A 31-year-old woman with confirmed right tubal ectopic pregnancy measuring 32 mm with no fetal heartbeat is being considered for medical management. Serum beta-hCG is 2800 IU/L. She is haemodynamically stable with minimal pain. She has normal renal and liver function. Which additional factor would be an absolute contraindication to methotrexate treatment?
Q42
What is the primary reason that women with previous ectopic pregnancy are at increased risk of recurrent ectopic pregnancy?
Q43
A 38-year-old woman with heavy menstrual bleeding has been using a levonorgestrel intrauterine system for 8 months. She initially experienced reduced bleeding for the first 4 months, but for the past 3 months has noticed increasing menstrual blood loss returning to previous heavy levels. Pelvic examination reveals a mobile uterus with no palpable masses. What is the most appropriate next investigation?
Q44
A 45-year-old woman presents with a 9-month history of heavy menstrual bleeding. She has tried tranexamic acid and mefenamic acid with minimal improvement. She has completed her family. Pelvic examination reveals a 12-week sized, irregular, non-tender uterus. Pelvic ultrasound shows multiple intramural and subserosal fibroids, the largest measuring 7 cm. Her haemoglobin is 88 g/L. She wishes to avoid major surgery if possible. What is the most appropriate next management option?
Q45
A 27-year-old nulliparous woman undergoes laparoscopy for suspected ectopic pregnancy. At surgery, a 3.5 cm unruptured left ampullary ectopic pregnancy is identified. The left fallopian tube appears healthy apart from the ectopic gestation. The right tube appears normal. She wishes to preserve her fertility. What is the most appropriate surgical management?
Q46
A 42-year-old multiparous woman presents with a 14-month history of heavy menstrual bleeding. She reports flooding and clots, requiring double protection. Examination is unremarkable with a normal-sized uterus. Full blood count shows haemoglobin 95 g/L. She has completed her family and requests definitive treatment. Pelvic ultrasound shows a uniformly enlarged uterus measuring 11 cm in length with heterogeneous myometrium and no focal lesions. What is the most likely diagnosis?
Q47
A 50-year-old woman presents to her GP with a 7-month history of irregular heavy vaginal bleeding. Her periods were previously regular 28-day cycles but are now unpredictable, occurring every 18-45 days with variable flow. Her last menstrual period was 3 weeks ago. She is a non-smoker with BMI 26 kg/m². On examination, her abdomen is soft and non-tender. Speculum examination shows a healthy-appearing cervix with no active bleeding. Her cervical screening is up to date with normal results. What is the most appropriate initial investigation?
Q48
A 32-year-old woman is admitted with suspected ectopic pregnancy. She has 8 weeks amenorrhoea and right-sided pelvic pain. Initial serum beta-hCG is 3200 IU/L. Transvaginal ultrasound shows an empty uterus and a 32mm right adnexal mass with no fetal heartbeat. There is minimal free fluid in the pelvis. She is haemodynamically stable. Following counselling, she opts for expectant management. Under which circumstance during expectant management should medical or surgical intervention be initiated?
Q49
A 36-year-old woman with heavy menstrual bleeding has been using a levonorgestrel intrauterine system for 18 months with good initial symptom control. She now presents with recurrence of heavy bleeding over the past 3 months. Examination shows the IUS threads are visible at the cervical os and the uterus is normal size. Pelvic ultrasound confirms the IUS is correctly positioned in the uterine cavity and shows a 4cm subserosal fibroid on the posterior uterine wall that was not present on her pre-insertion scan. What is the most likely explanation for her recurrent heavy bleeding?
Q50
A 29-year-old woman presents to the emergency department with sudden onset severe right-sided abdominal pain and shoulder tip pain. She has 7 weeks amenorrhoea. On examination, she is pale, with blood pressure 88/55 mmHg and heart rate 122 beats per minute. She has generalised abdominal tenderness with guarding and rebound tenderness. Her cervical os is closed with minimal old blood in the vagina. A bedside urine pregnancy test is positive. What physiological mechanism is responsible for the shoulder tip pain in this patient?
