Drop In Fertility Research Articles

Antioxidant Capacity of Thyme (Thymus vulgaris) Essential Oil and Its Effect on In Vivo Fertility of Rams Subjected to Testicle Heat Stress.

The detrimental effects of hyperthermia on the testes and the protective effect of thyme essential oil against testicular damage induced by this stress in rams were studied. Twenty-four rams of the Barbarine breed with an average weight of 62.5 ± 0.3 kg and an average age of 24 ± 0.6 months. The experiment consisted of inducing localized heat stress on the first group of rams by applying heat bags to both testicles of six rams (G s). The second group underwent the same heat stress on the testes but received orally 100 µL/day/animal of thyme essential oil (G s-he). A positive control did not undergo stress but received thyme essential oil (G he) with the same doses as the (G s-he) group, and the negative control did not undergo either stress or receive the essential oil of thyme (G c). One hundred twenty-eight adult ewes of the same breed divided into four groups of 32 ewes were used to study the effect of different treatments on the in vivo ram's fertility. Ewes are synchronized and we have applied natural mating with oestrus control, the reproduction balance sheet is calculated after lambing. The results showed that tests of heat stress (HS) negatively affect semen quality but did not cause infertility. However, neither tests for heat stress nor treatment with thyme EO significantly affected the haematological profile. The study of the effect of heat stress on the testes on fertility in vivo showed a drop in the number of females who were fertilized at the first oestrus and consequently a drop in fertility. However, the rams that suffered the same stress but were treated with EO thymus recorded an improvement in these parameters.

Cucumeropsis mannii seed oil mitigates bisphenol-A-induced sperm and hormonal damages in F1-generation of F0-exposed male rats: An in-vivo and in-silico analysis

Exposure to endocrine-disrupting chemicals such as bisphenol A (BPA) has been linked to the sharp drop in male fertility observed worldwide. This study evaluates the protective benefits of Cucumeropsis mannii seed oil (CMSO) against BPA-induced transgenerational sperm indices and reproductive hormone disruptions in rats. Twenty-four F0-male rats (aged 4–5 weeks) were randomly assigned to six groups (n = 4 each) after CMSO characterization for flavonoids. Group A received 1 ml of olive oil. Group B received 100 mg/kg body weight (BW) of BPA whereas Group C had a BW of 7.5 ml/kg CMSO. Groups D, E, and F were administered 100 mg/kg_BW of BPA in addition to 7.5, 5.0, and 2.5 ml/kg_BW of CMSO, respectively. After two weeks of treatment, four mature female rats were introduced to each group and allowed to stay together with male rats for seven days to confirm mating. Thereafter, the pregnant female rats were separated from the male according to their groups and allowed to give birth after 21 days of gestation period. At six weeks, the F1-male rats were isolated from each group and sacrificed for biochemical analysis. In-silico, CMSO flavonoids were assessed for drug-likeness and oral absorbability, followed by molecular docking to study their androgen receptor targeting mechanisms. Results showed that total flavonoids were 17.3652 ± 8.85 g/100 g. In-vivo, BPA significantly (p < 0.005) dysregulated sperm indices and male fertility hormones in F1 rats, but co-administration with CMSO restored these dysregulations in F1 rats. In-silico, the druglike molecules exhibited stronger binding affinities (−6.2 to −8.5 kcal/mol) for the androgen receptor than BPA (−6.1 kcal/mol) within the binding pockets. We postulated that CMSO mitigates transgenerational sperm indices and male fertility hormone disruption in F1 male offspring following F0 male exposure to BPA perhaps by utilizing androgen receptor signaling.

