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Obs & gynae clinic – red degeneration of fibroids

The case

A 37-year-old primigravida 27 weeks advanced in her pregnancy presented to her GP with a two day history of worsening dull pain in the right side of her abdomen. This was associated with nausea and vomiting and did not respond to paracetamol tablets. The GP arranged urgent admission so she could be assessed in the hospital gynaecology department.

On examination the abdomen was soft with significant tenderness on the right side of the pregnant uterus. Her temperature was 37.8°C, blood pressure 135/87 mmHg and pulse 98 bpm. Blood count, urine analysis and LFTs were normal.

Abdominal ultrasound scan revealed a fundal placenta with no evidence of retroplacental haematoma. The foetal growth was normal. A fibroid 60 x 48 x 71 mm in size was identified in the right side of the uterus with cystic changes at the centre (see right). The gallbladder was normal. On admission the pain was controlled with narcotic analgesics, and the patient was discharged a week later on co-codamol 8/500 tablets. She had an uneventful delivery at term.

The problem

Uterine fibroids are the most common benign gynaecologic tumors, affecting 40-60% of reproductive age women.1 They originate from the myometrium but the underlying etiology is not clear. There is evidence that genetic predisposition and the fibroid promoting effect of oestrogen and progesterone, which is mediated through insulin-like growth factor, have significant role to play.2 The incidence of fibroids and their complications are significantly higher in African-Caribbean women compared to Asian/European and Hispanics.

The incidence of fibroids during pregnancy may be as high as 12.5% of all pregnancies.3 Fibroids  over 50 mm in diameter may undergo a red degeneration, which is more likely during the second and third pregnancy trimesters than in a non-pregnant uterus. It is estimated that 9% of fibroids undergo red degeneration during pregnancy based on ultrasound scan evidence, but only 70% of these experienced severe abdominal pain.4 The red degeneration and associated pain may be attributed to:

1. Fibroid tissue outgrowing its blood supply causing ischemia and haemorrhagic necrosis, giving the degenerating fibroid its typical red colour.5 (see figure 1)

2. The growing uterus may cause distortion and kinking of the blood vessels, thus disrupting the blood supply to the fibroid.6

3. The prostaglandins produced by damage of the cells in the fibroid. This may explain why ibuprofen and other prostaglandin synthetase inhibitors quickly and effectively control the pain.7


Figure 1: Ultrasound scan appearance of a uterine fibroid with red degeneration. Degenerative changes can take place in fibroids with areas of necrosis and haemorrhage and result in varying appearances from cystic to inhomogenous appearances. There is reduced vascularity with little or no Doppler flow demonstrated


·         A history of pre-existing uterine fibroids in some cases

·         Moderate to severe localised abdominal pain

·         Nausea and vomiting

·         Fever

·         Tachycardia but normal blood pressure

·         In pregnant women fibroid red degeneration may induce uterine contractions, which could lead to premature labour or miscarriage.

Other causes of acute and severe abdominal pain during pregnancy include accidental haemorrhage, torsion of pedunculated fibroid, ureteric colic, biliary colic, complicated ovarian cyst, and appendicitis.


·         Localised acute tenderness of the uterus corresponding to the affected fibroid. During pregnancy fibroids are not palpable as a discrete mass because fibroids become softer inconsistency and flatter in shape. Evidence of premature labour (uterine activity, cervical effacement and dilatation) should be sought.

·         Ultrasound scan shows a heterogeneous echogenic pattern and cystic changes with no evidence of blood flow (figure 1).


The pain usually resolves within 7-10 days and is treated conservatively by bed rest, hydration (IV fluid) and simple analgesics. When the pain is severe narcotic analgesics or epidural analgesia are used.8 NSAIDs should not be used for more than 48 hours in the third trimester as it may lead to premature closure of the ductus arteriosus in utero and pulmonary hypertension.

Myomectomy during pregnancy may be considered only in very exceptional circumstances because of the risk of bleeding and pregnancy loss.5,9

Dr Nabil Aziz is a consultant in gynaecology and reproductive medicine at the Liverpool Women’s Hospital & The University of Liverpool


  1. Day Baird D, Dunson DB, Hill MC, Cousins D, Schectman JM. (2003) High cumulative incidence of uterine leiomyoma in black and white women: ultrasound evidence. American Journal of Obstetrics and Gynaecology, 188 (1); 100-110.
  2. Flake PG, Andersen J, Dixon D. (2003) Etiology and pathogenesis of uterine leiomyomas: a review. Environmental Health Perspectives, 111 (8); 1037-1057
  3. Cooper NP, Okolo S. (2005) Fibroids in pregnancy – common but poorly understood. Obstetrical and gynaecological survey, 60(2): 132-138.
  4. Lev-Toaff AS, Coleman BG, Arger PH, Mintz MC, Arenson RL, Toaff ME. (1987) Leiomyomas in pregnancy: sonographic study. Radiology, 164 (2): 375-380.
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  6. Parker WH. (2007) Etiology, symptomatology, and diagnosis of uterine myomas. Fertility and sterility, 87 (4); 725-736
  7. Katz VL, Dotters DJ, Droegemueller W. (1989) Complications of uterine leiomyomas in pregnancy. Obstetrics and Gynaecology, 73 (4); 593-596
  8. Seki H, Takizawa Y, Sodemoto T. (2003) Epidural analgesia for painful myomas refractory to medical therapy during pregnancy. International Journal of Gynaecology and Obstetrics,  83 (3): 303-304
  9. Wittich AC, Salminen ER, Yancey MK, Markenson GR. (2000) Myomectomy during early pregnancy. Military Medicine, 165 (2): 162-164.