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

Influence of ovarian manipulation on reproductive endocrinology in polycystic ovarian syndrome and regularly cycling women

OBJECTIVE

Little is known about the function of the ovarian neuronal network in humans. In many species, copulation influences endocrinology through this network. As a first step, the possible influence of ovarian mechanical manipulation on pituitary and ovarian hormones was evaluated in polycystic ovarian syndrome (PCOS) and regularly cycling women.

DESIGN

Prospective case-control study (2008-2010).

METHODS

Ten PCOS women (Rotterdam criteria) undergoing ovulation induction with recombinant-FSH and ten normal ovulatory controls were included in an academic fertility clinic. In the late follicular phase blood was drawn every 10 min for 6 h. After 3 h the ovaries were mechanically manipulated by moving a transvaginal ultrasound probe firmly over each ovary ten times. Main outcome measures were LH and FSH pulsatility and ovarian hormones before and after ovarian manipulation.

RESULTS

All PCOS patients showed an LH decline after the ovarian manipulation (before 13.0 U/l and after 10.4 U/l, P<0.01), probably based on a combination of a longer LH pulse interval and smaller amplitude (P=0.07). The controls showed no LH change (before 9.6 U/l and after 9.3 U/l, P=0.67). None of the ovarian hormones (estradiol, progesterone, anti-Müllerian hormone, inhibin B, androstenedione and testosterone) changed in either group.

CONCLUSIONS

Ovarian mechanical manipulation lowers LH secretion immediately and typically only in preovulatory PCOS patients. The immediate LH change after the ovarian manipulation without any accompanying ovarian hormonal changes point to nonhormonal communication from the ovaries to the pituitary. A neuronal pathway from the ovaries communicating to the hypothalamic-pituitary system is the most reasonable explanation.

Acute stress may induce ovulation in women

BACKGROUND

This study aims to gather information either supporting or rejecting the hypothesis that acute stress may induce ovulation in women. The formulation of this hypothesis is based on 2 facts: 1) estrogen-primed postmenopausal or ovariectomized women display an adrenal-progesterone-induced ovulatory-like luteinizing hormone (LH) surge in response to exogenous adrenocorticotropic hormone (ACTH) administration; and 2) women display multiple follicular waves during an interovulatory interval, and likely during pregnancy and lactation. Thus, acute stress may induce ovulation in women displaying appropriate serum levels of estradiol and one or more follicles large enough to respond to a non-midcycle LH surge.

METHODS

A literature search using the PubMed database was performed to identify articles up to January 2010 focusing mainly on women as well as on rats and rhesus monkeys as animal models of interaction between the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes.

RESULTS

Whereas the HPA axis exhibits positive responses in practically all phases of the ovarian cycle, acute-stress-induced release of LH is found under relatively high plasma levels of estradiol. However, there are studies suggesting that several types of acute stress may exert different effects on pituitary LH release and the steroid environment may modulate in a different way (inhibiting or stimulating) the pattern of response of the HPG axis elicited by acute stressors.

CONCLUSION

Women may be induced to ovulate at any point of the menstrual cycle or even during periods of amenorrhea associated with pregnancy and lactation if exposed to an appropriate acute stressor under a right estradiol environment.

Coitus-induced ovulation and its implications for estimates of some reproductive parameters

It is estimated here that, at the time of conception, the mean coital rate of young women who subsequently bear DZ twins is about 6% higher than that of the general population of young married women. This differential seems too small to account wholly for the greater promptness in conceiving DZ twins. Accordingly, it is suggested that coital rate is associated with DZ twinning in two ways. The major link seems to be indirect and mediated by erotic response which causes an increase in gonadotrophin levels and thus in double ovulation. In a minority of cases, frequent coitus may give rise to DZ twins via superfecundation, but it seems that, in human beings, the corpus luteum of one ovum will usually inhibit fertilization of any further ova after a short interval. The evidence presented here, though indirect, seems to suggest that, under particularly erotic conditions, double ovulation is sometimes induced. It seems reasonable to infer that coitus also occasionally provokes or accelerates single ovulations, thus impugning some rhythm methods of contraception. But there seems no very good evidence that rape induces ovulation. Some notes are added on the implications of induced ovulation for estimates of fecundability and of the length of the fertile period.

Peak coital rate coincides with onset of luteinizing hormone surge

Twenty-five married women who were not using contraceptives provided daily urine specimens and coital reports for at least 90 days. The authors used urinary luteinizing hormone (LH) as a hormonal marker to determine ovulatory phase, onset of LH surge day, and LH peak day. Coital rate was elevated during the ovulatory phase of the menstrual cycle. Peak coital rate (0.72) occurred on onset of LH surge day, and was significantly greater (P less than 0.05) than the mean rate (0.44 +/- 0.06) across the entire menstrual cycle. The authors discuss possible social and hormonal mechanisms that might underlie an ovulatory peak in coitus, as well as the relevance of their findings to current models of fecundability.

The diagnostic and therapeutic potential of the postcoital test

An analysis was made of postcoital tests carried out on 423 couples attending the Rotunda and St. James Hospitals in Dublin. Initially 66.6% of tests were abnormal, but 21.3% of these were invalid because of the presence of seminal or cervical abnormalities, leaving 57.7% of couples with initially valid negative tests. Retesting showed 30.3% of couples to have persistently negative tests, 24.5% of whom achieved pregnancy. Three per cent of abnormalities were immunologic in origin. The most common cause why a subsequently positive test was initially negative was failure to observe correct clinical procedures, but unadmitted psychosexual problems were present in 17.6% of cases. Of the best postcoital tests, 78.5% correlated well with semen analyses and 90.9% with basal body temperature charts. In total, 6.2% of all pregnancies achieved in the clinics followed postcoital testing.

Infertility and age at first coitus: a possible relationship

Reported age at first coitus was shown to be associated with incidence and degree of infertility. Infertility patients reported later first coital ages than gynaecological patients in a sample of 792 women seen in a major infertility service. Among the infertility patients, those who had never conceived presented a later first coital age than those who had previously conceived. Routine gynaecological patients reported the youngest first coital age of the groups studied.