Gynaecology UK Medical PG Practice Questions and MCQs
Question 41: A 31-year-old woman with confirmed right tubal ectopic pregnancy measuring 32 mm with no fetal heartbeat is being considered for medical management. Serum beta-hCG is 2800 IU/L. She is haemodynamically stable with minimal pain. She has normal renal and liver function. Which additional factor would be an absolute contraindication to methotrexate treatment?
A. Body mass index of 32 kg/m²
B. Previous caesarean section
C. Breastfeeding her 14-month-old child (Correct Answer)
D. Taking folic acid supplementation
E. Mild asthma controlled with salbutamol inhaler
Explanation: ***Breastfeeding her 14-month-old child***
- **Methotrexate** is an absolute contraindication in breastfeeding women as it is excreted into **breast milk** and can cause serious adverse effects, including **bone marrow suppression** and gastrointestinal toxicity in the infant.
- The patient meets criteria for medical management based on **ectopic size (<35 mm)**, **beta-hCG (<3000 IU/L)**, and haemodynamic stability, but must stop breastfeeding if choosing this route.
*Body mass index of 32 kg/m²*
- A high **Body Mass Index (BMI)** is not a contraindication to methotrexate; however, dosing is typically calculated based on **Body Surface Area (BSA)** to ensure efficacy.
- While obesity can theoretically impact drug distribution, it does not preclude the use of medical management in a stable patient.
*Previous caesarean section*
- A history of **caesarean section** is not a contraindication for methotrexate and does not interfere with the mechanism of **folate antagonism**.
- It is only clinically relevant for locating the pregnancy, such as excluding a **caesarean scar ectopic**, but does not change the suitability for medical therapy if guidelines are met.
*Taking folic acid supplementation*
- **Folic acid** is a relative concern because it acts as an **antagonist** to methotrexate, potentially reducing the drug's effectiveness in resolving the ectopic pregnancy.
- However, this is not an absolute contraindication; patients are simply instructed to **discontinue supplements** and avoid folate-rich foods during treatment.
*Mild asthma controlled with salbutamol inhaler*
- **Mild asthma** is not a contraindication for methotrexate therapy; concerns are usually reserved for patients with severe **pulmonary fibrosis** or active lung disease.
- Absolute contraindications typically include established **immunodeficiency**, significant **renal/hepatic impairment**, or active **peptic ulcer disease**.
Question 42: What is the primary reason that women with previous ectopic pregnancy are at increased risk of recurrent ectopic pregnancy?
A. Hormonal imbalance affecting tubal motility
B. Underlying tubal pathology affecting ciliary function and transport (Correct Answer)
C. Increased circulating beta-hCG affecting implantation
D. Uterine factors preventing normal intrauterine implantation
E. Immunological factors causing rejection of intrauterine pregnancy
Explanation: ***Underlying tubal pathology affecting ciliary function and transport***- A previous ectopic pregnancy often indicates **damage to the fallopian tubes**, typically from conditions like **pelvic inflammatory disease (PID)**, endometriosis, or previous tubal surgery.- This damage impairs the **ciliary function** and **muscular contractions** of the tube, hindering the normal transport of the fertilized ovum to the uterus. *Hormonal imbalance affecting tubal motility*- While hormones like **progesterone** can influence tubal smooth muscle activity, they are not the primary cause of the structural damage leading to recurrent ectopic pregnancy.- The main issue is a **structural defect** or functional impairment of the tube, not transient hormonal fluctuations affecting motility.*Increased circulating beta-hCG affecting implantation*- **Beta-hCG** is a hormone produced by the placenta after implantation and indicates pregnancy, it does not determine the **site of implantation**.- High levels of hCG are a consequence of a developing pregnancy, whether intrauterine or ectopic, not a cause of its mislocation.*Uterine factors preventing normal intrauterine implantation*- Uterine issues such as **fibroids** or **polyps** are more likely to cause infertility or recurrent miscarriage by affecting the uterine cavity.- These factors do not primarily explain why an embryo would specifically implant in the **fallopian tube** rather than the uterus.*Immunological factors causing rejection of intrauterine pregnancy*- **Immunological factors** are more commonly associated with recurrent **miscarriage** due to the body's rejection of an otherwise normal intrauterine pregnancy.- They do not account for the embryo's initial implantation in an **extrauterine location**, which is fundamentally a problem of ovum transport.
