Publisher Summary This chapter discusses the endocrinology of parturition. The mechanism
underlying the initiation of primate parturition is almost as mysterious as before the rapid …

It is well recognized that in many species the maternal ovaries are not essen¬ tial for the
maintenance of pregnancy throughout the gestation period, and this has led to the idea that …

The role of the uterus and that of the embryo in regulating luteal progesterone secretion
appear to differ greatly, depending on the mammal. However, the situation is analogous in …

At present the sequence of events at parturition in nonhuman primates is less clear than in
some other mammals. In at least the macaque, the best studied of the nonhuman primates, it …

The process of parturition is remarkable. The changes that occur before and during
parturition allow the uterus to contract in a precise manner and the cervix to dilate efficiently …

Estrogen and progesterone play pivotal roles in the regulation of pregnancy and parturition.
These steroids cause dramatic changes the maternal physiology which advantage the …

Publisher Summary A striking aspect of human pregnancy is the variability of blood estrogen
and progesterone levels that are consistent with a normal outcome. If, indeed, characteristic …

Progesterone levels in peripheral plasma were similar in ewes with single and twin fetuses
during the first SO days of gestation (2–3 ng/ml). A gradual upward trend in progesterone …

When fetuses and placentas were removed on Day 18 in normal pregnant rabbits, plasma
progesterone levels declined rapidly to non-pregnant values within 48 h. This decline was …

Among long‐living primates the attainment of fertile menstrual cycles requires concerted and
sequential interactions between the hypothalamus, pituitary, ovaries, and uterus over many …