W01: Pregnancy Physiology; Antenatal Care & Screening; Contraception Flashcards
Outline how the cardiovascular system adapt to pregnancy
Changes persist from 1st trimester all the way to post-natal normalisation to pre-preg conditions of all systems
*⇧ LV EDV, CO, HR
- complications w/ dilated cardiomyopathy or lesions; mitral stenosis or pulm. hypertension
- CO increases put pt with AO stenosis at risk
- fall in systemic vascular resistance dt ⇧circulating vasodilators and diversion into low pressure of uteroplacental unit
- ⇧O2 demand in myocardium
- risk of MI
• Warm red hands and feet
• ⇧Nose bleed risk
• Stuffiness or congestion
Outline how the respiratory system adapt to pregnancy
*⇧ O2 requirements
*⇧ Tidal Volume; ⇧Minute ventilation; RR (percieved as dyspnea)
- relative CO2 lower
- diaphragm pushed up
- ⇧Progesterone = bronchodilates = ashtma improves in some
Outline how the renal system adapt to pregnancy
- smc relaxation of ureter dt progesterone + mechanical compression of uterus = dilatation of urinary collecting system
- phys. hydronephrosis pronounced on right
- fall in systemic resistance = ⇧renal plasma flow; ⇧⇧Creatinine clearance
- ⇧Excretion of protein, vit d, renin, EPO but RETENTION OF WATER ⇧
- Microscopic haematuria commonly dt bleeds from dilated vessels
- Glycosuria common; UTI common
Outline how the haematological system adapt to pregnancy
*⇧BV, Red cell mass
* haemodilution = anemia
* Physiological Anemia = 105Gb at 28weeks = normal
- ⇧ Fe requirements dt foetal use = Fe def anemia common (likelihood ⇧ with twins)
- ⇩Serum Folate but normal liver folate
- ⇧ WCC and Neutrophils
- ⇧FACTORS PROMOTING CLOTTING
Outline how these changes may impact on disease and management in pregnancy
Immune modulation = sometimes AuImm conditions improve during preg. such as Crohns, RArth.
*Existing cardiac disease = complications and fatality as well as dx of undiagnosed disease
- cardiac disease leading indirect cause of maternal death
- ⇧ DVT RISK dt thrombotic state and venodilation = ⇧venous stasis = Pulmonary Embolus common cause of death
Outline how normal values for lab testing are different in pregnant compared to non- pregnant women
⇧TBG in pregnancy but raised T3 and T4 thus normal levels
⇧ Catecholamines
- Physiological Anemia = 105Gb at 28weeks = normal
WCC of 16x109/L = normal
HYPERCOAGUABLE STATE
- ⇩Lower urea and creatinine dt raised clearance
Describe the role of pre-pregnancy counselling
a
Mechanical and Metabolic changes during pregnancy
*RELAXIN, OESTROGEN, PROGESTERONE = ⇧pliability, extensibility
- lumbar lordosis
- pubic symphyseal gap increase
- ⇧Relative insulin insensitivity
- placental lactogen acts against maternal insulin
- hormones = relaxed oesoph sphincter = ⇧risk of reflux + pressure of uterus contributes + delayed gastric emptying
- ⇧Na and Water retention = oedema in 80% of preg people
+ ⇧BV and compression on IVC = ⇩venous return = peripheral oedema
Significance of oedema
sign of pre eclampasia
Changes in Thyroid function in preg
⇧TBG form liver; however T4 and T3 increasede thus levels remain same
I2 deficiency dt active transportation + excretion doubled thus ⇧GOITRE likelihood
BHCG hormone structurally similar to TSH thus similar consequence to hyperthyr.
> propanolol
Role of Pain during Pregnancy
⇧circulating catecholamines = ⇧HR, BP, CO
Commonest haem. abnormalities in pregnancy
- Fe def anemia (⇧⇧ in twins)
- Folate def anemia
UTI mgmt in Pregnancy
> Nitrofurantoin
or
Amoxicillin
Cefalexin
Levels of ESR in pregnancy…
ESR: erythrocyte sedimentation rate increases during pregnancy due to an increase in fibrinogen and globulin levels; there is however a fall in the amount of albumin.