Question 43: A 38-year-old woman with heavy menstrual bleeding has been using a levonorgestrel intrauterine system for 8 months. She initially experienced reduced bleeding for the first 4 months, but for the past 3 months has noticed increasing menstrual blood loss returning to previous heavy levels. Pelvic examination reveals a mobile uterus with no palpable masses. What is the most appropriate next investigation?
A. Hysteroscopy
B. Transvaginal ultrasound to check LNG-IUS position (Correct Answer)
C. Serum progesterone level
D. Endometrial biopsy
E. Full blood count and ferritin
Explanation: ***Transvaginal ultrasound to check LNG-IUS position***
- When a **levonorgestrel intrauterine system (LNG-IUS)** initially reduces bleeding but then fails, the primary concern is a **change in its position**, such as partial expulsion or malposition, reducing its local effect.
- A **transvaginal ultrasound** is the most appropriate first-line investigation to quickly and non-invasively confirm the **fundal placement** of the IUS and rule out other uterine pathologies like **polyps** or **fibroids**.
*Hysteroscopy*
- **Hysteroscopy** is an invasive procedure that is usually reserved for cases where **ultrasound findings are inconclusive**, or when there is a need for direct visualization, removal of a displaced device, or biopsy of a suspected lesion.
- It is not the initial investigation of choice when a less invasive method like **ultrasound** can provide crucial diagnostic information first.
*Serum progesterone level*
- A **serum progesterone level** is primarily used to assess **ovulation** or luteal phase function and has no relevance in diagnosing the cause of a failing **LNG-IUS**.
- The therapeutic effect of the LNG-IUS is mainly local on the **endometrium**, making systemic hormone levels unhelpful in this context.
*Endometrial biopsy*
- While an **endometrial biopsy** is crucial for investigating abnormal uterine bleeding in certain situations, especially to exclude **endometrial hyperplasia** or **carcinoma**, it is not the first step when device malfunction is suspected.
- This invasive procedure should be considered if the **LNG-IUS position is confirmed correct** and heavy bleeding persists, or if other risk factors warrant it.
*Full blood count and ferritin*
- **Full blood count (FBC)** and **ferritin** are important tests to assess the **secondary effects of heavy menstrual bleeding**, such as **iron-deficiency anemia**.
- However, these tests do not help in diagnosing the **underlying cause** of the LNG-IUS failure or the return of heavy bleeding, making them less immediate than checking device integrity.
Question 44: A 45-year-old woman presents with a 9-month history of heavy menstrual bleeding. She has tried tranexamic acid and mefenamic acid with minimal improvement. She has completed her family. Pelvic examination reveals a 12-week sized, irregular, non-tender uterus. Pelvic ultrasound shows multiple intramural and subserosal fibroids, the largest measuring 7 cm. Her haemoglobin is 88 g/L. She wishes to avoid major surgery if possible. What is the most appropriate next management option?
A. Levonorgestrel intrauterine system insertion
B. Uterine artery embolisation (Correct Answer)
C. Total abdominal hysterectomy
D. Oral norethisterone
E. GnRH agonist therapy
Explanation: ***Uterine artery embolisation***
- This is the most appropriate choice for a patient with **large symptomatic fibroids** (7 cm) and **menorrhagia** who explicitly wishes to **avoid major surgery**.
