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PubMed1982

Coitus and chorioamnionitis: a prospective study.

Amniotic fluid infections have been strongly associated with coitus during pregnancy. If the relationship is causal it may be possible to identify a time sequence between coitus, penetration of bacteria through the mucous plug in the cervix, the development of infection in the extraplacental membranes near the cervical os, spread of the infection to the amniotic fluid and complications of the infection. The present study looked for such a sequence in an analysis of 541 pregnancies. A peak frequency of chorioamnionitis limited to the extraplacental membranes was present when labor and delivery took place within two days of the last coitus. In the next two days the infection spread to the amniotic fluid as evidenced by a peak frequency of maternal neutrophils migrating through the placental plate toward the amniotic cavity. Premature delivery was 4 times more frequent when there had been recent coitus and an amniotic fluid infection was present than when either factor was absent (P less than 0.01). Spontaneous rupture of the fetal membranes before the onset of and the membranes were inflamed than when these factors were absent (P less than 0.01). This raises the possibility that orgasm further weakened or ruptured membranes that had already been weakened by infection.

Amnion↗

PubMed1986

Adolescent coitus and infant birthweight.

Seventy-nine percent of a group of adolescent mothers reported coitus during pregnancy. There was a significant difference between the mean birthweight and gestational age of infants born to mothers who reported coitus within 90 days of delivery compared to the mean birthweight and gestational age of infants of mothers who reported no gestational age of infants of mothers who reported no coitus within 90 days of delivery. Thirty-nine percent of the variance in birthweight was explained by maternal factors alone, but only 1.0% of the variance in birthweight was accounted for by the interval between last coitus and delivery. Prepregnancy weight (r = 0.380) and weight gain during pregnancy (r = 0.327) contributed 19.1% and 7.4% of the variance in birthweight, respectively.

Adolescent↗

PubMed1986

Ejaculate composition after masturbation and coitus in the human male.

The levels of fructose, acid phosphatase, citric acid, zinc, maltase, testosterone, prostaglandin E, putrescine, spermidine and spermine were compared in ejaculates collected by masturbation and after coitus in the same individuals. Coitus was associated with a significantly larger semen volume and increased concentrations and total amounts of prostaglandin E and polyamines in the ejaculate. In contrast, the concentrations of the conventional glandular parameters remained relatively unaffected, although a slight dilution of the seminal vesicle contribution to the ejaculate occurred after coitus. In the majority of cases, ejaculates provided by masturbation were significantly enriched in spermatozoa, but the total contributions under both conditions remained the same. It is concluded that the assessment of semen quality in male individuals using the conventional parameters of accessory gland function can be made with ejaculates provided by masturbation or coitus.

Acid Phosphatase↗

PubMed2002

Self-esteem as a predictor of initiation of coitus in early adolescents.

OBJECTIVE: To examine the role of self-esteem in predicting coitus initiation in a population of early adolescents. METHODS: Questionnaires assessing coital status, self-esteem, and pubertal maturation were collected from 188 participants who had not engaged in coitus by enrollment. Data were collected longitudinally while the participants were in the seventh and ninth grade. Ages ranged from 12 to 14 (mean: 12.50; standard deviation: 0.57) at Time 1 and from 14 to 16 (mean: 14.30; standard deviation: 0.49) at Time 2. RESULTS: Boys with higher self-esteem ratings at Time 1 were more likely to initiate intercourse by Time 2. Girls with higher self-esteem at Time 1 were more likely to remain virgins than girls with lower self-esteem. Pubertal status was unrelated to initiation of coitus in this sample. CONCLUSIONS: Self-esteem, regardless of pubertal status, predicted coitus transition differentially in boys and girls. Results from this longitudinal study seem to fit within traditional problem behavior theory.

Adolescent↗

PubMed1996

Coitus and menstruation in perimenopausal women.

The objective of the study was to determine whether coitus during menstruation in perimenopausal women is associated with increased menstrual flow defined as either heavier flow, more days of flow, or both. Initial interviews for the Stanford Menopause Study were conducted locally with 160 perimenopausal women. Six weeks later, additional data were gathered from 121 women. At a third interview, 6-10 weeks later at Stanford University, 56 of 57 subjects (mean age 48.8 +/- 3.9 SD) provided data on menstrual flow and coital behavior. At both the first and third interview, more than half of the women reported a pattern of increased menstrual flow. At the third interview, 83% of those reporting increased menstrual flow also reported a behavioral pattern of coitus during menses. Only 10% with diminished flow acknowledged such a pattern. Women who abstained from sex during menses were not less regular in coital activity at other times nor did the data reveal them to be less orgasmic than women who did not abstain. Our data reveal an association between coitus during menstruation and longer and/or heavier menstrual flow. The etiology of such increased flow is usually believed to be hormonal, but coitus during menstruation may be another important variable.

