Oxford Handbook of Obstetrics and Gynaecology (3 edn)
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Fibroids in pregnancy
Incidence in pregnancy varies from 0.1% to 3.9%.
May be higher in women over 35, primigravida, and those of Afro-Caribbean origin.
USS is usually used to make the diagnosis, but fibroids can be confused with solid ovarian or other tumours.
Only 42% of fibroids in pregnancy are detected clinically.
Effects of pregnancy on fibroids
Whether fibroids increase, decrease, or stay the same after pregnancy remains controversial.
Red degeneration (necrobiosis).
Torsion of a pedunculated fibroid.
Fibroid impaction.
Pain may be severe enough to require morphine via PCA.
Risk of spontaneous miscarriage may be ↑: preconception myomectomy seems to improve likelihood of successful pregnancy with recurrent pregnancy loss, especially when no other cause found.
May ↑ the risk of 2nd-trimester miscarriages.
Invasive procedures, such as amniocentesis and CVS, may be technically difficult.
↑ Risk of threatened preterm labour (reported rate up to 22%).
Placentation over a fibroid is a strong risk factor for abruption.
It is unclear whether fibroids are associated with IUGR.
Large fibroids may exert pressure on the fetus, causing limb reduction defects, congenital torticollis, and head deformities (fetal compression syndrome).
Very rare complications include disseminated intravascular coagulation, spontaneous haemoperitoneum, uterine inversion, uterine incarceration, acute renal failure, and urinary retention.
Incidence of CS is doubled, as malpresentations, dysfunctional labour, and obstructed labour are more common, especially when fibroids are in lower uterine segment.
↑ Risk of PPH.
Higher incidence of retained placenta (may be due to lower-segment fibroids obstructing delivery of placenta).
Conservative management:
symptomatic treatment of pain
monitoring of the fetus.
Surgical procedures for fibroids during pregnancy carry risk of significant haemorrhage. Therefore myomectomy not performed in pregnancy.
A myomectomy during CS is also avoided as it carries a high
morbidity from haemorrhage: rarely, it may be necessary to remove a fibroid to gain access to the fetus or to facilitate uterine repair.
Ovarian cysts in pregnancy
Incidence of 1–2%.
The majority are small (3–4cm), persistent follicular cysts.
Cysts 6cm occur in 0.5–2:1000 pregnancies.
Most common ovarian cysts seen in pregnancy include:
functional ovarian cysts (follicular, corpus luteum, and theca-lutein)
benign cystic teratomas
serous cystadenomas
mucinous cystadenomas
endometriomas
malignant tumours (2–3%).
Effects of ovarian cysts on pregnancy
Impaction of the cyst may lead to urinary retention.
↑ Risk of miscarriage or preterm delivery.
May cause discomfort if very large.
Large cysts may prevent engagement of the fetal head and predispose to malpresentation (rarely, may cause obstructed labour).
Complications are same as in non-pregnant state:
Torsion most likely to occur at end of 1st trimester or in puerperium (risk of torsion is between 3 and 25%).
Cyst haemorrhage may occur as a result of ↑ vascularity.
Rupture (may follow impaction during labour).
Acute complications should be treated by surgery at any gestation.
Asymptomatic, non-enlarging cysts, cystadenomas, and dermoids should be managed conservatively.
Cystectomy performed in patients with:
symptoms or acute complications (torted, haemorrhagic, ruptured)
suspicion of malignancy (if strong suspicion, unilateral oophectomy should be performed)
enlargement or large size (>8–10cm).
Elective surgery should be performed at 16–20wks:
risk of miscarriage is lower
access to the pedicle is easy.
The choice of laparotomy or laparoscopy is dependent on:
risk of malignancy
urgency of the procedure
skills of the surgeon.
The risk of miscarriage after emergency surgery for ovarian torsion can be as high as 22.2%.
If cyst causes obstruction of labour, delivery should be by CS and cyst dealt with at the same time.
