المؤلفون: Spaegele, Nina¹ (AUTHOR), Ditzer, Julia^1,2 (AUTHOR) julia.ditzer@gmail.com, Rodrigues, Mariana¹ (AUTHOR), Talmon, Anat^1,3 (AUTHOR) atalmon@mail.huji.ac.il

المصدر: BMC Pregnancy & Childbirth. 2/5/2024, Vol. 24 Issue 1, p1-10. 10p.

مصطلحات موضوعية: *PREMATURE labor, *SOMATIC sensation, *SELF-presentation, *PREGNANT women, *DOULAS, *INFANT mortality

مستخلص: Background: Preterm birth, which occurs when a baby is born before 37 weeks, has enormous implications for public health. It is the leading cause of infant death and mortality in children under the age of five. Unfortunately, the multifaceted causes of preterm birth are not fully understood. One construct that has received increasing attention in women's transition to motherhood is body boundaries, i.e., the metaphorical barriers that separate the self from the outer, surrounding "not self." This study aims to examine the role of well-defined and disturbed body boundaries in predicting preterm birth. Methods: A sample of 655 Israeli pregnant women reported their sense of body boundaries (BBS, as measured by the Sense of Body Boundaries Survey) pre- and postnatally. We performed a General Linear Model (GLM) testing the effect of the BBS total score on the days women delivered before their due date and controlling for whether it was the women's first child. Results: Our GLMs controlling for whether it was the women's first child showed that the BBS total mean exhibited a significant predictive effect on the number of days delivered before the due date (F(57,313) = 3.65, p <.001). Conclusions: These results demonstrate heterogeneity in women's sense of body boundaries during pregnancy and are the first to disentangle a link between disturbed body boundaries and preterm birth. Mediating mechanisms in this relation, e.g., psychosocial stress, as well as clinical implications are discussed in detail. [ABSTRACT FROM AUTHOR]

المؤلفون: Gebreslasie, Kahsay Zenebe, Weldemariam, Solomon, Gebre, Gelawdyos, Zenebe, Dawit, Mehari, Mihreteab, Birhane, Aklil, Dewey, Rebecca Susan

المصدر: Scientific Reports; 1/16/2024, Vol. 14 Issue 1, p1-7, 7p

مصطلحات موضوعية: INTIMATE partner violence, LOW birth weight, BIRTH weight, PREGNANCY, PREMATURE labor, CHILDBIRTH, PREGNANT women

مصطلحات جغرافية: TIGRAY Kifle Hager (Ethiopia), ETHIOPIA

مستخلص: Intimate partner Violence (IPV) can affect any woman, irrespective of their economic status, religion, or culture. This is a human-rights issue and due to its prevalence and adverse effects on pregnancy and birth, it must be given greater attention. Further, there is a lack of data in the Tigray region about adverse birth outcomes due to intimate partner violence during pregnancy. The aim of this study was to assess intimate partner violence during pregnancy and its association with low birth weight and preterm birth in Tigray region. Across-sectional study design was used. 647 women were involved in the study. Simple random sampling techniques were employed to select health facilities and systematic sampling was used to select study participants. Data were entered using Epi info version 3.5.1 and was analyzed using SPSSversion 20. Logistic regression analysis was conducted to assess the association between exposure to intimate partner violence during pregnancy and preterm birth and low birth weight while adjusting for possible confounders. The prevalence of intimate partner violence during pregnancy was 7.3% and the prevalence of low birth weight and preterm birth were 18.5% and 10.8% respectively. There was a statistically significant association between exposure to intimate partner violence during pregnancy and low birth weight. After adjustment for socioeconomic status, women's habits and obstetric factors, the pregnant women who were exposed to intimate partner violence during pregnancy were two times more likely to have a child with a low birth weight (2.39 (95% CI: 1.26–4.55)). The prevalence of intimate partner violence during pregnancy, low birth weight, and preterm birth in this study was high. Women who experienced intimate partner violence during pregnancy had an increased risk of low birth weight. These findings justify a call to the federal minster of health to take measures aimed at avoiding intimate partner violence during pregnancy to reduce adverse birth outcomes. [ABSTRACT FROM AUTHOR]

