electronic health record and dichotomized as "none" if the participant declined all forms of contraception both at delivery and at the postpartum visit. Bivariable and multivariable analyses were performed. RESULTS: Of the 1871 participants that met the inclusion criteria, 160 (8.5%) had postpartum Patient Health Questionnaire-9 scores of >14, representing moderately severe or worse depressive symptoms, and 43 (2.3%) had severe (Patient Health Questionnaire-9 of >19) depressive symptoms. Birthing people with higher Patient Health Questionnaire-9 scores were more likely to have medical comorbidities; to have a higher body mass index; to self-identify as Black, Native Hawaiian or Pacific Islander, or Hispanic or Latina; and to have a preterm delivery and less likely to be married or nulliparous than those with Patient Health Questionnaire-9 scores of ≤14. There was no difference in any other sociodemographic or clinical characteristics. The choice to use any contraceptive method decreased with increasing depressive symptoms in bivariable and multivariable analyses, reaching statistical significance in birthing people with severe depressive symptoms (adjusted odds ratio, 2.92; 95% confidence interval, 1.46-5.84). CONCLUSION: Severe perinatal depressive symptoms are associated with a declination of any form of postpartum contraception. This finding becomes increasingly relevant as abortion access continues to be threatened across the United States, compounding the potential effect of opting not to use contraception.

Fear of childbirth prolongs interpregnancy interval: A nationwide register-based quantile logistic regression analysis.

Introduction: It is not well studied how fear of childbirth (FOC) influences the interpregnancy interval (IPI). Thus, we aimed to analyze the association between FOC and the length of the IPI. Methods: All women having their first and second pregnancies during the study period (2004-2018) were gathered from the Finnish Medical Birth Register. A logistic regression model was used to assess the association between the FOC and subsequent length of the IPI. The length of the IPI was assessed separately for women with FOC in the first pregnancy, and for women who developed the FOC in the second pregnancy. IPIs with a length in the lower quartal were considered short IPIs, and length in the upper quartal as long IPIs. Adjusted odds ratios (aOR) with 95% CIs were compared between the groups. Results: A total of 52 709 women with short IPI (<1.05 years), 105 604 women with normal IPI, and 52 889 women with long IPI (>2.57 years) were included. A total of 3606 women had FOC in the first pregnancy, and a total of 11 473 had their first FOC diagnosis in the second pregnancy. Women with FOC in the first pregnancy had lower odds for short IPI (aOR 0.88, CI 0.81-0.95) and higher odds for long IPI (aOR 1.30, CI 1.21-1.40). Women with the first FOC diagnosis in the second pregnancy had higher odds for long IPI (aOR 1.68, CI 1.61-1.75), When only vaginal deliveries in the first pregnancy were included, women with FOC in the second pregnancy had lower odds for long IPI (aOR 0.71, CI 0.66-0.75) and higher odds for long IPI (aOR 1.52, CI 1.41-1.62), when only cesarean section was included. Conclusion: The main finding of this study was that women with FOC had notably higher odds for long IPI. The etiologic and background factors behind FOC should be better recognized and prevented, and FOC should not only be considered as a complicating factor for pregnancy and delivery but also a factor that strongly affects the desire of women to get pregnant again.

Association of interpregnancy interval with adverse pregnancy outcomes according to the outcomes of the preceding pregnancy: a longitudinal study with 4.7 million live births from Brazil.

