Trends in Preterm Births in Italy and Maternal Risk Factors in 2018-2022-A Registry-Based Study.

The aim of the study is to evaluate the effect of the coronavirus disease 2019 (COVID-19) pandemic national lockdown period on the rate of singleton preterm births in Israel. This is a population-based cohort study of 3,41,291 singleton infants born in the months of January to July 2017 to 2020. Multivariable logistic regression analyses were used to estimate the influence of period and year on the rates of preterm births during the lockdown period (11th March - 5th May 2020) compared with rates before (January 1st 2020 - March 10th 2020), and after the lockdown (May 6th 2020-June 30th 2020) and to the corresponding periods in 2017to 2019. During the lockdown period the preterm birth rate (primary outcome) decreased by 9.7% from 5.05 to 4.56% in the pre-lockdown period (p = 0.006), an adjusted decrease of -0.52% (95% confidence interval -0.89%; -0.15%), odds ratio 0.898 (95% confidence interval 0.832; 0.970). The rate of singleton preterm births declined by 9.7% during the COVID-19 pandemic national lockdown period in Israel. · A 10% decline in all preterm deliveries was observed during the COVID-19 pandemic national lock-down period.. · The lock-down might influence environmental changes which contribute to the decrease in preterm deliveries.. · Changes in lifestyle, and societal behavior might contribute to the decrease in preterm deliveries..

Objective: To determine whether preterm birth in a twin pregnancy increases the risk of subsequent preterm birth (PTB) in a singleton pregnancy and to identify predictors for singleton PTB in women with previous twin PTB.Method: A retrospective cohort study of women with prior twin birth followed by a singleton birth in two tertiary referral centres between 2000 and 2016 was conducted. Rate of PTB in subsequent singleton pregnancy was compared between women who experienced previous preterm versus term twin birth. Analysis was further stratified by gestational age at twin and singleton birth, etiology for PTB and chorionicity in the twin pregnancy.Results: A total of 378 women met the inclusion criteria, of whom 252 (66.7%) experienced PTB in the index twin pregnancy. The overall rate of PTB in the subsequent singleton pregnancy was 11.6% (44/378). Women with prior twin PTB had a higher rate of PTB in the subsequent singleton pregnancy compared with women with prior term twin birth (17.5 versus 6.3%, p = .003, or 3.12, 95%-CI 1.42–6.85), mainly due to a higher rate of late singleton preterm birth (13.1 versus 4.0%, p = .005). Findings of higher odds of PTB in the subsequent singleton pregnancy was limited to women who gave birth before 340/7 weeks in the twin pregnancy and was related to the degree of prematurity (prior twin PTB at 300/7–336/7 weeks: OR 3.09, 95%-CI 1.12–8.51; prior twin PTB at <300/7 weeks: OR 5.8, 95%-CI 2.46–13.68). The association between previous twin PTB and subsequent singleton PTB was limited to women with prior spontaneous twin PTB (OR 3.34, 95%-CI 1.50–7.45).Conclusion: Women with a history of spontaneous PTB in a twin pregnancy are at increased odds of PTB in subsequent singleton pregnancies compared to women with prior term twin birth, and the risk is related to the severity of prematurity in the index twin pregnancy.

BACKGROUND:Conflicting reports have emerged for rates of preterm births and stillbirths during the COVID-19 pandemic. Most of these reports did not account for natural variation in these rates. We aimed to evaluate variations in preterm birth and stillbirth rates before and during the COVID-19 pandemic in Ontario, Canada.METHODS:We conducted a retrospective cohort study using linked population health administrative databases of pregnant people giving birth in any hospital in Ontario between July 2002 and December 2020. We calculated preterm birth and stillbirth rates. We assessed preterm birth at 22–28, 29–32 and 33–36 weeks’ gestation, and stillbirths at term and preterm gestation. We used Laney control P′ charts for the 18-year study period (6-mo observation periods) and interrupted time-series analyses for monthly rates for the most recent 4 years.RESULTS:We evaluated 2 465 387 pregnancies, including 13 781 that resulted in stillbirth. The mean preterm birth rate for our cohort was 7.96% (range 7.32%–8.59%). From January to December 2020, we determined that the preterm birth rate in Ontario was 7.87%, with no special cause variation. The mean stillbirth rate for the cohort was 0.56% (range 0.48%–0.70%). From January to December 2020, the stillbirth rate was 0.53%, with no special cause variation. We did not find any special cause variation for preterm birth or stillbirth subgroups. We found no changes in slope or gap between prepandemic and pandemic periods using interrupted time-series analyses.INTERPRETATION:In Ontario, Canada, we found no special cause variation (unusual change) in preterm birth or stillbirth rates, overall or by subgroups, during the first 12 months of the COVID-19 pandemic compared with the previous 17.5 years.