ZMYND12 serves as an IDAd subunit that is essential for sperm motility in mice

Inner dynein arms (IDAs) are formed from a protein complex that is essential for appropriate flagellar bending and beating. IDA defects have previously been linked to the incidence of asthenozoospermia (AZS) and male infertility. The testes-enriched ZMYND12 protein is homologous with an IDA component identified in Chlamydomonas. ZMYND12 deficiency has previously been tied to infertility in males, yet the underlying mechanism remains uncertain. Here, a CRISPR/Cas9 approach was employed to generate Zmynd12 knockout (Zmynd12−/−) mice. These Zmynd12−/− mice exhibited significant male subfertility, reduced sperm motile velocity, and impaired capacitation. Through a combination of co-immunoprecipitation and mass spectrometry, ZMYND12 was found to interact with TTC29 and PRKACA. Decreases in the levels of PRKACA were evident in the sperm of these Zmynd12−/− mice, suggesting that this change may account for the observed drop in male fertility. Moreover, in a cohort of patients with AZS, one patient carrying a ZMYND12 variant was identified, expanding the known AZS-related variant spectrum. Together, these findings demonstrate that ZMYND12 is essential for flagellar beating, capacitation, and male fertility.

Postpartum Uterine Diseases; Diagnostic Approaches and Management in Farm Animals: A Review

Postpartum uterine infections results from uterine contamination with bacteria during parturition. The postpartum environment of the uterine lumen supports the growth of a variety of aerobic and anaerobic bacteria. There are a number of risk factors for post-partum uterine disease in dairy cattle; cows having dystocia, retained placenta, twins or stillbirths and various metabolic disorders are more likely to develop uterine disease. Inflammation of the uterus slows down the process of involution in the uterus and delays the onset of activities of the ovaries leading to economic loss due to systemic illness, loss of milk and meat production and marked drop in fertility. Pyometra, metritis, clinical and subclinical endometritis are some of the most important illnesses during the postpartum period. A variety of methods such as uterine palpation, ultrasonographic features of the uterus, vaginoscopy, endometrial cytology, uterine culture, and uterine biopsy has been reported to identify postpartum diseases. Prevention of postpartum uterine disease would be better than cure, for both the animals and the economy. Thus, early diagnosis or predictions of uterine infections are important for effective postpartum management.

Postpartum Uterine Diseases; Diagnostic Approaches and Management in Farm Animals; A Review

Postpartum uterine infections result from uterine contamination with bacteria during parturition. The postpartum environment of the uterine lumen supports the growth of a variety of aerobic and anaerobic bacteria. There are a number of risk factors for post-partum uterine disease in dairy cattle; cows having dystocia, retained placenta, twins or stillbirths and various metabolic disorders are more likely to develop uterine disease. Inflammation of the uterus slows down the process of involution in the uterus and delays the onset of activities of the ovaries leading to economic loss due to systemic illness, loss of milk and meat production and marked drop in fertility. Pyometra, metritis, clinical and subclinical endometritis are some of the most important illnesses during the postpartum period. A variety of methods such as uterine palpation, ultrasonographic features of the uterus, vaginoscopy, endometrial cytology, uterine culture, and uterine biopsy has been reported to identify postpartum diseases. Prevention of postpartum uterine disease would be better than cure, for both the animals and the economy. Thus, early diagnosis or predictions of uterine infections are important for effective postpartum management.

Analysis of Chinas Birth Rate Prediction Based on Time Series

The birth rate in China has declined significantly since the last century, especially in recent years. Low fertility intentions and deferred childbirth were the main contributors to the drop in fertility. Nowadays, the aging problem has become more and more serious in our country. Therefore, raising the birth rate has become the top priority for the government and society. Our research modelled and predicted the fertility rate in China using R. We used the dataset from Health Nutrition and Population Statistics on Databank and selected the historical fertility rate data in China from 1964 to 2021. Firstly, we transformed these data to make the birth rate time series stationary. Then, we applied the ARIMA and the ETS models, respectively and chose the better model to forecast the short-term birth rate in China in the next five years. We found that the ARIMA model was more appropriate for predicting the short-term birth rate in China. As a result, we utilized the ARIMA(0,0,1) model for prediction. We calculated that the growth rate of the birth rate in China from 2022 to 2026 was - 0.117, which demonstrated that the fertility rate in China would decrease constantly at a rate of 0.117 each year over the ensuing five years. If the government of China still did not take any measures to improve the fertility problems, the fertility rate would further decline. Consequently, the fertility rate in China is facing an unprecedented crisis.

