Asexual Reproduction of Aurelia coerulea Polyps in situ on Settling Plates in Jiaozhou Bay,China

Jellyfish blooms are increasingly prevalent coastal phenomena,with Aurelia coerulea being a significant contributor.The complex life history of jellyfish,featuring a sessile polyp stage,is a key factor in bloom formation,yet it is challenging to study in the field.This study aimed to describe the asexual reproduction of A.coerulea polyps in Jiaozhou Bay,China,and to assess their ability to form sedentary colonies and their relationship with environmental factors.Using settling plates,we observed polyps in situ and documented three asexual reproduction modes:budding,strobilation,and podocyst formation.Environmental parameters including temperature,salinity,dissolved oxygen(DO),chlorophyll a(Chl a),and the biomass of phytoplankton and zooplankton were monitored.Budding was the predominant reproductive method,featuring stolon budding in autumn and direct budding during the winter and spring seasons.Strobilation took place in the colder months,releasing ephyrae between April and May.Polyp abundance was positively correlated with seawater temperature and negatively correlated with DO concentration.Polyps at 1.0 m depth showed higher survivorship and proliferation over 8 months,whereas those at 2.0 m depth experienced a steady decline and died within 4 months.The study enhances our understanding of the life cycle and asexual reproduction strategies of A.coerulea polyps in the field,with implications for predicting and managing jellyfish blooms.The findings underscore the importance of temperature and DO in polyp survival and suggest that initial polyp population proliferation is crucial for long-term survival.

The sexually dimorphic expression of glutamate transporters and their implication in pain after spinal cord injury

In addition to the loss of motor function,~60% of patients develop pain after spinal cord injury.The cellular-molecular mechanisms are not well understood,but the data suggests that plasticity within the rostral,epicenter,and caudal penumbra of the injury site initiates a cellularmolecular interplay that acts as a rewiring mechanism leading to central neuropathic pain.Sprouting can lead to the formation of new connections triggering abnormal sensory transmission.The excitatory glutamate transporters are responsible for the reuptake of extracellular glutamate which makes them a critical target to prevent neuronal hyperexcitability and excitotoxicity.Our previous studies showed a sexually dimorphic therapeutic window for spinal cord injury after treatment with the selective estrogen receptor modulator tamoxifen.In this study,we investigated the anti-allodynic effects of tamoxifen in male and female rats with spinal cord injury.We hypothesized that tamoxifen exerts anti-allodynic effects by increasing the expression of glutamate transporters,leading to reduced hyperexcitability of the secondary neuron or by decreasing aberrant sprouting.Male and female rats received a moderate contusion to the thoracic spinal cord followed by subcutaneous slow-release treatment of tamoxifen or matrix pellets as a control(placebo).We used von Frey monofilaments and the“up-down method”to evaluate mechanical allodynia.Tamoxifen treatment decreased allodynia only in female rats with spinal cord injury revealing a sexdependent effect.The expression profile of glutamatergic transporters(excitatory amino acid transporter 1/glutamate aspartate transporter and excitatory amino acid transporter 2/glutamate transporter-1)revealed a sexual dimorphism in the rostral,epicenter,and caudal areas of the spinal cord with a pattern of expression primarily on astrocytes.Female rodents showed a significantly higher level of excitatory amino acid transporter-1 expression while male rodents showed increased excitatory amino acid transporter-2 expression compared with female rodents.Analyses of peptidergic(calcitonin gene-related peptide-α)and non-peptidergic(isolectin B4)fibers outgrowth in the dorsal horn after spinal cord injury showed an increased calcitonin gene-related peptide-α/isolectin B4 ratio in comparison with sham,suggesting increased receptive fields in the dorsal horn.Although the behavioral assay shows decreased allodynia in tamoxifen-treated female rats,this was not associated with overexpression of glutamate transporters or alterations in the dorsal horn laminae fibers at 28 days post-injury.Our findings provide new evidence of the sexually dimorphic expression of glutamate transporters in the spinal cord.The dimorphic expression revealed in this study provides a therapeutic opportunity for treating chronic pain,an area with a critical need for treatment.