Coitus↗

PubMed1990

Cervical intraepithelial neoplasia. The role of age at first coitus in its etiology.

A case-control study was done on 115 women attending a colposcopy clinic. All the patients had definitive histologic confirmation of cervical intraepithelial neoplasia (CIN). A specially designed questionnaire sought information about their age, age at first coitus, gravidity, ethnic origin, religion and social class. Cases and controls were closely matched for age and the last three parameters mentioned above. There was no statistical difference between nulliparas and multiparas in the incidence of CIN. The time interval between age at first coitus and the diagnosis of CIN varied widely, with 47 years the maximum. Statistically significant differences existed between the age at first coitus for cases and controls under and over age 18. The estimated relative risk was 3.64-fold higher in those under 18 than in those 18 or over at first coitus.

Adolescent↗

PubMed2004

Expression of alpha 4 and alpha 7 nicotinic receptors in the brainstem of female rabbits after coitus.

Coital signaling in the female rabbit involves sequential events in the brainstem and hypothalamus, resulting in a massive release of hypothalamic gonadotropin-releasing hormone (GnRH) that peaks within 1-2 h after mating. The neural connections between coitus and GnRH release involves norepinephrine (NE) and acetylcholine (ACh) since administration of antagonists against NE (dibenamine or phentolamine) or ACh (atropine, alpha-bungarotoxin (alpha-BTX) or scopolamine) blocks or attenuates ovulating events. Moreover, hypothalamic NE release and brainstem tyrosine hydroxylase (TH, the rate-limiting enzyme for NE synthesis) expression in the noradrenergic areas increase prior to, or in concert with, the preovulatory GnRH surge. How ACh is involved in the control of ovulation in the rabbit is lesser known. In the present study, the number of brainstem neurons expressing TH, alpha4 and alpha7 subunits of the nicotinic ACh receptor (nAChR) before and after coitus was determined by immunocytochemistry. Compared to non-mated female rabbits, the number of alpha4, alpha7 and TH single-labeled neurons as well as alpha4/TH and alpha7/TH double-labeled neurons increased in the A1, A2 and A6 brainstem noradrenergic areas at 1 h, but not 2 h, after coitus. The results suggest that the participation of ACh in the control of coitus-induced ovulation may include activation of alpha4beta2 and alpha7 nAChRs in neurons within or adjacent to the brainstem noradrenergic areas in female rabbits.

Animals↗

PubMed2000

Molecular activation of noradrenergic neurons in the rabbit brainstem after coitus.

Our previous studies indicate that coitus in female rabbits induces a gonadotropin-releasing hormone (GnRH) surge that is preceded by an increase in hypothalamic norepinephrine (NE) release. The additional findings of an enhanced tyrosine hydroxylase (TH) mRNA expression in the female brainstem after coitus, in addition to the appropriate topographic distribution of TH and dopamine-beta-hydroxylase (DBH), lead us to hypothesize that coital signals are relayed to hypothalamic GnRH-secreting neurons via brainstem NE-containing perikarya. Here we analyzed coitally activated areas in the brainstem by in situ hybridization of the oncogene c-fos, as well as the expression of TH mRNA at 0, 30 and 60 min postcoitus using specific 35S-labeled probes for c-fos and TH. To establish the identity of activated brainstem neurons, we immunocytochemically double-labeled cells with specific antibodies against Fos protein and DBH at 90 min postcoitus. Both c-fos and TH mRNAs were present at 0 min (control) in the A1, A2 and A6 brainstem-noradrenergic areas. At 30 min after coitus the expression of both genes significantly increased (P<0.01) in the A1 and A2 areas. By 60 min postcoitus the expression of c-fos mRNA decreased to control levels, while that of TH mRNA remained stimulated. Double-labeling of Fos and DBH indicated that the number of dual-labeled neurons increased (P<0.05) over control levels only in the A1 and A2 areas (not in A6) at 90 min postcoitus. These findings support the hypothesis that coitus activates transcriptional/translational events within brainstem NE neurons that culminate in the release of hypothalamic NE and hence a GnRH surge.

Animals↗

PubMed1986

Olfactory environment and coitus-induced ovulation and/or luteinization in the cyclic female rat.

