Obs & Gynae Flashcards
Explain the role of the Hypothalamic-Pituitary-Gonadal Axis and the roles of LH and FSH
The hypothalamus releases GnRH. GnRH stimulates the anterior pituitary to produce LH and FSH
LH and FSh stimulate the development of follicles in the ovaries. The theca granulosa cells around the follicles secrete oestrogen. Oestrogen has a negative feedback on the anterior pituitary and hypothalamus to suppress the release GnRH, LH and FSH
Explain the role of Oestrogen
It stimulates: Breast tissue development, Growth and development of the female sex organs at puberty, Blood vessel development in the uterus and development of the endometrium
Explain the role of progesterone
Prodcued by the corpus luteum after ovulation. It acts to: Thicken and maintain the endometrium, Thicken the cervical mucus, Increase the body temperature
Why do overweight children start puberty earlier
Aromatase, an enzyme foudn in adipose tissue, has an important role in making oestrogen. Therefore the more adipose tissue the higher the quantity of the enzyme that produces oestrogen.
What is the first episode of menstruation called?
Menarche
What are the five stages of puberty according to Tanner staging?
1 - Under 10 - No pubic hair, no breast development
2 - 10-11 - Light and thin pubic hair - Breast buds develop from behind areola
3 - 11-13 - Coarse and curly - Breasts begin to elevate
4 - 13-14 - Adult like but no reaching thigh - Areolar mound forms and projects
5 - Above 14 - Hair extending to medial thigh - Areolar mounds reduce, and adult breasts form
What are the two phases of the menstrual cycle
Follicular and luteal phase
Follicular - from menstruation to ovulation (at day 14)
Luteal - From day 14 to 28
What are immature ovums called
oocytes
What cells surround oocytes to from follicles
granulosa cells
What are the four keys stages in follicle development in the ovaries
Primordial follicles, Primary follicles, Secondary follicles, Antral follicles (aka Graafian follicles)
What is required for further developemnt after the secondary follicle stage
FSH
What does oestrogen do during the follicular phase of the menstrual cycle
Oestrogen has a -ve feedback effect on the pituitary gland, reducing the quantity of LH and FSH produced. It also causes the cervical mucus to become more permeable so that sperm can penetrate during ovulation
Role of LH in the follicular phase
Spikes during ovulation causing the dominant follicle to release the ovum from the ovary.
What does the corpus luteum do
It forms from the follicle once the ovum is released. It releases high levels of progesterone which maintains the endometrial lining. It also secretes a small amount of oestrogen
Role of progesterone in the luteal phase
Causes the cervical mucus to thicken and no longer penetrable
After fertilisation occurs what is secreted from the embryo
HCG from the synctiotrophblast
What does HCG do
Maintains the corpus luteum
What happens when no fertilisation occurs
The corpus luteum degenerates and stops producing oestrogen and progesterone. This causes the endometrium to break down and for menstruation to occur. Also the stromal cells of the endometrium release prostaglandins which encourage the endometrium to break down and the uterus to contract. Menstruation is on the first day of menstrual cycle
Explain the three stages of labour
First stage: From onset of labour (true contractions) until 10cm cervical dilatation
Second stage: From 10cm to delivery
Third stage: From delivery of the baby to delivery of the placenta
Role of prostaglandins
Local hormones. Play a crucial role in menstruation and labour by stimulating contraction of uterine muscles, role in ripening of the cervix before delivery
Key prostaglandin to be aware of
Prostaglandin E2 - used in pessaries to induce labour
What is a Braxton-Hicks contraction
Occasional irregular contractions of the uterus. Felt during second and third trimester. Temporary and irregular tightening or mild cramping. They don’t progress or become regular. Stay hydrated and relax
What is cervical effacement
The cervix gets thinner from back to front
What is the cervical ‘show’?
Refers to the mucus plug falling out and creating space for the baby to pass through
Explain the three phases of the first stage of labour
Latent: From 0 to 3cm dilation, progress at 0.5cm per hour
Active: From 3 to 7cm, progress at 1cm per hour, regular contractions
Transition: From 7 to 10cm. 1cm an hour, strong and regular contractions
What does the success of the second stage of labour depend on?
Power, Passenger and Passage
Explain power
The strength of uterine contractions
What are the four descriptive qualities of the fetus
Size, Attitude, Lie and Presentation
Explain the descriptive qualities of the fetus
Size: Particularly head size
Attitude: posture of the fetus, how the back is rounded and how the head and limbs are flexed
Lie: position of fetus in relation to mothers body e.g. longitudinal (fetus is straight up and down), Transverse (side to side), Oblique (at an angle)
Presentation: Cephalic, Shoulder, Breech
Passage: Size and shape on the passageway, mainly the pelvis
What are the different types of breech presentation?