ObjectiveThe COVID-19 lockdown impacted interactions with the health care system and societal stress levels. Previous US-based studies suggest that pandemic lockdowns may have lowered preterm birth rates although there are mixed findings from different settings. We evaluated the impact of COVID-19 on preterm birth and low birthweight rates at two San Francisco hospitals.MethodsWe compared rates of preterm birth (< 37 weeks) and low birthweight (< 2500 g) in San Francisco at a safety net hospital and an academic medical center during two time periods early in the COVID-19 pandemic compared with the same months from the prior year: from March to May 2019 and 2020 and August to December 2019 and 2020. We calculated crude rates for preterm birth and low birth weight as well as compared maternal and infant birth demographics and health characteristics during these same time periods using descriptive statistics. Secondly using a cross-sectional study design, we used logistic and linear regression models to evaluate risk for preterm birth, gestational age at birth, and low birthweight adjusting for confounders comparing the lockdown period with the pre-COVID year. All analyses were conducted using Stata 15.0.ResultsFrom August to December 2019 to 2020, the preterm birth rate decreased from 13.20 to 7.96% in the combined hospital data (p < 0.01), and the low birthweight rate decreased from 11.33 to 9.70% during the same time period (p = 0.13). We did not find a comparable reduction from March to May 2019 to 2020. Maternal age at delivery was significantly younger during the lockdown period, August to December, than in the prior year (36.29 ± 5.69 versus 37.15 ± 5.68 years p < 0.01) and parity was greater (0.83 ± 1.15 versus 0.74 ± 1.04, p = 0.03) but there were no other significant differences in race or ethnicity, infant sex or type of delivery (vaginal versus Cesarean section) from 2019 to 2020. In a logistic and linear regression model adjusting for maternal age and infant sex and other confounders, the lockdown period from August to December was protective against preterm birth (OR 0.65, 95%CI 0.51–0.82) and associated with overall longer gestational duration (Coeff 0.23, 95%CI 0.07–0.39). The August to December lockdown period was also associated with greater birthweight (Coeff 43.76, 95%CI 2.19–85.34).ConclusionsIn San Francisco, COVID-19 lockdowns lowered the preterm birth and increased gestational duration in infants comparing 2019 with 2020 for August to December. The reduced in preterm birth rates may be related to the overall strict lockdown measures that San Francisco implemented compared with other US cities.What this Study Adds to the Clinical Work?This study suggests that COVID-19 lockdowns lowered the preterm birth rate in August -December 2020 compared with the same months in 2019 in two hospitals in San Francisco. San Francisco had strict lockdowns compared with other areas of the country and fewer deaths. The stay-at-home measures could possibly have reduced stress for pregnant women or had other positive benefits that reduced the preterm birth rate.