- It is highly effective for reducing bleeding and shrinking fibroids in a **12-week sized uterus**, providing a minimally invasive alternative to hysterectomy.
*Levonorgestrel intrauterine system insertion*
- The presence of a **7 cm fibroid** and a **12-week sized irregular uterus** suggests significant cavity distortion, which increases the risk of **expulsion** and reduces efficacy.
- It is generally not the first-line choice when fibroids are large enough to significantly alter the **uterine anatomy**.
*Total abdominal hysterectomy*
- While this provides a definitive cure for fibroids and anemia, the patient specifically requested to **avoid major surgery**.
- Hysterectomy carries a longer **recovery time** and higher surgical risk compared to interventional radiological procedures like UAE.
*Oral norethisterone*
- This is a hormonal treatment that is generally **less effective** for managing heavy bleeding caused by large structural lesions like **intramural fibroids**.
- It does not address the **bulk symptoms** or provide a long-term solution for a patient who has already failed first-line medical therapies.
*GnRH agonist therapy*
- These are typically used as **short-term** measures (3-6 months) to shrink fibroids **pre-operatively** or to bridge to menopause.
- They are not suitable as a standalone long-term management option due to significant **side effects** like bone mineral density loss and menopausal symptoms.
Question 45: A 27-year-old nulliparous woman undergoes laparoscopy for suspected ectopic pregnancy. At surgery, a 3.5 cm unruptured left ampullary ectopic pregnancy is identified. The left fallopian tube appears healthy apart from the ectopic gestation. The right tube appears normal. She wishes to preserve her fertility. What is the most appropriate surgical management?
A. Left salpingectomy (Correct Answer)
B. Left salpingotomy
C. Bilateral salpingectomy
D. Left salpingectomy with right prophylactic salpingectomy
E. Milking the ectopic pregnancy from the fimbrial end
Explanation: ***Left salpingectomy***- Current **NICE/RCOG guidelines** recommend **salpingectomy** as the first-line surgical treatment for women with a healthy contralateral tube, even when desiring future fertility.- It offers a lower risk of **persistent trophoblastic disease** (requiring methotrexate) and avoids the significantly increased risk of a **repeat ectopic pregnancy** in the same tube associated with salpingotomy.*Left salpingotomy*- This procedure involves making an incision to remove the pregnancy while leaving the tube; however, it is generally reserved for patients with only **one functioning fallopian tube** or significant contralateral tubal disease.- It carries a **20% risk** of **persistent trophoblast** and does not significantly improve long-term **intrauterine pregnancy rates** compared to salpingectomy when the other tube is healthy.*Bilateral salpingectomy*- There is no clinical indication to remove the **normal-appearing right tube**, which is essential for future natural conception in this young woman.- This procedure would render the patient **permanently sterile**, necessitating **In Vitro Fertilization (IVF)** for any future pregnancy.*Left salpingectomy with right prophylactic salpingectomy*- Removing a healthy fallopian tube is medically unjustifiable and contradicts the patient's goal of **preserving fertility**.- **Prophylactic salpingectomy** is only considered in specific contexts like reducing ovarian cancer risk in high-risk patients during unrelated pelvic surgeries, which does not apply here.*Milking the ectopic pregnancy from the fimbrial end*- This technique is associated with a high rate of **retained products of conception** and subsequent pelvic hemorrhage or persistent hCG elevation.- It is discouraged due to a higher likelihood of **tubal damage** and failure compared to established surgical excision methods.
Question 46: A 42-year-old multiparous woman presents with a 14-month history of heavy menstrual bleeding. She reports flooding and clots, requiring double protection. Examination is unremarkable with a normal-sized uterus. Full blood count shows haemoglobin 95 g/L. She has completed her family and requests definitive treatment. Pelvic ultrasound shows a uniformly enlarged uterus measuring 11 cm in length with heterogeneous myometrium and no focal lesions. What is the most likely diagnosis?