Advances in Small RNAs and Sexual Reproduction in Plants

Small RNAs are non-coding RNA molecules with 20-30 nucleotides （nt） in length that mainly play regulatory roles in gene expression at the post-transcription level by directly cutting target mRNA or inhibiting its translation. Small RNAs play regulatory roles in the growth and development process of plants at the core of gene regulatory networks, which has been widely studied and confirmed in sporophyte generation of plants. However, few researches have been conducted on small RNAs and gametophyte generation. It is reported that small RNAs play important roles in floral organ development, gametogenesis, fertilization, and early zygotic development of plants. In addition, various small RNAs also play roles in controlling genetic integrity, cell differentiation and functions during the sexual reproduction process of plants. However, most of the specific functions of small RNAs in the sexual reproduction process are unknown yet. This study mainly aimed to introduce small RNAs in plants, summarize the latest advances in researches of small RNAs and plant sexual reproduction, and make prospect on its future.

Effects of sexual reproduction of the inferior competitor Brachionus calyciflorus on its fitness against Brachionus angularis

Sexual reproduction adversely affects the population growth of cyclic parthenogenetic animals. The density-dependent sexual reproduction of a superior competitor could mediate the coexistence. However, the cost of sex may make the inferior competitor more vulnerable. To investigate the effect of sexual reproduction on the inferior competitor, we experimentally paired the competition of one Brachionus angularis clone against three Brachionus ealyciflorus clones. One of the B. calyciflorus clones showed a low propensity for sexual reproduction, while the other two showed high propensities. The results show that all B. calyciflorus clones were excluded in the competition for resources at low food level. The increased food level promoted the competition persistence, but the clones did not show a clear pattern. Both the cumulative population density and resting egg production increased with the food level. The cumulative population density decreased with the mixis investment, while the resting egg production increased with the mixis investment. A trade-off between the population growth and sexual reproduction was observed in this research. The results indicate that although higher mixis investment resulted in a lower population density, it would not determinately accelerate the exclusion process of the inferior competitor. On the contrary, higher mixis investment promoted resting egg production before being excluded and thus promised a long- term benefit. In conclusion, our results suggest that mixis investment, to some extent, favored the excluded inferior competitor under fierce competition or some other adverse conditions.

Reexamination of Sexual Dimorphism and Female Reproduction in the Many-Lined Sun Skink Eutropis multifasciata from China

We reexamined sexual dimorphism and female reproduction in the Many-Lined Sun Skink Eutropis multifasciata from Hainan,China. Our data confirm that adults are sexually dimorphic in body size and shape,with males being the larger sex and larger in head size but shorter in abdomen length than females of the same snoutvent length(SVL). The rate at which head width increased with SVL was greater in males as opposed to the previous conclusion that the rate does not differ between the sexes. Maternal size was the main determinant of reproductive investment,with larger females generally producing more,as well as larger,offspring. Females produced up to nine offspring per litter as opposed to the previously reported 2–7. Most females gave birth between March and August,a time period approximately four months longer than that(May–June) reported previously. Females with a higher fecundity tended to produce smaller offspring as opposed to the previous conclusion that females do not tradeoff offspring size against number. Litter size,neonate mass and litter mass remained remarkably constant among years,and litter mass was more tightly related to female body size than litter size or neonate mass. Smaller females could produce relatively heavier litters without a concomitant reduction in postpartum body condition.

