scholarly journals Age, the environment and our reproductive future: bonking baby boomers and the future of sex

Reproduction ◽  
2014 ◽  
Vol 147 (2) ◽  
pp. S1-S11 ◽  
Author(s):  
R John Aitken

There has never been a greater need for scientists trained in reproductive science. Most developed countries are witnessing unprecedented rates of recourse to assisted conception sitting cheek-by-jowl with high rates of induced abortion. This article addresses these two incongruous faces of reproductive healthcare. Every year at least 44 million abortions are performed worldwide, many under unsafe and insanitary conditions that carry a significant risk to the lives of women deprived of safe, effective methods for controlling their fertility. Although birth control is a complex issue involving myriad social and political factors, the technical vacuum in this area is significant. Through no fault of the family planning authorities, there have been no radically new methods of fertility control since the oral contraceptive pill was introduced in 1960 and even this contribution to planned parenthood has its roots in the biochemistry of the 1920s and 1930s. Moreover, the pharmaceutical industry has, by and large, turned its back on fundamental research activities in this area. At present, our major investment in reproductive healthcare involves treating ever-increasing numbers of couples with assisted reproductive technologies (ART). However, these treatments are often delivered without critically considering the underlying causes of this condition or seriously contemplating the long-term consequences of the current enthusiasm for such therapy. Significantly, the clinical factors underpinning the commitment of couples to ART include advanced maternal age and a variety of lifestyle factors, such as smoking and obesity, which are known to compromise the developmental potential of the oocyte and DNA integrity in spermatozoa.

2012 ◽  
Vol 24 (1) ◽  
pp. 68 ◽  
Author(s):  
Olivier Sandra ◽  
Nadéra Mansouri-Attia ◽  
Richard G. Lea

Successful pregnancy depends on complex biological processes that are regulated temporally and spatially throughout gestation. The molecular basis of these processes have been examined in relation to gamete quality, early blastocyst development and placental function, and data have been generated showing perturbations of these developmental stages by environmental insults or embryo biotechnologies. The developmental period falling between the entry of the blastocyst into the uterine cavity to implantation has also been examined in terms of the biological function of the endometrium. Indeed several mechanisms underlying uterine receptivity, controlled by maternal factors, and the maternal recognition of pregnancy, requiring conceptus-produced signals, have been clarified. Nevertheless, recent data based on experimental perturbations have unveiled unexpected biological properties of the endometrium (sensor/driver) that make this tissue a dynamic and reactive entity. Persistent or transient modifications in organisation and functionality of the endometrium can dramatically affect pre-implantation embryo trajectory through epigenetic alterations with lasting consequences on later stages of pregnancy, including placentation, fetal development, pregnancy outcome and post-natal health. Developing diagnostic and prognostic tools based on endometrial factors may enable the assessment of maternal reproductive capacity and/or the developmental potential of the embryo, particularly when assisted reproductive technologies are applied.


2020 ◽  
Vol 32 (2) ◽  
pp. 227
Author(s):  
A. R. Moawad ◽  
H. Benham ◽  
J. P. Barfield