Background: Earlier studies have proposed a link between the Interpregnancy Interval (IPI) and unfavorable birth outcomes. However, it remains unclear if the outcomes of previous births could affect this relationship. We aimed to investigate whether the occurrence of adverse outcomes-small for gestational age (SGA), preterm birth (PTB), and low birth weight (LBW)-at the immediately preceding pregnancy could alter the association between IPI and the same outcomes at the subsequent pregnancy. Methods: We used a population-based linked cohort from Brazil (2001-2015). IPI was measured as the difference, in months, between the preceding birth and subsequent conception. Outcomes included SGA (<10th birthweight percentile for gestational age and sex), LBW (<2500 g), and PTB (gestational age <37 weeks). We calculated risk ratios (RRs), using the IPI of 18-22 months as the reference IPI category, we also stratified by the number of adverse birth outcomes at the preceding pregnancy. Findings: Among 4,788,279 births from 3,804,152 mothers, absolute risks for subsequent SGA, PTB, and LBW were higher for women with more adverse outcomes in the preceding delivery. The RR of SGA and LBW for IPIs <6 months were greater for women without previous adverse outcomes (SGA: 1.44 [95% Confidence Interval (CI): 1.41-1.46]; LBW: 1.49 [1.45-1.52]) compared to those with three previous adverse outcomes (SGA: 1.20 [1.10-1.29]; LBW: 1.24 [1.15-1.33]). IPIs ≥120 months were associated with greater increases in risk for LBW and PTB among women without previous birth outcomes (LBW: 1.59; [1.53-1.65]; PTB: 2.45 [2.39-2.52]) compared to women with three adverse outcomes at the index birth (LBW: 0.92 [0.78-1.06]; PTB: 1.66 [1.44-1.88]). Interpretation: Our study suggests that women with prior adverse outcomes may have higher risks for adverse birth outcomes in subsequent pregnancies. However, risk changes due to differences in IPI length seem to have a lesser impact compared to women without a prior event. Considering maternal obstetric history is essential in birth spacing counseling. Funding: Wellcome Trust225925/Z/22/Z.

Interpregnancy interval and early infant neurodevelopment: the role of maternal-fetal glucose metabolism.

BACKGROUND: Interpregnancy interval (IPI) is associated with a variety of adverse maternal and infant outcomes. However, reports of its associations with early infant neurodevelopment are limited and the mechanisms of this association have not been elucidated. Maternal-fetal glucose metabolism has been shown to be associated with infant neurodevelopmental. The objective of this study was to determine whether this metabolism plays a role in the relationship between IPI and neurodevelopment. METHODS: This prospective birth cohort study included 2599 mother-infant pairs. The IPI was calculated by subtracting the gestational age of the current pregnancy from the interval at the end of the previous pregnancy. Neurodevelopmental outcomes at 12 months in infants were assessed by the Ages and Stages Questionnaire Edition 3 (ASQ-3). Maternal fasting venous blood was collected at 24-28 weeks and cord blood was collected at delivery. The association between IPI and neurodevelopment was determined by logistic regression. Mediation and sensitivity analyses were also conducted. RESULTS: In our cohort, 14.0% had an IPI < 12 months. IPI < 12 months increased the failure of the communication domain, fine motor domain, and personal social domain of the ASQ (relative risks (RRs) with 95% confidence interval (CI): 1.73 [1.11,2.70]; 1.73 [1.10,2.72]; 1.51 [1.00,2.29]). Maternal homeostasis model assessment of insulin resistance (HOMA-IR) and cord blood C-peptide was significantly associated with failure in the communication domain [RRs with 95% CI: 1.15 (1.02, 1.31); 2.15 (1.26, 3.67)]. The proportion of the association between IPI and failure of the communication domain risk mediated by maternal HOMA-IR and cord blood C-peptide was 14.4%. CONCLUSIONS: IPI < 12 months was associated with failing the communication domain in infants. Maternal-fetal glucose metabolism abnormality may partially explain the risk of neurodevelopmental delay caused by short IPI.

Association between interpregnancy interval and risk of autism spectrum disorder: a systematic review and Bayesian network meta-analysis.

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.

Association between interpregnancy interval and gestational diabetes mellitus: A cohort study of the National Vital Statistics System 2020.

