Ethical and moral perspectives of individuals who considered/used preimplantation (embryo) genetic testing.

This study examined perspectives on the ethical implications of preimplantation genetic testing (PGT) among individuals who actually (not hypothetically) used or considered using PGT. Most of the prior patient-centered research on PGT ethics used qualitative designs (9 out of the 11 articles) and focused only on single gene testing. This cross-sectional study used an anonymous online questionnaire; 15 items assessed potential ethical concerns involved in PGT decision-making, including clinical indications for PGT, the greater implications of PGT for society, and unused embryo disposition. N = 207 individuals (mean female/male age 35.7/38.9 years, 21% Hispanic or non-White) who had recently used or considered using PGT for single gene (60%) or for chromosomal testing (40%) completed the questionnaire. Most respondents supported PGT screening for disease conditions with childhood or adult onset that are untreatable (64%-85% across items); most opposed PGT for trait selection (76%-81%). Most respondents agreed that PGT aids in parental decision-making (66%-67%), although some expressed concern over potential unforeseen consequences (25%-30%). Regarding disposition of embryos without known genetic abnormalities, most respondents favored freezing indefinitely (86%) or donating to another family (69%), while for embryos with genetic abnormalities, most respondents favored donating to research (78%) or destroying them (62%). Stratification by religious affiliation revealed several differences, such as less acceptance of PGT for diseases that occur in adulthood and have no treatment options among Protestants (p = .015) and greater willingness to donate surplus embryos to research among participants without a religious affiliation (p < .001). These results are limited by the relatively homogeneous sample of participants (mostly White, married, and predominantly college-educated). In summary, participants who considered/used PGT found PGT acceptable overall for screening for disease conditions; most opposed using PGT for trait selection. Our novel questionnaire provides a structured tool for assessing the ethical perspectives surrounding the use of PGT.

Improved method for revising the Israel birthweight references.

OBJECTIVES: Birthweight is often used as an indicator of fetal health. Categorization of infants as small or large for gestational age has clinical significance. Due to growth differences between countries, it is important to have local reference data. The aim of the study was to describe an Israel population-based reference of birthweight by gestational age stratified for singletons/multiple births and gender. METHODS: Data on birthweight and gestational age were obtained for the years 2010-2019 from the Ministry of Health Birth Registry. Implausible birthweight and gestational age values were excluded in a two step process. First, overtly implausible values were excluded using visual mapping. Then, infants whose birthweight was below or above the fifth interquartile range for each completed week were excluded. RESULTS: During the 10-year period there were 1,761,884 infants delivered in Israel; 1,689,696 were included in the analysis. 4.4% of the live born infants were from multiple births. The mean birthweight of singletons (3251 g) was 947 ± 4 g higher than that of multiples (2304 g). The birthweight of the male multiple births began to differ from that of the singletons at 30 weeks; female multiple births began to deviate at 31 weeks. The increase in birthweight of singletons leveled after 42 weeks and those born after 43 weeks weighed less than infants born earlier. Comparison of the curves for singletons from the present study to those reported for the years 1993-2001 reveal a similar median but significant differences in the distribution of lower and higher percentiles. CONCLUSIONS: Improved data collection and validation permitted inclusion of 96% of births for analysis. Use of interquartile range distribution to exclude values of birthweight/gestational age that were implausible improved validity. Compared to curves reported previously, changes were found in the distribution of birthweights for the upper and lower percentiles. Periodic updates of growth curve references are important.

Between-country analysis of implementing an obesity prevention intervention using RE-AIM: HENRY in Israel and UK.