Bison are an important species in North America, both economically and culturally. Although assisted reproductive technologies have been applied to preserve the genetic diversity of bison, development of these technologies remains limited for this species. The objective of the present study was to compare success rates of oocyte maturation, fertilization, and embryo development invitro in bison versus cattle (experiment 1). Cumulus-oocyte complexes obtained from abattoir-derived cattle and bison ovaries were matured, fertilized with frozen semen, and cultured invitro using standard procedures (De La Torre-Sanchez et al. 2006 Reprod. Fertil. Dev. 18, 585-596). At least three replicates were repeated for each experimental group. Oocyte recovery rate was lower in bison than in cattle (4.3; 2797/699 vs. 6.7; 4138/677, oocyte/ovary; P<0.01, t-test). Nuclear maturation (oocytes at MII, 23h post-IVM) and fertilization rates (oocytes with 2 pronuclei 18h post-insemination; p.i.) evaluated by Hoechst stain were lower (P<0.01, chi-square) for bison (65.1%; 56/86 and 32.7%; 18/55, respectively) than for cattle (88.3%; 83/94 and 70.9%; 39/55, respectively). Polyspermy tended to be higher in bison than in cattle (12.7% vs. 3.6%, P=0.08). The percentages of 2-cell embryos tended to be lower in bison than in cattle (13.5% vs. 25.0%, P>0.05) at 24h p.i. but by 30h p.i., this difference increased (33.7% vs. 67.0%, P<0.01, chi-square). Cleavage (Day 3) and blastocyst (Day 7) rates were lower (P<0.01, chi-square) for bison (58.2%; 280/481 and 14.6%; 70/481, respectively) than for cattle (90.8%; 405/446 and 22.9%; 102/446, respectively). Total cell number (74.9±4.8 vs.114.2±5.8), trophectoderm cell numbers (57.9±4.6 vs. 89.2±4.8) and inner cell mass cell numbers (16.9±2.3 vs. 25±1.9) as determined by Hoechst and propidium iodide were all lower (P<0.01, t-test) in bison than in cattle blastocysts. To improve oocyte competence in bison, we evaluated effects of L-carnitine (LC) supplementation during IVM on developmental potential of bison oocytes (experiment 2). Cumulus-oocyte complexes were matured in IVM medium supplemented with 0, 0.15, 0.3, 0.6, or 1.2mgmL−1 LC. No differences were observed in cleavage rates of control (0mgmL−1 LC) and LC-treated groups (values ranged from 60.0 to 66.4%). Interestingly, a dose-dependent increase in blastocyst development was found with the lowest value recorded in control group (10.4%; 14/134) and the highest value in the 1.2mgmL−1 LC supplemented group (22.2%; 23/105; P<0.01, chi-square, n=4). Adding 1.2mgmL−1 LC to the IVM medium improved the percentage of hatching blastocysts compared with the control. In conclusion, bison oocytes exhibited lower invitro maturation, fertilization, and developmental rates compared with cattle oocytes using our system, and bison embryos were delayed in the timing of first cleavage. L-Carnitine supplementation during IVM of bison oocytes improved the preimplantation development and quality of invitro-produced blastocysts.


2019 ◽  
Vol 20 (17) ◽  
pp. 4169
Author(s):  
Marina La Rovere ◽  
Marica Franzago ◽  
Liborio Stuppia

About 1–4% of children are currently generated by Assisted Reproductive Technologies (ART) in developed countries. These babies show only a slightly increased risk of neonatal malformations. However, follow-up studies have suggested a higher susceptibility to multifactorial, adult onset disorders like obesity, diabetes and cardiovascular diseases in ART offspring. It has been suggested that these conditions could be the consequence of epigenetic, alterations, due to artificial manipulations of gametes and embryos potentially able to alter epigenetic stability during zygote reprogramming. In the last years, epigenetic alterations have been invoked as a possible cause of increased risk of neurological disorders, but at present the link between epigenetic modifications and long-term effects in terms of neurological diseases in ART children remains unclear, due to the short follow up limiting retrospective studies. In this review, we summarize the current knowledge about neurological disorders promoted by epigenetics alterations in ART. Based on data currently available, it is possible to conclude that little, if any, evidence of an increased risk of neurological disorders in ART conceived children is provided. Most important, the large majority of reports appears to be limited to epidemiological studies, not providing any experimental evidence about epigenetic modifications responsible for an increased risk.