Effects of temperature and salinity on the asexual reproduction of Aurelia coerulea polyps

Aurelia coerulea polyp is an important stage in the outbreaks of this species.To test the combined effects of salinity and temperature on the survival and asexual reproduction of polyps,we maintained 864 polyps at various salinities(15,25,33,and 40)and temperatures(9,12,15,18,21,and 24℃).Polyps could mostly survive in all treatment combinations except in salinity 15 treatments with low temperatures(9-15℃).Budding occurred at all temperatures(9-24℃),while strobilation only occurred at the low temperatures(9-15℃).The range of 12-15℃was suitable for strobilation and ephyrae release.The optimal range of salinity for asexual reproduction was 25-33.Low(15)or high(40)salinity could significantly reduce the numbers of new buds or ephyrae,and low salinity of 15 retarded and even prevented strobilation at low temperatures.The optimal treatment for budding and strobilation was 21℃-salinity 25 and 12℃-salinity 33,respectively.Salinity had less of an impact than temperature on asexual reproduction,except for the polyps in high or low osmotic pressure conditions.

Effect of Female Reproduction and Mate Choice on Sexual Size Dimorphism in the Northeast Treefrog Hyla ussuriensis (Anura:Hylidae) in China

Sexual size dimorphism(SSD) plays a significant role in understanding the evolution of life history and mating behavior. In this study,we analyzed the morphological data from a treefrog,Hyla ussuriensis,in northeastern China and found that there are significant differences between males and females. Females that are larger in body size increase fecundity as the total number of eggs is positively correlated to female body size. Males are smaller in body size due to the mate choice by females based on the size dimorphism index(SVL mean of female divided by that of male) for the population,which may be an evolutionary stable strategy(ESS). SSD can be influenced not only through mate choice,but also reproductive behavior by analyzing the female reproduction output in the field. Our data are consistent with many previous studies,indicating that fecundity selection and sexual selection may be the common cause for sexual dimorphism in this species. Furthermore,there are no significant morphological differences between mated and unmated frogs of both sexes,which suggests that any frog can obtain a breeding chance when it matures. It further indicates that males may not affect female choice except by their snout-vent length(SVL) and body mass. It is,of course,possible that females adopt a mating strategy to mate with males whose SVL and body mass are smaller than paired females. Our research provides unequivocal evidence for effective female choice and information on the evolution of SSD in the production of anuran pairing patterns.

Underground water affects sexual behavior and gene expression of hormones related to reproduction in blue gourami males

This study examined the effect of underground water on reproduction- and growth-related hormones in blue gourami males under non-reproductive and reproductive conditions. An increase in the percentage of males building nests under the highest percentage of underground water were compared to fish that maintained a lower percentage of underground water in the first two days. The % Gonado-somatic index (GSI) of males building nests was higher than non- reproductively active males in water containing the lowest concentration of underground water. In non- reproductively active males, brain gonadotropin releasing hormone 1 (GnRH1) and pituitary β subunit of gonadotropins (GtHs) and prolactin (PRL) mRNA levels were significantly higher in males maintained in underground water. In reproductively active males, mRNA levels of brain GnRH1, gonadotropin releasing hormone 3 (GnRH3) and pituitary PRL mRNA levels were significantly higher than males maintained in underground water. Thus, it is suggested that underground water with high salinity and conductivity levels affects the gene expression of repro- duction-related hormones;in reproductively active males, it shortened the duration of nest-building by blue gourami males.

Sexual reproduction and short-term fitness advantage in the rotifer Brachionus calyciflorus:implications for the coexistence of sympatric clones

Large numbers of rotifer eggs from sediment resting egg banks may hatch simultaneously under appropriate conditions; therefore, natural populations are likely to be multiclonal in a growing season. A recent field investigation showed that subordinate and ephemeral clones were able to establish populations in an environment with several strongly dominant clone populations. However, it was not clear how the subordinate populations maintained their growth under these conditions where the crowding signal would induce high levels of sexual reproduction in the dominant clone populations. In the present study, we conducted a continuous passage to 60 generations for new populations at three different temperatures （15~C, 25~C, and 35~C）. These populations emerged from resting eggs produced by a clone population. At the first, 30th, and 60th generations, the populations were sampled and fitness was assayed using the life-table method. We found a significant short-term fitness advantage for populations newly emerged from resting eggs produced by a clone population of the rotifer Brachionus calycifiorus, followed by a significant decrease in relative fitness with long-term continuous passage. Our results suggested that the early short- term fitness advantage was important for later-hatched and subordinate clone populations in an environment with multiple sympatric clones. The early short-term fitness might also promote the coexistence of sympatric clones because it could help to offset the cost of early sexual reproduction.