Health Exercise Nutrition for the Really Young (HENRY) is a UK community-based early childhood obesity prevention intervention that was adopted and implemented in Israel between 2013 and 2018. The aim of this study was to explore the implementation process in Israel and compare it with that of the 'parent' programme in the UK, in order to throw light on the challenges of introducing complex interventions into different countries and cultures. Published reports from HENRY and Haifa University's evaluation of the Israeli implementation were reviewed and comparisons between the UK and Israel were carried out utilizing the RE-AIM framework. In both countries, the intention was to implement in lower SES communities. When comparing the individual items, Reach and Effectiveness, we found a difference in the Reach although Effectiveness was similar: Reach was proportionally lower in Israel, but parent and professional changes in behaviour were positive in both countries. For the organizational items Adoption, Implementation and Maintenance, we found large differences between the countries. Major challenges identified in Israel included: failing to take adequate account when planning and implementing the intervention of the different ways social and health services are organized and how local authorities are structured and provide services. In addition, differences in culture beyond language and professional variations were challenges, when trying to transfer the intervention with high fidelity from the UK to Israel. Lessons learnt may benefit others in attempting cross-country implementation of complex interventions.

Bereavement risk screening: A pathway to psychosocial oncology care.

OBJECTIVE: This qualitative study sought to obtain feedback from stakeholder cancer caregivers and bereaved family members on the implementation of bereavement risk screening in oncology. METHODS: Semi-structured interviews were conducted with 38 family members of patients with advanced cancer (n = 12) and bereaved family members (n = 26) on when and how to effectively implement bereavement risk screening. Data were analyzed using thematic analysis. RESULTS: Many participants indicated that they would be open to completing a self-report screening measure before and after the patient's death. Several suggested screening at multiple timepoints and the importance of follow-up. Participants viewed screening as an opportunity to connect to psychosocial support. CONCLUSIONS: The findings suggest that family members appear supportive of sensitively approached bereavement risk screening before and after a patient's death as an important component of quality psychosocial care. To optimize implementation, bereavement risk screening would involve screening at multiple timepoints and include follow-up. Findings suggest standardized risk screening using a brief, validated self-report tool would be a pragmatic approach to increasing access to bereavement care.

Initial psychometric analysis of novel instruments to assess decisional distress and decisional uncertainty in women who have considered using preimplantation genetic testing.

OBJECTIVE: To analyze psychometric properties of two novel instruments assessing decisional distress and uncertainty experienced by individuals considering preimplantation genetic testing (PGT). METHODS: The new PGT Decisional Distress instrument (22 items) assesses negative/positive emotions. The new PGT Decisional Uncertainty instrument assesses Clarity about test benefits/disadvantages (5 items) and Certainty of having adequate information/support to make a good decision (7 items). Scales ranged from 0 to 4. Psychometrics (central tendencies, internal consistency reliability, and discriminant validity) were evaluated. Stratified analysis by decision stage was conducted. All participants had considered or used PGT in the previous 6 months. RESULTS: N = 106 females (mean age 36.5 ± 4.8 years; 16% non-Caucasian; 9% Hispanic) across 16 US states completed an online anonymous questionnaire. On average, respondents reported minimal distress (mean 0.96), high clarity (mean 3.26), and high certainty (mean 3.06), particularly those who had already decided compared to undecided women (P ≤ .02). Instruments had excellent internal consistency (Cronbach's α's 0.92-0.94) and displayed sufficient inter-individual variability (SD's 0.75-0.89). Correlations confirmed expected patterns of association between instruments (P's < .01), indicating discriminant validity. CONCLUSION: We document initial reliability and validity of new instruments to measure emotional distress and uncertainty in female patients who have recently considered PGT for single-gene or chromosomal disorders.

Maternal and child health in Israel: building lives.