Optimal policies in an ageing society

We analyze optimal social security in an overlapping generations model with demographic change and endogenous retirement. Households choose to spend the second period of their lives in full retirement if the tax rate on labor income exceeds a threshold. This threshold is increasing in life expectancy and decreasing in the fertility rate, which implies that both types of demographic change increase the relevance of the partial retirement case: both an increase in life expectancy and a drop in fertility imply that retirement is delayed. We also show that when the government decides about retirement, the command optimum can be replicated through social security policies if the laissez-faire equilibrium features capital overaccumulation. When households decide about their retirement themselves, however, replication of the command optimum is not possible. In both cases, it is optimal to expand social security when longevity increases and to reduce it when fertility drops.

Child survival and contraception choice: Theory and evidence

This paper asks whether increases in child survival bring down fertility and incentivize couples to switch from traditional to modern methods of contraception. Our parsimonious model predicts the answer in each case is, yes. We test these connections using household-level Demographic and Health Surveys from recent fertility transitions using arguably exogenous variation in child survival at the regional level. We find a 1% increase in ambient child survival leads to a fertility drop of 1.2%. The same raises the chance of switching to modern birth control (and sticking to it) by 0.4%. Our finding supports the notion that prevailing rates of child survival influence the effectiveness of family planning programs that promote modern contraceptive use.

Effect of genotype and season on fertility and hatchability of eggs in Dahlem Red, Native and DND chicken under intensive system in Himachal Pradesh

The present study assessed the effect of genotype, season and period on fertility and hatchability of chicken eggs during five year period (April 2017 to March 2022). The eggs for hatching were collected from birds belonging to three genotypes viz. Dahlem Red (DR), Native and cross of (Dahlem Red × Native) with Dahlem Red (DND). Average fertility percentage was observed highest in DND followed by native and Dahlem Red. Hatchability percentage on fertile egg set and total egg set was 80.91 &amp; 70.20, 80.83 &amp; 70.29 and 76.78 &amp; 66.52 in native, DND and Dahlem Red respectively. Significant difference in hatchability percentage of Dahlem Red with native and DND was observed. Hatchability percentage was found better in native and DND bird. Season wise, fertility percentage was observed highest in winter (87.40) followed by rainy (86.34) and summer (86.01). Hatchability percentage on fertile egg set and total egg set was observed highest in rainy (81.22 &amp; 70.09) followed by summer (80.60 &amp; 69.36) and winter (77.31 &amp; 67.63). Mean difference in hatchability on fertile egg set in winter was significant from rainy and summer season. Dead embryo percentage was observed significantly higher in winter than summer and rainy season. Hatchability percentage on fertile egg set and total egg set was highest in 2021-22 (83.73 &amp; 76.54) followed by 2017-18 (80.91 &amp; 69.48), 2018-19 (80.58 &amp; 70.19), 2019-20 (76.76 &amp; 66.08) and 2020-21 (76.38 &amp; 65.93). The hatchability operations under sub temperate condition of the region can be carried out efficiently throughout the year without a significant drop in fertility and hatchability. However, greater care and managerial precision are required in winter season during the hatching.

What do female medical students know about planned oocyte cryopreservation and what are their personal attitudes?