: Copyright of Scientific Reports is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: PAŘÍZEK, Antonín, HILL, Martin, DUŠKOVÁ, Michaela, KOLÁTOROVÁ, Lucie, SUCHOPÁR, Josef, ŠIMJÁK, Patrik, ANDERLOVÁ, Kateřina, KUDOVÁ, Eva, ROGALEWICZ, Vladimír, VACEK, Jaroslav, KOUDELKOVÁ, Marcela, CHLOUPKOVÁ, Renata, ALBLOVÁ, Miroslava, PAŘÍZKOVÁ, Petra, LAŠTŮVKA, Zdeněk, BARTÁK, Miroslav

المصدر: Physiological Research; 2023 Supplement, Vol. 72, pS381-S387, 7p

مصطلحات موضوعية: CANNABINOIDS, PREMATURE labor, MISCARRIAGE, PREGNANT women, CHILDBIRTH

مستخلص: Spontaneous preterm birth (sPTB) is a major cause of perinatal morbidity and mortality, even in developed countries. Prediction of sPTB is therefore a valuable tool to reduce the associated risks. The current standard for the prediction of sPTB consists, in addition to anamnestic data, of previous sPTB and previous second trimester miscarriage, measurement of cervical length by transvaginal ultrasound (TVU CL) together with assessment of fetal fibronectin levels in cervicovaginal fluid. Other evaluation parameters, such as the level of endocannabinoids in the pregnant woman's blood, could increase the sensitivity of this management. Endocannabinoids (eCBs) are a part of the endocannabinoid system (ECS); out of them anandamide (arachidonoyl-ethanolamide, AEA), in particular, plays an important role in the regulation of pregnancy and childbirth. We present the protocol for an open, non-randomized study to evaluate concentrations of AEA and other endocannabinoids: 2-linoleoylglycerol (2-AG), 2-linoleoylglycerol (2-LG), 2-oleoylglycerol (2-OG), and 2-arachidonoyldopamine (2-ADOPA or also NADA) in the blood of pregnant women as potential predictors of sPTB. In a total of 230 women with a history of sPTB or miscarriage, eCBs levels between 22 and 28 weeks of gestation will be assessed from maternal blood, in addition to the standard procedure. The aim of the study is to determine the relationship between blood concentrations of the endocanna-binoids tested and the risk of sPTB. The results of this study will describe the prognostic significance of maternal blood eCBs levels for sPTB, and could subsequently enable improved screening programs for early identification of sPTB. [ABSTRACT FROM AUTHOR]

: Copyright of Physiological Research is the property of Institute of Physiology, Academy of Sciences of the Czech Republic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Ünal, Canan, Tanaçan, Atakan, Fadiloğlu, Erdem, Çağan, Murat, Yücesoy, Halise Meltem, Beksaç, Mehmet Sinan

المصدر: Journal of the Turkish-German Gynecological Association; Dec2023, Vol. 24 Issue 4, p241-245, 5p

مصطلحات موضوعية: OBSTRUCTIVE lung disease diagnosis, ECHOCARDIOGRAPHY, CHILDBIRTH, STATURE, LENGTH of stay in hospitals, PNEUMONIA, ACADEMIC medical centers, BODY weight, PERICARDIAL effusion, PREGNANT women, RETROSPECTIVE studies, MANN Whitney U Test, GESTATIONAL age, PREGNANCY outcomes, VITAL capacity (Respiration), PREECLAMPSIA, RISK assessment, SCOLIOSIS, SYMPTOMS, PULMONARY function tests, DESCRIPTIVE statistics, CHI-squared test, BIRTH weight, FORCED expiratory volume, HOSPITAL care, PUERPERIUM, DATA analysis software, CESAREAN section, LONGITUDINAL method, PREMATURE labor

