Common Pathologies in Pregnancy Flashcards
Ovary is a ________ factory
hormone
Fallopian tube – has a uterine end connecting to the uterus and a _______ end which is not fully connected to the ovary
fimbrial
Cervix is the neck to the womb/uterus and the ______ is the recess around the cervix, the role of the cervix is to stop bacteria coming into the uterus but can allow ___________ to come in so important role of cervical mucus
fornix
spermatozoa
Hormonal cycle – identify the hormones produced by the ovary
First half of the cycle is oestrogen
Second half is the progesterone/progestogen (many different names usually meaning the same thing)
what has happened?
Progesterone keeps rising as egg has been fertilized
What does progesterone (or progestogen) do to endometrium?
Main effect is on endometrium – it thickens the lining of the womb
Progesterone = thickening of lining, changes cells
Reaches maximum thickness late in the cycle then it gets shed
Progesterone turns endometrium into decidua
Increases vascularity
Between glands and vessels the stromal cells enlarge and become procoagulant - stops bleeding
Egg fertilised by sperm = ????
‘chorion’
Outer edge of chorion = ???????
trophoblast cells on outside of fertilised egg
Trophoblast cells produce which hormone?
Trophoblast produces B-hCG or Beta-human Chorionic Gonadotrophin
Trophic means makes it grow and acts on the gonads (ovary in women)
Its form the chorion
B-hCG – target is _____ ______ in ovary
corpus luteum
Blue is the fertilized egg
Send its hormone off to the ovary to the corpus luteum which has formed from the cells that surrounded the egg that has went to the endometrium
Corpus luteum forms once a month and normally shrivels and dies but B-hCG can keep it alive and it gets bigger
Corpus luteum is then stimulated to make progestogen to stop shedding of the endometrium
what is the function of B-hCG?
function is to stimulate corpus luteum to produce progestogen, which stops decidua from shedding
Allows fertilized egg to have a home in the decidua
B-hCG:
Forms basis of _________ tests
Stimulates the ovary to produce __________ throughout pregnancy, and stops decidua from _________
pregnancy
progesterone
shedding
Fertilised egg burrows in to _______
decidua
Trophoblast cells stream off to invade mother’s _____ _______ and (eventually) link these vessels up with those of the ________
Decidual _______ cells are between the vessels
Trophoblast cells stream off to invade mother’s blood vessels and (eventually) link these vessels up with those of the fetus
Decidual stromal cells are between the vessels
Trophoblast cell = ??????
placental cell. Only exists in pregnancy. It is a fetal cell
Decidual stromal cells are what?
procoagulant and stop trophoblast cells causing too much bleeding
Projections of chorion (chorionic villi), covered in ________ cells, start to move into the ______ (TOP ARROW)
The decidual cells are ________ and help stop ______ when the trophoblast cells invade mother’s blood vessels (BOTTOM ARROW)
Projections of chorion (chorionic villi), covered in trophoblast cells, start to move into the decidua
The decidual cells are procoagulant and help stop bleeding when the trophoblast cells invade mother’s blood vessels
Eventually the chorionic villi, covered by trophoblast cells, are bathed in the mother’s blood, forming the forerunner of the _______
Never should foetal ___ _____ _____ and mothers red blood cells mix
placenta
red blood cells
Rest of this lecture = series of cases – all of these cases are common or relatively common
Case 1:
- Woman, 26 yrs
- Misses period
- Pregnancy test positive (Beta-hCG in her blood and urine as she is pregnant and it is being produced by the fertilized egg)
- Vaginal bleeding 7 weeks after missed period (Had a fertilized egg for 7.5 weeks)
- What has probably happened?
- US scan: No fetus present but membranes and decidua lining uterus still there = miscarriage
- Removal of remaining tissue by obstetrician to avoid bleeding and infection
- Tissue sent to pathology: (Decidua is round about in dark purple, Open at one end where the foetus has probably come out)
A microscope slide of this case as sent to the pathologist:
what is seen?
Sac broken at open end where the foetus has come out
Chorionic villi come off in all directions early
Chorion redeveloped into a much bigger structure
This spaces is where the fetus was and has now been lost due to the miscarriage
Case 1 follow up:
- No problems afterwards
- B-hCG returns to normal (ie zero)
Why did miscarriage happen?
- Unknown in this case (it is very common for no cause to be obvious)
- Causes include: 1. Fetal problem eg chromosomal abnormality (Downs syndrome is one example of a chromosomal abnormality causing miscarriage but many chromosomal abnormalities are lethal early on in pregnancy), 2. Placenta/membranes/cord problem eg infection, 3. Uterus/cervix problem (eg cervical incompetence) and 4. maternal health issues (eg drug taking)
Case 2:
Pathology = ????
ectopic pregnancy
Fimbrial end next to ovary
Red dots is bleeding
Few decidua cells in the fallopian tube
Case 3:
- Woman 23 years
- Sudden severe abdominal pain. Collapses.
- Admission to A&E = Pulse fast. BP low.
No knowledge that she is pregnant
Low BP and a fast pulse then that combinations is one of the most worrying things in medicine – circulatory shock – many causes but the three main ones are hypovolemic shock (due to bleeding and no blood volume left), cardiogenic shock (due to heart disease), septic shock (due to infection)
Hypovolemic shock is first place to go as no history of heart disease and young and not ill with fever
- Blood given
- Emergency laparotomy:
- At operation - several litres of blood in abdomen
- Blood flowing from fallopian tube area - clamped, removed and sent to pathology
- Pathology:
Pathology = blood +++, fragmented fallopian tube with placenta and sac
- Microscopy = blood, fragments of fallopian tube and occasional chorionic villi (part of what will become the placenta and therefore tissue which confirms pregnancy)
- Diagnosis = ruptured ectopic pregnancy
Similar to previous case but it has birth and ruptured from the fallopian tube and massive bleeding into peritoneal cavity
Case 4:
• Microscopy = enlarged abnormal chorionic villi with abundant trophoblast = ???