This study aimed to assess medical student knowledge and attitudes regarding oocyte cryopreservation, as well as attitudes regarding future intentions of utilizing this procedure. This cross-sectional web-based survey study was distributed to 873 medical students at the University of Kansas from July through September 2018. The survey was self-reported and female medical student responses were analyzed. Students were surveyed through a variety of multiple-choice questions on demographics, knowledge of oocyte cryopreservation, and factors and attitudes that would impact personal and professional use of oocyte cryopreservation. A total of 122 female responses were collected (30%). A majority of female medical students were aware of oocyte cryopreservation, less than half correctly identified a dramatic drop in female fertility as well as oocyte cryopreservation success and cost-effectiveness. Three-quarters felt pressure to delay childbearing and nearly two-thirds would consider freezing their oocytes. Several factors were found to alter their decision toward oocyte cryopreservation including personal factors, procedure complexity and availability, and outcomes. A majority of female medical students are amenable to the possibility of using oocyte cryopreservation to delay childbearing. Though nearly all knew of oocyte cryopreservation, knowledge regarding fertility and oocyte cryopreservation was low.

Declining Quantity and Quality of Births in Chile amidst the COVID‐19 Pandemic

AbstractExtensive demographic scholarship shows that the population‐level implications of mortality crises such as the COVID‐19 pandemic extend beyond mortality dynamics to affect fertility and family‐formation strategies. Using novel municipality‐level data from Chile covering all births that occurred between January 2017 and December 2021, this study explores trends in fertility and implications of the COVID‐19 pandemic for “quantum” and “quality” of births in the Chilean context. Building both a monthly and a yearly panel of 346 municipalities and leveraging fixed‐effects regression analyses, we focus on births and crude birth rates to measure quantum, while quality is assessed through the share of births that are low‐weight (LBW) and preterm (PTB). Our findings provide evidence of a significant drop in fertility in the wake of COVID—of the magnitude of a reduction of 1.3 live births per 1,000 individuals—which reaches a minimum around February 2021, followed by an incipient rebound in late 2021. Moreover, estimates on child health at birth suggest that the COVID period was associated with an increase in LBW and, foremost, PTB, by 1 and 2.2 percentage points, respectively. Findings from this study shed light on the role of policy interventions in the health arena and the linkages between short‐ and long‐run effects in relation to the various COVID‐19 waves in Chile.

Knockout of OsSWEET15 Impairs Rice Embryo Formation and Seed-Setting.

We show that the knockout of a sugar transporter gene OsSWEET15 led to a significant drop in rice fertility with around half of the knockout mutant's spikelets bearing blighted or empty grains. The rest of the spikelets bore fertile grains with a slightly reduced weight. Notably, the ovaries in the blighted grains of the ossweet15 mutants expanded after flowering but terminated their development before the endosperm cellularization stage and subsequently aborted. β- glucuronidase (GUS) and Green Fluorescent Protein (GFP) reporter lines representing the OsSWEET15 expression showed that the gene was expressed in the endosperm tissues surrounding the embryo, which supposedly supplies nutrients to sustain embryo development. These results together with the protein's demonstrated sucrose transport capacity and plasma membrane localization suggest that OsSWEET15 plays a prominent role during the caryopsis formation stage, probably by releasing sucrose from the endosperm to support embryo development. By contrast, the empty grains were probably caused by the reduced pollen viability of the ossweet15 mutants. Investigation of ossweet11 mutant grains revealed similar phenotypes to those observed in the ossweet15 mutants. These results indicate that both OsSWEET15 and OsSWEET11 play important and similar roles in rice pollen development, caryopsis formation and seed-setting, in addition to their function in seed-filling that was demonstrated previously.