Urate levels in pregnancy…
During early pregnancy serum uric acid levels fall, often to 3 mg/dl or below, related to the uricosuric effects from estrogen and from the increase in renal blood flow. Uric acid levels then increase during the third trimester, reaching levels of 4–5 mg/dl by term
ALP levels in pregnancy…
Alkaline phosphatase is known to be produced by syncytiotrophoblasts in the placenta and its levels are normally increased in pregnancy.
Significance of haematuria in pregnancy
Common
Nil protein, infection, and renal uss normal = bleeds from dilated renal vasc
Outline the procedure and implications of the antenatal examination
- maternal, foetal, and social aspects of health
- routine enquiry: general wellness and feeling of fetal movements
- BP, urinalysis
• SYMPHYSEAL FUNDAL HEIGHT
+ estimate size of baby
+ estimate liquor volume: amniotic fluid index
• Fetal presentation: palpation and auscultation
Outline the basis of screening for fetal abnormality
Counselling prior to screening vital; allows detection of symptomless population
Outline what screening tests are offered to pregnant women and understand their limitations
Infection screen = Hep B; Syphilis; HIV; MSSU
> Penicillin (syphilis)
Anemia screen: Fe def.
Isoimminisation screen: rhesus disease, anti-c, anti-kell
First Visit Scan: ensure viable preg.; abnormalities
+ Offer Down’s Syndorme screening
= offers risk of baby affected
+ follow up. test offered to definitively tell
Outline the ethical dilemmas associated with detection of fetal abnormalities
- termination of life dt possible diagnosis
Pre-pregnancy counselling
Ideally for all women; aim of improving general health measures; smoking cessation;
*1/3 of pregnancies are unplanned
*ID known medical problems: psychiatric; existing medications
- Risks and previous pregnancy issues recurring
- DVT; pre-eclampsia
- pre-term delivery; intrauterine growth restriction
First Trimester Screening
at 10-14w gestation
- B-hCG
- Preg. associated plasma protein A (PAPP-A)
- fetal nuchal translucency (NT measurement)
- increases with gestational age
High Risk Results
- CVS
- Amniocentesis
- Non-invasive prenatal testing: maternal blood detect fetal cell free DNA
CVillus Sampling Vs Amniocentesis
Both Invasive and risk of miscarriage
CVS = 10-14w
Amniocentesis = 15w
Neural Tube Defect Screening
Not routinely offered
* only for increased risk
>5mg folic acid to reduce risk
- First trimester USS detects anencephaly and sometimes spina bifida
- Second trimester screening
- good for structural abn but poor test for chromosmal abn.
Describe the methods of male and female sterilisation along with their indications and
Laparocscopic Sterilisation: filshie clips across f tubes
* irreversible; nil effect on periods/hormones
* ⇩risl of ovarian ca.
Salpingectomy: removal of a Fallopian tube. This may be done to treat an ectopic pregnancy or cancer, to prevent cancer, or as a form of contraception.
Vasectomy: divided and ends cauterised w/ midline scrotal incision (most done in 1º care)
+ sperm samples required after
* irreversible; low risk of testicular pain; nil effect on hormones or sexual function
* nil effect on risk of ca.
Outline the issues involved during counselling of a couple prior to sterilisation
- irreversibility
- risk of failure; thus require follow up
- other low risk of complications such as pain
Describe the Abortion Act
• first 24 weeks
• abortion treatment must be carried out in a hospital or a place approved by Scottish Government Minister
• prevent continuation of greater risk to maternal health and wellbeing and any existing children
• prevent significant great risk of poor quality of life for the potential chil; suffering from great physical or mental abnormality
- consideration of infection risk and blood transfusion and contraception education
- nil impacts: fertility, cancer risk but emotional impact yet much safer taht fullterm delivery
LARC (Long Acting Reversible Contraception)
Less user input thus minimises user failure rates (dt incorrect usage) Vs MEthod Failure - pregnancy despite correct use of method
Combined Hormonal Contraception
Pill, patch, vaginal ring
- ETHINYL ESTRADIOL (EE) and SYNTHETIC PROGESTOGEN
= stops ovulation, affects cervical mucus and endometrium - 21d, one week off
- Pill taken daily
- Patch changed weekly
- Ring changed every 3 weeks
+ reduced bleeding: benefits heavy/painful periods
+ improve premenstrual syndrome
+ reduced functional ovarian cysts
+ reduction in ovarian and endometrial ca.