2014 ◽  
Vol 60 (5) ◽  
pp. 34-42 ◽  
Author(s):  
Irina I Vityazeva ◽  
Mariya V Altashina ◽  
Ekaterina A Troshina

The excessive body weight and obesity in the men of the reproductive age exert the negative influence on their reproductive system and can promote the development of infertility. The high prevalence of obesity and the reduction of the birth rate in the developed countries stimulate the extensive investigations into the mechanisms by which the excess adipose tissue affects male fertility. The authors overview the literature publications concerning the hormonal profile and the adipokine level, as well as disturbance of spermatogenesis in the men with disordered fat metabolism with special reference to the peculiarities of the management of infertility with the application of the assisted reproductive technologies.


2006 ◽  
Vol 91 (3) ◽  
pp. 760-771 ◽  
Author(s):  
Robert F. Casper ◽  
Mohamed F. M. Mitwally

Abstract Context: For the last 40 yr, the first line of treatment for anovulation in infertile women has been clomiphene citrate (CC). CC is a safe, effective oral agent but is known to have relatively common antiestrogenic endometrial and cervical mucous side effects that could prevent pregnancy in the face of successful ovulation. In addition, there is a significant risk of multiple pregnancy with CC, compared with natural cycles. Because of these problems, we proposed the concept of aromatase inhibition as a new method of ovulation induction that could avoid many of the adverse effects of CC. The objective of this review was to describe the different physiological mechanisms of action for CC and aromatase inhibitors (AIs) and compare studies of efficacy for both agents for ovulation induction. Evidence Acquisition: We conducted a systematic review of all the published studies, both controlled and noncontrolled, comparing CC and AI treatment, either alone or in combination with gonadotropins, for ovulation induction or augmentation, identified through the Entrez-PubMed search engine. Evidence Synthesis: Because of the recent acceptance of the concept of using AIs for ovulation induction, few controlled studies were identified, and the rest of the studies were pilot or preliminary comparisons. Based on these studies, it appears that AIs are as effective as CC in inducing ovulation, are devoid of any antiestrogenic side effects, result in lower serum estrogen concentrations, and are associated with good pregnancy rates with a lower incidence of multiple pregnancy than CC. When combined with gonadotropins for assisted reproductive technologies, AIs reduce the dose of FSH required for optimal follicle recruitment and improve the response to FSH in poor responders. Conclusions: Preliminary evidence suggests that AIs may replace CC in the future because of similar efficacy with a reduced side effect profile. Although worldwide experience with AIs for ovulation induction is increasing, at present, definitive studies in the form of randomized controlled trials comparing CC with AIs are lacking.


2018 ◽  
Vol 28 (2) ◽  
pp. 629-636
Author(s):  
Anna Mihaylova ◽  
Nikoleta Parahuleva ◽  
Elina Petkova-Gueorguieva ◽  
Stanislav Gueorguiev

Premature birth is a significant medical, social and economic problem worldwide. In the 21st Century in developed countries, this problem accounts for over two thirds of neonatal deaths. In Bulgaria, statistics show that 10-12% of all pregnancies end with premature birth. Despite the number of studies in this field and the efforts made by obstetricians and gynecologists, the tendency to increase the number of preterm births has continued in the last decade. Its consequences are multiple complications who lead to a high neonatal mortality in the national and global world. Preterm birth is characterized by complex and vague etiology. A specific cause of premature birth can not be defined, but a set of risk factors is considered, divided into three main groups of etiological factors: socio-economic, medical-biological, and behavioral. Associated with preterm birth socio-economic and behavioral risk factors include poverty, unemployment, low education, poor prenatal care, harmful habits such as smoking, alcohol, drugs and other harmful substances, unhealthy family environment, severe and prolonged stress, excessive physical exercise (lifting weights), trauma (hits or violence), new pregnancies less than 6 months after previous birth, unhealthy diet and low mother BMI, etc. Essential for the preterm birth is also the medico - biological etiological factors. One of these is uterine enlargement, as the main reason for this may be the presence of: multiple pregnancies that occurred naturally or after using assisted reproductive technologies or polyhydramnios (increased amount of amniotic fluid). Other risk factors include: placenta previa, incorrect position of the fetus, myoma, uterine cervix malformations (including cerebrovascular insufficiency), preeclampsia, uterine contractions, acute infections during pregnancy (vaginal - chlamydia, trichomonas, mycoplasma , toxoplasmosis, bacterial vaginosis, viral rubella, cytomegalovirus, herpes, influenza, adenovirus infection, chronic diseases (hypertension, cardiovascular diseases, diseases of the lungs, liver or kidney anemia and etc.), genetic factors, previous premature birth, etc. These risk indicators are subject to detailed analysis in the work of a number of authors. To limit preterm births, a number of studies have been conducted to identify and identify the risk factors that are relevant to it. Identifying and recognizing their effects and impact leading to premature birth will significantly reduce the severe health, economic and social consequences as well as reduce the risk of neonatal death. In order to reduce the frequency of preterm births, adequate and specialized prenatal care is essential. They must be individually tailored for each particular case of pregnancy and take into account the complex of risk predispositions.