Climate Change, Fertility and Sahelian Demographics

Climate change, especially in Africa&amp;rsquo;s central Sahel region, is occurring in the context of exponential population rise with countries like Chad and Niger still in the &amp;ldquo;early expanding phase&amp;rdquo; of demographic growth. While many experts predict a mid-century climate and demographic &amp;lsquo;mega crisis&amp;rsquo; for the region; our paper looks at the effect of the rising temperature, through the medium of increased temperature and precipitation variability upon fertility and hence demographic trends as we advance into the 21st century. The paper uses climate data and DHS (Demographic and Health Survey) data from Chad, which has demonstrated significant warming since the late 1960&amp;rsquo;s. We create a weather shock variable that is defined as a t&amp;gt;2 departure from the post-1960 mean of temperature and precipitation by month, year, and GIS location. We regress the following years&amp;rsquo; human fertility outcomes by month and GIS location upon these shocks when occurring in the growing months of June, July, and August. We find that the effect is highly negatively significant with a one-year lag. Then we go on to look for the mechanism behind this significance; the literature suggesting that climate effects fertility through biological or food security related channels. We then regress the male/female sex ratio on the same weather shocks to see if there is a rise in miscarriages among male fetuses due to either the direct effect of heat or as an effect of increased female malnutrition. By running both these models with weather shocks from Chad&amp;rsquo;s dry season months of December, January, and February, we discern whether the significance is driven by pure temperature or by some sort of food security/household income channel. Though we see some dry season effect, most of the significance is driven by the shocks in the growing season and with the significant effect of these shocks on the sex ratio, we can assume that increased female malnutrition is a key driver of both the rise in miscarriages and the drop-in fertility. We then run these models within each of the three Chadian climate zones: the Sahara, the Sahel, and the Sudan. Seeing that the Sahel zone is the major driver for the significance of our models, we discuss if this can have implications for the wider African Sahel.

Chromosome Segregation in the Oocyte: What Goes Wrong during Aging.

Human female fertility and reproductive lifespan decrease significantly with age, resulting in an extended post-reproductive period. The central dogma in human female reproduction contains two important aspects. One is the pool of oocytes in the human ovary (the ovarian reserve; approximately 106 at birth), which diminishes throughout life until menopause around the age of 50 (approximately 103 oocytes) in women. The second is the quality of oocytes, including the correctness of meiotic divisions, among other factors. Notably, the increased rate of sub- and infertility, aneuploidy, miscarriages, and birth defects are associated with advanced maternal age, especially in women above 35 years of age. This postponement is also relevant for human evolution; decades ago, the female aging-related fertility drop was not as important as it is today because women were having their children at a younger age. Spindle assembly is crucial for chromosome segregation during each cell division and oocyte maturation, making it an important event for euploidy. Consequently, aberrations in this segregation process, especially during the first meiotic division in human eggs, can lead to implantation failure or spontaneous abortion. Today, human reproductive medicine is also facing a high prevalence of aneuploidy, even in young females. However, the shift in the reproductive phase of humans and the strong increase in errors make the problem much more dramatic at later stages of the female reproductive phase. Aneuploidy in human eggs could be the result of the non-disjunction of entire chromosomes or sister chromatids during oocyte meiosis, but partial or segmental aneuploidies are also relevant. In this review, we intend to describe the relevance of the spindle apparatus during oocyte maturation for proper chromosome segregation in the context of maternal aging and the female reproductive lifespan.

Overview of the mortality from external causes of reproductive-age women in Brazil.

Studies have shown that a new demographic and epidemiological profile has been emerging in women of childbearing age, mainly due to the increase in life expectancy, reduction in infant mortality, higher survival in old age, and the drop in fertility rate.To evaluate the external (violence) causes of mortality among women in Brazil from 2007 to 2016.This is a quantitative, ecological study of temporal trends and correlations of the main causes of mortality of women of childbearing age and their association with age, from 2007 to 2016 in Brazil. The collected data were extracted from the Departamento de Informática do Sistema Único de Saúde database called the Mortality Information System.It was possible to identify a considerable increase among the Brazilian states, with the highest coefficient of mortality from external causes, especially the northern regions. The highest coefficient identified among the evaluated states was 3.57 per 10,000, and in the northeast and southeast, external causes mainly affected young women aged 10 to 29 years.It is necessary for managers and health professionals to be more aware of the diseases that affect this population.