Study of light signal receptor of Stephanopyxis palmeriana during sexual reproduction

We collected centric diatom Stephanopyxis palmeriana samples in coastal waters of Xiamen for charac- teristic red light/far red light (R/FR) phytochrome reactions to identify its photoreceptor in the course of sexual repro- duction. The result showed that pre-illumination of 2-3h red light before darkness could induce sexualization of S. palmeriana, while the follow-up illumination of far red light could reverse the effect of red light, which is a featured reaction of phytochrome. The Southern Dot Blot was carried out to identify the type of phytochrome that induces the sexualization. The result also showed high homogeneity of DNA fragment of S. palmeriana with phyB, but phyA. This means the photoreceptor in the process of sexual reproduction of S. palmeriana is phytochrome B (phyB).

Coerced group collaborative evolution as an explanation for sexual reproduction’s prevalence

The prevalence of sexual reproduction has long been an outstanding problem of evolutionary biology. Different explanations have been offered to explain the prevalence of sexual reproduction. These explanations mainly focus on the benefits of sexual reproduction’s ability to shuffle and recombine genes. In this paper, we propose an alternative and comprehensive point of view to this important problem. We first hypothesize that sexual reproduction leads to genetic homogeneity and maintains adaptational advantages of organisms. In stable conditions with strong selective pressures, the maintenance of desired adaptational advantages is one benefit of sexual reproduction. We further hypothesize that sexual reproduction provides a mechanism by which entire populations of similar genomes can interact and collaborate with one another in order to improve the population’s average genomic fitness, a phenomena we call coerced collaborative group evolution. We show that groups of individuals will improve as a whole, even though each individual is still operating under their own best interests. We also argue that the so-called ‘two-fold cost of males’ is misguided if we take limited resources in any environment into consideration. Finally, we propose an intuitive and visualized view to connect different theories on sexual reproduction to establish a comprehensive theory to explain sexual reproduction’s prevalence.

Sexual Reproduction One Billion Years Ago

The facts regarding to the early stages of algae evolution in the Precambrian are very rare (more than 542 million years ago). In this paper, the author describes the first discovered evidence that the sexual reproduction process took place one billion years ago. As it is known, sexual reproduction led to the diversity of living organisms on the Earth, and in general, accelerated the evolution process.

Sex-specific facilitation and reproduction of the gynodioecious cushion plant Arenaria polytrichoides on the Himalaya-Hengduan mountains,SW China

When benefiting other beneficiaries,cushion plants may reciprocally receive feedback effects.The feedback effects on different sex morphs,however,remains unclear.In this study,taking the gynodioecious Arenaria polytrichiodes as a model species,we aimed to assess the sex-specific facilitation intensity of cushion plant by measuring the beneficiary cover ratio,and to assess the potential costs in cushion reproductive functions by measuring the flower and fruit cover ratios.The total beneficiary cover ratio was similar between females and hermaphrodites.Females produced much less flowers but more fruits than hermaphrodites.These results suggested that females and hermaphrodites possess similar facilitation intensity,and female cushion A.polytrichoides may allocate more resources saved from pollen production to seed production,while hermaphrodites possibly allocate more resources to pollen production hence reducing seed production.The surface areas covered by beneficiaries produced less flowers and fruits than areas without beneficiaries.In addition,strong negative correlations between beneficiary cover and flower cover were detected for both females and hermaphrodites,but the correlation strength were similar for these two sex morphs.However,the correlation between beneficiary cover and fruit cover was only significantly negative for females,suggesting that beneficiary plants negatively affect fruit reproduction of females while have neutral effects on hermaphrodites.All the results suggest that to facilitate other beneficiaries can induce reproductive costs on cushion A.polytrichoides,with females possibly suffering greater cost than hermaphrodites.Such differentiation in reproductive costs between sex morphs,in long-term perspective,may imply sex imbalance in population dynamics.