Malignancy in pregnancy: overview
Cancer is rare under the age of 30. However, so are other causes of death, and therefore cancer is still the leading cause of death in England and Wales in this age group. Consequently, cancer in pregnancy is relatively rare. The last CEMD (2003–2005) reported 82 cancer-related deaths. However, upward shift in age of motherhood in the UK means that more women are now pregnant when incidence of cancer is starting to increase. During reproductive years, breast cancer is the most common cancer diagnosis being 10-fold more common than other cancers. This incidence increases dramatically in the over-40s. Principal cancers in younger women are melanoma and cervical cancer.
Pregnancy-associated cancer is defined as a cancer diagnosis during pregnancy or within 12mths of a delivery.
The incidence of cancer in pregnancy is about 1:6000 live births.
This is about 50% lower than in non-pregnant women.
Women diagnosed within the 12mth postnatal period are more likely to have advanced disease and a poorer prognosis is most likely due to a delay in diagnosis, either because the pregnancy masked signs and symptoms, especially true of breast cancer, or because of a reluctance to perform necessary investigations.
There does not appear to be any difference in the stage-for-stage survival and mortality figures, and the prognosis.
Some cancers, particularly hormone-dependent ones, can grow rapidly in pregnancy, but factors related to tumour growth in relation to the endocrine and physiological changes in pregnancy are still poorly understood.
Compromise between interest of fetus and mother.
Some treatments cause fetal demise: pelvic radiotherapy (60Gy).
Some are probably OK after 1st trimester, including chemotherapy.
carboplatin (avoid paclitaxel)
careful counselling regarding termination of the pregnancy should be undertaken.
Each case has to be individualized, based on:
gestation
tumour histology
patient choice.
Cervical cancer in pregnancy: diagnosis
Most common cancer of the genital tract to present in pregnancy, with estimated incidence of 2.4/100 000 pregnancies. There has been a decline in invasive carcinoma of the cervix in developed countries, which may be attributed to cancer screening programmes (see 
Cancer screening in gynaecology: overview, p. 702).
The UK National Cervical Screening Programme ensures the majority of women have routine screening with appropriate referral.
Allows women to delay pregnancy if they have had abnormal cytology.
May be more difficult to interpret cytology result in a pregnant woman and therefore routine screening deferred until >6wks post-partum, if previously adequately screened. Follow-up smears after treatment or abnormal smear should not be delayed.
Where clinically indicated, referral for colposcopy should be made.
At colposcopy, it is more difficult to interpret changes in colour following application of acetic acid and iodine in pregnancy.
Biopsy of the cervix can lead to brisk bleeding and, where possible, should be avoided in pregnancy.
Risk of miscarriage or preterm labour following biopsy is low.
Presentation and diagnosis
Cervical carcinoma can present as recurrent bleeding in pregnancy in a woman not up to date with her smear tests.
Pregnancy does not accelerate progression of cervical intraepithelial neoplasia (CIN) to invasive.
Prognosis may depend on duration from diagnosis to treatment.
Delaying treatment to achieve fetal maturity is not known to worsen prognosis.
Of those women with cervical cancer in pregnancy, nearly 7% are diagnosed at the time of their pregnancy confirmation.
Most women are asymptomatic at presentation (up to 65%).
Diagnosis may follow assessment of abnormal smear or colposcopy.
Colposcopy and cervical punch biopsy are safe in pregnancy.
A large loop excision of the transformation zone (LLETZ) or knife cone biopsy carries a significant risk of haemorrhage and miscarriage.
Staging of the disease may be difficult when the uterus is enlarged:
Avoid exposure of the fetus to ionizing radiation.
MRI is safe in pregnancy.
Cervical cancer in pregnancy: management and prognosis
Risk of haemorrhage, infection, miscarriage, preterm labour, and prelabour rupture of membranes.
80% of pregnancies result in term deliveries and fetal survival is over 90%.
In the 1st and 2nd trimesters radical hysterectomy and lymphadenectomy may be performed with the fetus in utero.
