A sizable problem in our understanding of the control of parturition has been a desire by different investigators to explain the whole mechanism in terms of their current theory. We have been offered explanations in terms of factors such as withdrawal of the systemic progesterone block, the local progesterone block, the volume:progesterone ratio, the progesterone:estrogen ratio, the oxytocin effect, the progesterone:oxytocin effect, the fetal role, and the prostaglandin role. With the coming of age of Endocrinology and the ability to reduce hormone assays to a routine laboratory service, we have at last begun to understand that many, if not all, rather than any one of these individual explanations may be implicated in the control of parturition. We now recognize that in late pregnancy a train of events is initiated that ultimately results in the delivery of the fetus. However, we still do not know exactly how and where that train starts, or exactly how it exerts its ultimate action on the myometrial cell. It is a major objective of this chapter to try to bring together some of the abovementioned theories, and particularly to show that, for example, the role of the fetus in the initiation of parturition and the concept of progesterone withdrawal may be part of the same mechanism. It would be folly to say that at the present time either or both of these concepts explain parturition in all species, but by examining a number of different species we hope to illustrate as many of the discrepancies as similarities.

Endocrine control of parturition

Objective To review the most current literature in order to provide evidence-based recommendations to obstetrical care providers on induction of labour. Options Intervention in a pregnancy with induction of labour. Outcomes Appropriate timing and method of induction, appropriate mode of delivery, and optimal maternal and perinatal outcomes. Evidence Published literature was retrieved through searches of PubMed, CINAHL, and The Cochrane Library in 2010 using appropriate controlled vocabulary (e.g., labour, induced, labour induction, cervical ripening) and key words (e.g., induce, induction, augmentation). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to the end of 2010. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. Values The evidence in this document was rated using criteria described in the Report of the Canadian Task Force on Preventative Health Care (Table 1).

https://www.jogc.com/article/S1701-2163(15)30842-2/pdf

Induction of Labour

THERAPEUTIC ABORTION USING PROSTAGLANDIN F2α

New concepts in dysmenorrhea.

Influence of acetylsalicylic acid, an inhibitor of prostaglandin synthesis, on the duration of human gestation and labour

Induction of labour with prostaglandin e2

INDUCTION OF LABOUR WITH PROSTAGLANDIN F2α

THE EFFECTS OF PROSTAGLANDINS E2 AND F2α ADMINISTERED BY DIFFERENT ROUTES ON UTERINE ACTIVITY AND THE CARDIOVASCULAR SYSTEM IN PREGNANT AND NON-PREGNANT WOMEN

K. Hillier

Papers

Induction of labour with prostaglandin e2

INDUCTION OF LABOUR WITH PROSTAGLANDIN F2α

THE EFFECTS OF PROSTAGLANDINS E2 AND F2α ADMINISTERED BY DIFFERENT ROUTES ON UTERINE ACTIVITY AND THE CARDIOVASCULAR SYSTEM IN PREGNANT AND NON-PREGNANT WOMEN

EFFECTS OF PROSTAGLANDINS E1, E2, F1α, F2α ON ISOLATED HUMAN UMBILICAL AND PLACENTAL BLOOD VESSELS

The action of prostaglandins on the human isolated non-pregnant cervix