Israel is home to a child-oriented society that values strong family ties, universal child benefits, and free education for all children from 3 years of age to school grade 12. Alongside the universal health-care services that are guaranteed by the National Health Insurance Law and strong, community-based primary and preventive care services, these values have resulted in good maternal and child health. In 2015, infant and maternal mortality (3·1 deaths per 1000 livebirths and 2·0 deaths per 100 000 livebirths, respectively) were lower than the mean infant and maternal mortality of countries within the Organisation for Economic Co-operation and Development. Israel has already exceeded the developed regions' Sustainable Development Goal 2030 targets for maternal mortality, neonatal mortality, and mortality in children younger than 5 years in all population groups. Yet these accomplishments are marred by Israel's high prevalence of child poverty (more than 30%), particularly among Arabs (63%) and ultra-Orthodox Jews (67%). Although infant mortality has improved in all subpopulations since Israel was founded in 1948, infant mortality among Arabs is still more than twice as high as among Jews. To address these disparities in health, the Israeli Ministry of Health has created a special division and has funded an intervention programme to reduce the infant mortality among Bedouin Arabs. Other interventions include targeted and culturally appropriate health-care programmes and services for communities with a high number of at-risk children and young adults, dental health service for all children up to 15 years, and improved collaboration between health, education, and welfare services. The challenges faced by the Israeli health-care system include a growing trend towards medicalisation of prenatal care, ensuring staff are trained to treat developmental, behavioural, and psychosocial issues in children and their families, securing sustainable funding for health promotion and injury prevention programmes, expanding and improving the coordination of services for children with special needs or who are at risk, and programme assessment. Ensuring adequate funding for dedicated, preventive paediatric care and taking action on a nationwide scale to reduce child poverty are essential for maintaining health gains in children. In this Series paper, we describe the health indices, highlight disparities, and discuss the challenges in delivering and maintaining maternal and child health care in Israel.

Child Health Care in Israel.

Israel is a relatively rapidly growing country with a high fertility rate and a young population. These data emphasize the importance of an efficient and appropriate pediatric service for its population. Although the pediatric service in Israel has attained several achievements, such as a relatively low infant mortality, high vaccination rates, and a primary care service that is mainly based on licensed pediatricians, several challenges, such as overcoming inequalities in health care and health indices between different regions and different populations within the country and the provision of a more organized mental and dental health care service to children, need to be addressed.

Once you're choosing, nobody's perfect: is more information necessarily better in oocyte donor selection?

Despite a growing body of research examining the psychosocial issues involved in oocyte donation, few studies have examined the role of information in the process of donor selection. The aim of this interview-based qualitative study was to understand how donor oocyte recipients relate to information provided about potential oocyte donors, how they use this information to select donors and their preferences for, and reactions to, various types of information provided to them. Donor oocyte recipients who underwent treatment between 1995 and 2011 were recruited for participation from an academic centre for reproductive medicine. Twenty-two oocyte donor recipients participated. Findings indicate that recipients use information to select donors who they believe would enable them to fulfill their priorities: having a healthy child and 'passing' as genetically related. Obtaining more specific information prompted a focus on donor imperfections and presented a burden of choosing. Moreover, for participants preferring distance, having more information created dilemmas by making the donors less abstract. Although more information and options are often desired by oocyte donor recipients, increased choice can also present psychological dilemmas and emotional costs. Further research is needed to investigate the influence of information-related conflicts on patient decision-making, post-treatment emotional adjustment and disclosure decisions.

Support needs and resources of sexual minority women with breast cancer.

OBJECTIVE: The current paper utilizes qualitative methods to better understand the support needs and resources of sexual minority women (SMW) breast cancer patients. METHODS: Thirteen semi-structured interviews were conducted with SMW, who were recruited from community-based organizations and had undergone mastectomy for treatment of breast cancer. Interviews explored support needs and resources. Data were analyzed using thematic analysis. RESULTS: Three key domains emerged: support groups, family of origin support, and partner support. Participants emphasized the value of cancer support groups and resources tailored to SMW while stating that other dimensions of identity or experience, particularly age and cancer stage, were also important. Participants noted the dearth of social support resources for same-sex partners. Family of origin and partners were typically participants' primary sources of tangible and emotional support; participants often engaged in protective buffering to mitigate caregivers' distress. Single women faced the greatest challenges in terms of support needs and resources. Former partners were often key sources of support. CONCLUSIONS: SMW and their partners have many shared and unique support resources and barriers. Heteronormativity that is implicit in the structure of support resources can serve as a barrier to support for SMW and their partners. Flexibility in relationship roles enabling some SMW to include former partners as significant means of support may be a source of resiliency, particularly for unpartnered SMW cancer patients. Support needs and resources of SMW are best understood through an intersectionality framework that considers sexual orientation, relationship status, cancer stage, age, healthcare access, and other important identities and experiences.