مصطلحات جغرافية: TURKEY

مستخلص: Objective: To demonstrate the impact of scoliosis on pregnancy and gestational outcome. Material and Methods: We retrospectively evaluated gestational outcomes of pregnant women with scoliosis at Hacettepe University Hospital between 2008 and 2018. Cases were grouped according to the presence of previous scoliosis surgery and compared in terms of gestational week at birth, birthweight, rate of neonatal intensive care unit admission, hospitalization during pregnancy, route of delivery, type of anesthesia at labor and postpartum intensive care unit admission rate. Ejection fraction (EF), functional vital capacity (FVC), forced expiratory volume (FEV1) and FEV1/FVC ratio values were also recorded. Results: A total of 23 women were included, of whom 12 (52.2%) had a prior scoliosis surgery. One of the 23 (4.3%) cases was terminated due to respiratory problems, while the remaining 22 cases resulted in deliveries. The median gestational week at birth was 38.2 and the median birth weight was 3150 g. Median (range) maternal height was 143 (80-160) cm while median (range) maternal weight was 51 (35-86) kg. Three (13.6%) were diagnosed with restrictive lung disease. No significant difference was found between operated and non-operated groups in terms of respiratory function test results, cardiac EF and other related demographic and clinical features. Overall cesarean delivery rate was 63.6% (14/22) and cesarean section rate was significantly higher in the operated group (83.3% versus 40%) (p=0.04). Conclusion: Cesarean section rate was increased in this cohort of pregnancies in women with scoliosis and who had previous scoliosis surgery. [ABSTRACT FROM AUTHOR]

: Copyright of Journal of the Turkish-German Gynecological Association is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Baas, Melanie A. M., Stramrood, Claire A. I., Dijksman, Lea M., Vanhommerig, Joost W., de Jongh, Ad, van Pampus, Mariëlle G.

المصدر: Acta Obstetricia et Gynecologica Scandinavica; Nov2023, Vol. 102 Issue 11, p1575-1585, 11p

مصطلحات موضوعية: EMDR (Eye-movement desensitization & reprocessing), FEAR of childbirth, PREGNANT women, INDUCED labor (Obstetrics), RANDOMIZED controlled trials, PREMATURE labor

مصطلحات جغرافية: NETHERLANDS

مستخلص: Introduction: Pregnant women with fear of childbirth display an elevated risk of a negative delivery experience, birth‐related post‐traumatic stress disorder, and adverse perinatal outcomes such as preterm birth, low birthweight, and postpartum depression. One of the therapies used to treat fear of childbirth is eye movement desensitization and reprocessing (EMDR) therapy. The purpose of the present study was to determine the obstetric safety and effectiveness of EMDR therapy applied to pregnant women with fear of childbirth. Material and methods: A randomized controlled trial (the OptiMUM‐study) was conducted in two teaching hospitals and five community midwifery practices in the Netherlands (www.trialregister.nl, NTR5122). Pregnant women (n = 141) with a gestational age between 8 and 20 weeks and suffering from fear of childbirth (i.e. sum score on the Wijma Delivery Expectations Questionnaire ≥85) were randomly allocated to either EMDR therapy (n = 70) or care‐as‐usual (CAU) (n = 71). Outcomes were maternal and neonatal outcomes and patient satisfaction with pregnancy and childbirth. Results: A high percentage of cesarean sections (37.2%) were performed, which did not differ between groups. However, women in the EMDR therapy group proved seven times less likely to request an induction of labor without medical indication than women in the CAU group. There were no other significant differences between the groups in maternal or neonatal outcomes, satisfaction, or childbirth experience. Conclusions: EMDR therapy during pregnancy does not adversely affect pregnancy or the fetus. Therefore, therapists should not be reluctant to treat pregnant women with fear of childbirth using EMDR therapy. [ABSTRACT FROM AUTHOR]

: Copyright of Acta Obstetricia et Gynecologica Scandinavica is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Artymuk, Natalia V., Belokrinitskaya, Tatiana E., Filippov, Oleg S., Frolova, Nataly I., Surina, Maria N.

