Andrology, Embryology & Placental Pathology Flashcards
What is andrology?
- Branch of physiology and medicine dealing with diseases and conditions specific to men
- Sperm
- Reproductive Medicine: Post-vasectomy/ infertility
Post vascetomy. Post-vascetomy sample conditions
Sperm count checked to ensure vascetomy has wprked.
Sample conditions:
Semen sample received within 60 minutes of production
Collected directly into the container
No ejaculation within the previous 48 hours
Two clear samples required
Infertility
- Determines whether difficulties in conceiving may relate to the male.
- Sample conditions: same as for post vascetomy but with addedd stress that condoms (as they contain spermicide) and similar must not be used.
- an analysis of sperm as well as a count is perofmed in cytology
Assessment criteria for male fertility
-semen volume: 1.5 ml or more
-pH: 7.2 or more
-sperm concentration: 15 million spermatozoa per ml or more
-total sperm number: 39 million spermatozoa per ejaculate or more
total motility (percentage of progressive motility and non‑progressive motility): 40% or more motile or 32% or more with progressive motility
-vitality: 58% or more live spermatozoa
- sperm morphology (percentage of normal forms): only 4% or more to be considered fertile,
Azoospermia
- Lack of sperm in semen:
- canbe Pretesticular, testicular, post-testicular, unknown
- can be caused by reproductive duct obstruction or by issue in testies ( non obstructive genetic mutations, hormonal issues)
-Biopsy may be needed to diagnose - Treatment can be resection of tubes/ catheter
- Biopsy may enable sperm extraction
What is Embryology?
What trimester is the mebryonic stage
- Branch of biology and medicine concerned with the study of embryos and their development.
- Embryology id the 1st trimester: embryonic stage lasts from about the third week of pregnancy until the eighth week of pregnancy.
- 2nd and 3rd trimesters are foetal development
Major stages of Embryology
Blastocyst formation
Implantation
Gastrulation
Neurulation
What is a blastocyst?
- a cluster of dividing cells made by a fertilized egg
- early stage of an embryo.
Blastocyst formation - Early blastocyst
Trophoblasts form outer structure, builds placenta
Inner cells differentiate into germ layers
Blastocyst formation - post-fertilisation
post fertilisation - 1/2 weeks
four cell types (three germ layers and neural cells)
cell types grouped - no layers
Implantation - Requirements
Uterus must be receptive : Correct point in cycle
- Linked with ovulation (usually 7-9 days after ovulation)
Implantation - What happens
Blastocyst sheds zona pellucida
Microvilli on trophoblasts adhere to endometrium
Trophoblasts differentiate into syncytiotrophoblasts
What are trophoblasts? When are they formed? What do they do?
- cells forming the outer layer of a blastocyst, which provides nutrients to the embryo.
- develops into a large part of the placenta.
- formed during the first stage of pregnancy
- the first cells to differentiate from the fertilized egg.
What is Gastrulation? What is the blastula? What is the grastula?
- early developmental process
- embryo transforms from a one-dimensional layer of epithelial cells - called a blastula,
- reorganizes into a multilayered and multidimensional structure - called the gastrula
What is neurulation?
Formation of the neural tube that occurs in two stages (primary and secondary)
Developmental disorders: common effect on pregnancy
- Lead to miscarriage in embryogenesis
- 75% of pregnancies end before a positive test result
- 1 in 4 pregnancies don’t lead to a live birth
- Miscarriage is very common
Developmental Disorders - Examples in embryogenesis leading to live births: Spina Bifida
73% of pregnancies that detect spina bifida are terminated.
Neurulation defect
Failure to close the tube fully
Characterized by nerve damage and the presence of meningoceles on the back
May present with physical or mental impairment
Developmental Disorders - Examples in embryogenesis leading to live births: Hydrocephalus
- Defect of Cerebrospinal fluid (CSF) flow, excess fluid production or impaired fluid
- 1 in 1000 live births
- Leads to enlarged ventricles and head, separated skull cranial sutures and fontanelles.
Marginal/ peripheral / velamentous cord insertion: Placental Attachment
Improper attachement of umbilical cord to placenta
- Usually picked up on scan
- C section needed
- Hysterectomy needed
- Risk of death from haemorrhage during vaginal delivery
- Percreta - Risk of death prior to delivery if myometrium / placental rupture
What is a hydatidiform mole/ Molar Pregnancy ?
- Uterine mass arising from fertilisation.
- Occurs when fertilisation of the egg by the sperm goes wrong leading to to the growth of abnormal cells or clusters of water filled sacs inside the womb.
Complete and partial Molar pregnancy
Complete – no foetus forms, just the abnormal cells
Partial – some foetal development occurs alongside the abnormal cells, but this is not viable
Treatment of Molar Pregnancy
- Dilation and curettage
- Hysterectomy
- Monitoring of HCG levels to ensure complete removal
