Session 7 Flashcards
What is contraception?
Any method to prevent pregnancy
Possible methods:
- Blocking transport of sperm to avoid fertilisation of oocyte
- Disrupting the HPG axis to interfere with ovulation
- Inhibiting implantation of the conceptus into endometrium
Categories of contraception?
- Natural 2. Barrier 3. Hormonal Control 4. Prevention of implantation 5. Sterilisation 6. Emergency contraception
Best contraception?
There is no perfect contraception
• All have advantages and disadvantages
• Important to consider contraindications, particularly with hormonal contraception
• None are 100% effective other than abstinence
Balance patient preference with patient safety
Natural contraception?
Abstinence - Not having sex
Advantages • Only 100% reliable method of contraception
Disadvantages: No sex
Withdrawal method - Withdrawing before ejaculation
Advantages • No devices/hormones
Disadvantages • Not reliable ◦ ? “will-power” to withdraw on time ◦ Some sperm may be released in the preejaculate ◦ No protection for STI’s
Fertility Awareness Methods - Use of fertility indicators to identify fertile and infertile points of the menstrual cycle: • Cervical secretions • Basal body temperatures • Length of menstrual cycle
Advantages • No hormones/contraindications
Disadvantages • Unreliable • No protection from STI’s
Lactational amenorrhoea method - Breastfeeding delays the return of ovulation after childbirth
• Suckling stimulus disrupts release of GnRH • Affects feedback cycle of HPG axis
Relies on exclusive breast feeding (so no top up feeds). Only effective up to 6 months after giving birth. Female must be amenorrheic
Advantages • No hormones/contraindications Disadvantages • Unreliable • No STI prevention
Barrier contraception?
Male/Female condoms
Diaphragm/Caps
Physical barriers- preventing entrance of sperm into the cervix
Can also used with spermicide so additional chemical barrier
Advantages •Reliable – 98% effective (if used correctly) •Protection from STIs •Male condom is widely available
Disadvantages •“Disrupt romantic nature of sexual intercourse” •“Reduce sexual pleasure“ •Danger of expiring! •Allergy/sensitivity to latex/ spermicide
Describe the role of progesterone in HPG axis
At MODERATE/HIGH doses, progesterone enhances the negative feedback of natural oestrogen, this will reduce LH and FSH secretion.
At MODERATE/HIGH doses, progesterone inhibits the positive feedback of oestrogen →no LH surge →no ovulation
At LOWER doses, progesterone does not inhibit the LH surge → ovulation still likely. LOWER dose of progesterone will thicken cervical mucus
Contraception using hormonal control? (Short acting control)
NB: Progestogen is a synthetic form of progesterone
Combined Oral Contraceptive Pill
Pill containing combination of progestogen and synthetic oestrogen
Lots of types available - strength of each hormone varies
Principal action: •Prevents ovulation
Secondary action: •Reduces endometrial receptivity to inhibit implantation •Thickens cervical mucus to inhibit penetration of sperm
Taken for either 21 days followed by 7 day break OR taken for 21 days with 7 days of a ‘placebo’ pill.
Missed pill rules - If one pill is missed… take the pill you missed even if it means two in one day, and carry on as normal.
If >48 hours has been missed… take the most recent forgotten pill (i.e. yesterdays) as above, and leave the other forgotten pills. Use extra protection i.e. condoms or barrier contraception. If there are less than 7 pills left, don’t have a break and start the next pack straight away.
Advanatges: 98% effective, can relieve mentrrual disorder (heavy periods), reduces risk of ovarian cysts, reduces risk of ovarian cancer and endometrial cancer due to preventing ovulation and thinning ueterine wall so prevnting hyperplasia.
Disdavantages: No protection from STIs, Contraindications (•Eg BMI, migraine, breast cancer), side effects (breakthrough bleeding, breast tenderness, mood disturbance), Increased risk of: breast and cervical cancer, VTE, MI/Stroke
Missed pill rules
User dependent
Low Dose Progestogen
PROGESTOGEN ONLY PILL
Taken every day, without a break
Principal action:
Thicken cervical mucus
Ovulation is usually not prevented
If taken correctly, it can be more than 99% effective
At LOWER doses, progesterone does not inhibit the LH surge, therefore ovulation still likely. LOWER dose of progesterone will thicken cervical mucus
Advantages:
Quickly reversible It does not interrupt sexual intercourse
Can be used where the COCP is contraindicated
Disadvantages
User dependant - some have a 3 hour window to take it otherwise not protected. missed pill rules apply
Menstrual problems are common - period irregularity, spotting.
Interacts with other medication
Risk of ectopic pregnancy - progesterone affects egg motility so more likely to implant outside of uterus
Does not protect from STI’s
Contraception using hormonal control? Long acting reversible contraception
High Dose Progestogen
PROGESTOGEN INJECTION– DEPO PROVERA
Intramuscular injection given at intervals
Principal action: •Prevents ovulation
Secondary action: •Thickens cervical mucus to inhibit penetration of sperm • Prevents endometrial proliferation
If used correctly more than 99% effective
Advantages Reliable – eliminates risk of user failure
Does not disrupt sexual intercourse
It can be useful for women who can’t use contraception that contains oestrogen.
Disadvantages
Appointment needed every 12 weeks!!!
Contraindications and side effects
Delay in fertility returning - after 6 months of this it can take 18 months to 2 years for fertility to return.
No STI protection
PROGESTOGEN IMPLANT
Small flexible tube about 40mm long is inserted under the skin
Lasts for three years
Principal action: •Inhibits ovulation most of the time (hormone levels can fluctuate towards end)
Secondary action: •Thickens the cervical mucus •Prevents endometrial proliferation
It’s more than 99% effective
Advantages
Reliable – eliminates risk of user failure
Long acting reversible contraception
It can be useful for women who can’t use contraception that contains oestrogen.
