General Obstetrics Flashcards
define infertility?
unable to conceive after 1 year of unprotected sex
how frequent should couples have sex in order to conceive?
sexual intercourse every 48 hrs up to and beyond ovulation
how does clomiphene work in infertility?
Competitively antagonises oestrogen receptors in the hypothalamus. This interferes with normal negative feedback mechanisms and increases the release of pituitary gonadotrophins, especially LH, inducing ovulation.
what are some female causes of infertility?
Hypothalamic causes: Increasing age Stress Low weight Kallman's syndrome
Pituitary issues:
Prolactinoma
Thyroid issues
Iatrogenic:
Radiation
Genetic:
Turner syndrome/Fragile X syndrome
Autoimmune causes
Lupus/RA etc
Diagnosis of exclusion
Idiopathic/PCOS
Anatomical causes: PID Adhesions Mullerian abnormalities Sexual differentiation issues Endometriosis Fibroids
what are main male mechanisms for infertility?
azoospermia/oligospermia (not enough sperm)
problems with sperm motility/morphology
anti-sperm antibodies
sexual dysfunction
what are the screening tests available in the first trimester of pregnancy, and what do they screen for?
screen for down’s syndrome trisomy 21
the combined first trimester screening test includes
- bHCG
- PAPP-A
- Nuchal translucency test (ultrasound)
- Maternal age
what other chromosomal abnormalities can the first trimester screening test screen for?
trisomy 18
trisomy 13
XO (turner’s syndrome)
what are the two tests we can offer a pregnant woman that will definitively diagnose chromosomal abnormalities during pregnancy (if you already have a high suspicion of abnormality)?
aminocentesis
CVS sampling
–> invasive tests so you must have a high index of suspicion before performing
when is the first screening test performed during pregnancy?
at 11 weeks gestation
define preterm baby?
infant born before 37 weeks gestation
how do we calculate corrected age for preterm babies? how long should we use this corrected age until?
corrected age= actual age- no of weeks premature
use corrected age until 2 yrs old
at what gestation age do we deem a baby ‘viable’?
> 24 weeks gestation= viable and can be born preterm
what are the general risks of preterm rupture of membranes?
increased risk of preterm labour, chorioamioniitis, and uterine cord prolapse
how might we diagnose preterm rupture of membranes?
vaginal speculum examination- fluid in the posterior fornix is suggestive
analyse the fluid looking for alkaline pH, presence of fetal squamous cells and diagnostic phospholipids
administer oral pyridium tablet to mother–> if urine instead of liquour, then it will turn the urine orange
define shoulder dystocia?
shoulder dystocia refers to the difficulty in delivering the fetal shoulders after the fetal head has been delivered
define caesarean section?
delivery of the contents of the uterus (>20 weeks gestation) via abdominal incision aka laparotomy
what is the standard type of c-section performed nowadays?
lower uterine segment caesarean section
–> transverse incision
what are the key management principles when preparing a woman for a c-section?
- review of maternal obstetric and medical hx or antenatal hx inc allergies etc
- obtain consent
- discussion with anaesthetist, theatre etc
- obtain IV access and order group and hold for blood, coags, FBE etc
- position patient in left lateral supine position
- auscultate fetal heart- ensure that the baby is still alive
- ensure bladder is empty and insert IDC
- antibiotic prophylaxis pre-surgery
what is the difference between major placenta praevia and minor placenta praevia?
major- placenta covers the internal cervical OS
minor- low lying placenta but does not cover the internal OS
what is the difference between placenta accreta, placenta increta and placenta percreta?
placenta accreta- placenta is adherent to myometrium
placenta increta- placenta has invaded into the myometrium
placenta percreta- placenta has invaded through the myometrium to surrounding structures
what is cervical ectropium
eversion of the endocervix exposes columnar epithelium to the vagina
define vasa praevia?
fetal vessels in the membrane are below the fetal presenting part over the internal cervical os
define recurrent miscarriages?
3 or more consecutive miscarriages
where anatomically are ectopic pregnancies most likely to occur?
in the fallopian tubes
define pregnancy of unknown location
PUL = positive pregnancy test with no signs of intra/extrauterine pregnancy on transvaginal sonography
define ectopic pregnancy?
any pregnancy occurring outside the uterus
what are the general clinical features on history associated with ectopic pregnancies?
acute low abdominal pain with vaginal bleeding
+/- shoulder tip pain +/- acute abdomen +/- hypotension/fainting
what are the ddx of abdominal pain in early pregnancy?
appendicitis UTI ectopic pregnancy ovarian cyst renal colic musculoskeletal cause gastroenteritis
what does PAPP-A stand for?
pregnancy associated plasma protein A
what does cfDNA stand for?
cell free fetal DNA
what do we mean by ‘soft marker’ of Down’s syndrome?
A soft marker is a physical characteristic of the Down syndrome phenotype detectable with ultrasound which does not in itself pose any health risk to the fetus.
when is the u/s for the second trimester performed in pregnancy?
between 18-22 weeks gestation
what is the first line medication option for hyperemesis gravidarum? what are some other management options?
pyridoxine vitamin B6= first line
+/- anti-emetics
corticosteroids for refractive cases
hospital admission for IV fluids and TPN for severe cases
what is the difference between APH and miscarriage and show causing vaginal bleeding during pregnancy/labour?
APH generally refers to > 20 weeks gestation before onset of labour
miscarriage refers to pregnancy loss before 20 weeks gestation
if bleeding occurs around labour then more likely to be a show rather than APH
what is the surgery for cervical insufficiency?
cervical cerclage
a lady who you suspect is at risk of preterm labour has a fetal fibronectin test at 29 weeks gestation. It comes back positive. what is the implications of this result?
A positive test between 24 and 36 weeks’ is associated with a positive predictive value for delivery within 7 days of about 15 to 30%.
what antibiotic is commonly used for prolonged rupture of membranes to prevent risk of infection?
ampicillin or amoxicillin
what is the risk of classical caesarean section vs LUSCS?
classical c-section has a higher risk of uterine rupture in subsequent pregnancies
when is a hysterectomy indicated during a c-section for delivery of a baby?
in the case of uncontrolled primary haemorrhage or placenta accreta
what does VBAC stand for?
vaginal birth after caesarean section
what is your stepwise medical management of hyperemesis gravidarum?
Mild to moderate cases:
- pyridoxine
- H1 antagonist
- antihistamine like phenergan
- oral anti-emetics like metoclopramide and stemitil
severe refractive cases
- ondanestron orally
- IV antiemetics
- prednisolone
define hyperemesis gravidarum
persistent vomiting and nausea during pregnancy associated with 5% maternal weight loss, dehydration, ketonuria and electrolyte imbalance
for which women do we give intrapartum antibiotics?
For prevention of early onset Group B Streptococcus (GBS) infection
• For women at risk of chorioamnionitis or other bacterial infection is suspected – E.g. fever
> 38 on one occasion or > 37.5 on two occasions.
- Rupture of membranes > 18 hours.
- For women with cardiac lesions susceptible to infective endocarditis.
