First intercourse, contraception and first pregnancy in Flanders: changes during the past 30 years.
Explore the source record for details and available documents.
Adolescent↗
SEARCH · Search PubMed
Results for “Reproductive Behavior”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Knowledge of likely time of ovulation and contraceptive use in unintended pregnancies.
This investigation analyzed social and demographic characteristics of women having an unwanted or mistimed pregnancy (unintended pregnancies at the current time) in South America. A sample of 5135 women having had a normal non-malformed live-born infant were interviewed immediately postpartum at 18 hospitals participating in the Latin American Collaborative Study of Congenital Malformations (Spanish acronym: ECLAMC). Half (2568/5135 = 50%) reported that their pregnancies had been unintended, and, of those, 59.3% (1522/2568 = 59.3%) declared that they were trying to avoid conception. The latter group (n = 1522) was the main sample for this study. Patients were asked about their knowledge of when during the menstrual cycle conception is most likely to occur, their biomedical and social characteristics, the type of contraceptive methods used, their opinion of reasons for contraceptive failure, and their reasons for not using contraceptive methods. Among women with unintended pregnancies who attempted to avoid conception, only 61.6% were using contraceptive methods. Reasons given for not using contraceptives included health problems, lack of knowledge and lack of access to contraception. Women with unintended pregnancies who had not attempted to avoid conception were younger, often primigravid, less educated, and less knowledgeable concerning when during the cycle pregnancy is most likely to occur. Thus, reproductive health policies should be aimed at this target group.
Age Factors↗
Identification and synthesis of a male-produced sex pheromone from the stink bug Chlorochroa sayi.
The reproductive behavior of the stink bug Chlorochroa sayi was studied in the laboratory. There was a sexual maturation period of about 10 days before bugs began mating. Sexually mature adult bugs engaged in courtship consisting of antennation and head-butting of the female by the male, before the female adopted a receptive posture and copulation occurred. Both sexes mated multiple times during their life-spans, with the mean duration of copulations of virgin bugs (42.3 +/- 19.6 min) and experienced bugs (37.3 +/- 28.4 min) being similar. Most matings were initiated in the late afternoon or evening, when pheromone production by males was greatest. Males transferred sperm and nutrients constituting about 17% of their body weight to females during mating. Three male-specific components, methyl geranate, methyl citronellate, and methyl (E)-6-2,3-dihydrofarnesoate in a ratio of 100:0.45:1.6, were first detected in volatiles collected from male bugs on green beans about 9-12 days after the final molt to the adult stage. In vertical Y-tube bioassays, females were attracted to odors from mature male bugs, and to a blend of the three male-produced components. Low numbers of females also were attracted in field trials with the three-component blend. The relatively weak attraction may be a result of other, as yet unknown cues being required in addition to the pheromone, such as visual or substrate-borne vibrational cues.
Animals↗
The effects of pregnancy experience on contraceptive practice.
Explore the source record for details and available documents.
Adolescent↗
Age and season affect chemical discrimination of Liolaemus bellii own space.
We explored chemical discrimination of own vs. novel space by different age classes (neonates, juveniles, and adults) of the lizard Liolaemus bellii, during pre- and post-hibernation seasons. We recorded the number of tongue flicks (TF) lizards produced during 10 min in their own or a novel enclosure. Age class and season affected chemical discrimination. Only adults and neonates discriminated their own space, albeit using different strategies: while adults made fewer TF in their own enclosure, neonates made more TF in their own enclosure. This difference was interpreted in terms of different requirements for discrimination of individuals during their lives. Increased chemical exploration by juveniles and adults at the onset of the post-hibernation season was associated with food-searching and reproductive behaviors.
Age Factors↗
A woman's choice? On women, assisted reproduction and social coercion.
This paper critically discusses an argument that is sometimes pressed into service in the ethical debate about the use of assisted reproduction. The argument runs roughly as follows: we should prevent women from using assisted reproduction techniques, because women who want to use the technology have been socially coerced into desiring children--and indeed have thereby been harmed by the patriarchal society in which they live. I call this the argument from coercion. Having clarified this argument, I conclude that although it addresses important issues, it is highly problematic for the following reasons. First, if women are being coerced to desire to use AR, we should eradicate the coercive elements in pro-natalist ideology, not access to AR. Second, the argument seems to have the absurd implication that we should prevent all women, whether fertile or not, to try to have children. Third, it seems probable that women's welfare will be greater if we let well informed and decision-competent women decide for themselves whether they want to use AR.
Coercion↗
Relations between cuticular hydrocarbon (HC) polymorphism, resistance against desiccation and breeding temperature; a model for HC evolution in D. melanogaster and D. simulans.
