O&G Flashcards
Describe how to calculate estimated delivery date?
280 days (40 weeks) from the 1st day of the LMP
Describe the hormone levels of - oestrogen - progesterone - beta-hCG in early pregnancy
After ovulation and fertilisation, oestrogen and progesterone continue to gradually rise, but bHCG peaks around week 12 of pregnancy and then plateaus
Define miscarriage (early and late)
Miscarriage = spontaneous termination of pregnancy <24 weeks gestation
- early = <12 weeks
- late = 12-24 weeks
Define stillbirth
Any foetus born dead >24 weeks gestation
Define livebirth
Any foetus born at any gestation showing any signs of life after delivery
Define the following types of miscarriage:
- Threatened
- Inevitable
- Incomplete miscarriage
- Complete miscarriage
- Missed (silent)
- Septic
- Recurrent
- Anembryonic
- Threatened = vaginal bleeding, closed cervix, alive foetus with continuing intrauterine pregnancy
- Inevitable = vaginal bleeding and open cervix, non-continuing intrauterine pregnancy
- Incomplete miscarriage = retained POC in the uterus after miscarriage
- Complete miscarriage = all pregnancy tissue expelled after miscarriage and uterus now empty
- Missed (silent) = foetus no longer alive but no symptoms have occurred
- Septic = miscarriage complicated by intrauterine infection
- Recurrent = 3 or more consecutive miscarriages (before 24 weeks) with the same biological father
- Anembryonic = Gestational sac is present, but contains no embryo
What is the rate of miscarriage?
1/5 pregnancies
Describe how a miscarriage may present
- pelvic pain
- vaginal bleeding (from brown spotting to heavy +/- tissue)
- asymptomatic
Describe how to investigate a miscarriage
Hx - quantify pain, bleeding, LMP…
Ex - are they haemodynamically stable?, is the cervix open or closed?
USS TV - look for 3 things…
Describe how USS is used as the gold standard method of investigating miscarriages
Look for 3 things:
- mean gestational sac diameter
- fetal pole and crown-rump length
- fetal heartbeat
Heartbeat should be expected when CRL is >7mm (-> if there is no heartbeat, check 1 week later on scan before confirming non-viable pregnancy)
Fetal pole is expected once mean gestational sac diameter is >25mm (-> if the sac diameter is >25mm with no fetal pole, repeat scan one week later before confirming an anembryonic pregnancy)
List differentials of a miscarriage
Ectopic pregnancy
Ruptured ectopic pregnancy
Describe the management flowchart of miscarriage
<6 weeks gestation = expectant management
>6 weeks gestation = refer to early pregnancy assessment service, USS to rule out ectopic, then one of three management options (expectant, medical, surgical)
Describe the 3 management options of miscarriage
- Expectant - spontaneous passage with follow up scans 7-10 days later. Further referral if continued pain or bleeding.
- Medical - Mifepristone (an anti-progesterone drug) to prime and then 24-48hrs later… Misoprostol (a prostaglandin analogue - binds to prostaglandin receptors and activates them) which softens the cervix and stimulates uterine contraction, given orally or as a vaginal suppository, dose depending on gestation) can then do at home
- 70% success
- S/Ex: GI upset and pain, heavy bleeding, diarrhoea and vomiting -> provide anti-emetics - Surgical - for unacceptable pain/bleeding or retained POC on scan
- Can be MVA (manual vacuum aspiration = LOCAL ANAES.) or EVA (electric vacuum aspiration = GENERAL ANAES.) -> both >98% success
- Requires cervical priming (usually misoprostol is given to soften the cervix)
Define an ectopic pregnancy
When a pregnancy is implanted outside of the uterus (most commonly in fallopian tube but can occur at entrance to fallopian tube/ovary/cervix/abdomen)
List RFx for ectopic pregnancies
Previous ectopic
Endometriosis
Pelvic infection particularly chlamydia/PID (causes scarring)
Previous STI - causes scarring
Pelvic surgery – including C-sec, sterilisation, appendicectomy
Contraception – progesterone only pill, IUD (contains copper)/IUS (contains progesterone)
Assisted conception techniques
Cigarette smoking
Age 40+
What is the incidence of ectopic pregnancies?
1/200 women
Describe how an ectopic pregnancy may present
Should be a differential for any sexually active woman who presents with pain, irregular bleeding and/or amenorrhea!!!
- Missed period
- Constant lower abdominal pain in the right or left iliac fossa
- Vaginal bleeding
- Lower abdominal or pelvic tenderness
- Cervical motion tenderness (pain when moving the cervix during a bimanual examination)
How are ectopic pregnancies investigated?
Are they haemodynamically stable? (if not this could be an emergency)
Hx - possibility of pregnancy, unprotected sex, missed periods
Examination (bimanual)
USS - Transvaginal
□ May see an empty uterus
□ May see a gestational sac containing a yolk sac or fetal pole may be seen in the fallopian tube (or may see an empty gestational sac)
□ A mass moving separately to the ovary represents a tubal ectopic pregnancy
□ A mass moving with the ovary represents the corpus luteum
Describe pregnancy of unknown location and how a blood marker can be tracked to help with diagnosis
PUL = when woman has +ve pregnancy test but there is no evidence of pregnancy on USS scan
An ectopic cannot be excluded in this case, so the hormone hCG is measured (two readings taken 48hrs apart)
Normally the developing syncytiotrophoblast will produce this hormone.
- In an intrauterine pregnancy, hCG will double every 48hrs
If >63% increase in hCG after 48hrs - intrauterine pregnancy (repeat USS 1-2 weeks later)
If <63% increase in hCG after 48hrs - ectopic
Fall of <50% = miscarriage (repeat urine pregnancy test 2 weeks later to confirm pregnancy has ended)
At what hCG hormone level should a pregnancy be visible on USS?
> 1500 IU/L
Describe the management of ectopic pregnancy
All ectopics need to be terminated as they are not viable pregnancies!
3 options depending on clinical situation and the location of the ectopic
Describe expectant management of ectopic pregnancies and the criteria
Criteria:
- Follow up needs to be possible to ensure successful termination
- The ectopic needs to be unruptured
- Adnexal mass < 35mm
- No visible heartbeat
- No significant pain
- HCG level < 1500 IU / l
Describe medical management of ectopic pregnancies and the criteria
Methotrexate, can only be used if the following criteria are met:
- HCG level must be < 5000 IU / l
- Confirmed absence of intrauterine pregnancy on ultrasound
- Able to return for follow up
- No medical contraindications (e.g. anaemia, renal, hepatic impairment, UC, peptic ulcer)
- Pain free
- Unruptured ectopic
- <35mm
- No fetal heartbeat visible
Method:
- Antifolate medication (injection) -> stops DNA synthesis
- No new pregnancy until 3 months after HCG<5 (time required to replenish folic acid) methotrexate is teratogenic
- Must use a reliable form of contraception for 3 months after as any future pregnancy could be harmed by remaining folate antagonist in the system! (omen advised not to get pregnant in these 3 months)
Describe surgical management of ectopic pregnancies and the criteria
Criteria:
- If ruptured
- Pain
- Adnexal mass > 35mm
- Visible heartbeat
- HCG levels > 5000 IU / l
Methods:
- Laparoscopic salpingectomy - removal of tube (where contralateral tube looks healthy no need to remove)
- Laparoscopic salpingotomy - opening of affected tube and removal of POC
- Requires HCG follow up
- 1 in 5 require further management as pregnancy may not be removed (may need methotrexate or salpingectomy)
Anti-rhesus D is given to women who are rhesus negative and requiring surgical management of their ectopic