المصدر: Journal of Maternal-Fetal & Neonatal Medicine; Dec2022, Vol. 35 Issue 25, p5427-5430, 4p

مصطلحات موضوعية: PREGNANT women, COVID-19 pandemic, COVID-19, PERINATAL death, PREMATURE labor

مصطلحات جغرافية: SIBERIA (Russia), EAST Asia

مستخلص: Objective: To assess the incidence and perinatal outcomes of COVID-19 in pregnant women in the Far Eastern and Siberian Federal Districts of Russian Federation over 10 months of a pandemic. Materials and methods: This was secondary analysis of Public Data basis on 25 Dec 2020. Statistics included descriptive statistics, analysis of contingency tables, which assessed the value of x², the achieved significance level (p). Results: During the first year of the SARS-CoV-2 pandemic, 8485 cases of COVID-19 were registered in pregnant women in the Far Eastern Federal District and the Siberian Federal District, accounting for 5.9% of registered pregnant women and 1.71% of the total affected population. The morbidity rate in pregnant women was 3.02 times higher than in the general population: 5933.2 vs 1960.8 per 100 thousand population. 27.4% of mothers had asymptomatic disease; 52.7% – mild; 16.6% – moderate, 2.5% – severe, 0.5% – critical disease. The incidence of hospitalization in ICU of pregnant women was higher relative to the general population (3.57% vs 2.24%, p < .001), but the frequency of mechanical ventilation was lower (0.48% vs 1.05%, p < .001). Preterm delivery had 18.3% (p < .001 CS - 42.0%. The mortality rate in pregnant women was 0.14% vs 1.95% – in the general population (p < .001). Perinatal mortality was 37 cases (1.56%), of which there were 31 stillbirths (1.26%), and 6 (0.25%) cases of early neonatal mortality. 148 (6.2%) COVID-19(þ) newborns were identified, despite anti-epidemic measures. Conclusion: The incidence of COVID-19 in pregnant women in Siberia and the Far East is higher than in the general population, but the disease is characterized by a milder. Women with COVID-19 have a high rate of preterm birth and CS. 148 (6.2%) newborns isolated COVID-19. [ABSTRACT FROM AUTHOR]

: Copyright of Journal of Maternal-Fetal & Neonatal Medicine is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Casteleiro, Ana¹ (AUTHOR), Paz-Zulueta, María^2,3 (AUTHOR) maria.paz@unican.es, Parás-Bravo, Paula^2,4 (AUTHOR), Ruiz-Azcona, Laura² (AUTHOR), Santibañez, Miguel^2,4 (AUTHOR)

المصدر: PLoS ONE. 11/26/2019, Vol. 14 Issue 11, p1-13. 13p.

مصطلحات موضوعية: *MATERNAL age, *PREMATURE labor, *CROSS-sectional method, *AGE groups, *GESTATIONAL diabetes, *PREGNANT women, *CHILDBIRTH

مستخلص: Background and objective: Over recent decades, a progressive increase in the maternal age at childbirth has been observed in developed countries, posing a health risk for both women and infants. The aim of this study was to analyze the association between advanced maternal age (AMA) and maternal and neonatal morbidity. Material and methods: A cross-sectional study of 3,315 births was conducted in the north of Spain in 2014. We compared childbirth between women aged 35 years or older, with a reference group of women aged between 24 and 27 years. AMA was categorized based on ordinal ranking into 35–38 years, 39–42 years, and >42 years to estimate a dose-response pattern (the older the age, the greater the risk). As an association measure, crude and adjusted Odds Ratios (OR) were estimated by non-conditional logistic regression and 95% Confidence Intervals (95%CI) were calculated. Results: Repeated abortions were more common among women of AMA in comparison to pregnant women aged 24–27 years (reference group): adjusted OR = 2.68; 95%CI (1.52–4.73). A higher prevalence of gestational diabetes was also observed among women of AMA, reaching statistical significance when restricted to first time mothers: adjusted OR = 8.55; 95%CI (1.12–65.43). In addition, the possibility of an instrumental delivery was multiplied by 1.6 and the possibility of a cesarean by 1.5 among women of AMA, with these results reaching statistical significance, and observing a dose-response pattern. Lastly, there were associations between preeclampsia, preterm birth (<37 weeks) and low birthweight, however without reaching statistical significance. Conclusion: Our results support the association between AMA and suffering repeated abortions. Likewise, being of AMA was associated with a greater risk of suffering from gestational diabetes, especially among primiparous women, as well as being associated with both instrumental deliveries and cesareans among both primiparous and multiparous women. [ABSTRACT FROM AUTHOR]