A. Endometrial hyperplasia
B. Adenomyosis (Correct Answer)
C. Multiple small intramural fibroids
D. Endometrial polyp
E. Dysfunctional uterine bleeding
Explanation: ***Adenomyosis***- The presence of **heavy menstrual bleeding** in a multiparous woman with a **uniformly enlarged uterus** and **heterogeneous myometrium** on ultrasound, without focal lesions, is highly characteristic of **adenomyosis**.- This condition involves the invasion of endometrial tissue into the myometrium, leading to diffuse thickening of the uterine wall and often causes **dysmenorrhea** and **menorrhagia**.*Endometrial hyperplasia*- This condition is characterized by an **abnormal proliferation of the endometrial glands**, typically resulting in a **thickened endometrial stripe** on ultrasound.- It does not explain the **uniformly enlarged uterus** or the **heterogeneous myometrium** described, as it primarily affects the lining, not the muscle.*Multiple small intramural fibroids*- Fibroids are **well-defined, focal masses** within the myometrium, which would be visible as distinct lesions on ultrasound.- The report explicitly states **"no focal lesions"**, making this diagnosis unlikely despite potentially causing heavy menstrual bleeding and uterine enlargement.*Endometrial polyp*- An endometrial polyp is a **focal growth arising from the endometrium** and protruding into the uterine cavity, visible as an intracavitary mass on ultrasound.- It does not cause the diffuse **heterogeneous myometrium** or the overall **uniformly enlarged uterus** observed in this case.*Dysfunctional uterine bleeding*- This is a diagnosis of **exclusion**, implying no identifiable structural or histological abnormality to account for the bleeding.- The ultrasound findings of a **uniformly enlarged uterus** and **heterogeneous myometrium** clearly indicate a structural abnormality (adenomyosis), thereby ruling out dysfunctional uterine bleeding.
Question 47: A 50-year-old woman presents to her GP with a 7-month history of irregular heavy vaginal bleeding. Her periods were previously regular 28-day cycles but are now unpredictable, occurring every 18-45 days with variable flow. Her last menstrual period was 3 weeks ago. She is a non-smoker with BMI 26 kg/m². On examination, her abdomen is soft and non-tender. Speculum examination shows a healthy-appearing cervix with no active bleeding. Her cervical screening is up to date with normal results. What is the most appropriate initial investigation?
A. Transvaginal ultrasound scan (Correct Answer)
B. Serum follicle-stimulating hormone and luteinising hormone levels
C. Outpatient hysteroscopy with endometrial biopsy
D. Full blood count and thyroid function tests
E. Pelvic MRI scan
Explanation: ***Transvaginal ultrasound scan***
- In a 50-year-old woman with **irregular heavy vaginal bleeding**, a **transvaginal ultrasound scan** is the most appropriate initial investigation to assess for **endometrial pathology** like hyperplasia or malignancy.
- It can effectively measure **endometrial thickness** and identify structural abnormalities such as **fibroids** or **polyps** which could be contributing to the bleeding.
*Serum follicle-stimulating hormone and luteinising hormone levels*
- While the patient's age and symptoms suggest **perimenopause**, hormone levels are not the primary investigation to rule out significant **endometrial pathology**.
- Clinical diagnosis of perimenopause often suffices, and these tests do not identify the structural causes of heavy bleeding.
*Outpatient hysteroscopy with endometrial biopsy*
- **Hysteroscopy with biopsy** is a more invasive procedure and is typically performed *after* a transvaginal ultrasound has identified suspicious findings like **endometrial thickening**.
- It is not the initial investigation but rather a follow-up if ultrasound results are concerning or inconclusive, allowing for direct visualization and tissue sampling.
*Full blood count and thyroid function tests*
- A **full blood count** is important to check for **anaemia** due to heavy bleeding but does not determine the underlying cause of the bleeding itself.
