Obstetrics and Gynaecology
Early Pregnancy Complications
Abortion, ectopic pregnancy, molar pregnancy and hyperemesis gravidarum for MBBS, with beta-hCG interpretation and Rh prophylaxis, mapped to NMC code OG9.
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Early Pregnancy Complications
Abortion, ectopic pregnancy, molar pregnancy and hyperemesis gravidarum for MBBS, with beta-hCG interpretation and Rh prophylaxis, mapped to NMC code OG9.
This chapter deals with the emergencies and complications of the first half of pregnancy: the spectrum of abortion, ectopic pregnancy, gestational trophoblastic disease and hyperemesis gravidarum, together with Rh prophylaxis. It emphasises the bedside distinction between an open and closed cervical os and the safe use of beta-hCG and ultrasound.
High-yield: Early Pregnancy Complications
- Threatened abortion presents with bleeding through a closed cervical os and a viable intrauterine pregnancy.
- In inevitable and incomplete abortion the cervical os is open; missed abortion has a closed os with a non-viable pregnancy retained.
- The classic triad of ectopic pregnancy is amenorrhoea, abdominal pain and vaginal bleeding, and the ampulla is the commonest site.
- A ruptured ectopic causes acute abdomen, shoulder-tip pain and shock and is a surgical emergency.
- A beta-hCG above the discriminatory zone with an empty uterus on transvaginal scan strongly suggests ectopic pregnancy.
- Methotrexate can treat a small, unruptured ectopic in a stable woman with low beta-hCG and no foetal cardiac activity.
- A hydatidiform mole classically shows a large-for-dates uterus, very high beta-hCG and a snowstorm appearance on ultrasound.
- Molar pregnancy is managed by suction evacuation followed by serial beta-hCG monitoring to detect gestational trophoblastic neoplasia.
- A complete mole has a 46,XX karyotype of paternal origin with no foetal parts; a partial mole is triploid with foetal parts.
- Hyperemesis gravidarum is severe vomiting causing weight loss, ketosis and electrolyte disturbance, needing intravenous fluids and antiemetics.
- Thiamine is given in prolonged hyperemesis to prevent Wernicke's encephalopathy.
- Anti-D immunoglobulin is given to Rh-negative women after a bleeding or intervention in early pregnancy to prevent isoimmunisation.
- Any woman of reproductive age with abdominal pain and a positive pregnancy test has an ectopic pregnancy until proven otherwise.
- Serial beta-hCG that rises by less than about 66 percent in 48 hours suggests an abnormal, possibly ectopic, pregnancy.
Types of abortion at a glance
- **Threatened:** Bleeding, closed os, viable pregnancy. May settle.
- **Inevitable or incomplete:** Open os; products partly expelled or about to be lost.
- **Missed:** Closed os, non-viable pregnancy retained in utero.
- **Ectopic red flags:** Amenorrhoea, pain, bleeding, shoulder-tip pain, shock. Emergency.
NMC competencies in this chapter
- **OG9.1:** Abortion and early pregnancy loss
- **OG9.2:** Ectopic pregnancy and acute abdomen in early pregnancy
- **OG9.3:** Gestational trophoblastic disease and neoplasia
- **OG9.4:** Hyperemesis gravidarum
- **OG9.5:** Rh-negative pregnancy in early gestation
- **OG12.8:** Rh isoimmunisation and red cell alloimmunisation
Frequently Asked Questions
How do you tell the types of abortion apart at the bedside?
The state of the cervical os is key. A closed os with bleeding is threatened or missed, while an open os means inevitable or incomplete abortion. Ultrasound confirms viability.
What is the classic presentation of an ectopic pregnancy?
Amenorrhoea, abdominal pain and vaginal bleeding, with shoulder-tip pain and shock if it ruptures. Any positive pregnancy test with pain is an ectopic until proven otherwise.
How is a hydatidiform mole recognised and managed?
A large-for-dates uterus, very high beta-hCG and a snowstorm ultrasound suggest it. Treatment is suction evacuation with serial beta-hCG follow-up to catch trophoblastic neoplasia.
Why is thiamine important in hyperemesis gravidarum?
Prolonged vomiting depletes thiamine, and giving glucose without it can precipitate Wernicke's encephalopathy, so thiamine is supplemented in severe or protracted cases.
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