The role of pheromones in the process of ovulation and/or luteinization induced by coitus was studied in female rats primed with estradiol benzoate (EB) and early mated during 4-day cycles. The effects of coitus were evaluated by using 1) the proportion of females displaying postovulatory corpora lutea (POCL) and/or luteinized unruptured follicles (LUF), and 2) the ovulation coefficient (OC) computed in each female by dividing the number of POCL by the total number of POCL and LUF. A greater proportion of females displayed ovulation and/or luteinization following coitus than those given EB only. This proportion was slightly but significantly increased when females were exposed to bedding soiled with 5 ml of male urine prior to mating, an effect prevented by complete olfactory bulbectomy. However, in the females given EB only, the pheromonal stimulus remained inefficient. Weak ovulatory effects of coitus, as assessed by low OC values, were noted whether the females were exposed or not to male urine. An increase in the frequency of lordosis occurred after olfactory bulbectomy, but no significant changes in OC values were observed in this experimental group. It was concluded that pheromones, act as a primer on the neuroendocrine mechanisms governing ovulation in the cyclic female rat, as in other species of rodents.

Animals↗

PubMed2006

Effects of coitus and the artificial insemination of different volumes of fresh semen on uterine contractions in mares.

Uterine contractions may play an important role in the transportation of spermatozoa towards the site of fertilisation in the oviduct of mares. M-mode ultrasound was used to measure the number, amplitude and duration of uterine contractions in each uterine horn and the uterine body of oestrous mares for four minutes before and four minutes after either coitus, or the artificial insemination of either 80.0 ml of fresh semen or 10.0 ml of fresh semen. The direction of the uterine contractions in each uterine horn and the uterine body was measured before and after coitus. Coitus and the insemination of 80.0 ml semen significantly increased the total number, mean amplitude and mean duration of contractions in all parts of the uterus. The insemination of 10.0 ml of semen did not affect the total number or the mean duration of contractions in the uterine horns. Their mean amplitude was increased, but largely owing to the results from one mare; it also did not affect the contractions in the uterine body. There was no significant difference between the percentage of contractions moving in a cervicotubal or tubocervical direction after coitus in any part of the uterus examined.

Animals↗

PubMed1977

Dysplasias of uterine cervix: epidemiological aspects: role of age at first coitus and use of oral contraceptives.

Age at first coitus and use of oral contraceptives were studied in a highly homogeneous population (French Canadian) during a cytologic cervical cancer screening program. Both factors were known in 84,540 women without cervical lesions and in 2017 patients with mild and moderate dysplasia. Highly significant correlations were found between: early onset of sexual activity and occurrence of dysplasia; oral contraceptive use and occurrence of dysplasia; early age at first coitus and oral contraceptive use. When correlated for age at first coitus, there was a significant excess of dysplasias in oral contraceptive users. Dysplasia of the uterine cervix behaves epidemiologically like carcinoma in situ and invasive squamous carcinoma, that is, essentially as a venereal disease. It remains to be seen whether all dysplasias form one continuum or whether there are two morphologically similar but biologically distinct forms of dysplasia: one more frequent, regressing spontaneously, the other relatively rare, progressing to carcinoma in situ and invasive squamous carcinoma of the cervix.

Adolescent↗

PubMed1976

Prematurity and orgasmic coitus during pregnancy: data on a small sample.

Nineteen mothers of premature infants were interviewed in an attempt to determine a possible relationship between prematurity and orgasmic coitus during pregnancy. Although the limited number of subjects precludes tests of statistical significance and definite conclusions, the findings do suggest possible associations. While there appeared to be no relationship between prematurity and coitus per se during pregnancy, the association of frequent or intense orgasm with prematurity does raise some questions that further investigation might answer. Because of the hazard of prematurity to the subsequent development of the child, further exploration of the possible relationship of prematurity to orgasmic coitus during pregnancy appears warranted.

Coitus↗

PubMed1977

A study of the relationship between coitus and the luteinizing hormone surge.

Twenty-seven wives participating in a study of sexual activity patterns had identifiable shifts in basal body temperature and midcycle surges of serum luteinizing hormone (LH). When sexual activity data were examined using the LH surge as a centering point, it was observed that the day before the LH surge had only an average probability of coitus and organism. These findings suggest that neither coitus nor orgasm often triggers ovulation in humans. This cannot be taken as evidence that coitus-induced ovulation never occurs.

Adult↗

PubMed2001

Vaginal laceration and perforation resulting from first coitus.

Vaginal laceration resulting from coitus is not uncommon and is well described. Perforation of the vagina during coitus is a very rare occurrence, and there is scant literature reporting it. This is a case of a 14-year-old female who suffered both laceration and perforation of the vagina as a result of her first coitus, which was consensual. The characteristics of vaginal laceration and perforation, presentation, treatment, complications, as well as predisposing factors, are discussed.

Abdominal Pain↗

PubMed2006

Effect of coitus at term on length of gestation, induction of labor, and mode of delivery.