The integration of the cancer experience into identity: Perspectives from young adults.

The study explored how young adults with cancer create a cancer identity across the illness trajectory. Young adults with hematological cancers (n = 53, ages 20-39) completed a semi-structured interview and brief questionnaire. Deductive thematic analysis was used to code interviews. Four identity categories (Acceptance, Enrichment, Engulfment, and Rejection) were coded and linked to the cancer stage (pre-treatment, active treatment, post-treatment). Pre-treatment, there was minimal expression about identity. Acceptance during active treatment involved identity work around disclosure and the integration of pre-cancer identity with the treatment experience. Post-treatment, acceptance involved actively making sense of the cancer experience and its long-term impact; Enrichment was more frequent post-treatment. Engulfment was expressed most during treatment. Individuals who remained engulfed post-treatment expressed difficulties moving beyond the patient's identity. Rejection of a cancer identity was rarely expressed. Understanding how young adults integrate the cancer experience into their identity may suggest intervention strategies.

Adverse health effects of exposure to plastic, microplastics and their additives: environmental, legal and policy implications for Israel.

BACKGROUND: Israel is a regional "hotspot" of plastic pollution, with little discussion of potential adverse health effects from exposure to plastic. This review aims to stimulate discussion and drive policy by focusing on these adverse health effects. MAIN BODY: Plastics are synthetic polymers containing additives which can leach from food- and beverage-contact plastic into our food and beverages, and from plastic textiles onto our skin. Plastics persist in the environment for generations, fragmenting into MNPs: Micro (1 micron-5 mm)-Nano (1 nm-1 micron)-Plastic, which contaminate our atmosphere, water, and food chain. MNP can enter the human body through ingestion, inhalation and touch. MNP < 10 microns can cross epithelial barriers in the respiratory and gastrointestinal systems, and fragments < 100 nm can cross intact skin, enabling entry into body tissues. MNP have been found in multiple organs of the human body. Patients with MNP in atheromas of carotid arteries have increased risk of a combined measure of stroke, cardiovascular disease, and death. Toxic additives to plastics include bisphenols, phthalates, and PFAS, endocrine-disrupting chemicals (EDCs) which cause dysregulation of thyroid function, reproduction, and metabolism, including increased risk of obesity, diabetes, endometriosis, cancer, and decreased fertility, sperm count and quality. Fetal exposure to EDCs is associated with increased rates of miscarriages, prematurity and low birth weight. There is likely no safe level of exposure to EDCs, with increasing evidence of trans-generational and epigenetic effects. There are several existing Israeli laws to reduce plastic use and waste. Taxes on single-use plastic (SUP) were recently cancelled. There are many gaps in regulatory standards for food-, beverage- and child- safe plastic. Existing standards are poorly enforced. CONCLUSION: Reduction in production and use of plastic, promotion of recycling and reduction of leaching of toxic additives into our food and beverages are essential policy goals. Specific recommendations: Periodic monitoring of MNP in bottled beverages, food, indoor air; Strengthen enforcement of standards for food-, beverage-, and child-safe plastic; Renew tax on SUPs; National ban on SUP at public beaches, nature reserves and parks; Ban products manufactured with MNP; Increase research on sources and health outcomes of exposure to MNP and EDCs.

Stigma and mental health in endometriosis.