THE WAR CONSEQUENCES ON NATURAL RESOURCES OF UKRAINE: ANALYSES AND METHODOLOGIES

THE WAR CONSEQUENCES ON NATURAL RESOURCES OF UKRAINE: ANALYSES AND METHODOLOGIES

Oncogenic papillomaviruses: reproductive problems in infected males

Human papillomaviruses (HPV) of the high-risk types cause carcinomas in cervix uteri, vulva, vagina, penis, anus, as well as in certain sites of head and neck – oral cavity, oropharynx, tonsils, larynx. HPV of types 16 and 18 are the most widespread ones. Papillomaviruses of low oncogenic risk, HPV of types 6 and 11, cause recurrent respiratory papillomatosis and anogenital warts. Preventive vaccinations against HPV are not included into the National mandatory immunization schedule in Russia; however, they are being executed in several country areas in a form of regional programs. Substantial contingents are not embraced by the procedures as yet. A family can make decision of its own whether to vaccinate the adolescent child on paid basis. To make decision in favor of vaccination complete awareness is needful on the HPV infection consequences. As far as viruses of the given group became primarily known as cervical cancer etiological agents certain risk persists of “feminization” of notions about unfavorable effects of the HPV infection thus resulting in debates on usefulness of boys’ preventive vaccination.In this connection the purpose of the review was consideration of HPV effects on male reproductive potential. Oncogenic HPVs are frequently found in healthy donors’ sperm. HPV DNA can penetrate from sperm into oocyte under experimental conditions. Seminal fluid of HPV-positive males is a storage tank of the virus as well as the source of its distribution throughout population. DNA of oncogenic HPV was detected in endosomes of seminal lymphocytes. The latter fact opposes the canonic notion of strict HPV epitheliotropy. Correlation exists between the seminal fluid HPV-positivity of a certain man and his fertility drop. Reproductologists believe failures of some married couples when using assisted reproductive technologies may result from partner’s seminal HPV positivity. The successful attempt is known of semen parameters’ normalization in men with reduced fertility after inoculation with the quadrivalent Gardasil vaccine.It seems reasonable to consider the data on unfavorable effects of HPV infection on male reproductive potential as an argument for boys’ preventive HPV vaccination. It would help not only to prevent the HPV-associated oncological diseases in men but the distribution of the given infection around the population as a whole; it would contribute to more successes in solving demographic problems.

P–093 The use of donor sperm improves post-ICSI live birth rates in advanced maternal age women