Sexual Dimorphism and Female Reproductive Characteristics in the Hainan Water Skink(Tropidophorus hainanus)from Hainan,South China

We studied sexual dimorphism in body size and shape and female reproductive characteristics in the Hainan Water Skink(Tropidophorus hainanus)from Hainan,South China.In our sample the largest female and male were 61.1 and 55.2 mm snout-vent length(SVL),respectively.The mean SVL was larger in adult females(52.0 mm)than in adult males(48.3 mm).Juveniles were sexually dimorphic in head length but not in other examined morphological variables.Adult males were longer in head length and shorter in abdomen length and fore-limb length than adult females of the same SVL.Ontogenetic shifts in sexual dimorphism in body shape were evident,as revealed by the fact that morphological differences between the sexes were more pronounced in adults than in juveniles.Females produced a single litter of 3–6 offspring per season from early August to early September.Litter size,litter mass and offspring(neonate)mass were positively related to female SVL.Neonate mass was independent of relative fecundity.From the above findings we draw three main conclusions.First,females are the larger sex in T.hainanus,and sexual dimorphism in body shape is more pronounced in adults than in juveniles.Second,larger female T.hainanus produce more and larger offspring and thus heavier litters than smaller ones.Third,the offspring size-number trade-off does is not evident in T.hainanus.

Smart Approaches to Efficient Text Mining for Categorizing Sexual Reproductive Health Short Messages into Key Themes

To promote behavioral change among adolescents in Zambia, the National HIV/AIDS/STI/TB Council, in collaboration with UNICEF, developed the Zambia U-Report platform. This platform provides young people with improved access to information on various Sexual Reproductive Health topics through Short Messaging Service (SMS) messages. Over the years, the platform has accumulated millions of incoming and outgoing messages, which need to be categorized into key thematic areas for better tracking of sexual reproductive health knowledge gaps among young people. The current manual categorization process of these text messages is inefficient and time-consuming and this study aims to automate the process for improved analysis using text-mining techniques. Firstly, the study investigates the current text message categorization process and identifies a list of categories adopted by counselors over time which are then used to build and train a categorization model. Secondly, the study presents a proof of concept tool that automates the categorization of U-report messages into key thematic areas using the developed categorization model. Finally, it compares the performance and effectiveness of the developed proof of concept tool against the manual system. The study used a dataset comprising 206,625 text messages. The current process would take roughly 2.82 years to categorise this dataset whereas the trained SVM model would require only 6.4 minutes while achieving an accuracy of 70.4% demonstrating that the automated method is significantly faster, more scalable, and consistent when compared to the current manual categorization. These advantages make the SVM model a more efficient and effective tool for categorizing large unstructured text datasets. These results and the proof-of-concept tool developed demonstrate the potential for enhancing the efficiency and accuracy of message categorization on the Zambia U-report platform and other similar text messages-based platforms.