OBJECTIVE: To assess the association between interpregnancy interval (IPI) and gestational diabetes mellitus (GDM). METHODS: Data of this retrospective cohort study were obtained from the National Vital Statistics System (NVSS) 2020. The participants were divided into different groups according to different IPI (<6, 6-11, 12-17, 18-23, 24-59 (reference), 60-119, ≥120 months). Multivariate logistic models were constructed to evaluate the association between IPI and GDM. Subgroup analysis was further performed. RESULTS: A total of 1 515 263 women were included, with 123 951 (8.18%) having GDM. Compared with the 24-59 months group, the <6 months (odds ratio [OR] 0.64, 95% confidence interval [CI] 0.46-0.90, P = 0.009), 12-17 months (OR 0.96, 95% CI 0.94-0.98, P < 0.001), and 18-23 months (OR 0.94, 95% CI 0.93-0.96, P < 0.001) groups had a significantly lower risk of GDM, while the 60-119 months (OR 1.13, 95% CI 1.11-1.15, P < 0.001) and ≥120 months (OR 1.18, 95% CI 1.15-1.21, P < 0.001) groups had a significantly higher risk of GDM. No significant difference was observed in the risk of GDM between the 6-11 and 24-59 months groups (P = 0.542). The PI-GDM association varied across different groups of age, pre-pregnancy body mass index, pre-pregnancy smoking status, history of cesarean section, history of preterm birth, prior terminations, and parity. CONCLUSION: An IPI of 18-23 months may be a better interval than 24-59 months in managing the risk of GDM.

Severe Perineal Lacerations in First Delivery: Association with Subsequent Reproductive Outcomes.

Background: Severe perineal lacerations (SPLs), common worldwide, are associated with short- and long-term complications: pelvic floor disorders, fecal incontinence, fistula, and profound psychological impacts. Limited research suggests that experiencing SPL may influence future reproductive intentions, but research on outcomes is lacking. Methods: We analyzed the effect of experiencing SPL during a first delivery among a large cohort of Swedish births between 1992 and 2013. We used linear and multinomial logistic regression to estimate the associations between SPL and four reproductive outcomes: subsequent total birth number, probability of a second birth, interpregnancy interval (IPI), and subsequent scheduled cesarean birth. Results: Among 947,035 singleton live-born first-births, we found that experiencing SPL was associated with slightly fewer overall births in fully adjusted models (a decrease of -0.020 births; 95% confidence interval [CI]: -0.028 to -0.012), but no difference in the probability of a second birth (risk ratio [RR]: 1.00; 95% CI: 0.99 to 1.00) or IPI. Scheduled cesarean was increased in births after SPL (adjusted RR: 4.57; 95% CI: 4.42 to 4.73). A secondary comparison of SPL to severe postpartum hemorrhage suggests that some of these observed differences may be related to experiencing any severe outcome, and some specifically to perineum disruption. Conclusion: This study provides a deeper understanding of the long-term impacts of SPL, which may be useful in informing best clinical practices for supporting women who have experienced SPL.

Social determinants among Black people during pregnancy following a short interpregnancy interval.