Natural fertility returns quickly when removed
Disadvantages
Minor procedure to insert.
Side effects - 1/3 no periods, 1/3 normal periods, 1/3 regular bleeding
No STI protection
Inhibit implanatation - method of contraception
Inhibit implantation – Coil
Both sit in the enck of the uterus
Both are 99% effective
Intrauterine System– IUS
Progestogen-releasing plastic device
Works for 3–5 years
Principal action: Prevents implantation and reduces endometrial proliferation
Secondary action: thickens cervical mucus
Can help with heavy periods
Intrauterine device - IUD
Plastic device with added copper
Works for 5-10 years
Principal action: Copper is toxic to sperm and ovum
Secondary action: endometrial inflammatory reaction preventing implantation and changes consistency of cervical mucus
Withcopper coil, theres no change to periods.
Advantages:
Convenient
Long duration of action
Disadvantages
Insertion may be unpleasant
Risk of uterine perforation ~2/1000
Menstrual irregularity
Don’t prevent STI - if reproductive tract infection occurs then the coil adds risk to pelvic inflammatory disease
Displacement/expulsion may occur
Both are 99% effective
Sterilisation - method of contraception
- Sterilisation is permanent with no long or short-term serious side effects. (permanent on NHS but no guarantee)
- Should not be chosen if in any doubt about having children in the future.
VASECTOMY
Vas deferens cut or tied to prevent sperm entering ejaculate
Performed under local anaesthetic
Must confirm success by post-operative semen analysis to confirm no sperm in ejaculate (approx. 12-16 weeks after surgery)
Failure rate: 1 in 2,000 for males
TUBAL LIGATION/ CLIPPING
Fallopian tubes cut or blocked to stop the ovum travelling from the ovary to the uterus
Can be done under local or general anaesthetic
Failure rate: 1 in 200/500 (depending on method)
Emergency contraception - method of contraception
Emergency pill is most common, essentially high dose progestogen, can be taken up to 72 hours after sexual intercourse. Longer the delay means higher risk of failure
If within 5 days theres another emergency pill or insertio n of an emergency IUD (coil - copper)
What is subfertility?
Defined as: Failure of conception in a couple having regular, unprotected coitus for one year
Primary infertility: When someone who’s never conceived a child in the past has difficulty conceiving
Secondary infertility: When someone has had one or more pregnancies in the past, but is having difficulty conceiving again (Includes abortion and ectopic pregnancy)
- Around 1 in 7 couples may have difficulty in conceiving- approx. 3.5million people in the UK
- About 84% of couples will conceive naturally within one year if they have regular unprotected sex (every two or three days)
- For couples who’ve been trying to conceive for more than three years without success, the likelihood of getting pregnant naturally within the next year is 25% or less.
Main Causes
•Factors in the male - 30% •Unexplained infertility -25% •Ovulatory disorders - 25% •Tubal damage -20% •Uterine or peritoneal disorders 10% •Other- coital problems, concurrent health problems e.g chemotherpay, illness
In about 40% of cases, problems are found in both the man and the woman.
Male causes: General health/systemic illness, hypothyroidism, genetic e.g klinefelter syndrom (XXY) or Y chromosome deletion, STIs, chemotherapy, testicular torsion, varicocoele, erectile dysfunction, vascetomy
What problems with the female reproductive system can cause subfertility?
Ovulatory disorders
Can be classified into 3 groups:
Group 1-hypothalamic-pituitary failure– 10% e.g anorexics and very high BMI
◦ Hypothalamic amenorrhea ◦ Hypogonadotrophic hypogonadism
Group 2-hypothalamic-pituitary-ovarian dysfunction – 85%
◦ Polycystic ovary syndrome ◦ Hyperprolactinaemic amenorrhoea
Group 3-ovarian failure - 5%
oCongenital (Eg Turners X0) oPremature ovarian failure / Primary ovarian insufficiency
Uterine/Peritoneal disorders
Uterine Fibroids / Asherman syndrome
Endometriosis
Pelvic inflammatory disease
Previous surgery
Cervical stenosis
Müllerian developmental anomaly:
- Agenesis - failure for the uterus or tubes to form
- Didelphys- Complete duplication of the uterus, cervix, and vagina
- Bicornuate - two uteri sharing a single cervix and vagina
- Septate - a single uterus with a fibrous band going down the centre of the uterus
Tubal Damage
Endometriosis
Ectopic pregnancy
Pelvic surgery
Past pelvic infection e.g. Chlamydia
Müllerian developmental anomaly • Agenesis - failure of the tubes to form
How would a GP question and examine a male patient for subfertility?
Question:
General health
? Father already
Alcohol/smoking
Surgical history- ie previous surgery to the testes
Drug History
Sexual health history
Sexual dysfunction
Examination:
Do not usually perform a male examination in the absence of relevant history.
If needed:
Testicular examination to check for descent, swellings etc.
How would a GP question and examine a female patient for subfertility?
Questions:
Age General health (PMH) Drug history Alcohol/smoking history Obstetric/gynae history Menstrual cycle –length and predictability of cycle, age of menarche Surgical history- Tubal or pelvic surgery Sexual health history - PID or STIs
Examination:
BMI
Signs of secondary sexual characteristics
Breast examination - ?Galactorrhoea
Pelvic examination
◦ visual external inspection ◦ insertion of the speculum ◦ bimanual examination to determine the size and character of the uterus and ovaries