The life-history trait trade-offs mediated by reproduction and immunity in the brown planthopper,Nilaparvata lugens Stål

Reproduction and immune defense are costly functions,and they are expected to tradeoff with each other to drive evolution.The brown planthopper(BPH),Nilaparvata lugens Stål(Hemiptera,Delphacidae),is a global superpest that mostly damages rice crops.Yeast-like symbionts(YLS)exist in the abdominal fat body tissue and are tightly associated with the development,growth,and reproduction of BPH.Our previous research demonstrated that mating behavior promotes the release of YLS from the fat body into the hemolymph in the BPH,thereby triggering an immune response.Additionally,the fitness costs related to life-history traits of BPH(such as survival rate)have a strong dependence on the relative abundance of YLS.However,the possible relationship between reproduction and the immune response in BPH has not been identified.In this study,an omics-based approach was used to analyze the transcriptome of fat body tissues in mated and unmated BPH at 72 h post-eclosion,from which two antimicrobial peptide genes,NlDefensin A(NlDfA)and NlDefensin B(NlDfB),were selected since they were highly expressed in mated BPH.Subsequently,the full-length cDNA sequences of the NlDfA and NlDfB genes were cloned and analyzed.qPCR results showed up-regulation of the NlDfA and NlDfB genes in mated BPH when compared to unmated BPH.Spatial-temporal expression analysis indicated that the NlDfA and NlDfB genes were expressed in all tissues and developmental stages,and they were most highly expressed in the fat body at 24 h post-eclosion.Moreover,the symbionts in BPH were significantly inhibited by the in vitro expression of the NlDfA and NlDfB proteins.Furthermore,RNA interference(RNAi)-mediated suppression of NlDfA and NlDfB dramatically increased the relative abundance of YLS in the fat body,while YLS in the hemolymph decreased significantly.These BPHs also displayed some fitness disadvantages in survival,fecundity,hatchability,and possibly the vertical transmission of YLS from hemolymph to egg.Our results indicated that mating could heighten the immunity of BPH by upregulating the expression of the NlDfA and NlDfB genes,which protect the host from pathogen challenges during reproduction.However,the reduced content of YLS may act as a fitness disadvantage in dictating the life-history traits of BPH.This work has significant theoretical and practical implications for the precise green control technology that involves crucial gene targeting,as well as for the“endosymbionts for pest control”strategy in insects.

Sexuality after Childbirth: Analysis of the Experiences of Central African Women in Bangui

Introduction: In many societies, sexuality is still a taboo subject. In the Central African Republic, this topic is rarely discussed outside the context of gynecological consultations and infertility, whereas the sexual life of couples is often disrupted by the arrival of a child, particularly by the ordeal of childbirth. The aim of the study is to analyze the sexual experience of Central African women after childbirth in order to contribute to improving the health of the population, in particular that of mother and child, and to facilitate harmony within the couple. Methodology: Descriptive and analytical cross-sectional study covering the period from July 1 to August 30, 2023, at the maternity ward of the Center University Hospitalier Communautaire. The study concerned only women who had given birth between the second week and the sixth month postpartum. The sampling was exhaustive. Results: A total of 303 women agreed to take part in our study, aged between 15 and 44, more than half of whom had completed secondary school. The eagerness of the women to take part in the study shows that they are ready to express themselves about their sexuality despite certain biases linked to the method of patient selection. Resumption of sexual relations was initiated by the partners within six weeks in the vast majority of cases. Conclusion: Resumption of sexual intercourse was delayed, often at the partner’s initiative. Further studies are needed to understand the cultural, religious and psychological dimensions of postpartum sexuality in the Central African context.

Transgenerational and Sexual Auto-Dissemination Within Anopheles Mosquitoes of the Malaria Parasite Transmission Blocking Microsporidia Sp MB in Burkina Faso