BACKGROUND: Short interpregnancy interval has been shown to be a key contributor to infant mortality. Black pregnant people have a higher incidence of short interpregnancy interval than people of other races and ethnicities, as well as higher rates of infant mortality. Understanding the factors related to racial disparities in short interpregnancy interval and infant mortality are a public health priority. OBJECTIVE: This study aimed to examine the relationship between social determinants of health and interpregnancy interval in Black pregnant people by comparing those with a short interpregnancy interval defined as <18 months with those with a referent interpregnancy interval defined as ≥18 months. STUDY DESIGN: This was a nested case-control study from a prospective cohort analyzing social determinants of health in 576 postpartum patients at an urban medical center, 2011-2021. Sociodemographic, pregnancy, and maternal characteristic data were collected from participants' medical records. Structured interviews measured participants' health behaviors, physical environment, social support, health literacy, and structural drivers. Differences in social determinants of health among Black study participants were compared between those with a short interpregnancy interval (<18 months) and those with a referent interpregnancy interval (≥18 months). The odds ratios were calculated to assess the association between short interpregnancy interval and social determinants. Factors with significant differences between the short interpregnancy interval and referent interpregnancy interval groups in Black participants were compared with that of White groups for social context. RESULTS: Black participants with a short interpregnancy interval were more likely to report financial support from the Special Supplemental Nutrition Program for Women, Infants, and Children (odds ratio, 2.4; 95% confidence interval, 1.2-5.1), negative feelings toward the pregnancy (odds ratio, 2.4; 95% confidence interval, 1.2-4.9), choosing not to breastfeed because they do not like it (odds ratio ,12.0; 95% confidence interval, 1.5-543.1), not receiving prenatal care as early as desired (odds ratio, 3.4; 95% confidence interval, 1.6-7.2) because of consid- eration of pregnancy termination (odds ratio, 5.2; 95% confidence interval, 1.2-30.5) and less likely to report low levels of social support (odds ratio, 0.3; 95% confidence interval, 0.1-0.8) than Black participants with a referent interpregnancy interval. CONCLUSION: Social determinants of health that differed between participants with a short interpregnancy interval and those with a referent interpregnancy interval were Special Supplemental Nutrition Program for Women, Infants, and Children support, feelings toward the pregnancy, social support, breastfeeding intent, and delayed prenatal care because of consideration of abortion. Previous studies examining infant mortality risk factors used White people as the referent group when analyzing social determinants. Our study focused specifically on understanding the lives of Black pregnant people so that future public health initiatives focused on social determinants may attenuate the racial disparity of infant mortality in the United States.

Subsequent pregnancy outcomes and risk factors following conservative treatment for placenta accreta spectrum: a retrospective cohort study.

BACKGROUND: Placenta accreta spectrum can lead to uncontrollable massive hemorrhage in the perinatal period. Currently, the first-line treatment for placenta accreta spectrum recommended worldwide is hysterectomy. However, adverse outcomes after hysterectomy, including surgical complications, such as difficulty in performing the procedure, and sequelae, such as infertility and psychological issues, cannot be ignored. Several surgical approaches for conservative treatment have been proposed. There are few reports on the effectiveness, safety, and long-term complications of conservative treatments, especially subsequent pregnancy outcomes. OBJECTIVE: This study aimed to investigate the clinical outcomes and identify risk factors of subsequent pregnancies among patients with placenta accreta spectrum who had undergone conservative surgery. STUDY DESIGN: This was a retrospective cohort study of subsequent pregnancy cases after cesarean delivery with conservative treatment for placenta accreta spectrum from 2011 to 2019 at The First Affiliated Hospital of Zhengzhou University to identify clinical outcomes of subsequent pregnancies and the risk factors of adverse pregnancy outcomes. RESULTS: A total of 883 patients undergoing conservative surgery were included in this study, among which 604 (68.4%) were successfully followed up. There were 75 successful pregnancies in 72 patients, including 22 full-term or near-term deliveries, 1 induced labor in the second trimester of pregnancy, 6 cesarean scar pregnancies (8.0%), 2 ectopic pregnancies, and 44 first-trimester pregnancies (3 miscarriages and 41 elective abortions and 12 medical abortions and 32 vacuum aspirations). All newborns survived in the 22 full-term or near-term deliveries. Moreover, 5 placenta accreta spectrum cases (22.7%) and 6 placenta previa cases were observed. Postpartum hemorrhage was observed in 2 cases, with an incidence rate of 9.1%. All parameters, including age at subsequent pregnancy, gravidity, number of cesarean deliveries, type of previous placenta accreta spectrum, gestational week of pregnancy termination, interpregnancy interval, and the use of vascular occlusion techniques, were not found to be associated with recurrent placenta accreta spectrum and cesarean scar pregnancy. CONCLUSION: Our findings show that treatment for placenta accreta spectrum does not automatically preclude a subsequent pregnancy. However, patients should be fully informed about the risk of recurrent placenta accreta spectrum, scar pregnancy, and postpartum hemorrhage.

