PHYSIOLOGY - Pregnancy Maintenance and Diagnosis Flashcards
What is the endocrine function of the placenta?
The placenta produces hormones to support the growth of the conceptus and maternal adaptations
What are the three hormones produced by the placenta?
Progesterone
Placental lactogens
Oestrogens
Other than the placenta, which other structure can produce progesterone during pregnancy?
Corpus luteum
In which species’ does the placenta not take over the corpus luteum for progesterone production?
Sow
Bitch
In which species does both the corpus luteum and the placenta produce progesterone?
Cow
Why is it clinically important to know the source of progesterone during gestation?
It is important to know the source of progesterone during gestation for pharmacological termination of pregnancy if necessary
Within the ruminant placenta, which cells produce progesterone?
Uninuclear and binuclear trophectoderm cells
Other than progesterone, which other hormone is produced by binuclear trophectoderm cells in the ruminant placenta?
Placental lactogens
What are the three main functions of placental lactogens?
‘Uterine milk’ production to support conceptus growth
Regulate maternal glucose metabolism
Mammogenesis
Describe the formation of endometrial cups in the mare?
After maternal recognition of pregnancy in the mare, foetal cells invade the maternal endometrium to form a chorionic girdle. Endometrial cups develop along this chorionic girdle
Which hormone is produced by endometrial cups in the mare?
Equine chorionic gonadotrophin (eCG)
Between which days of gestation are endometrial cups present in the mare?
Endometrial cups are present between 35 to 120 days of gestation
What is the function of Equine chorionic gonadotrophin (eCG)?
Equine chorionic gonadotrophin (eCG) promotes the production of accessory corpus lutea allowing for elevated progesterone production to maintain the pregnancy between 35 to 120 days of gestation
What is the immunological function of the placenta?
The placenta protects the antigenically different placenta from the maternal immune system
Give an example of maternal rejection of foetal cells in the mare that is actually essential for foetal survival?
There is localised rejection of foetal cells at the level of the chorionic girdle leading to endometrial cup rejection, loss of function and sloughing off. This however ensures there is no generalised placenta rejection which is required for foetal survival
What are the three main oestrogens produced by the placenta?
Oestrodiol
Oestrone
Oestriol
What can oestrone sulphate levels be used too detect in all animals?
Oestrone sulphate can be used to detect pregnancy in all species. It can be measured in the blood, milk, urine and faeces
What can oestriol levels be used to detect in all animals?
Oestriol is a biomarker or foetal health
What are the two horse specific oestrogens produced by the mare placenta?
Equilin
Equilenin
Which eight organs are influenced by placental hormones to mediate maternal metabolism changes during pregnancy?
Thyroid
Kidneys
Liver
Bones
Pancreas
Uterus
Mammary glands
Adrenal glands
Why is progesterone not used to diagnose pregnancy in the bitch?
Progesterone cannot be used for pregnancy diagnosis in the bitch as progesterone levels are the same in pregnant bitches compared to cyclic bitches
Why is prolactin not used to diagnose pregnancy in the bitch?
Prolactin cannot be used for pregnancy diagnosis in the bitch as prolactin is luteotrophic and thus will support pregnancy but also the corpus luteum in cyclic bitches
Which hormone can be used to diagnose pregnancy in the bitch?
Relaxin hormone
When can ultrasonography be used to diagnose small animal pregnancies?
Ultrasonography can be used from four weeks of gestation