D. simulans and D. melanogaster present two types of polymorphism in their cuticular hydrocarbon (HC) composition. Especially both sexes of D. simulans, and D. melanogaster males display 7-tricosene (7T) as the major compound type [7T]s and [7T]m, or 7-pentacosene (7P) [7P]s and [7P]m. D. melanogaster females display 7,11-heptacosadiene (7,11HD) as the major compound: [7,11HD]m, or 5,9-heptacosadiene (5,9HD): [5,9HD]m. The [7P]s, [7P]m and [5,9HD]m are mainly present in central Africa. A significant correlation was found between latitude and the proportion of compounds with 23 and 25 carbon atoms, especially 7T and 7P in both sexes of D. melanogaster. [7P]m type of D. melanogaster, characterized with an excess of C25 compounds, presents a higher resistance against desiccation than [7T]m type, where C23 compounds are more abundant. These differences can be correlated with calculated HC fusion temperatures. Moreover, increasing the breeding temperature from 18 to 29 degrees C induces in D. melanogaster males an increase in 25C compounds and a decrease in 23C compounds, but the opposite effect in D. simulans. A mathematical model of biosynthesis, based on kinetics of elongation and decarboxylation enzymes, suggests that a simple variation of the efficiency of an elongation enzyme may account for the differences observed between the [7T]m and [7P]m types of D. melanogaster and [7T]s and [7P]s types D. simulans. Finally on the basis of the geographical distribution of the HC types of both Drosophila species, an evolutionary dispersal pathway is proposed and discussed in relation to the environment and reproductive behavior.
Africa↗
Stress and genetic testing for disease risk.
Healthy people who believe they are at risk for a life-threatening disease appear to carry a substantial stress burden because of threat of disease and uncertainty of risk. Testing for risk factors may be helpful by reducing this uncertainty, but diseases with multiple causes, like breast cancer, appear to be determined by genetic factors and by age, reproductive behavior, exposure to environmental toxins, or unknown antecedents. For diseases caused by inherited genetic defects, testing brings different benefits and stressors. A model is proposed that predicts long-term distress when risk analysis suggests a very high risk, when uncertainty is not reduced, when results of testing are at odds with preventive actions already taken, and when people who receive a positive, risk-increasing result lack strong social support, coping skills, other psychosocial resources, or all of these.
Adaptation, Psychological↗
Sexual dimorphism and species differences in HVC volumes of cowbirds.
Cowbirds exhibit extensive variation in their social, territorial, and reproductive behaviors. Nissl-stained brain sections of specimens from a previous study (J. C. Reboreda, N. S. Clayton, & A. Kacelnik, 1996) were used to study the gross anatomy of a song control nucleus in 3 South American cowbirds (bay-winged, Molothrus badius; shiny, M. bonariensis; and screaming, M. rufoaxillaris). Cowbird high vocal center (HVC) volumes were consistently higher in males than in females in all 3 species. The largest HVC size of females found in bay-winged cowbirds is consistent with observations that females of this species, but not of the other 2 species, occasionally sing. The extent of the sexual dimorphism of relative HVC size was highest for the sexually dichromatic and promiscuous shiny cowbirds and smaller for the monochromatic and monogamous bay-winged and screaming cowbirds, suggesting that selection pressures associated with morphological traits and social systems are reflected in brain architecture.
Animals↗
Differential effects of lesions in three limbic areas on ultrasound production and lordosis by female hamsters.
Ultrasound production and lordosis were examined in ovariectomized, hormone-primed female hamsters before and after sham operations or bilateral electrolytic lesions in the lateral septum/bed nucleus, corticomedial amygdala, or lateral habenula. During 2-min exposures to synthetic ultrasounds and 1-min exposures to stimulus males, females with corticomedial amygdala lesions exhibited reduced ultrasound rates and lordosis durations. Following lesions in the lateral septum/bed nucleus, females showed significant increases in ultrasound rates with no pre- to postoperative change in lordosis. Ablations of the lateral habenula had no effect on calling but were associated with shorter lordosis durations. These results demonstrate that two reproductive behaviors, ultrasound production and lordosis, are differentially affected, depending on lesion placement within the limbic system. In turn, these differences demonstrate that the neural mechanisms for two elements of a single major class of behavior can be quite distinct, both in terms of the likelihood that particular brain areas will be involved and in the nature of their involvement.
Amygdala↗
Recovery of structure and function following transection of the primary olfactory nerves in pigeons.
Preliminary experimentation on ring doves to ascertain whether they might regulate any aspects of their reproductive behavior in terms of olfactory cues was vitiated by the discovery that their sectioned olfactory nerves had apparently regenerated. Concurrent work on frogs has shown that the olfactory receptors degenerate after axotomy and are replaced by new ones. This phenomenon was studied in pigeons. All transected nerves were found to be healed. Electrical recording from the regenerated nerves revealed apparently normal receptor function and, indirectly, autonomic reflex responsiveness. Previously untrained pigeons learned an olfactory discrimination after reconstitution of the peripheral olfactory system using a conditioned suppression procedure. The olfactory nerves of trained pigeons were sectioned and the behavioral response recovered within 16-82 days. The gross sizes of primary olfactory nerves and olfactory bulbs were frequently much less than those of controls, but on the ultrastructural level there was no recognizable morphological deficiency in the receptor cellular organelles or terminal synaptic contacts in bulbar glomeruli. Recent results by other workers indicate that pigeons utilize olfactory cues in homing performance.
Action Potentials↗
Gender-specific induction of enhanced sensitivity to odors.