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.

Effects of Short Interpregnancy Intervals on Adverse Pregnancy Outcomes - Haidian District, Beijing Municipality, China, 2017-2019.

What is already known about this topic?: Interpregnancy intervals (IPIs) that are either excessively long or short have been linked with an elevated risk of adverse perinatal outcomes. Presently, no pertinent guidelines have been established in China to provide clear direction with regard to optimal IPI. What is added by this report?: A brief interpregnancy interval may elevate the risk of miscarriage, postpartum hemorrhage, and fetal distress among expectant women. What are the implications for public health practice?: These results could inform prenatal consultations, guiding pregnant women towards an ideal interpregnancy interval of no less than 24 months.

Interbirth Intervals of Immigrant and Refugee Women in the United States: A Cross-Sectional Study.

Background and Objective: Despite guidelines recommending an interval of at least 18-24 months between a live birth and the conception of the next pregnancy, nearly one-third of pregnancies in the United States are conceived within 18 months of a previous live birth. The purpose of this study was to examine the associations between multiple immigration-related variables and interbirth intervals among reproductive-aged immigrant and refugee women living in the United States. Methods: This was a cross-sectional, quantitative study on the sexual and reproductive health (SRH) of reproductive-aged immigrant and refugee women in the United States. The data were collected via an online survey administered by Lucid LLC. We included data on women who had complete information on nativity and birth history in the descriptive analysis (n = 653). The exposure variables were immigration pathway, length of time since immigration, and country/region of birth. The outcome variable was interbirth interval (≤18, 19-35, or ≥36 months). We used multivariable ordinal logistic regression, adjusted for confounders, to determine the factors associated with having a longer interbirth interval among women with second- or higher-order births (n = 245). Results: Approximately 37.4% of study participants had a short interbirth interval. Women who immigrated to the United States for educational (aOR = 4.57; 95% CI, 1.57-9.58) or employment opportunities (aOR = 2.27; 95% CI, 1.07-5.31) had higher odds of reporting a longer interbirth interval (19-35 or ≥36 months) than women born in the United States. Women born in an African country had 0.79 times the odds (aOR = 0.79; 95% CI, 0.02-0.98) of being in a higher category of interbirth interval. Conclusion and Global Health Implications: Although all birthing women should be counseled on optimal birth spacing through the use of postpartum contraception, immigrant and refugee women would benefit from further research and policy and program interventions to help them in achieving optimal birth spacing. SRH research in African immigrant and refugee communities is especially important for identifying ameliorable factors for improving birth spacing.

The influence of birth outcomes and pregnancy complications on interpregnancy interval: a quantile regression analysis.

PURPOSE: To ascertain whether adverse pregnancy outcomes at first pregnancy influence subsequent interpregnancy intervals (IPIs) and whether the size of this effect varies with IPI distribution METHODS: We included 251,892 mothers who gave birth to their first two singletons in Western Australia, from 1980 to 2015. Using quantile regression, we investigated whether gestational diabetes, hypertension, or preeclampsia in the first pregnancy influenced IPI to subsequent pregnancy and whether effects were consistent across the IPI distribution. We considered intervals at the 25th centile of the distribution as 'short' and the 75th centile as 'long'. RESULTS: The average IPI was 26.6 mo. It was 0.56 mo (95% CI: 0.25-0.88 mo) and 1.12 mo (95% CI: 0.56 - 1.68 mo) longer after preeclampsia, and gestational hypertension respectively. There was insufficient evidence to suggest that the association between previous pregnancy complications and IPI differed by the extent of the interval. However, associations with marital status, race/ethnicity and stillbirth contributed to either shortening or prolonging IPIs differently across the distribution of IPI. CONCLUSION: Mothers with preeclampsia and gestational hypertension had slightly longer subsequent IPIs than mothers whose pregnancies were not complicated by these conditions. However, the extent of the delay was small (<2 mo).