- **Thyroid function tests** are not routinely indicated as a first-line investigation for irregular bleeding unless other clinical symptoms suggest thyroid dysfunction.
*Pelvic MRI scan*
- A **pelvic MRI scan** is a more advanced and expensive imaging modality not used as a first-line investigation for abnormal uterine bleeding.
- It is usually reserved for complex cases, further characterization of findings from ultrasound, or for **surgical planning** in conditions like extensive fibroids or adenomyosis.
Question 48: A 32-year-old woman is admitted with suspected ectopic pregnancy. She has 8 weeks amenorrhoea and right-sided pelvic pain. Initial serum beta-hCG is 3200 IU/L. Transvaginal ultrasound shows an empty uterus and a 32mm right adnexal mass with no fetal heartbeat. There is minimal free fluid in the pelvis. She is haemodynamically stable. Following counselling, she opts for expectant management. Under which circumstance during expectant management should medical or surgical intervention be initiated?
A. Beta-hCG level plateaus for 7 days without rising or falling
B. Patient develops mild increase in abdominal pain but remains stable
C. Beta-hCG rises by 15% over 48-hour period (Correct Answer)
D. Repeat ultrasound shows increase in adnexal mass size to 38mm
E. Beta-hCG level remains above 1000 IU/L after 2 weeks
Explanation: ***Beta-hCG rises by 15% over 48-hour period***
- Intervention is required if **beta-hCG levels rise** or plateau, as this indicates the **ectopic pregnancy** is viable or not resolving spontaneously.
- A **15% increase** in initial monitoring periods suggests active trophoblastic growth, necessitating a shift to **medical management** (methotrexate) or surgery.
*Beta-hCG level plateaus for 7 days without rising or falling*
- A **plateauing beta-hCG** is considered a failure of expectant management because it signifies persistent **trophoblastic activity**.
- Decisions for intervention are typically made within shorter windows (48-72 hours) rather than waiting for **7 days** to verify a plateau.
*Patient develops mild increase in abdominal pain but remains stable*
- Mild increases in pain can occur during the **spontaneous resolution** of an ectopic pregnancy and do not always mandate immediate surgery if the patient is **hemodynamically stable**.
- Only significant clinical deterioration, signs of **hemoperitoneum**, or hemodynamic instability are absolute indications for abandoning expectant management.
*Repeat ultrasound shows increase in adnexal mass size to 38mm*
- Changes in **adnexal mass size** on ultrasound are less reliable indicators of failure than **biochemical trends** and clinical status.
- An increase in size may be due to **hematoma formation** rather than continued trophoblastic growth and is not an absolute indication for intervention on its own.
*Beta-hCG level remains above 1000 IU/L after 2 weeks*
- The **absolute value** of beta-hCG after two weeks is less important than the **downward trend** of the hormone levels.
- Expectant management is considered successful as long as the **beta-hCG levels continue to fall** appropriately, regardless of the baseline value.
Question 49: A 36-year-old woman with heavy menstrual bleeding has been using a levonorgestrel intrauterine system for 18 months with good initial symptom control. She now presents with recurrence of heavy bleeding over the past 3 months. Examination shows the IUS threads are visible at the cervical os and the uterus is normal size. Pelvic ultrasound confirms the IUS is correctly positioned in the uterine cavity and shows a 4cm subserosal fibroid on the posterior uterine wall that was not present on her pre-insertion scan. What is the most likely explanation for her recurrent heavy bleeding?
A. The levonorgestrel intrauterine system has lost its efficacy over time
B. The subserosal fibroid is causing increased menstrual blood loss
C. The intrauterine system has become partially expelled
D. Endometrial polyps have developed despite the intrauterine system
E. Adenomyosis has developed and is not controlled by the intrauterine system (Correct Answer)
Explanation: ***Adenomyosis has developed and is not controlled by the intrauterine system***
- **Adenomyosis** involves endometrial tissue within the **myometrium**, which can progress over time and lead to recurrent **heavy menstrual bleeding (HMB)** even when an IUS is in place.