Induction of olfactory sensitivity in humans was first illustrated when men and women who were initially unable to smell the volatile steroid androstenone (5alpha-androst-16-en-3-one) developed that ability after repeated, brief exposures. Because this finding has not been replicated with other compounds in humans, it has been assumed that olfactory induction is a narrowly constrained phenomenon, occurring only in individuals with specific anosmias, perhaps only to androstenone (compare ref. 2). Here we show that induction of enhanced olfactory sensitivity seems to be a more general phenomenon, with marked changes in olfactory acuity occurring during repeated test exposures to several odorants among people with average baseline sensitivity to these compounds. This increased sensitivity (averaging five orders of magnitude) was observed only among females of reproductive age. These observations provide convincing evidence that female olfactory acuity to a variety of odorants can vastly improve with repeated test exposures. They also suggest a sensory basis for the anecdotal observation of greater olfactory sensitivities among females and raise the possibility that the olfactory-induction process may be associated with female reproductive behaviors such as pair bonding and kin recognition.
Benzaldehydes↗
Use of antibiotics during pregnancy.
Explore the source record for details and available documents.
Anti-Bacterial Agents↗
Ulcerative colitis: female fecundity before diagnosis, during disease, and after surgery compared with a population sample.
BACKGROUND & AIMS: Women with ulcerative colitis generally have normal fertility. The aim of this study was to compare patients' fecundability before and after restorative proctocolectomy with ileal pouch-anal anastomosis with the fecundability of the general population. METHODS: Historical follow-up was performed on 343 consecutive female patients aged 10.6-40.5 years at surgery and a reference population of 1200 women aged 25-40 years. A total of 290 (85%) patients and 661 (55%) women in the reference population agreed to participate in a structured telephone interview concerning reproductive behavior and waiting times to pregnancy. Cox regression and Kaplan-Meier plots were used for analysis. RESULTS: Surgery significantly reduced the ratio of patient to reference population fecundability, which decreased to 0.20 (P < 0.0001). Before diagnosis and from diagnosis until colectomy, the fecundability of the patients was similar to that of the reference population. CONCLUSIONS: Female patients with ulcerative colitis have normal fecundity before surgical treatment. Surgery severely reduces female fecundity. Information about this reduction in fecundity should be given before surgery, and if a woman has an unfulfilled wish for pregnancy after surgery, early referral to a gynecologist is recommended.
Adult↗
Obstetrical emergencies.
This article discusses different techniques that can be used in the diagnosis and treatment of obstetrical emergencies. Female reproductive emergencies commonly encountered by small animal practitioners include pyometra, dystocia, cesarean section, mastitis, eclampsia, uterine torsion, and uterine prolapse. A thorough knowledge of normal and abnormal reproductive behavior will aid the emergency veterinarian in successfully managing such cases. Timely diagnosis and treatment of these emergencies will often give a good outcome.
Animals↗
Advanced maternal age--how old is too old?
Explore the source record for details and available documents.
Abortion, Spontaneous↗
Evolutionary deterioration of the vomeronasal pheromone transduction pathway in catarrhine primates.
Pheromones are water-soluble chemicals released and sensed by individuals of the same species to elicit social and reproductive behaviors or physiological changes; they are perceived primarily by the vomeronasal organ (VNO) in terrestrial vertebrates. Humans and some related primates possess only vestigial VNOs and have no or significantly reduced ability to detect pheromones, a phenomenon not well understood at the molecular level. Here we show that genes encoding the TRP2 ion channel and V1R pheromone receptors, two components of the vomeronasal pheromone signal transduction pathway, have been impaired and removed from functional constraints since shortly before the separation of hominoids and Old World monkeys approximately 23 million years ago, and that the random inactivation of pheromone receptor genes is an ongoing process even in present-day humans. The phylogenetic distribution of vomeronasal pheromone insensitivity is concordant with those of conspicuous female sexual swelling and male trichromatic color vision, suggesting that a vision-based signaling-sensory mechanism may have in part replaced the VNO-mediated chemical-based system in the social/reproductive activities of hominoids and Old World monkeys (catarrhines).
Animals↗
Sex-peptide is the molecular basis of the sperm effect in Drosophila melanogaster.
Mating elicits two major changes in the reproductive behavior of many insect females. The egg-laying rate increases and the readiness to accept males (receptivity) is reduced. These postmating responses last approximately 1 week in Drosophila melanogaster. Males that do not transfer sperm but transfer seminal fluid during mating induce a short-term response of 1 day. The long-term response of 1 week requires the presence of sperm (sperm effect). Hence, sperm is essential for the long-term persistence of the postmating responses. Three seminal fluid peptides elicit postmating responses: ovulin, sex-peptide (SP), and DUP99B. Using the technique of targeted mutagenesis by homologous recombination, we have produced males with mutant SP genes. Here, we report that males lacking functional SP elicit only a weak short-term response. However, these males do transfer sperm. Thus, (i) SP is the major agent eliciting the short-term and the long-term postmating responses and (ii) sperm is merely the carrier for SP. The second conclusion is supported by the finding that SP binds to sperm. The 36-aa-encoding SP gene is the first small Drosophila gene knocked out with the method of homologous recombination.
Alleles↗