Obstetrics and gynaecology for PLAB 1

A 27 year old woman who is 9 weeks pregnant by dates has light vaginal bleeding and mild cramping for a day. She is haemodynamically stable. A transvaginal ultrasound shows an intrauterine gestational sac with a fetal pole and a heartbeat, and the cervical os is closed on speculum. She is rhesus positive. What is the SINGLE most likely diagnosis?

1. Cervical polyp Painless bleeding from a visible polyp at the os, found on speculum rather than on scan. A closed os with a fetal heartbeat on scan at 9 weeks raises it.
2. Molar pregnancy Heavy bleeding with a uterus large for dates, hyperemesis and a very high hCG, with a snowstorm appearance on ultrasound. A closed os with a fetal heartbeat on scan at 9 weeks suggests it.
3. Ectopic pregnancy Unilateral pain with bleeding and an empty uterus on scan despite a positive test. The diagnosis that kills, so it is excluded before anything else is called a miscarriage. A closed os with a fetal heartbeat on scan at 9 weeks raises it.
4. Cervical ectropion Painless postcoital spotting with a friable cervix on speculum, common in pregnancy and not a threat to it. A closed os with a fetal heartbeat on scan at 9 weeks points to it.
5. Threatened miscarriage correct Correct. Bleeding with a closed os and a viable intrauterine pregnancy. Around three quarters of these pregnancies continue, and the bleeding itself does not change that.

The point: Bleeding before 12 weeks means a pregnancy of unknown location until a scan says otherwise, and ectopic pregnancy is the diagnosis you cannot afford to miss. An open cervical os with products passing is an inevitable or incomplete miscarriage; a closed os with a viable fetus is a threatened one. Expectant management for 7 to 14 days is first line where the woman is stable and there is no infection, with medical or surgical management if that fails or she does not want to wait. Anti-D is given after surgical management and after any bleeding from 12 weeks in a rhesus negative woman, not for a threatened miscarriage before 12 weeks with no instrumentation.

Source: NICE NG126 — Ectopic pregnancy and miscarriage: diagnosis and initial management NICE · tier 1, national regulator or guidance

A 27 year old woman who is 9 weeks pregnant by dates has light vaginal bleeding and mild cramping for a day. She is haemodynamically stable. A transvaginal ultrasound shows an intrauterine gestational sac with a fetal pole and a heartbeat, and the cervical os is closed on speculum. She is rhesus positive. What is the SINGLE most appropriate initial investigation?

1. Urinary pregnancy test Confirms the pregnancy in the first place, and it stays positive for some weeks after a miscarriage, which is why it does not confirm completion. A closed os with a fetal heartbeat on scan at 9 weeks makes it a starting point rather than an endpoint.
2. Transvaginal ultrasound correct Correct. The scan has already answered the two questions that matter: where the pregnancy is and whether it is alive. Nothing else needed doing first.
3. Histology of the products of conception Confirms an intrauterine pregnancy and identifies a molar pregnancy, which needs registration and follow-up. A closed os with a fetal heartbeat on scan at 9 weeks makes it important.
4. Speculum examination Tells you whether the os is open and whether products are sitting in the canal, which changes the diagnosis and can relieve the pain and shock. A closed os with a fetal heartbeat on scan at 9 weeks makes it worth doing.
5. Blood group and antibody screen Identifies the rhesus negative woman who will need anti-D, and is needed before any surgical management. A closed os with a fetal heartbeat on scan at 9 weeks makes it necessary.

The point: Bleeding before 12 weeks means a pregnancy of unknown location until a scan says otherwise, and ectopic pregnancy is the diagnosis you cannot afford to miss. An open cervical os with products passing is an inevitable or incomplete miscarriage; a closed os with a viable fetus is a threatened one. Expectant management for 7 to 14 days is first line where the woman is stable and there is no infection, with medical or surgical management if that fails or she does not want to wait. Anti-D is given after surgical management and after any bleeding from 12 weeks in a rhesus negative woman, not for a threatened miscarriage before 12 weeks with no instrumentation.

Source: NICE NG126 — Ectopic pregnancy and miscarriage: diagnosis and initial management NICE · tier 1, national regulator or guidance

A 27 year old woman who is 9 weeks pregnant by dates has light vaginal bleeding and mild cramping for a day. She is haemodynamically stable. A transvaginal ultrasound shows an intrauterine gestational sac with a fetal pole and a heartbeat, and the cervical os is closed on speculum. She is rhesus positive. What is the SINGLE most appropriate immediate management?

1. Vaginal misoprostol Medical management where expectant management has failed or is not wanted, with a repeat pregnancy test at three weeks to confirm completion. A closed os with a fetal heartbeat on scan at 9 weeks makes it the next step.
2. Anti-D immunoglobulin For a rhesus negative woman having surgical management, and for any bleeding from 12 weeks. Not needed for a threatened miscarriage before 12 weeks with no instrumentation. A closed os with a fetal heartbeat on scan at 9 weeks makes it indicated.
3. Remove products from the cervical os with sponge forceps For cervical shock: products distending the os cause vagal bradycardia and hypotension that resolve the moment they are removed. A closed os with a fetal heartbeat on scan at 9 weeks demands it.
4. Expectant management for 7 to 14 days First line in a stable woman with no infection and no heavy bleeding, and it succeeds in most cases without any intervention. A closed os with a fetal heartbeat on scan at 9 weeks makes it appropriate.
5. Reassure and offer a follow-up scan in one week correct Correct. No intervention improves the outcome of a threatened miscarriage. Progesterone is considered only where there is a history of previous miscarriage, which she does not have.

The point: Bleeding before 12 weeks means a pregnancy of unknown location until a scan says otherwise, and ectopic pregnancy is the diagnosis you cannot afford to miss. An open cervical os with products passing is an inevitable or incomplete miscarriage; a closed os with a viable fetus is a threatened one. Expectant management for 7 to 14 days is first line where the woman is stable and there is no infection, with medical or surgical management if that fails or she does not want to wait. Anti-D is given after surgical management and after any bleeding from 12 weeks in a rhesus negative woman, not for a threatened miscarriage before 12 weeks with no instrumentation.

Source: NICE NG126 — Ectopic pregnancy and miscarriage: diagnosis and initial management NICE · tier 1, national regulator or guidance