= molar pregnancy
Form of pre cancer (dysplasia)
Normal ovary in adult females:
• Mum to be switches off certain genes in ova (eggs) by _________ them
methylating (Switches off genes by adding methyl groups)
Normal testis in adult males:
• Dad to be switches off _______ genes in sperm by methylating them
different
Normal fertilisation:
Mum and dad’s changes lead to _______ genes being swiched off
Mum’s changes promote _____ ____ _______
Dad’s changes promote early _______ _______ via trophoblast proliferation
Overall effect is _________ ______ of baby and placenta
different
early baby growth
placenta growth
balanced growth
what is the cuase of molar pregnancies?
Molar pregnancy – various causes but often caused by 2 sperm fertilising one egg with no chromosomes (Both fertilize this empty ovum)
• Result is imbalance in methylated (switched off) genes
2 sperm fertilising one egg with no chromosomes - what is the result of this?
May have normal number of chromosomes but typically you have too many of dads methylated genes which cause placental overgrowth as that’s what his genes do
Baby doesn’t grow well and disappears and miscarriages in 2-3 weeks
Case 5:
- 40 year old woman
- 10 weeks pregnant
- Scan: nuchal thickening (Thickening of the back of the neck, normal in mammals, Between 8 and 13 weeks, If particularly pronounced then more common in certain chromosomal abnormalities)
- Amniocentesis: Trisomy 21 (Down syndrome)
- Termination Of Pregnancy For Abnormality (TOPFA) at 20 weeks
- Postmortem: what does it show?
External – various anomalies including:
Done a post mortem as a form of audit to check genetics were correct and see how the baby was
Single palmar crease - Single palmar crease is normal but much more normal in chromosomal abnormalities
Internal - Interrupted duodenum = duodenal atresia (This one is life threatening, Would limit your life if left there)
- External features of Down syndrome (several minor anomalies eg single palmar crease, epicanthic folds, protuberant tongue….and several others)
- Duodenal atresia (a major anomaly)
Decision for TOPFA - Very much the parent’s decision
Case 6 – Why is baby so big?
- Effects of too much glucose in mother
- Does Glucose cross the placenta? - yes
- Glucose crosses the placenta and raises babies blood glucose. What happens to babies insulin?
- Insulin goes up in baby
- Can baby then reduce its glucose to normal? Baby has a pancreas and is not diabetic so increases its insulin production from its pancreas. Mum is diabetic and baby is not
- Baby cannot reduce babies glucose as mum keeps sending more across the placenta
Case 7:
- 35 year old woman
- Well throughout pregnancy
- 36 weeks – spontaneous labour
- Labour progresses well but mum has fever
- Heart beat lost minutes before birth
- Resucitation unsuccessful
- ‘Fresh’ stillbirth
- Examine placenta in all cases of stillborn babies (and babies who go to neonatal unit…….)
what is seen onplacenta exam?
Placental examination – cut off membranes - microscopy
Membranes contain neutrophils
- Trilobed nucleus is easily deformable and allows them to move easily into tissues.
- Phagocytose (ingest) and destroy micro-organisms
examine cord – take 2 cross sections - microscopy shows neutrophils in cord
Placental examination – examine cord – take 2 cross sections - microscopy shows neutrophils in cord
Look at the cord with its 3 vessels
Placental microscopy – cut placenta and take sections
Case 7 – Diagnosis = acute chorioamnionitis
what is it?
•Acute inflammation = neutrophils present in membranes (chorioamnionitis), cord, and fetal plate of placenta
Acute chorioamnionitis = Ascending infection
•Bacteria are typically perineal or perianal flora (eg E.coli) which ascend vagina and get into the amniotic sac
Nearly always bacterial and not viral
How does ascending infection affect baby’s brain?
Neutrophils prodcuce cytokine ‘storm’. This activates some brain cells, which then get damaged by normal hypoxia of labour
Cerebral palsy is one of the biggest causes of long term disability
Very common cause of premature labour
Case 8:
- 24 year old woman
- Intravenous heroin addict
- Also on methadone (Methadone – liquid opiate (green liquid) – handed out by the pharmacist), cocaine, temazapam, + other drugs
- Do opiates cross the placenta?
•Opiates do cross the placenta
Opiates are very small molecules and so can cross the placenta.
Baby becomes an addict to the opiates
Case 9:
- 32 year old woman
- Normal pregnancy to term
- Decreased movements of baby at 40 weeks
- Scan – No heart movement
Diagnosis = itrauterine death
Postmortem findings = Baby morphologically normal
Postmortem findings of placenta, cord and membranes - what are they?
Cord is abnormal
Twisting of a cord too much and it gets too tight then risk of babies own blood supply not going down the cord
Case 10:
- 33 year old woman
- Hypertension during pregnancy
- Vaginal bleed at 35 weeks
Ultra sound: Separation of part of the placenta from uterus with collection of blood (a haematoma) behind placenta. Haematoma enlarging during ultrasound
treatment - Emergency caesarian section
what is the outcome?
- Baby has low APGARS
- Unwell in neonatal unit for 5 days then much better.
Abruption:
- Means separation of placenta from uterine wall
- Results in hypoxia in baby
- Often causes antepartum haemorrhage in mother
Not a pathology diagnosis, diagnosis made clinically and ultrasound
Often an emergency
Hemorrhage before the baby is born
Any separation of placenta from uterine wall decreases baby’s supply of _______ from mother
oxygen