Abstract Study question Can the use of donor sperm improve post-ICSI live birth rate in advanced maternal age (AMA) patients? Summary answer The use of donor sperm increases post-ICSI live birth rate while substantially reducing abortion occurrence in AMA patients. What is known already Oocyte DNA repair capacity decreases with maternal age, when sperm DNA integrity is particularly important to avoid the transfer of gene truncations and de novo mutations to the zygote. Optimal DNA repair activity in the zygote requires paternal inheritance of 8-oxoguanine DNA glycosylase (OGG1), a rate-limiting enzyme in the base excision repair pathway. However, the involvement of paternal aging and sperm quality in the severe drop in fertility observed in AMA patients has not been addressed. While strategies to mitigate the impact of AMA on fertility have exclusively targeted oocyte quality, the sperm contribution in this scenario remains somehow neglected. Study design, size, duration Retrospective, multicentric, international study including 755 first ICSI cycles with patients’ own oocytes achieving a fresh ET between 2015 and 2019, 337 of which using normozoospermic partner semen and 418 using donor sperm. The association of sperm origin (partner vs. donor) with live birth was assessed by univariate/multivariate analysis in non-AMA (&amp;lt;37 years, n = 278) and AMA (≥37 years, n = 477) patients. ICSI outcomes were compared between partner and donor sperm in non-AMA and AMA patients. Participants/materials, setting, methods The study was conducted in 3 fertility clinics including 755 Caucasian patients aged 24 to 42 years. Univariate/multivariate analyses were performed to test the association of sperm origin with live birth; infertility factor, maternal age, oocyte yield and number of embryos transferred were included in the model as confounding variables. In addition, ICSI outcomes were compared between donor and partner sperm groups with the Chi-square (percentages) or with the Wilcoxon sum rank (continuous variables) tests. Main results and the role of chance The multivariate analysis revealed that the use of donor sperm was positively and independently associated with live birth occurrence in AMA [1.82 OR (1.08–3.07) 95% IC; p = 0.024], but not in non-AMA patients [1.53 (0.94–2.51); p = 0.090]. Maternal age [0.75 (0.64–0.87); p &amp;lt; 0.001], number of MII oocytes recovered [1.14 (1.05–1.23); p = 0.001] and number of embryos transferred [1.90 (1.27–2.86); p = 0.002] were also independently associated with live birth in AMA patients. Live birth and delivery rates were 70–75% higher, while miscarriage rate was less than half in donor sperm compared to partner sperm AMA cycles (LBR: 25.4% vs. 14.5%, p = 0.003; DR: 22.5% vs. 13.5%, p = 0.008; MR: 18.0% vs. 39.5%; p = 0.009). Implantation (17.4% vs. 13.5%; p = 0.075) and clinical pregnancy rates (27.5% vs. 22.3%; p = 0.121) did not significantly differ between sperm donation and partner sperm AMA cycles. Male age was substantially lower (23.6 ± 5.2 vs. 41.4 ± 5.0; p &amp;lt; 0.0001) and oocyte yield was higher (5.1 ± 3.1 vs. 4.3 ± 2.6; p &amp;lt; 0.0001) in sperm donation compared to partner sperm AMA cycles, while maternal age did not vary (39.8 ± 1.6 vs. 39.6 ± 1.7; p = 0.348). Limitations, reasons for caution This study is limited by its retrospective nature and by differences in patients’ profiles between sperm donation and homologous cycles, although this variation has been controlled for in the statistical analysis. Wider implications of the findings: The findings suggest that donor sperm can improve live birth rates by drastically reducing miscarriage occurrence in AMA patients. Therefore, the present results may influence AMA treatment decisions and, above all, contribute for AMA patients to achieve a healthy birth. Trial registration number Not applicable

Fertility Drain or Fertility Gain? Emigration and Fertility During the Great Recession in Italy.

How does emigration affect fertility in the country of origin? We address this question by estimating counterfactual fertility during the Great Recession in order to understand what the effect of the recession on fertility would be in the absence of emigration. Between 2009 and 2014, Southern European countries suffered from harsh economic instability, which triggered a sharp drop in fertility and a spike in emigration. We focus on Italy, exploiting the richness of the Italian Administrative Registry of Italians Residing Abroad (AIRE), which records information about all Italian citizens moving their residence abroad, as well as Italian birth records. Using an instrumental variable approach, which helps overcome endogeneity issues in the fertility-migration relationship, we find a positive impact of emigration on the total fertility rate at the Italian province level. This result suggests that emigrants are selected among those individuals who have a lower risk of having children. Therefore, in the absence of emigration, counterfactual fertility would have been lower than it actually is. Such a positive effect of out-migration on fertility in the area of origin could thereby lead to an underestimation of the effect of the recession on fertility.

Being born and growing up in the Ribeirão Preto and São Luís cohorts.

This thematic issue consists of 14 articles derived from studies of the BRISA birth cohort (Ribeirão Preto, State of São Paulo and São Luís, State of Maranhão, northeastern Brazil, a socially and economically less developed region). In these more than 40 years of existence, these cohorts have been able to document the increase in women's education, the improvement of health conditions, the creation of a public Unified Health System (SUS) that provides universal and free access to health care, eradication of hunger, and transition of the nutritional status characterized by a decrease in malnutrition rates and an increase in obesity in Brazil. Particularly in reproductive health, the country experienced a significant drop in fertility, a decrease in maternal and child mortality, and an increase in breastfeeding rates. Universal access to prenatal care and hospital delivery was accompanied by an excessive number of cesareans without clinical indication and early-term births and premature births, largely due to scheduled cesareans. Articles with a longitudinal and transversal methodological approach are presented, using structural equation analysis and propensity score, together with multivariate regressions, which gave a robust analytical treatment to articles in this thematic issue.