OBJECTIVE: To determine coital incidence at term and to estimate its effect on labor onset and mode of delivery. METHODS: Healthy women with uncomplicated pregnancies and established gestational age were recruited to keep a diary of coital activity from 36 weeks of gestation until birth and to answer a short questionnaire. Two hundred women with complete coital diaries were available for analysis. Outcome measures include coitus, postdate pregnancy (defined as pregnancy beyond the estimated date of confinement), gestational length of at least 41 weeks, labor induction at 41 weeks of gestation, and mode of delivery RESULTS: Reported sexual intercourse at term was influenced by a woman's perception of coital safety, her ethnicity, and her partner's age. After multivariable logistic regression analysis controlling for the women's ethnicity, education, occupation, perception of coital safety, and partner's age, coitus at term remained independently associated with reductions in postdate pregnancy (adjusted odds ratio [AOR] 0.28, 95% confidence interval [CI] 0.13-0.58, P = .001), gestational length of at least 41 weeks (AOR 0.10, 95% CI 0.04-0.28, P < .001), and requirement for labor induction at 41 weeks of gestation (AOR 0.08, 95% CI 0.03-0.26, P < .001). At 39 weeks of gestation, 5 (95% CI 3.3-10.3) couples needed to have intercourse to avoid one woman having to undergo labor induction at 41 weeks of gestation. Coitus at term had no significant effect on operative delivery (adjusted P = .15). CONCLUSION: Reported sexual intercourse at term was associated with earlier onset of labor and reduced requirement for labor induction at 41 weeks. LEVEL OF EVIDENCE: II-2.

Adult↗

PubMed1997

The frequency of coitus during breastfeeding.

BACKGROUND: New mothers and clinicians would benefit from an understanding of typical sexual behavior during breastfeeding. Unfortunately, little information is available about both the typical length of time to resumption of coitus and the frequency of sexual relations during breastfeeding. This paper describes the commencement and frequency of coitus among breastfeeding women in a variety of settings. METHODS: The analysis draws on data from two separate research studies. The first was undertaken in three sites (Birmingham, United Kingdom; Montreal, Canada; Sydney, Australia), the purpose of which was to correlate natural observations of fertility with the underlying hormonal profile among breastfeeding women using the symptom-thermal method of natural family planning. The second was a clinical trial of the lactational amenorrhea method of family planning conducted in Manila, the Philippines. RESULTS: Coital frequency reported by these populations of breastfeeding women appears to be lower than that reported in other studies for married women in general. As other research demonstrated, we found coital frequency and postpartum resumption of coitus to be associated with age, but not with the number of children in the household. CONCLUSIONS: A better understanding of the level of sexual activity among breastfeeding women could inform and improve programs that offer postpartum support and counseling about family planning.

Adult↗

PubMed1996

Female adolescent contraceptive use or nonuse at first and most recent coitus.

The purpose of this study was to determine factors that differentiate contraceptive use behaviors of sexually active adolescent women. A sample of 159 subjects, recruited from three publicly supported family planning clinics, were classified according to nonuse, inconsistent, or consistent use of contraceptives at first and most recent coitus. The Health Promotion Model provided the organizing framework for this study. Factors entered into the discriminate functions included self-image, problem solving, health-promoting behavior, race, age at first coitus, previous pregnancy, contraceptive history, chronological age, family structure and size, mother's education, and Medicaid status. Three-group multivariate discriminate analysis resulted in two significant functions that explained 38.7% of the variance in contraceptive behavior. The three groups of adolescents were discriminated by age at first coitus, history of previous pregnancy, health-promoting behavior, self-image, problem-solving skill, chronological age, family size, and race. In particular, the findings suggest public health nurses and other health care providers can reduce unintended pregnancy through interventions that address the alterable factors.

Adolescent↗

PubMedDate not supplied

Magnetic resonance imaging of male and female genitals during coitus and female sexual arousal.

OBJECTIVE: To find out whether taking images of the male and female genitals during coitus is feasible and to find out whether former and current ideas about the anatomy during sexual intercourse and during female sexual arousal are based on assumptions or on facts. DESIGN: Observational study. SETTING: University hospital in the Netherlands. METHODS: Magnetic resonance imaging was used to study the female sexual response and the male and female genitals during coitus. Thirteen experiments were performed with eight couples and three single women. RESULTS: The images obtained showed that during intercourse in the "missionary position" the penis has the shape of a boomerang and 1/3 of its length consists of the root of the penis. During female sexual arousal without intercourse the uterus was raised and the anterior vaginal wall lengthened. The size of the uterus did not increase during sexual arousal. CONCLUSION: Taking magnetic resonance images of the male and female genitals during coitus is feasible and contributes to understanding of anatomy.

Adult↗