There are well-documented racial and ethnic disparities in preterm birth in the US. The role of household income in temporal preterm birth trends remains largely unexplored. To examine US preterm birth trends by household income from 2011 to 2021, as well as associations between income and preterm birth according to race and ethnicity. This US population-based, cross-sectional study used data on 411 469 mothers of infants aged 2 to 4 months from the nationally representative Pregnancy Risk Assessment Monitoring System database from 2011 to 2021. Data were analyzed from January to April 2024. Mothers reported annual household income, which was categorized as less than 100% of the federal poverty level (FPL), 100% to 199% of the FPL, and 200% or more of the FPL based on year, state, and household size. The main outcome was preterm birth, defined as birth at less than 37 weeks' gestation. Maternal self-reported race and ethnicity was defined as American Indian or Alaska Native, Asian, Hispanic (any race), non-Hispanic Black, non-Hispanic White, and other or multiracial. Trends in preterm birth by income categories were examined, and modified Poisson regression models were built to (1) examine the association between income and preterm birth, (2) adjust for sociodemographic and pregnancy-related covariates, (3) adjust additionally for race and ethnicity, and (4) introduce an interaction between race and ethnicity and income. Among 411 469 (weighted 20 million) mother-infant dyads (0.8% American Indian or Alaska Native, 5.5% Asian, 15.5% Hispanic, 14.1% non-Hispanic Black, 58.9% non-Hispanic White, and 3.1% other or multiracial), rates of preterm birth increased significantly over time in the groups reporting an annual household income of less than 100% of the FPL (2011, 9.7%; 2021, 11.1%) and 100% to 199% of the FPL (2011, 7.8%; 2021, 10.0%). The preterm birth rate was highest among households reporting household income less than 100% of the FPL within all racial and ethnic groups except Asian. Non-Hispanic Black mothers had the highest rates of preterm birth across all income categories. The association of income with preterm birth remained significant after adjusting for covariates but attenuated to the null after including race and ethnicity in the model. In the lowest income group, non-Hispanic Black mothers had a 19% greater risk of preterm birth compared with non-Hispanic White mothers (adjusted relative risk [ARR], 1.19; 95% CI, 1.11-1.27), whereas in the highest income group, non-Hispanic Black mothers had a 13% greater risk of preterm birth compared with non-Hispanic White mothers (ARR, 1.13; 95% CI, 1.01-1.26). In this population-based cross-sectional study, household income disparities in preterm birth widened over time. Black race moderated the association between income and preterm birth, underscoring the need to examine the role of racism in preterm birth disparities.

A universal mid-trimester transvaginal cervical length screening program and its associated reduced preterm birth rate

Introduction: The incidence of low birth weight (LBW), preterm birth (PB) and small for gestational age (SGA) in Alberta has been greater than the national average in the last decade, raising a public health concern. Understanding the effects (individual and interactions) of maternal, social and environmental risk factors on adverse birth outcomes (ABOs) is currently a subject of active research. We present the effects of nitrogen dioxide (NO2) emissions in the ambient air on the incidence of LBW, PB, and SGA by considering maternal risk factors and socioeconomic status, for both urban and rural areas in Alberta. Methods: We analyzed all singletons live births with 22-42 weeks of gestational age (n=334,894) in Alberta (2006-2012), and 24 maternal risk factors (e.g. diabetes). We used available postal code data for NO2 levels and socioeconomic status. We classified the mothers’ residential postal code as urban/rural. We applied multivariate logistic regression for estimating the effect (Odds ratios) of NO2 levels on LBW, spontaneous PB (categorized as 22-26 weeks; 27-28 weeks; 29-33 weeks, and 34-36 weeks), and SGA (categorized as &lt;3rd, 3rd to 5th, and 5th to 10th percentiles), in urban and rural areas. Odds ratios were adjusted for significant maternal risk factors and socioeconomic status. Results: We detected significant (OR 95%CIs &gt; 1) effects of ambient air NO2 with LBW in rural (OR=1.10), and urban areas (OR=1.01); PB in urban areas [27-28 weeks (OR = 1.04), 29-33 weeks (OR = 1.02), and 34-36 weeks (OR = 1.01)]; SGA in rural [3rd and 5th percentiles (OR=1.06 and OR=1.07, respectively)], and in urban areas for all percentiles [3rd and 5th (OR=1.01), 10th (OR=1.02)]. Currently, we are assessing the contribution of other industrial emissions on ABOs. Conclusions: Ambient air nitrogen dioxide levels were associated with increased risk of adverse birth outcomes between 1% and 7%, mainly impacting PB (27-28 weeks) in urban areas, and LBW and SGA in rural areas.

Objective: To determine if there are any maternal factors that might be linked to low birth weight (LBW). Methodology: This cross-sectional study was done at Al-Batool Teaching Hospital from January and March 2022 with 150 mothers who gave birth to babies who lived. Within 24 hours of being born, all babies were weighed. A birth weight of less than 2500 grams was thought to be low. All mothers were interviewed within 24 to 72 hours of giving birth, and the results were recorded. Results: There was significant differences (p&lt;0.05) among socio demographic characteristics of mothers, except residence. There were significant differences (p&lt;0.05) among maternal risk factors, except infant’s sex. There were significant differences (p&lt;0.05) among disorders that associated with mothers. Conclusion: In Diyala province, LBW is linked to maternal socioeconomic status, risk factors, and disorders. Antenatal visits by well-educated and well-off women may decrease LBW.