2020 ◽  
Vol 32 (2) ◽  
pp. 125
Author(s):  
I. Lorenzo ◽  
Z. Li ◽  
M. Torres ◽  
Z. Machaty ◽  
D. Nolte

Assisted reproductive technologies are powerful tools for enhancing production in livestock or treating infertility in humans. Unfortunately, the success rate of the technologies is rather low. A major reason for the poor efficiency is the lack of methods to reliably assess the developmental potential of the embryos before transfer into recipients. Therefore, a noninvasive method to ensure the selection of only the best embryos for transfer would be highly desirable. Biodynamic imaging is a compelling new microscopy that uses intracellular Doppler spectroscopy to perform label-free, noninvasive optical measurements of cellular fitness. The aim of this study was to investigate whether biodynamic imaging can be used to assess the energy status of the embryos, which may be indicative of their viability. Porcine oocytes matured invitro were parthenogenetically activated by an electrical pulse and cultured for 2 days. The parthenotes were then divided into two groups, and approximately half of them were incubated for an additional 2 days in the presence of 20mM sodium azide. Sodium azide is an inhibitor of oxidative phosphorylation and is known to block ATP production. The rest of the embryos were cultured without sodium azide and used as a control to indicate normal ATP levels. At the end of the culture period embryos that reached the 8- to 16-cell stage were evaluated by our biodynamic imaging system to assess their energy status, after which they were lysed and their ATP contents were determined by means of a bioluminescence assay. A total of 68 embryos (32 treated with the inhibitor and 36 control) were evaluated. The ATP content analysis showed that the control embryos had significantly more ATP than those treated with sodium azide as determined by Student's t-test (5.04±1.07 vs. 1.31±0.57; P<0.05). A correlative study was then completed where biodynamic biomarkers were used to classify embryos to estimate the ability of biodynamic imaging to identify embryos with high or low energy status. A set of 13 biomarkers representing each embryo as a feature vector was used to train a classifier. We found that the cross-validated classifier had a sensitivity and specificity of ~80%. In addition, a receiver-operator curve constructed by varying the ATP threshold of the independent bioluminescence assay had an area-under-the-curve of 0.81. These results indicate that biodynamic imaging is able to determine the energy status of the embryos noninvasively and has great potential in the assessment of embryo viability.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mutyala Satish ◽  
Sandhya Kumari ◽  
Waghela Deeksha ◽  
Suman Abhishek ◽  
Kulhar Nitin ◽  
...  