This review provides an overview of patient experiences of endometriosis, endometriosis-related types and sources of stigma pertaining to menstruation, chronic pain, and infertility, and their impact on patients' mental health with particular implications for patient care. Because endometriosis is a complex disease with multifactorial etiology, complicated pathophysiology, and a spectrum of clinical features, diagnosis of endometriosis is typically a lengthy process, and many patients experience initial misdiagnosis. A hallmark symptom is severe menstrual pain with other symptoms including chronic pelvic pain, dysmenorrhea, and infertility. Prior research documents that the diagnostic odyssey, complex management, disabling and unpredictable nature of the disease, and painful symptom profile affect multiple life domains of patients, resulting in poor physical, social, and psychological functioning and clinically-significant rates of anxiety and depression for many. More recently, stigma has been recognized as a potent contributor to poor mental health in endometriosis patients, but existing research is limited and largely atheoretical. We identify major sources of stigma related to endometriosis, including menstrual stigma, chronic pain stigma, and infertility stigma, and their likely impact on patients and health care provision. An integrative theoretical approach is described to facilitate research on the prevalence and effects of endometriosis stigma and their explanatory mechanisms, highlighting specific well-validated psychological instruments to assess stigma. Implications for patient care are emphasized. Better understanding of stigma and mental health in people with endometriosis will enhance the standard of care for this patient population.

Energy Trade-off and 4 Extreme Human Body Types.

BACKGROUND: Resource trade-off theory suggests that increased performance on a given trait comes at the cost of decreased performance on other traits. METHODS: Growth data from 1889 subjects (996 girls) were used from the GrowUp1974 Gothenburg study. Energy Trade-Off (ETO) between height and weight for individuals with extreme body types was characterized using a novel ETO-Score (ETOS). Four extreme body types were defined based on height and ETOI at early adulthood: tall-slender, short-stout, short-slender, and tall-stout; their growth trajectories assessed from ages 0.5-17.5 years.A GWAS using UK BioBank data was conducted to identify gene variants associated with height, BMI, and for the first time with ETOS. RESULTS: Height and ETOS trajectories show a two-hit pattern with profound changes during early infancy and at puberty for tall-slender and short-stout body types. Several loci (including FTO, ADCY3, GDF5, ) and pathways were identified by GWAS as being highly associated with ETOS. The most strongly associated pathways were related to "extracellular matrix," "signal transduction," "chromatin organization," and "energy metabolism." CONCLUSIONS: ETOS represents a novel anthropometric trait with utility in describing body types. We discovered the multiple genomic loci and pathways probably involved in energy trade-off.

"I'm 'just' a community pediatrician" views and challenges of pediatricians working in the community in Israel.

BACKGROUND: There are ongoing changes around the world in the training and practice of pediatricians who work in the community. These changes are driven by the understanding that pediatricians are required to provide not only acute primary care but also to address more comprehensive concerns, particularly the 'new morbidities'. The present study examines the professional identity of Israeli pediatricians in the community in light of these changes, the barriers and challenges to their work and professional adaptations in the field. METHODS: We used a mixed-methods approach, collecting the perspectives of 137 pediatricians who work in the community through an anonymous online survey, followed by in-depth semi-structured interviews with 11 community pediatricians. RESULTS: The survey results show that community pediatricians in Israel have limited knowledge on a variety of developmental, behavioral and emotional issues; that they lack working relationships with medical or other professionals; and are rarely engaged with other community services. Three main themes arose from the interviews that support and deepen the survey results: perceptions of the profession (pediatrics in the community vs. community pediatrics), the stature of pediatricians in the community (during residency, the choice to work in the community, their daily work) and barriers and change in community pediatrics (isolation, limited resources and challenges arising from the nature of community work). CONCLUSIONS: The present study sheds light on the professional identity and the day-to-day challenges and successes of pediatricians working in the community. Continuing medical education, providing a supportive framework and professional community, better resources, more time with patients, and tools and opportunities for professional development would help pediatricians who work in the community to overcome some of these challenges. The research findings reinforce the need for policy change in the field of community pediatrics with a specific community training curriculum, provision of more resources and ongoing support for pediatricians. This requires partnership between the HMOs, the Ministry of Health, the Scientific Council (Israel Medical Association, professional organizations) and NGOs in order to turn individual-level solutions into system-level and policy-changing solutions.

Gender representation of cancer patients in medical treatment and psychosocial survivorship research: changes over three decades.

