Fertility and contraception

Question 1

contraceptives

Answer 1

• Contraceptives = family planning/birth control methods
• Range of devices, procedures and medications which assist women to prevent pregnancy.
• Hormonal -> chemicals are added to the body
  o Prevent ovulation
  o Change cervical mucus to make it impenetrable to sperm
  o Slow down/kill sperm
  o Reduction of endometrial lining –> fertilized egg cannot implant
• Barrier dependent: Physical barrier between semen and vagina/uterus

Question 2

the pill

Answer 2

• Oral contraceptive taken daily
• Best taken at the same time to ensure constant hormone levels
• Can contain estrogen, progestin or mix
• Prevents ovulation
• Thin uterine lining
• Progestin thickens cervical mucus
• Estrogen: prevents pituitary form releasing LH – no ovulation
• Side effects include moodiness, headaches, nausea, blood clots (estrogen), heart attack & stroke
• Not effective if diarrhoea or vomiting

Question 3

mechanism of the pill

Answer 3

• Combined oral contraceptive pill contains synthetic estrogen & progesterone
• High levels of estrogen and progesterone in blood
  o negative feedback to hypothalamus and anterior pituitary
  o less production of FSH and LH
  o Inhibited follicle maturation in female ovaries
  o Progesterone prevents LH surge
  o No ovulation
• During placebo pills of package estrogen and progesterone in blood will fall
  o no negative feedback to hypothalamus and anterior pituitary
  o LH and FSH will be produced by anterior pituitary
  o follicles will start to mature
  o after ~2days progesterone levels low enough for menstruation to occur

Question 4

plasma concentration profile of chemicals taken orally

Answer 4

• With oral intake of chemicals at first spike in plasma drug levels
• Drug levels in plasma then decline over time
• Drug becomes ineffective at the suboptimal plasma concentration
  o A second tablet has to be taken before plasma levels drop to suboptimal levels
• Decrease in plasma drug concentration determines when next tablet has to be taken
• Most drugs coated/in capsules & chemically modified –> get reabsorbed slower but also maintain their effective levels longer
• Companies invest in chemical modifications of drugs to make their administration convenient – e.g. 1 tablet a day (not e.g. 1 every 3.2hours)

Plasma concentration profile of oral contraceptive pill: To prevent suboptimal levels, orally administered drugs best taken at the same time every day

Question 5

the mini pill

Answer 5

• Contains only synthetic progesterone and does not contain estrogen = progestin only pill
• Pill is taken continuously without any breaks between packets
• Thickens cervical mucus –> prevents passage of sperm into uterus
• May prevent ovulation
• Thins endometrial lining so no implantation
• Usually no menstruation
• Not effective if diarrhoea or vomiting

Question 6

morning after pill - plan B

Answer 6

• Emergency contraception
• Can be taken up to 5 days after unprotected intercourse but effectiveness decreases after 24h
• Same hormones as in birth control pill but higher dosage
• High amount of hormone prevents ovulation
• Will not stop an existing pregnancy

Question 7

vaginal ring combined contraceptive

Answer 7

• Clear soft flexible circular ring inserted in vagina around cervix and left for 3 weeks
• Releases progestin and estrogen
• Hormones from ring absorbed through vaginal wall

Question 8

plasma concentration of depot chemicals - time profile

Answer 8

• Depot chemicals aim to have therapeutical drug level maintained
• Aim to avoid toxic levels and high concentrations to avoid side effects
• Aim to avoid suboptimal/ineffective concentrations
• Less fluctuation of chemical levels in blood
• Hormone releasing implants etc. have to have high dosages as they are only administered e.g. once every month (infrequently)
• They release chemicals more constantly than orally administered ones

Question 9

combined contraceptive patch

Answer 9

• Bandage like hormone patch
• Changed weekly, no patch in 4th week
• Releases progestin and estrogen into blood
• Hormones absorbed through skin
• Can cause skin irritation
• Less effective in obese people

Question 10

contraceptive implants

Answer 10

• Soft rod placed under skin in upper arm
• Slow release of hormones into system
• Prevents pregnancy for >3 years but can be removed any time
• Risk that implant moves –> can be ”lost” in muscle

Question 11

3 month shot

Answer 11

• Long acting hormone injection
• Given every 3 months in muscle of arm or buttocks
• Not reversible – if rejection occurs hormones cannot be taken out
• Constant levels of progestin from muscle into blood
• Can take a long time to get pregnant after one shot

Question 12

IUD (intrauterine devices)

Answer 12

• Inserted into the uterus
  A) copper
• > 10 years
• Interferes with sperm, fertilization and prevents implantation
• Side effect: heavy or irregular menstruation

