Use Of Progestagens Research Articles

Progestagen supplementation of exogenous oestrogens and risk of endometrial cancer

The favourable effects of exogenous progestagen on the endometrium are well known, but have not been adequately quantified with respect to endometrial cancer. The benefits of progestagen need to be weighted against its possible untoward effects on the risk of breast cancer and cardiovascular disease. A population-based case-control study of endometrial cancer was undertaken to evaluate the benefits of progestagen use. 158 incident cases were identified between 1985 and 1987 among women aged 40-64 years who were residents of King County, Washington. Detailed interviews were conducted and the responses were compared with those of 182 controls selected by random telephone digit dialling. The risk of endometrial cancer among women who had used unopposed oestrogen for more than 3 years was over five times that of women who had used no hormones (relative risk [RR] 5·7, 95% confidence interval [Cl] 2·5-12·8), whereas those who had also used a progestagen for at least six months of that time had an RR of only 1·6 (95% Cl 0·6-3·9). The RR differed according to days per month that progestagen was used: 2·4 (0·6-9·3) for progestagen use of less than 10 days per month versus 1·1 (0·4-3·6) for use of 10 or more days per month. These results provide additional evidence that the use of progestagen for 10 or more days per cycle can reduce the excess risk of endometrial cancer associated with long-term postmenopausal oestrogen use.

Correlation between the birth prevalence of isolated hypospadias and parental subfertility

Factors associated with the occurrence of isolated hypospadias have been studied. We previously reported a secular trend association between hypospadias occurrence and progestagen use by the Hungarian population. Further study does not support that secular trend association. The use of progestagens for the treatment of reproductive problems is a very complex issue, and there are other factors relating to male and female fertility that differentiate the hypospadias families from the controls. It appears that families with problems of subfertility are at increased risk for the occurrence of hypospadias. Our data support more recent studies, which do not demonstrate an association between the occurrence of hypospadias and the administration of progestagens in humans.

PROGESTAGEN USE IN POSTMENOPAUSAL WOMEN

PROGESTAGEN USE IN POSTMENOPAUSAL WOMEN

Transfer of superovulated sheep embryos obtained with different FSH-P

Embryo transfer is one way of accelerating genetic improvement in sheep. One of the main obstacles has been the production of good-quality embryos. The use of progestagens and the stimulation of ovulation with follicle stimulating hormone pituitary extract (FSH-P) has permitted the superovulation of donor and recipient ewes and the synchronization of their cycles. The injection of 16 mg FSH-P at the end of progestin treatment gave means of 9 ± 1.5, 12 ± 1.5, and 19.5 ± 2.6 corpora lutea per ewes in the Préalpes, Lacaune, and Romanov × Préalpes breeds respectively (this last breed is particularly prolific). Twenty Préalpes donor ewes produced 133 embryos that were recovered surgically at Day 6 of gestation; of these, 99 morulae were transferable. Forty-five morulae transferred surgically into 24 Préalpes recipient ewes yielded 16 pregnant ewes and 27 lambs (1.7 per ewe). Twenty-two Lacaune ewes yielded 204 embryos, of which 152 morulae were transferable. Of 76 recipients, 58 became pregnant and gave birth to 97 lambs (1.7 per ewe). During anoestrus, the mean ovulation rate decreased from 11.2 to 8.4; 40.6% of the embryos recovered were of transferable quality versus 74.5% during the normal breeding season. An improved superovulation technique, based on the use of FSH-P with a known follicle stimulating hormone to luteinizing hormonal (FSH/LH) ratio, provided us with good-quality embryos. This treatment must be adapted to the season.

Use of progestagens for prevention of miscarriages and malformed embryos

Use of progestagens for prevention of miscarriages and malformed embryos

The veterinary uses of progestagens

Abstract Extract This paper is very relevant to the theme of “Manipulation of Populations”, as set by the 1975 N.Z.V.A. Conference, because it concerns the use of progestagens in preventing conception and controlling ovulation for farm and domestic animals. It discusses first the basic principles behind the use of progestagens and then, by species, examines the applications that have been developed and some of the difficulties that have arisen.

The use of progestagens in the control of the canine oestrous cycle.

ABSTRACTThis review deals with three topics. First, a description of the biological effects and possible site of action of progestagens in the bitch. Second, a discussion of published work on the clinical use of progestagens with particular reference to the time of administration and side effects attributable to dosing. The final section of the paper is concerned with the effect of the long‐term oral administration of medroxyprogesterone acetate and megestrol acetate on reproductive function in the Beagle bitch.Résumé. Cet article porte sur trois matières. Les auteurs commencent par dérire les effets biologiques et le site éventuel oú agiront les progestagénes chez la chienne. Ensuite, ils passent en revue les publications existantes sur l'emploi clinique des progestagènes, en faisant une allusion particulière au choix du moment de leur administration et aux effets secondaires causés par le dosage. Dans la dernière partie de l'article, ils se penchent sur l'effet d'une administration orale, pendant une période prolongée, d'acétate de médroxyprogestérone et d'acétate magestrol sur la fonction reproductrice de la chienne beagle.Zusammenfassung. Diese Arbeit behandelt drei Themen. Das erste ist eine Beschreibung der biologischen Wirkungen und der möglichen Wirkungsstellen von Progestagenen bei der Hündin. Das zweite ist eine Besprechung veröffentlichter Arheiten über die klinische Anwendung von Progestagenen unter besonderer Berücksichtigung der Anwendungszeit und der Nebenwirkungen, die sich der Dosierung zuschreiben lassen. Der letzte Teil der Arbeit befasst sich mit der Wirkung langzeitiger oraler Verabreichung von Medroxyprogesteronacetat und Magestrolacetat auf die Fortpflanzungsfunktion bei der Beaglehündin.