- While the LNG-IUS provides local suppression of the **endometrium**, its hormonal effect may be insufficient to control symptoms if the adenomyosis is deep or extensive within the muscle wall.
*The levonorgestrel intrauterine system has lost its efficacy over time*
- The **LNG-IUS (Mirena)** is licensed for 5 years and maintains a therapeutic **hormone release rate** well beyond the 18-month mark mentioned.
- A sudden recurrence of bleeding after 18 months of good control is more suggestive of **new pathology** than drug exhaustion.
*The subserosal fibroid is causing increased menstrual blood loss*
- **Subserosal fibroids** grow on the outer surface of the uterus and do not distort the **endometrial cavity**, meaning they typically do not cause HMB.
- Only **submucosal** or large **intramural fibroids** significantly increase the surface area of the uterine lining or interfere with contractility to cause heavy bleeding.
*The intrauterine system has become partially expelled*
- Ultrasound confirmation shows the device is **correctly positioned** in the uterine cavity, and the **threads** are visible at the os.
- Clinical and radiological evidence directly contradicts **expulsion** as the cause of the recurrent bleeding.
*Endometrial polyps have developed despite the intrauterine system*
- Although polyps can cause irregular bleeding, the **pelvic ultrasound** would likely have identified them as discrete lesions within the cavity.
- The scenario points toward a more likely progressive myometrial condition like **adenomyosis**, especially given the development of other uterine growth (the fibroid).
Question 50: A 29-year-old woman presents to the emergency department with sudden onset severe right-sided abdominal pain and shoulder tip pain. She has 7 weeks amenorrhoea. On examination, she is pale, with blood pressure 88/55 mmHg and heart rate 122 beats per minute. She has generalised abdominal tenderness with guarding and rebound tenderness. Her cervical os is closed with minimal old blood in the vagina. A bedside urine pregnancy test is positive. What physiological mechanism is responsible for the shoulder tip pain in this patient?
A. Direct compression of the brachial plexus by haemoperitoneum
B. Stretching of the round ligament causing referred pain
C. Inflammation of the parietal peritoneum adjacent to the fallopian tube
D. Irritation of the diaphragm by intraperitoneal blood (Correct Answer)
E. Ischaemia of the shoulder muscles due to hypovolaemic shock
Explanation: ***Irritation of the diaphragm by intraperitoneal blood***
- This patient presents with a **ruptured ectopic pregnancy** and **haemoperitoneum**, where blood irritates the **phrenic nerve** (C3-C5) under the diaphragm.
- Pain is referred to the **C3-C5 dermatomes**, which correspond to the **shoulder tip**, a classic sign of significant internal bleeding known as **Kehr's sign**.
*Direct compression of the brachial plexus by haemoperitoneum*
- The **brachial plexus** is located in the neck and axilla, which are anatomically isolated from the **peritoneal cavity**.
- Blood in the abdomen cannot exert the physical pressure required to compress these nerves directly.
*Stretching of the round ligament causing referred pain*
- **Round ligament pain** typically manifests as sharp, pulling sensations in the **lower quadrants** or inguinal area during pregnancy.
- It does not cause **shoulder tip pain** or the sudden hemodynamic collapse seen in this patient.
*Inflammation of the parietal peritoneum adjacent to the fallopian tube*
- Irritation of the **parietal peritoneum** near the tube causes localized **rebound tenderness** and guarding in the lower abdomen.
- Somatic nerves in the lower abdomen do not share pathways that would result in **referred pain** to the shoulder.
*Ischaemia of the shoulder muscles due to hypovolaemic shock*
- While **hypovolaemic shock** causes systemic hypoperfusion, it leads to general symptoms like **tachycardia** and **pallor**, not focal muscle ischaemia.
- Musculoskeletal ischaemia does not present as localized **shoulder tip pain** following a sudden abdominal event.