+ improve acne/ hirsutism
+ ⇩ benign breast disease, Rheum Arth., colon ca., osteoporosis
Combined Hormonal Methods Sfx & Considerations
Breast tenderness
Nausea
Headache
IRregular bleeding first 3mos
Wt gain - not causal
• increased risk of DVT: BMI >34, hx of VTE
• risk of thrombosis: smokers, hx of., migraines, 50yo+
• gall bladder disease, liver tum. hx
• cervical ca. risk increased
• breast ca risk increased
Progesterone-only Pill (POP) mini-pill
No pill-free interval, not ideal if frequent GI upset
- Desogestrel pill - 12 hour window
- nearly all cycles anovulant, affect mucus
- LNG NET pills - 3hr window
- Oestrogen free thus few contraindications
! personal hx breast ca / liver tum
Progesterone sfx
variable; troublesome sfx
* appetite
* hair loss/gain
* mood change
* bloating / fluid retention
* headache
* acne
nil thrombotic risks
! avoid if current breast ca or liver tum hx/present
Injectable Progestogen
solution of medroxyprogesterone acetate dose every 13 weeks
1ml deep intramusc injection upper outer quadrant of buttock / or 0.6ml of thigh
- prevents ovulation
- alters cervical mucus = hostile to sperm
- makes endometrium unsuitable for implantation
- 12-14week intervals
- estrogen-free
Injectable Progestogen Sfx
- delay in return to fertility: 9mos
- reversible reduction in bone density: osteoporosis risk
- problematic bleeding first 2 doses
- weight gain: casual effect on wt gain
Subdermal progestogen implant
Inhibits ovulation and effect on vervical mucus
3 years or be removed: no user input, or effect on weight
Injectable Progestogen Sfx
- Population of users experience prolonged bleeding
- more frequent mood changes
Intrauterine contraception: coil
Long acting reversible contraception: 5-10yr use
- sfx immediately reversible upon removal
- offer STI testing dt infection risk in first 3 weeks
Unsuitable if untreated pelvic infection or distored endometrial cavity
+ Cu Coil = toxic to sperm; prevents implantation of egg
• hormone free; potentially heavier periods; can be fitted after 40th bday can work until menopause
Injectable Progestogen Sfx
- infection risk
- perforation risk on fitting
- expulsion risk
- ectopic risk if conception occurs
Levonorgestrel IUS
Coil which releases hormones
- slow rleease of progestogen = low circulating hormones vs other forms
- reduces bleeding
- MIRENA: 5yr option: bleed free 12mos; licenses to treat heavy bleeding
- KYLEENA: contraception only, less progestogen thus less sfx but also less likely to be bleed free
Emergency Contraception
- Copper IUD most effective
- Levonorgestrel pill: take within 72hrs
- Ulipristal pill: take within 120 hrs
! ci: breast feeding, enzyme inducing drugs
Drug interactions of common forms of female contraception
ENZYME INDUCING DRUGS:
* Carbamezapine
* topiramate
* rifampicin
* St johns wort
= ⇧metabolism of progestogen and oestrogen = ⇩effectiveness
Injections and copper IUD or levonorgestrel IUS unaffected
Describe the common medical and surgical methods of termination of pregnancy
- SURGICAL 5-12W
cervical priming = MISOPROSTOL 3hr preop = dilation reduces risk of perforation and haemorrhage
- GA or LA cervical block
- Transcervical: 6-10mm suction catheter
<10 mins
! perforation; cervical injury; GA risk
- MEDICAL 5-23 +5 weeks
MIFEPRISTONE: antiprogestogen tablet
* uterine contraction opens cervix and expels pregnancy
!failure risk => sx.
- EARLY MED. ABORTION AT HOME
MISOPROSTOL prescription to take home for self-administration
*under 10w gestation; healthy; have support; analgesia supplied
