Endo/Repro 3 Flashcards
STIs - high risk groups
More than half from young adults - higher rates of partner change and concurrent partners
Middle age emerging as high risk group now - experimentation and the internet
MSM
Black African/Caribbean
Inner cities
(internet allows easier access to new partners and commercial sex workers, as well as being disinhibiting, link to riskier sex)
Condoms most effective for transmission via genital secretions eg chlamydia/gonorrhoea, rather than genital warts/HIV
Chlamydia
MEN
50% no symptoms:
- urethral discharge, dysuria, urethral itch, rectal discharge/bleeding
WOMEN
70% no symptoms:
- urethral discharge, dysuria, pelvic paid, PCB/IMB, rectal discharge/bleeding
Investigate with NAAT (nucleic acid amplification test) by first catch urine for men, vaginal swab for women
Treat with doxycycline/azithryomycin
Contact tracing 4 weeks symptomatic/6 months asymptomatic
Complications of chlamydia
MEN
- prostatitis
- epididymitis
WOMEN
- pelvic inflammatory disease
- salpingitis (tubes) -> ectopic, infertility
Gonorrhoea
MEN
90% - urethral discharge, dysuria, urethral itch
7% - rectal discharge/bleeding
WOMEN
50% - vaginal discharge, dysuria, pelvic pain, IMB/PCB, rectal discharge/bleeding
More common in MSM
Investigate with NAAT (nucleic acid amplification test) by first catch urine for men, vaginal swab for women
Culture bacteria - concern about antibiotic resistance
Treat with ceftriaxone and azithromycin
Contact tracing 2 weeks symptomatic/3 months asymptomatic
Complications of gonorrhoea
MEN
- prostatitis
- urethral strictures
- epididymitis
WOMEN
- PID -> salpingitis -> ectopic/infertility
- Bartholin’s abscess
- chronic pelvic pain
- parihepatitis
can (1%) -> disseminated gonococcal infection
- arthritis
- necrotic pustules
- tenosynovitis
Genital warts
Very common - 50% those sexually active
Caused by Human papilloma virus
Transmitted by skin-skin contact - can have transmission by hands/fingers
Incubation period weeks-months
No test for infection - diagnose by visual recognition
Treat with cryotherapy/topical creams (some will resolve spontaneously)
HPV types 16 + 18 are oncogenic -> intraepithelial neoplasia
HPV vaccinations now for young girls - effective for heterosexual men by herd immunity, but still leaves MSM at risk
(pearly penile papules are not warts - normal, bumps at rim of penis head)
Molluscum contagiosum
Often mistaken for (genital) warts Caused by pox virus Transmitted skin-skin contact Common in children Treatment as for warts - eg freezing (doesn't need treating but is done for genital cases)
Why have STIs increased
Increase in duration of sex lives - younger first intercourse - emerging 'Middle youth' Number of partners increasing Increase in condom use - offset by increased partner change More testing, better tests Associated alcohol/drugs Increased overseas travel and immigration
R0
= basic reproductive rate
Number of new infections produced by an infected individual in a population with no immunity in the absence of intervention
R0 = βCD
= probability of transmission x rate of partner acquisition x duration of infectiousness
Spreading: R0>1
Maintenance: R0 = 1
Dead-end: R0<1
HIV prevention
PRIMARY PREVENTION Targeted at risk groups - post exposure prophylaxis with HAART - treatment of HIV +ve individuals - pre-exposure prophylaxis
SECONDARY PREVENTION
HIV testing - routine health care and antenatal care especially
25% of those infected in UK are unaware
Risk of transmission per episode - receptive anal sex 1/90 - insertive anal sex 1/600 - receptive vaginal sex 1/1000 - insertive vaginal sex 1/1200 (some risk with oral sex also)
Syphilis
Esp MSM and sex workers
Common in Africa and Far east
PRIMARY LESION
= chancre
- painless solitary shallow ulcer, like button under skin
- diagnosis with microscopy of ulcer exudate, blood test
- treat with penicillin
SECONDARY SYPHILIS
- polymorphic rash
- systemically unwell
- mucous patches
Foetus characteristics
- dependent on mother for nutrients for growth and survival
- independent in regulation of its development (controls own development)