In late mid-trimester (>24wks) CS may be performed followed by radical hysterectomy and lymphadenectomy: a classical section reduces the risk of encroaching on the tumour.
Little evidence to suggest any benefit, but if patient presents in labour, emergency CS may be performed to reduce dissemination of disease.
Treatment should not be delayed.
If pregnancy is >24wks, management must be individualized according to mother’s wishes; baby should be delivered at appropriate gestation, by classical CS, and radiotherapy instituted.
Prognosis
There is no evidence to suggest that when early-stage disease is diagnosed in pregnancy, the prognosis is worse than for non-pregnant women.
The 5yr survival in pregnant women with advanced disease is lower than for their non-pregnant counterparts: this difference could be due to radiation dosimetry during or soon after pregnancy.
See Cervical cancer: pathology and screening, p. 706.
Ovarian cancer in pregnancy
It is common to diagnose an ovarian mass in pregnancy, especially now that most women will have an early pregnancy ultrasound. Only 2–3% of the ovarian tumours that require surgery in pregnancy are malignant. Nearly 1/3 of these are dysgerminomas, teratomas, or germ-cell tumours (most likely due to the age of the patients).
Most tumours are asymptomatic: <25% are >10cm.
Some will present as abdominal pain due to cyst accident: torsion complicates 10–15% of tumours:
Tumour markers not reliable in pregnancy.
High incidence of germ cell tumours:
30% germ cell tumours
21% borderline tumours
28% epithelial carcinomas
3% krukenberg
8% others.
Ovarian cyst or mass identified in 1st trimester should be rescanned at 14wks (most corpus luteal cysts involute by then):
if it has not ↑ to >5cm, conservative management is appropriate
if >5cm, serial USS should be used to monitor any change in size or morphology (which may prompt surgery).
Where there are signs of malignancy in the mass:
surgery can be limited to unilateral opherectomy, but a complete staging must be performed
if staging at laparotomy is suggestive of spread beyond the ovary, or if histology determines the need for chemotherapy, a multidisciplinary approach should be taken and treatment guided by patient wishes, after appropriate counselling.
Breast cancer in pregnancy
Breast cancer is the most common cancer associated with pregnancy in countries that have an effective cervical screening programme. The incidences from the literature are quoted as between 1 in 3000 and one in 10 000 pregnancies. There is evidence that diagnosis of breast cancer is delayed by pregnancy as associated symptoms are often attributed to pregnancy itself.
Prognosis
Breast cancer in younger women has poorer prognosis.
Pregnancy itself does not appear to worsen prognosis.
Diagnosis
Women presenting with breast lump during pregnancy should be referred to breast specialist team, and any imaging or further tests should be conducted in conjunction with multidisciplinary team.
Decision to continue pregnancy should be based on careful discussion of cancer prognosis, treatment, and future fertility with the woman and her partner, and multidisciplinary team.
The multidisciplinary team review outcome should be forwarded to the obstetric team and family doctor.
Surgical treatment should be same as non-pregnant woman:
wide local excision
modified radical mastectomy
reconstruction should be delayed until after delivery.
Radiotherapy contraindicated until after delivery unless life-saving or to preserve organ function.
Chemotherapy may be offered after 1st trimester.
there is no evidence for an ↑ rate of 2nd-trimester miscarriage or fetal growth restriction, organ dysfunction, or long-term adverse outcome with the use of chemotherapy
tamoxifen and trastuzumab are contraindicated in pregnancy.
Birth of baby should be timed after discussion with woman and multidisciplinary team.
Each case has to be individualized, based on gestation and patient choice.
Breast-feeding
Reassure women that they can breast-feed from unaffected breast.
Women should not breast-feed when taking trastuzumab or tamoxifen, as it is unknown whether these drugs are transmitted in breastmilk.
Further reading
RCOG. (2011). Pregnancy and breast cancer, Green top guideline 12. 
http://www.rcog.org.uk/en/guidelines-research-services/guidelines/gtg12/.