المؤلفون: Pradhan, Jasmin^1,2 (AUTHOR) 518ls1008@nitrkl.ac.in, Mallick, Swarupa^1,2 (AUTHOR) 517ls6006@nitrkl.ac.in, Mishra, Neha² (AUTHOR) 516ls1001@nitrkl.ac.in, Tiwari, Aman¹ (AUTHOR), Negi, Vidya Devi¹ (AUTHOR) vidya@iisermohali.ac.in

المصدر: BBA: Molecular Basis of Disease. Oct2023, Vol. 1869 Issue 7, pN.PAG-N.PAG. 1p.

مصطلحات موضوعية: *PREMATURE labor, *COXIELLA burnetii, *PREGNANT women, *PREGNANCY, *EPIGENETICS, *FETAL development, *CHILDBIRTH, *MISCARRIAGE

مستخلص: A unique immunological condition, pregnancy ensures fetus from maternal rejection, allows adequate fetal development, and protects against microorganisms. Infections during pregnancy may lead to devastating consequences for pregnant women and fetuses, resulting in the mother's death, miscarriage, premature childbirth, or neonate with congenital infection and severe diseases and defects. Epigenetic (heritable changes in gene expression) mechanisms like DNA methylation, chromatin modification, and gene expression modulation during gestation are linked with the number of defects in the fetus and adolescents. The feto-maternal crosstalk for fetal survival during the entire gestational stages are tightly regulated by various cellular pathways, including epigenetic mechanisms that respond to both internal as well outer environmental factors, which can influence the fetal development across the gestational stages. Due to the intense physiological, endocrinological, and immunological changes, pregnant women are more susceptible to bacterial, viral, parasitic, and fungal infections than the general population. Microbial infections with viruses (LCMV, SARS-CoV, MERS-CoV, and SARS-CoV-2) and bacteria (Clostridium perfringens , Coxiella burnetii , Listeria monocytogenes , Salmonella enteritidis) further increase the risk to maternal and fetal life and developmental outcome. If the infections remain untreated, the possibility of maternal and fetal death exists. This article focused on the severity and susceptibility to infections caused by Salmonella , Listeria , LCMV, and SARS-CoV-2 during pregnancy and their impact on maternal health and the fetus. How epigenetic regulation during pregnancy plays a vital role in deciding the fetus's developmental outcome under various conditions, including infection and other stress. A better understanding of the host-pathogen interaction, the characterization of the maternal immune system, and the epigenetic regulations during pregnancy may help protect the mother and fetus from infection-mediated outcomes. • Pregnancy, a biological condition where the mother body protects its semi allogenic fetus from rejection • Pregnant women are more susceptible to various infections, due to hormonal and immunological changes • The immune system is tightly regulated during pregnancy • Epigenetic regulation plays an essential role in pregnancy during normal and infection condition [ABSTRACT FROM AUTHOR]

المؤلفون: Seabrook, Jamie A.^1,2,3,4,5,6 (AUTHOR), Smith, Alexandra¹ (AUTHOR), Clark, Andrew F.^4,6,7 (AUTHOR), Gilliland, Jason A.^{1,2,3,4,5,6,7,8} (AUTHOR) jgillila@uwo.ca

المصدر: Environmental Research. May2019, Vol. 172, p18-26. 9p.

مصطلحات موضوعية: *CHILDBIRTH, *PREMATURE labor, *PREGNANT women, *LOW birth weight, *GEOGRAPHIC information systems, *FOOD consumption, *FETAL macrosomia