Introduction: Malaria control needs the development of complementary and/or alternative strategies such as biological controls. Despite, malaria’s current control efforts, the spread and the emergence of insecticide resistance in vectors undermine the fight against vectors. Endonsymbiotic fungi can be a good candidate to include in the existence of Arsenal. However, we know little about endosymbiotic fungi transmission and its impact on malaria transmission. In this paper, the authors aimed to investigate Microsporidia sp MB transgenerational and sexual autodissemination and malaria parasites within Anopheline mosquitoes. Methods: An entomology survey was conducted in Burkina Faso for one year (June 2020 to June 2021) using the Residual Fauna Capture method. Infection rates in collected females, sexual autodissemination of Microsporidia sp MB in both Microsporidia sp MB negative females and Microsporidia sp MB negative males through mating, transgenerational prevalence from parents to offsprings and the correlation between Microsporidia sp MB and Plasmodium falciparum were investigated. Results: Results show Microsporidia sp MB infection in An. gambaie s.l in Burkina Faso. The prevalence was significantly higher (21.78%) in An. coluzzii than An. gambiae s.s (16.89%) (p-value = 0.03). Sexual auto-dissemination of Microsporidia sp MB in Microsporidia sp MB uninfected females was significantly 3-fold lower than those in Microsporidia sp MB uninfected males (9.23% and 33.33%, p-value = 0.03) during mating for An. coluzzii lines. Microsporidia sp MB prevalence was significantly higher through mosquitos’ generations in An. gambaie s.s than An. coluzzii (30.23% vs 26.41%, p-value Microsporidia sp MB and Plasmodium infection rate with 73% of Microsporidia sp MB positive mosquitoes which were negative at Plasmodium infection (p-value Conclusions: Our findings pave the road to developing new malaria control technologies by making Microsporidia sp MB-positive males sexually competitive with wild males to spread the fungus to wild female mosquitoes.

Emergency Care for Children and Adolescents after Sexual Violence, in Brazil’s Capital, Brasilia

Objective: Sexual violence affects women of all ages but, more commonly, children and adolescents. This study aimed to identify the extent to which services are being provided at the hospitals responsible for the emergency care of children and adolescents who have suffered sexual violence and to determine whether there is any difference in the provision of such services as a function of the victim’s age. Method: This cross-sectional study investigated differences in the care received by female children and adolescents who are victims of sexual violence in a capital city, comparing the treatment given to girls under 15 with that given to adolescents of 15 to 19 years of age. The data were extracted from the State Department of Health database between 01/01/2012 and 31/12/2016. Results: Children under 15 were much less likely to receive prophylaxis against HIV, sexually transmitted infections and hepatitis B, with the number of adolescent girls treated adequately corresponding to between twice and almost three times the number of children treated prophylactically. Only 10% of girls under 15 received emergency contraception. Conclusion: The lack of standard care established by the Ministry of Health highlights the need for urgent debates both locally and probably throughout the country, as the situation may be similar in other regions of the country.

Changes in sexual activity in young women during pregnancy

Objective:To conduct changes in sexual activity during pregnancy and its related factors in pregnant women.Methods:The present descriptive cross-sectional study was conducted in 2017 on pregnant women who referred to the women's clinic of Afzalipour Hospital in the southeast of Iran.Participants were included in the study through convenient sampling.The data collection tool was a researcher-made questionnaire consisting of two parts of personal social information of the couple and questions to measure the level of sexual activity and the attitude of the subjects during pregnancy compared to before pregnancy.Results:201 Pregnant women were included.The average age of pregnant women was(27.3±6.1)years and their average gestational age was(24.7±11.8)years.More than 62%of women had decreased sexual activity.There was a significant relationship between the amount of changes in sexual activity and delivery time(P=0.013),abortion history(P=0.001)and premature birth history(P=0.002).Most pregnant women believed that sex during pregnancy caused damage to the fetus(67.7%).A decrease in the intensity of sexual desire was reported in 63%of pregnant women.More than 60%of the subjects did not consult with doctors and midwives with regards to sexual issues(63.5%).The most common reason for not consulting was not feeling the need(32%).Most women experienced back pain during(42.8%)and after(39.8%)intercourse.Conclusions:Changes in sex life during pregnancy are often caused by the lack of sexual knowledge and the increase in misconceptions among couples,which can affect the quality of relationships.The role of education is essential.Therefore,it is suggested that by including sexual counseling along with pregnancy care,wrong beliefs and information among women will be corrected.