- exerts effects on mother to enhance her ability to meet the metabolic demands of pregnancy
- co-ordinates with mother in preparations for birth
Foetal growth and development stages
Pre-embryonic period
- 0-3 weeks
- histiotrophic nutrition
Embryonic period
- 3-8 weeks
- haemotrophic nutrient supply from placenta
- for organ system development
Foetal period
- 9-38 weeks
- haemotrophic nutrient supply from placenta
- for maturation and growth
42 cell divisions in this time - needs regulation
Determinants of foetal growth
Pattern of growth is determined by the foetus
Modulated by: Placenta Hormones - glucocorticoids, insulin, IGFs, thyroid hormones, hPL Environment - nutrition and health Metabolic
Growth measured by
- biparietal diameter of head
- circumference of skull
- circumference of abdomen
- length of individual
Intrauterine growth retardation
IUGR
~5% all pregnancies
= birthweight more than two standard deviations below the mean for gestation age
Substantial risk of morbidity and mortality
TYPE 1 (symmetric)
- occurs early in development
- due to chromosomal abnormalities, infections (rubella), alcohol, drugs
- decreased growth all over - hypoplasia and hypotrophy
TYPE 2 (asymmetric)
- restricted growth later on in development
- due to vascular diabetes, chronic hypertension, kidney disease
- head normal size with small body - hypotrophy only
INTERMEDIATE
- combination of types I and II
Human Placental Interface
Placenta - organ of gas exchange, nutrient uptake, excretion during pregnancy
(barrier for no mixing of maternal and foetal blood, though pass very close together for facilitated exchange of materials)
Terminal villi branch into pools of maternal blood
Spiral arteries provide slow delivery of blood to the interface - unresponsive to vasoconstrictors, tend to dilate, blocked by trophoblasts
Blood flow in the placenta
Developmental changes in the villous architecture during pregnancy
1 - thick trophoblast layer around villi thins so reduced distance for exchange
2 - terminal blood vessels in villi dilate, so slows down blood flow so enough time for exchange
Foetal
Umbilical artery - DEOXYgenated blood to placenta
Umbilical vein -OXYgenated blood to foetus
Maternal
Uterine vein - deoxygenated blood out from foetus/placenta
Uterine artery - oxygenated blood into foetus/placenta
Molecules and their transport across the placenta
Amino acids
- transported intact from mother, across placenta, to foetus
Oxygen
- partially consumed in placenta as goes to foetus
Glucose
- metabolised, 2/3 crosses to foetus, 1/3 metabolised to lactate in placenta which then crosses to foetus
Bilirubin
- not transported - can only cross from foetus to be broken down in maternal liver
Oxygen transfer across the placenta
Very good - higher oxygen saturation in every vessel in foetus (uterine/umbilical artery/vein)
Due to:
- Cardiac output of foetus proportionally higher than the mother when compared to body size
- O2 trapping properties of foetal haemoglobin (higher affinity) more effective than in the mother
- Increased amount haemoglobin in foetal blood than in adult
Foetal oxygen binding curve shifted to left of maternal
- 2 gamma units instead of beta units in haemoglobin, so have lower affinity for 2,3-DPG (regulatory molecule)
-> glucocorticoids needed to regulated switch from gamma to beta chains, and to switch site of RBC production from foetal liver to spleen and bone marrow
Glucose and carbohydrates in foetus
Foetus has little capacity for gluconeogenesis
- glucose supplied by mother
Maternal glucose depends on:
- nutrition
- endocrine control mechanisms - in diabetic mother, large baby, in diabetic foetus, small baby
In early pregnancy, progesterone
- increases maternal appetite, builds fat stores
In late pregnancy, maternal tissues insulin insensitive so more glucose available to foetus (gestational diabetes mellitus)
Roles of reproductive medicine
Safety and health of mother and baby \+ assist those with difficulty conceiving \+ assist in terminating a pregnancy \+ provide information about the foetus \+ help prepare for parenthood