Preterm birth disproportionately affects American Indian/Alaska Native (AI/AN) women. This disparity in birth outcomes may stem from higher levels of exposure to psychosocial, sociodemographic, and medical risk factors. This paper reviews relevant research related to preterm birth in American Indian and Alaska Native women. This narrative review examines disparities in preterm birth rates between AI/AN and other American women, and addresses several maternal risk factors and barriers that contribute to elevated preterm birth rates among this racial minority group. Additionally, this paper focuses on recent evidence that geographical location can significantly impact preterm birth rates among AI/AN women. In particular, access to care among AI/AN women and differences between rural and urban areas are discussed.

A reduction in preterm births has been observed in Haguenau (Eastern France) during a 12-year intervention study with a program for prevention of preterm deliveries. The Perinatal Study of Haguenau was an observation tool used in a stable population, and it allowed measurement of the way women have progressively responded to the new proposals in prenatal care. It also allowed measurement of the results of the interventions: low birth weight (less than 2,500 g) and preterm birth rates (less than 37 weeks of gestation) among single live births. The total duration of the study was divided into three periods of four years (1971 through 1974, 1975 through 1978, and 1979 through 1982), for which the numbers of single live births are 5,763, 4,957, and 5,919, respectively. For the same periods, the low-birth-weight rates, 4.6%, 4.0%, and 3.8%, respectively, showed a significant decrease (P less than .001). Following a similar pattern, the rates of preterm birth were 5.4%, 4.1%, and 3.7% (a significant reduction with P less than .001). These improvements in pregnancy outcome do not disappear after standardization of mother's age, high blood pressure, or social class distribution. These findings, which concur with the results of others, enhance the hypothesis of a direct relationship between a prevention program and a reduction in preterm birth rates.

Reduction in preterm birth among COVID-19–vaccinated pregnant individuals in the United States

Reproductive health advantages have been reported among selected immigrants, but few studies have included new immigrants and refugees, nor simultaneously adjusted for socioeconomic, behavioral, and medical disparities. We examined the risk of preterm birth (PTB, < 37weeks' gestation) among singleton live births in San Diego County from 2007 to 2012. Multivariable regression was used to compare PTB (1) by nativity within racial/ethnic groups and (2) among immigrants compared to United States (US) born Whites, while adjusting for sociodemographic, behavioral, reproductive and medical variables. Among 230,878 singleton live births, overall PTB prevalence was highest among parturient women who were US-born Blacks (10.9%), Philippine (10.8%) and US-born Filipinas (10.7%), and US-born Asians (8.6%) despite differences in socioeconomic and maternal risk factors, and lowest among Somali (5.5%) migrants. Blacks born in Somalia or outside of the US, had significantly lower overall PTB prevalence compared to US-born Blacks (5.5% vs 7.6% vs 10.9%). Compared to US-born Whites, spontaneous PTB risk was significantly lower among Somali migrants (4.8% vs 3.7%, adjusted relative risk, aRR 0.7 [95% Confidence Intervals 0.5-0.9]), but higher among Philippine migrants (4.8% vs 7.7%, aRR 1.4 [1.3-1.6]). The strongest risk factor for overall PTB among nulliparous US-born Blacks was preexisting diabetes (aRR 3.81 [2.05-7.08]), and preexisting hypertension among Filipinas (aRR: 3.27 [2.36-4.54] and US-born Asians (aRR: 3.64 [1.61-8.24]). Black migrants had lower PTB prevalence compared to US-born Blacks, but this immigrant advantage was not observed in other racial/ethnic groups. Compared to US-born Whites, Somali migrants had significantly lower risk of spontaneous PTB while Filipinas had elevated risk.