B) hormonal

• Plastic T shaped hormone reservoir
• Releases synthetic progestin
• Changes cervical mucus
• Reduced uterine lining
• Stops or slows sperm and oocyte
• > 5 years
• Can be removed at any time
• Side effect: missed periods (amenorrhea)/little menstruation, spotting

Question 13

diaphragm

Answer 13

• Soft silicone dome that covers cervix with a flexible rim that holds spermicide
• Once inserted held in place by pelvic muscles
  o barrier to prevent sperm from passing through cervix into uterus
  o sperm die off quickly in the vagina (spermicide)
• Needs to be left in for 6h after intercourse
• Can be used for up to 24 hours

Question 14

cervical cap

Answer 14

• Cervical cap is similar to the diaphragm but smaller
• Soft latex or silicone cup holding spermicide
• Designed to fit cover cervix only
• Can be used for up to 42 hours
• Needs to be left in for 6h after intercourse

Question 15

female condom

Answer 15

• Soft loose pouch that is inserted in the vagina
• Barrier method – prevents sperm from entering uterus
• Made of nitrile
• Flexible rings at each end hold it in place
• One time use only
• Can be put in 8h before intercourse

Question 16

spermicides

Answer 16

• Chemicals that are administered to vagina before intercourse (most 10min before)
• Come in from of jelly, foam, film, suppository
• Immobilizes/ kill sperm
• Key ingredient: Nonoxynol9

Question 17

tube ligation (female sterilisation)

Answer 17

• Permanent
• Small incision in abdomen to access fallopian tubes
• Fallopian tubes are then blocked, clipped or shut to prevent Oocyte from getting fertilized or reaching uterus

Question 18

temperature methods

Answer 18

• Before ovulation, during follicular phase, basal temperatures low
• After ovulation, when there is increased progesterone secreted from the corpus luteum, temperatures become elevated
• Can see the difference between pre-ovulation and post-ovulation temperatures when they are plotted on a graph
• Temperature will drop if fertilization does not occur

Question 19

calendar/rhythm method

Answer 19

• Predicting fertility based on menstrual cycles
• Prediction of fertile and infertile days based on previous menstrual cycle
• Abstinence during calculated fertile time

Question 20

withdrawal/pull out

Answer 20

• Man withdraws penis out of vagina before ejaculation
• Depends on male self knowledge and self control
• Pre-ejaculatory fluid can contain sperm

Question 21

condoms

Answer 21

• Barrier method
• Thin covering out of latex or polyurethane
• Unrolled over erect penis
• Best method to protect from STIs
• Several sizes available
• Can only be used once
• Sometimes allergy against latex
• Incorrect handling can lead to rapture of condom

Question 22

vasectomy (male sterilisation)

Answer 22

• Permanent
• Vas deferens is the sealed, tied or cut
• After vasectomy a man will still ejaculate but no sperm will be present (only seminal fluid)
• Sperm produced but cannot leave testes - sperm eventually deteriorates and gets phagocytosed/degraded
• Testosterone still produced – sex drive normal, male sex characteristics

Question 23

fertility measures

Answer 23

• Crude birth rate: number of live births occurring among the population of a given geographical area during a given year
  o most frequent measure of fertility
  o expressed per 1,000 in the population
• Fertility rate: Number of children born to women of child- bearing age
• Total fertility rate: Number of children a women in a particular population is expected to have based on current birth rates for the population
  o 2.1 is rate required to achieve a replacement level in the population

Question 24

factors affecting fertility

Answer 24

• Education or literacy rates
• Culture and religion
• Personal choices
• Standard of living and wealth
• Mortality rates and infant mortality
• Health issues
• Political policy – incentives disincentives
• Environment

Question 25

infertility

Answer 25

• Definition: Inability to conceive after 12 months of having sexual intercourse with average frequency without the use of any form of birth control
• Significant social and medical problem affecting couples worldwide
• Average incidence of infertility ~15% globally
• Unexplained infertility constitutes ~10% of all cases
• Main events for pregnancy to occur:
  o Ovulation
  o Fertilization
  o Implantation
  (any condition that interferes with these events may result in infertility)

Question 26

factors influencing infertility

Answer 26

• Frequency of intercourse
• Timing of intercourse
  o Sperm viable up to 5 days, oocyte only 1d -> sperm should be available in fallopian tubes before ovulation
• Infections
  o STI’s (gonorrhea, chlamydia etc.), inflammation, mumps
• Age of woman
  o Fertility rate decreases ~50% after 40 and miscarriage rate increases
  o menopause
• Age of man
  o Increased age affects coital frequency and sexual function
• Nutrition
  o 10%-15% underweight or obese may lead to less frequent ovulation
• Toxic substances
  o Lead, pesticides, alcohol, smoking -> problematic for sperm counts & fetal development
• Male and female factors equally responsible for infertility
• In~20% combination of female
  and male factors results in infertility