China
Africa
Explore chapters and articles related to this topic
Embryos and their Providers to Stem Cell Research
Published in Sarah Devaney, Stem Cell Research and the Collaborative Regulation of Innovation, 2013
There have been calls by SC scientists for changes in IVF practices to ensure that those embryos which become available to them are in a state which is more likely to facilitate the harvesting of SCs. For example, ‘a shift in practice from the cryopreservation of all embryo stages to that of only blastocysts’74 may allow the retrieval of more SCs due to the fact that scientists have more success in creating embryonic SC lines from entities frozen at blastocyst stage than at the earlier cleavage-stage embryos. In IVF treatment, allowing development to blastocyst stage can ‘improve the synchronicity of uterine and embryonic development and provide a mechanism for self-selection of viable embryos’.75 Studies have shown that this approach does not affect the miscarriage, clinical pregnancy or live birth rates per cycle, however ‘blastocyst transfer was associated with an increase in failure to transfer any embryos in a cycle and a decrease in embryo freezing rates. In the absence of data on cumulative live birth rates resulting from fresh and thawed cycles, it is not possible to determine if this represents an advantage or disadvantage’.76
Endocrine disrupting toxicity of aryl organophosphate esters and mode of action
Published in Critical Reviews in Environmental Science and Technology, 2023
Wenxin Hu, Peng Gao, Lei Wang, Jianying Hu
Epidemiologic studies have linked AOPEs exposure to reproductive dysfunction. The house-dust concentration of TPHP has been positively associated with prolactin and negatively associated with sperm concentration in men (Meeker & Stapleton, 2010), which is consistent with the AR antagonistic activity of TPHP. In a population of couples undergoing in vitro fertilization (IVF) treatment, a decreased proportion of cycles was observed as a function of increasing quartiles of urinary DPHP and isopropylphenyl phenyl phosphate (ip-PPP, a biotransformation product of mono-ITP) in an adjusted multivariable model, resulting in significant declines in successful implantation, clinical pregnancy, fertilization, and live birth. The concentration of DPHP in urine has been associated with the decreased rates of clinical pregnancy, and the concentration of ip-PPP was associated with lower rates of successful fertilization. A decreased live birth rate was also observed in the group with the highest quartile of DPHP and ip-PPP, but without statistical significance (Carignan et al., 2017). In a nested case-control study, DPHP was measured in maternal urine collected in the third trimester. Participants with DPHP concentrations in the highest quartiles had a 4.62-fold significantly increased risk of giving birth to low-birth-weight infants relative to those in the lowest quartiles. Interestingly, when stratified by newborn sex, the significant positive associations of DPHP concentration with low birth weight were only observed among female newborns, showing gender differences in toxicity (Luo et al., 2020).
Residential proximity to roadways and placental-associated stillbirth: a case–control study
Published in International Journal of Environmental Health Research, 2021
Lindsey Butler, Lisa Gallagher, Michael Winter, M. Patricia Fabian, Amelia Wesselink, Ann Aschengrau
Maternal residential address at delivery as indicated on the fetal death record or live birth certificate was geocoded to latitude and longitude using ArcGIS 10.0 (ESRI, Redlands, CA). The geocoding process assigned each address to a land parcel. If an address could not be assigned to a land parcel, then it was geocoded to the nearest parcel by street number. If a street number was not available (N = 6) then the address was geocoded to the middle of the street (if the street was less than or equal to 0.5 miles) or to the intersection of the address with the nearest cross-street (if the street was greater than 0.5 miles). We were able to successfully geocode 98.5% of maternal residential addresses. Study staff conducting the geocoding were blinded to both the exposure status and case/control status of the mother (Aschengrau et al. 2018).
Exposure to firework chemicals from production factories in pregnant women and risk of preterm birth occurrence in Liuyang, China
Published in Journal of Toxicology and Environmental Health, Part A, 2018
Xun Li, Hongzhuan Tan, Meiling Luo, Xinrui Wu, Xin Huang, Shujin Zhou, Lin Shen, Yue He, Yi Liu, Li Hu, Mengshi Chen, Shimin Hu, Shi Wu Wen
General information of maternal characteristics including maternal age, parity, pregnancy history, body mass index (BMI) health status, obstetric history and antenatal care records from Maternal Healthcare Booklet was obtained. Clinical diagnosis of preterm birth was obtained from the medical records. Preterm birth was defined as live birth prior to 37 weeks of completed gestation. Gestational age was primarily determined from the first day of the last menstrual period, but in cases of irregular menses or uncertainty regarding the date of last menstrual period, the earliest ultrasound assessment in her pregnancy prior to 20 weeks of gestation was used.