Complete: Hips and knees flexed (like a canonball)
Frank: Hips flexed knees extended
Footling: Foot hanging through the cervix
What are the seven cardinal movements of labour
Engagement, Descent, Flexion, Internal rotation, Extension, Restitution and external rotation and expulsion
Explain descent
Position of the babys head in relation to the mothers ischial spines during the descent phase, measured in centimetres from: -5 baby is high up around inlet
0 - when head is at the ischial spines
+5 - fetal head has descended further out
What is physiological management in the third stage
Where the placenta is delivered by maternal effort without meds or cord traction
What is active management of the third stage of labour
Midwife or doctor assist. Reduces risk of bleeding. Haemorrhage or more than a 60 minute delay in placental delivery triggers active management. Associated with N/V
What drug is given in active management of the third stage of labour
IM Oxytocin to help the uterus contract and expel the placenta
What is cord traction
Applied to the umbilical cord to guide the placenta out of the uterus and vagina
Causes of primary amenorrhoea
When the patient has never developed periods
Due to: Abnormal functioning of the hypothalamus or pituitary gland (hypogonadotrophic hypogonadism), Abnormal functioning of the gonads (hypergonadotrophic hypogonadism) or imperforate hymen or other structural abnormality
Causes of secondary amenorrhoea
Pregnancy, Menopause, Physiological stress due to excessive exercise, low body weight, chronic disease, psychosocial, PCOS, Meds such as contraceptives, Premature ovarian insufficiency, thyroid issue, Excessive prolactin, Cushings
Causes of irregular menstruation
Extremes of reproductive age, PCOS, Physiological stress, Meds (prog only pill, antidepressants and antipsychotics), Hormonal imbalance such as thyroid, Cushings and high repro age
Urgency of Intermenstrual bleeding
Red flag as it should make you consider cervical and other causes
Causes of IMB
Hormonal contraception, Cervical ectropion, polyps or cancer, STI, Endometrial polyps or cancer, Vaginal pathology, Pregnancy, Ovulation, Meds
Causes of dysmenorrhoea
Primary, Endometriosis or adenomyosis, Fibroids, PID, Copper coil, Cervical or ovarian cancer
Causes of Menorrhagia
Dysfunctional uterine bleeding, Extremes of repro age, Fibroids, Endometriosis or adenomyosis, PID, Contraceptives, Anticoags, Bleeding disorders, Endocrine disorders, Connective tissue disorders, Endometrial hyperplasia, PCOS
Urgency of post coital bleeding
Red flag for cancer
Causes of PCB
Cervical cancer, Trauma, Atrophic vaginitis, Polyps, Endometrial cancer, Vaginal cancer
Causes of vaginal discharge
BV, Candidiasis, Chlamydia, Gonorrhoea, Trichomonas vaginalis, Foreign body, Cervical ectropion, polyps, malignancy, pregnancy, ovulation, Hormonal contraception
Causes of pelvic pain
UTI, Painful periods, IBS, Ovarian cyst, Endometriosis, PID, Ectopic, Appendicitis, Mittelschmerz, Pelvic adhesions, Ovarian torsion, IBD
Causes of pruritus vulvae
Irritants, Atrophic vaginits, Infections such as candida and lice, Skin conditions, Vulval malignancy, Pregnancy related, Urinary or faecal incontinence, Stress
Definition of primary amenorrhoea
Not starting menstruation by age 13 if no other evidence of pubertal development or by age 15 if there are other signs such as development of breast buds
Explain the two types of hypogonadism
Hypogonadotrophic hypogonadism - deficiency of LH and FSH
Hypergonadotrophic hypogonadism - lack of response to LH and FSH by the gonads
Causes of Hypogonadotrophic hypogonadism
Hypopituitarism, Damage to the hypothalamus or pituitary, significant chronic conditions (CF or IBD), Excessive exercise or dieting, constitutional delay in growth and development, endocrine disorders such a hypothyroid/cushings/hyperprolactin, Kallman syndrome
Causes of Hypergonadotrophic hypogonadism
Previous damage to the gonads (e.g. torsion, cancer or infections), Congenital absence of ovaries, Turners
What is Kallman syndrome
Genetic condition causing hypogonadotrophic hypogonadism with failure to start puberty, associated with a reduced or absent sense of smell (anosmia)
Summarise congenital adrenal hyperplasia
Genetic condition causing underproduction of cortisol, aldosterone and an overproduction of androgens. Typical features are tall for age, facial hair, absent periods (pri amen), deep voice and early puberty
Summarise androgen insensitivity syndrome
Condition where tissues are unable to respond to androgens so typicall male sexual characteristics dont develop, resulting in a female phenotype. Normal external female genitalia and breast tissue, testes in abdo, absent uterus, upper vagina, fallopian tubes and ovaries
What structural abnormalities can cause primary amenorrhoea?
Imperforate hymen, Transverse vaginal septae, vaginal agenesis, absent uterus, FGM
Initial investigations for primary amenorrhoea
FNC and ferritin for anaemia, U&E for CKD, Anti-TTG or anti-EMA antibodies for coeliac
Hormonal blood tests for primary amenorrhoea
FSH and LH, TFT, Insulin like growth factor 1 for GH def, Prolactin, Testosterone is raised in PCOS/androgen insen, congenital adrenal hyperplasia