مصطلحات جغرافية: ONTARIO, CANADA

مستخلص: A growing body of research has examined the association between exposure to environmental factors during pregnancy and adverse birth outcomes; however, many studies do not control for potential covariates and findings vary considerably. To test the relative influence of environmental factors including exposure to air pollution, major roads, highways, industry, parks, greenspaces, and food retailers on low birth weight (LBW) and preterm birth (PTB) in Southwestern Ontario (SWO), Canada, while accounting for medical (e.g., previous preterm birth, gestational diabetes), behavioral (e.g., alcohol, smoking), demographic (e.g., maternal age, body mass index), and neighborhood-level socioeconomic (e.g., household income, education) factors. This retrospective cohort study consisted of a large sample of pregnant women from SWO who gave birth to singleton newborns between February 2009 and February 2014 at London Health Sciences Centre. Data on maternal postal codes were entered into a Geographic Information System to map the distribution of maternal residences and determine selected characteristics of their neighborhood environments (i.e., socioeconomic, built, natural). These variables were developed based on postal codes where the mothers lived prior to giving birth. Logistic regression was used to assess the relative effects of the physical environment, socioeconomic status, clinical history, and behavioral risk factors on mothers having a LBW or PTB infant. Out of 25,263 live births, 5.7% were LBW and 7.5% were PTB. Exposure to sulfur dioxide was a top predictor of both LBW and PTB. For every one-unit increase in sulfur dioxide, the odds of a LBW and PTB were 3.4 (95% CI: 2.2, 5.2) and 2.0 (95% CI: 1.4, 3.0) times higher, after controlling for other variables in the model, respectively (p < 0.001). Previous PTB was also highly associated with both birth outcomes. Health care providers should be informed about the hazards of air pollution to developing fetuses so that recommendations can be made to their pregnant patients about limiting exposure when air quality is poor. • Out of 25,263 live births, 5.7% were low birth weight and 7.5% were preterm birth. • Maternal exposure to sulfur dioxide was a top predictor of adverse birth outcomes. • Previous preterm birth was also highly associated with both birth outcomes. [ABSTRACT FROM AUTHOR]

المؤلفون: Sun, Shengzhi¹ (AUTHOR) Shengzhi_Sun@Brown.edu, Weinberger, Kate R.¹ (AUTHOR), Spangler, Keith R.¹ (AUTHOR), Eliot, Melissa N.¹ (AUTHOR), Braun, Joseph M.¹ (AUTHOR), Wellenius, Gregory A.¹ (AUTHOR)

المصدر: Environment International. May2019, Vol. 126, p7-13. 7p.

مصطلحات موضوعية: *PREMATURE labor, *COLD (Temperature), *CHILDBIRTH, *PREGNANT women, *COMMON cold, *CHORIOAMNIONITIS, *THERMAL tolerance (Physiology)

مصطلحات جغرافية: UNITED States

مستخلص: Abstract Background Days of extreme temperature may be associated with transiently higher risk of preterm birth, but prior studies have been limited and results have been heterogeneous. Objectives To evaluate the association between days of extreme heat and cold and risk of preterm birth among ~32 million live singleton births between 1989 and 2002 across 403 counties in the contiguous United States (US). Methods We used a distributed lag nonlinear model to estimate the association between population-weighted daily mean temperature and risk of preterm birth in each county and then pooled results across geographic regions and climate zones. We defined extreme heat and cold as the 95th and 5th percentile of the county-specific temperatures, respectively. Results Preterm birth accounted for 9.3% of deliveries. There was a monotonic association between ambient temperature and risk of preterm birth. Days of extreme heat and cold were associated with a relative risk of preterm birth of 1.025 (95% CI: 1.015, 1.036) and 0.985 (95% CI: 0.976, 0.993) over the subsequent four days, respectively, relative to the county-specific median temperature. If causal, the fraction of preterm births attributable to extreme heat was 0.17% (empirical 95% CI: 0.14%, 0.19%), corresponding to 154 (empirical 95% CI: 127, 173) preterm births per million births. Extreme heat was more strongly associated with preterm birth in regions with colder and drier climates, and among younger women. Days of extreme cold temperature were associated with lower rather than higher risk of preterm birth. Conclusions Days of extreme heat, but not extreme cold, are associated with higher risk of preterm birth in the contiguous US. If causal, these results may have important implications for the management of pregnant women during forecasted periods of extreme heat. Highlights • We examined the association between extreme temperature and PTB in the contiguous US. • Days of extreme heat were associated with higher risk of preterm birth. • The association was stronger in regions with typically colder and drier climates. [ABSTRACT FROM AUTHOR]