3. the post partum period Flashcards
outline the stages of parturition
what occurs post partum
- uterine involution (including restoration of the endometrium)
- elimination of bacterial contamination from reproductive tract
- resumption of ovarian function
- lactation/suckling
what is uterine involution
reduction of uterine size. involved:
- endometrial repair
- expulsion of lochia
- restoring uterus such that pregnancy can be re-established
what happens day 1 post partum in the cow
cervix closing, uterus still large
what happens day 4 post partum
shrinking uterus, lochia expulsion
what happens day 10 postpartum
follicular growth re-starts
what happens day 20 post partum
nearly involuted uterus
describe the mechanism behind uterus involution
myometrial contraction
- stimulated by oxytocin 1 and pgf2a
- peristaltic waves towards cervix
- discharge of fluid/tissue debris
- compress vasculature
- suckling increases oxytocin which increases onvlution
coordinated atrophy
- myometrium stretched during pregnancy
- reduction in myometrial cell size
what is lochia
blood tinged remnants of fetal placenta and endometrial tissue
up to 1.5 L in volume
odourless
NORMAL
contains lumps of tissue (caruncles)
how is the endometrium repaired in the cow
restoration of the caruncle by necrosis leading to sloughing of placentome
how long does uterine involution take across the species
is post partum infection in the horse normal
yes, usually - typically eliminated by the foal heat
why is uterine involution slow in the bitch
endometrium repair takes long time (3 months)
multiple tissue remodelling steps
2 lochia:
1st = immeditaely green then (D1-3 PP) red, watery and then mucoid
2nd = 4-6 weeks later, sloughing of tissue mass
state 3 conditions that would pre-dispose the uterus to bacterial contamination peri and post partum
- negative energy balance
- dystocia
- uterine inertia
- retained fetal membranes
what will be the effect of prolonged/ excessive uterine bacterial contamination on subsequent reproductive capability
- endometritis/metritis
- delayed involution
- delay/impact rebreeding/ovary
discuss endometritis
why do you have a period of post partum anoestrus
- CL from previous pregnancy will regress
- limited number of antral follicles
- period of low progesterone and low oestradiol leading to limited negative feedback
- will pick up
explain the mechanism behind ovarian rebound
explain ovarian rebound in the mare
- rapid onset
- detectable ovary activity within 2 days
- foal heat by 5-9 days PP
- pregnancy can be established but with lower fertility
- can be delayed due to season or maternal instict
discuss ovarian rebound in the sow
- profound suckling effects (early follicular activity but prolactin suppresses LH thus no ovulation)
- return to oestrus initiated by weaning and LH surge within 7 days
- affected by length of lactation/timing of weaning
discuss ovrian rebound in dogs
discuss ovarian rebound in cats
what factors affect ovarian rebound
- suckling (prolactin)
- milk yield/nutrition (decreasing BCS, negative energy balance)
- peri-parturient abnormalities (retained fetal membranes/endometritis)
- seasonal (melatonin in the ewe)
what is the clinical importance of abnormal ovarian rebound
- delayed onset of cyclicity
- cessation of ovarian activity
- ovarian pathology (follicular/luteal cysts, persisten CL)