BACKGROUND: Prior studies raise concern about gender bias in cancer research, including insufficient inclusion of women or men, or studying women and men differently. The 1993 National Institutes of Health Revitalization Act aimed to eliminate gender bias in medicine. To examine changes in medical and psychological literature, this study reviews gender representation in biomedical treatment studies and psychosocial survivorship studies published in a single year. METHODS: Research published in Cancer in 2007, and all empirical psychological studies about cancer published that year, provided a 15-year update to findings reported by Meyerowitz and Hart. The gender distribution and context of included articles were coded and compared with findings from 1983 and 1992. RESULTS: Across biomedical studies, 34.3% of subjects were women (vs 47% of new cancers and 48% of cancer deaths). Among men, 41.3% had sex-specific cancers (vs 12.5% [1983] and 12.3% [1992]). Among women, 46.1% had sex-specific cancers (vs 69.1% [1983] and 64.6% [1992]). Fewer women (36.8%) were represented in sex-nonspecific cancer studies (vs 41.4% [1983] and 42.5% [1992]); however, fewer studies had a significant (>20%) gender disparity. Across psychosocial studies, representation of men increased to 47.9% (vs 30.4% [1983] and 29.9% [1992]). The proportion of men in studies of feelings/relationships increased to 47% (vs 22.9% [1992]); the proportion of women in studies assessing physical/functional ability increased to 58.3% (vs 45.4%). CONCLUSIONS: Women remain under-represented in sex-nonspecific biomedical research, whereas men's representation in sex-specific research increased substantially. Psychosocial research trends suggest movement from research questions supporting traditional stereotypes that women feel and men act.

Incorporating information regarding preimplantation genetic diagnosis into discussions concerning testing and risk management for BRCA1/2 mutations: a qualitative study of patient preferences.

BACKGROUND: Studies have shown that BRCA1/2 mutation carriers are interested in learning about reproductive options such as preimplantation genetic diagnosis (PGD) to prevent passing their risk onto their children. However, attitudes vary widely, and the procedure raises complex ethical and psychosocial issues. This complexity, plus the highly technical nature of PGD, makes it difficult to integrate PGD information into genetic counseling sessions that already cover probabilistic, emotionally charged risk information. METHODS: A total of 33 carriers of the BRCA1/2 mutation who were of reproductive age and had previously undergone genetic counseling viewed a tutorial regarding PGD and were interviewed concerning their attitudes toward PGD and preferences about how to include PGD information in genetic counseling. RESULTS: The majority of participants preferred to be briefly informed of the availability of PGD information, and to receive written materials regarding PGD, but with the option of deferring detailed discussion if they already believed themselves to be overloaded or perceived that PGD was not immediately relevant to their risk management and/or childbearing plans. For some individuals, the stress of testing temporarily interfered with information processing, producing states of cognitive avoidance ("in a fog," or "tuning out"). Some preferred to discuss PGD with a physician with whom they had an ongoing relationship (eg, obstetrician/gynecologist, primary care provider, or oncologist). CONCLUSIONS: Providers offering cancer genetic testing may consider indicating the availability of PGD information to their patients, while attending to the patients' level of interest and ability to absorb information. Research is needed to link patient responses to information overload with psychosocial outcomes (eg, distress, and quality of decision-making). Continuing medical education is needed to support providers in facilitating informed decisions regarding PGD.

Family Size and the Age at Infancy-Childhood Transition Determine a Child's Compromised Growth in Large Families.

Background: Data on growth of Israeli school children show that children from Jewish ultra-orthodox Haredi and Bedouin Arab families have a higher prevalence of stature below the 3rd percentile. While these populations are usually from lower socioeconomic strata, they also have larger families. This study aimed to evaluate if family structure and the timing of a child's infancy-childhood transition (ICT) are central to variations in stature. Study Design: We analyzed the association between family size, birth order and inter-birth interval with child growth and the age at ICT in 3 groups of children, 148 high birth order children from large families (LF ≥ 6), 118 low birth order children from large families (LF ≤ 3) and 150 children from small families (SF). Results: High birth order children from large families were shorter in childhood than children from small families with a difference of 0.5 SDS in length. We found that birth length and birth order explained 35% of the total variance in infancy length whereas ICT age and infancy length explained 72% of the total variance in childhood length. Conclusion: Infancy and childhood length are compromised in children from large families. As the family grows larger the younger children tend to be shorter. Reduced length gain in the period between infancy to childhood is when growth is most affected.