-> increase choice in reproduction
Four approaches to reproductive choice
PROCREATIVE AND REPRODUCTIVE AUTONOMY
- liberal
- right of adults to make own choices based on own values
- only intervene where extreme circumstances
INTERESTS OF THE CHILD
- eg in assisted reproduction, don’t have to offer if not in the best interests of the future child
INTERESTS OF SOCIETY/STATE
(choices of a couple influences the makeup of future society)
- where significant cost implications, eg selecting child for non-disability
- or where choice has undesirable social consequences, eg sex selection
RESPECT FOR LIFE
(pro-life)
- killing a foetus is immoral as foetus is person
- contraception immoral as prevents life forming
Morality of abortion
MORAL STATUS
- dictates how you can be treated
- human>hamster>chair
- foetus is only potential life, has lower moral status than existing life
BODILY INTEGRITY
- woman has no obligation to use her body to support the life of another - putting herself at risk and doing something she doesn’t want to do
Abortion act 1967 (1990)
Two medical practitioners need to have opinion that:
PRE 24 WEEKS
- continuing pregnancy poses greater risk than not terminating of injury to physical/mental health of the mother or another child in her family
POST 24 WEEKS
- termination necessary to prevent grave permanent injury to physical/mental health of woman
- continuing pregnancy poses greater risk to woman’s life than not continuing
- substantial risk that child born would suffer from serious mental or physical abnormalities (life not worth living)
Practitioner allowed to conscientiously object, but must refer on to other doctor
Abortion act 1967 (1990)
Two medical practitioners need to have opinion that:
PRE 24 WEEKS
- continuing pregnancy poses greater risk than not terminating of injury to physical/mental health of the mother or another child in her family
POST 24 WEEKS
- termination necessary to prevent grave permanent injury to physical/mental health of woman
- continuing pregnancy poses greater risk to woman’s life than not continuing
- substantial risk that child born would suffer from serious mental or physical abnormalities (life not worth living)
Practitioner allowed to conscientiously object, but must refer on to other doctor
Early pregnancy more reasons accepted (can feel pain at 32 weeks)
80% abortions at under 10 weeks
Lifestyle in pregnancy
Legally, women not held liable for damage they cause to unborn child eg by alcohol
(at time of activity, foetus not a person, changes as soon as born)
Forced caesarean sections
Invasion of bodily integrity? It is assault and battery to perform surgery without consent
But is a woman in labour fully competent?
(if a woman has carried the baby to term but would now rather it died than have a C section then can they ever be competent?)
If have capacity, cannot override decision
Interests of foetus do not take precedence - unborn foetus does not have legal status until born
Assisted reproductive technology - legal aspects
ART
Legally regulated - all embryos outside of the body, use and storage of gametes
Potential recipients now include single women, older women, same sex couples, couples with ill health - as well as heterosexual couples
ART motivated by compassion, response to medical need (infertility is a disease), having children is intrinsically important
Just use of resources? One cycle of IVF £3000
Donor insemination
- sperm/egg donated
- need to try to match physical characteristics/ethnic background, cannot select irrelevant to health characteristics
- no payment beyond reasonable expenses
- low success rate
- anonymity now removed
Surrogacy
- commercially is criminal offence
- advertising for commercial arrangements also illegal
- legal mother is gestational mother unless relevant court proceedings carried out
- only allowed where mother is unable for physical/medical reasons to carry child herself
Compliactions of In vitro fertilisation
- risk multiple pregnancies
- incidence birth defects
- incidence pre-term delivery
+ don’t know long term effects (first IVF baby born in 1978)