AbstractPhosphodiesterase (PDE) inhibitors, such as pentoxifylline (PTX), are used as pharmacological agents to enhance sperm motility in assisted reproductive technology (ART), mainly to aid the selection of viable sperm in asthenozoospermic ejaculates and testicular spermatozoa, prior to intracytoplasmic sperm injection (ICSI). However, PTX is reported to induce premature acrosome reaction (AR) and, exert toxic effects on oocyte function and early embryo development. Additionally, in vitro binding studies as well as computational binding free energy (ΔGbind) suggest that PTX exhibits weak binding to sperm PDEs, indicating room for improvement. Aiming to reduce the adverse effects and to enhance the sperm motility, we designed and studied PTX analogues. Using structure-guided in silico approach and by considering the physico-chemical properties of the binding pocket of the PDEs, designed analogues of PTX. In silico assessments indicated that PTX analogues bind more tightly to PDEs and form stable complexes. Particularly, ex vivo evaluation of sperm treated with one of the PTX analogues (PTXm-1), showed comparable beneficial effect at much lower concentration—slower AR, higher DNA integrity and extended longevity of  spermatozoa and  superior embryo quality. PTXm-1 is proposed to be a better pharmacological agent for ART than PTX for sperm function enhancement.


2021 ◽  
Vol 10 (2) ◽  
pp. 90-100
Author(s):  
Dhafer Hamdan ◽  
Ali Rahim ◽  
Ula Al-Kawaz

For conception and the development of healthy embryos, sperm DNA integrity is crucial. According to a growing body of studies, there is a strong correlation between sperm DNA damage and male infertility. Among the new medicines being developed in the medical field, the application of Platelet Rich Plasma (PRP) in human reproduction has yet to be examined. A total of 100 semen samples were used in the current experimental investigation. From November 2020 to June 2021, the research was conducted at the High Institute for Infertility Diagnosis and Assisted Reproductive Technologies. Masturbation was used to get an ejaculated semen sample. After semen analysis, the samples were separated into two equal parts, one without autologous PRP and the other with 2% autologous PRP, with the DNA fragmentation assessed using the Sperm Chromatin Dispersion Test. There was highly significant reduction in DNA fragmentation index (p < 0.001). The mean sperm DNA integrity was reduced after adding PRP (33.85±16.73 vs 38.55±16.64), Mean (± SE). PRP has been shown to improve human sperm DNA integrity.


2020 ◽  
Vol 24 (7) ◽  
pp. 761-769
Author(s):  
M. V. Anisimova ◽  
Ya. Gong ◽  
N. S. Yudin ◽  
Yu. M. Moshkin ◽  
L. A. Gerlinskaya

Assisted reproductive technologies (ART) increasingly occupy the study of human reproduction. In addition, in developed countries they contribute to breeding of more than 50 % of cattle. In the management of collections of genetic lines of laboratory animals, these technologies are obligatory components of cryopreservation and rederivation. ART procedures include the development of early embryos outside the mother’s body and the high probability of incomplete synchronization of the physiological state of the surrogate mother and transplanted embryos. Since all this occurs at the stage of the highest susceptibility of embryos to epigenetic reprogramming, the full cycle of ART and its individual components can lead to stable phenotypic changes in the offspring. Their reality is confirmed by studies of the morphological and functional characteristics of sexually mature offspring of CD1 outbred mice, obtained using different variants of early embryo transplantation. Comparative studies of body mass and body composition, basal glucose level and response to glucose load (glucose-tolerance test – GTT) have been done on sexually mature males and females. Animals were separated in 4 groups according to the variant of embryo transplantation: group (control) – natural mating; group (2cl-bl) – incubation of 2-cell up to blastocysts; group (2cl-2cl) – removal and transplantation of the 2-cell embryo without incubation; group (Bl-bl) removal and transplantation of the blastocysts without incubation. All embryos were transplanted to recipient females of the same line. It was found that sexually mature offspring obtained with all variants of transplantations had a higher relative fat content and, correspondingly, lower lean mass compared to the control. This effect was more pronounced in females than in males. Unlike body compositions, embryo transplantations had a greater effect on basal glucose concentration and GTT in males than in females. In this case, the offspring of the 2cl-2cl and 2cl-bl groups were characterized by a higher tolerance to glucose load (GTT) compared with the control and the Bl-bl group. Stable deviations of body compositions and glucose homeostasis indices detected in experimental groups of progenies indicate the phenotypic significance of the embryo transplantations per se.


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