The effect of day care attendance on infant and toddler's growth.

AIM: We aimed to study the association between day care attendance and changes in the height, weight and weight/height ratio over a 6-month period. METHODS: Data were retrieved from three maternal and child health care centres. Parents were asked to fill a short questionnaire regarding the infant/toddler life style, the day care facilities and the family demographic information. RESULTS: One hundred and seventy infants participated in the study. The research group consisted of 85 infants that had placed in day care centre prior to the age of 18 months. The control group consisted of 85 infants who had placed in day care at a later age. The research group had significantly shorter stature 3 months after day care enrolment (mean height percentiles of 56.9 versus 66.3, respectively, p = 0.024,). This trend was more pronounced after 6 months (mean height percentiles of 52.3 versus 63.7, p = 0.022). We could not, however, demonstrate a concomitant significant deceleration in weight or weight/height percentiles. CONCLUSIONS: The explanation for this rather dramatic finding remains speculative. Possible mechanisms are stress-related growth hormone suppression. Our findings reinforce the importance of monitoring infant/toddler weight and height growth velocities, especially when he/she is introduced to day care.

Low and High Ambient Temperatures during Pregnancy and Birth Weight among 624,940 Singleton Term Births in Israel (2010-2014): An Investigation of Potential Windows of Susceptibility.

BACKGROUND: Exposure to heat during pregnancy has been associated with reduced fetal growth. Less is known about associations with cold and the potential for critical time windows of exposure. OBJECTIVES: We aimed to evaluate, in a national retrospective cohort, critical windows of susceptibility during pregnancy to extreme temperatures (low and high) and fetal growth, among 624,940 singleton term births in Israel during the period 2010-2014. METHODS: Temperature exposures were estimated using a spatially refined gridded climate data set with a 1-h and 1-km2 resolution. Percentiles of temperature were categorized by climatic zone for the entire pregnancy and by trimesters and weeks. Generalized additive models with the distributed lag nonlinear model framework were used to estimate unadjusted and adjusted associations between percentiles and categories of temperature and fetal growth markers: term [births after 36 weeks of gestational age (GA)] mean birth weight and term low birth weight (tLBW, term infants with birth weight below 2,500g). RESULTS: After adjustment, extreme temperatures (percentiles) during the entire pregnancy were associated with a lower mean birth weight {≤10th vs. 41st-50th percentile: -56g [95% confidence interval (CI): -63g, -50g)]; >90th vs. 41st-50th percentile: -65g; 95% CI: -72g, -58g}. Similar inverse U-shaped patterns were observed for all trimesters, with stronger associations for heat than for cold and for exposures during the third trimester. For heat, results suggest critical windows between 3-9 and 19-34 GA-weeks, with the strongest association estimated at 3 GA-weeks (temperature >90th vs. 41st-50th percentiles: -3.8g; 95% CI: -7.1g, -0.4g). For cold, there was a consistent trend of null associations early in pregnancy and stronger inverse associations over time, with the strongest association at 36 GA-week (≤10th vs. 41st-50th percentiles: -2.9g; 95% CI: -6.5g, 0.7g). For tLBW, U-shape patterns were estimated for the entire pregnancy and third trimester exposures, as well as nonsignificant associations with heat for 29-36 GA-weeks. Generally, the patterns of associations with temperatures during the entire pregnancy were consistent when stratified by urbanicity and geocoding hierarchy, when estimated for daily minimum and maximum temperatures, when exposures were classified based on temperature distributions in 49 natural regions, and when estimated for all live births. DISCUSSION: Findings from our study of term live births in Israel (2010-2014) suggest that exposure to extreme temperatures, especially heat, during specific time windows may result in reduced fetal growth. https://doi.org/10.1289/EHP8117.