Aims: The aim of this study was to analyse associations between maternal country of birth and preterm birth among women giving birth in Norway. Methods: A population-based register study was conducted employing official national databases in Norway. All singleton births, with neonates without major anomalies, between 1999 and 2014 were included (N=910,752). We estimated odds ratios (ORs) for extremely preterm birth (<28 weeks gestation), very preterm birth (28–33 weeks gestation) and late preterm birth (34–36 weeks gestation) by maternal country of birth. We conducted multivariable regression analyses, adjusting for maternal, obstetric and socio-economic confounders. Results: For extremely preterm births (0.4% of the study population), women with an unknown country of birth (adjusted OR (aOR)=3.09; 95% confidence interval (CI) 2.26–4.22) and women born in sub-Saharan Africa (aOR=1.66; CI 1.40–1.96) had the highest ORs compared to Norwegian-born women. For very preterm births (1.2% of the study population), women with an unknown country of birth (aOR=1.72; CI 1.36–2.18) and women born in South Asia (aOR=1.48; CI 1.31–1.66) had the highest ORs. For late preterm births (3.8% of the study population), women born in East Asia Pacific/Oceania (aOR=1.33; CI 1.25–1.41) and South Asia (aOR=1.30; CI 1.21–1.39) had the highest ORs. Conclusions: After adjusting for maternal, obstetric and socio-economic risk factors, maternal country of birth remained significantly associated with preterm birth. Women with an unknown country of birth and women born in sub-Saharan Africa were found to be at increased risk of extremely preterm birth.

Periodontal Disease and Preterm Birth

BackgroundTwo vitamin D pregnancy supplementation trials were recently undertaken in South Carolina: The NICHD (n=346) and Thrasher Research Fund (TRF, n=163) studies. The findings suggest increased dosages of supplemental vitamin D were associated with improved health outcomes of both mother and newborn, including risk of preterm birth (<37 weeks gestation). How that risk was associated with 25(OH)D serum concentration, a better indicator of vitamin D status than dosage, by race/ethnic group and the potential impact in the community was not previously explored. While a recent IOM report suggested a concentration of 20ng/mL should be targeted, more recent work suggests optimal conversion of 25(OH)D–1,25(OH)2D takes place at 40ng/mL in pregnant women. ObjectivePost-hoc analysis of the relationship between 25(OH)D concentration and preterm birth rates in the NICHD and TRF studies with comparison to Charleston County, South Carolina March of Dimes (CC-MOD) published rates of preterm birth to assess potential risk reduction in the community. MethodsUsing the combined cohort datasets (n=509), preterm birth rates both for the overall population and for the subpopulations achieving 25(OH)D concentrations of ≤20ng/mL, >20 to <40ng/mL, and ≥40ng/mL were calculated; subpopulations broken down by race/ethnicity were also examined. Log-binomial regression was used to test if an association between 25(OH)D serum concentration and preterm birth was present when adjusted for covariates; locally weighted regression (LOESS) was used to explore the relationship between 25(OH)D concentration and gestational age (weeks) at delivery in more detail. These rates were compared with 2009–2011 CC-MOD data to assess potential risk reductions in preterm birth. ResultsWomen with serum 25(OH)D concentrations ≥40ng/mL (n=233) had a 57% lower risk of preterm birth compared to those with concentrations ≤20ng/mL [n=82; RR=0.43, 95% confidence interval (CI)=0.22,0.83]; this lower risk was essentially unchanged after adjusting for covariates (RR=0.41, 95% CI=0.20,0.86). The fitted LOESS curve shows gestation week at birth initially rising steadily with increasing 25(OH)D and then plateauing at ∼40ng/mL. Broken down by race/ethnicity, there was a 79% lower risk of preterm birth among Hispanic women with 25(OH)D concentrations ≥40ng/mL (n=92) compared to those with 25(OH)D concentrations ≤20ng/mL (n=29; RR=0.21, 95% CI=0.06,0.69) and a 45% lower risk among Black women (n=52 and n=50; RR=0.55, 95% CI=0.17,1.76). There were too few white women with low 25(OH)D concentrations for assessment (n=3). Differences by race/ethnicity were not statistically significant with 25(OH)D included as a covariate.Compared to the CC-MOD reference group, women with serum concentrations ≥40ng/mL in the combined cohort had a 46% lower rate of preterm birth overall (n=233, p=0.004) with a 66% lower rate among Hispanic women (n=92, p=0.01) and a 58% lower rate among black women (n=52, p=0.04). ConclusionsIn this post-hoc analysis, achieving a 25(OH)D serum concentration ≥40ng/mL significantly decreased the risk of preterm birth compared to ≤20ng/mL. These findings suggest the importance of raising 25(OH)D levels substantially above 20ng/mL; reaching 40ng/mL during pregnancy would reduce the risk of preterm birth and achieve the maximal production of the active hormone.