In addition to these evidence-based recommendations, the guideline development group also identifies points of best clinical practice in the original guideline document.
Classification of evidence levels (1++ to 4) and grades of recommendations (A-D) are defined at the end of the "Major Recommendations" field.
How Are Molar Pregnancies Diagnosed?
D - Ultrasound examination is helpful in making a pre-evacuation diagnosis but the definitive diagnosis is made by histological examination of the products of conception.
Evacuation of a Molar Pregnancy
Is it Safe to Prepare the Cervix Prior to Surgical Evacuation?
D - Preparation of the cervix immediately prior to evacuation is safe.
Prolonged cervical preparation, particularly with prostaglandins, should be avoided where possible to reduce the risk of embolisation of trophoblastic cells. [Evidence level 4]
Histological Examination of Products of Conception in the Diagnosis of Gestational Trophoblastic Disease (GTD)
Should Products of Conception from All Miscarriages Be Examined Histologically?
D - The histological assessment of material obtained from the medical or surgical management of all failed pregnancies is recommended to exclude trophoblastic neoplasia.
Ploidy status and immunohistochemistry staining for P57 may help in distinguishing partial from complete moles. [Evidence level 3]
Should Products of Conception Be Sent for Examination after Surgical Termination of Pregnancy?
D - There is no need to routinely send products of conception for histological examination following therapeutic termination of pregnancy, provided that fetal parts have been identified on prior ultrasound examination.
How Should Persisting Gynaecological Symptoms after an Evacuation for Molar Pregnancy Be Managed?
C - Consultation with the relevant trophoblastic screening centre is recommended prior to second evacuation.
There is no clinical indication for the routine use of second uterine evacuation in the management of molar pregnancies.
If symptoms are persistent, evaluation of the patient with human chorionic gonadotrophin (hCG) estimation and ultrasound examination is advised. Several case series have found that there may be a role for second evacuation in selected cases when the hCG is less than 5000 units/litre. [Evidence level 2+]
Which Women Should Be Investigated for Gestational Trophoblastic Neoplasia (GTN) after a Non-molar Pregnancy?
D - Any woman who develops persistent vaginal bleeding after a pregnancy event is at risk of having GTN.
D - Symptoms from metastatic disease, such as dyspnoea or abnormal neurology, can occur very rarely.
How Is Twin Pregnancy of a Fetus and Coexistent Molar Pregnancy Managed?
D - In the situation of a twin pregnancy where there is one viable fetus and the other pregnancy is molar, the woman should be counselled about the increased risk of perinatal morbidity and outcome for GTN.
D - Prenatal invasive testing for fetal karyotype should be considered in cases where it is unclear if the pregnancy is a complete mole with a coexisting normal twin or a partial mole. Prenatal invasive testing for fetal karyotype should also be considered in cases of abnormal placenta, such as suspected mesenchymal hyperplasia of the placenta.
What Is the Optimum Follow-up Following a Diagnosis of GTD?
D - If hCG has reverted to normal within 56 days of the pregnancy event then follow-up will be for 6 months from the date of uterine evacuation.
D - If hCG has not reverted to normal within 56 days of the pregnancy event then follow-up will be for 6 months from normalisation of the hCG level.
What Is the Optimum Treatment for GTN?
D - Women with GTN may be treated either with single-agent or multi-agent chemotherapy for GTN. Treatment used is based on the International Federation of Gynecology and Obstetrics (FIGO) 2000 scoring system for GTN following assessment at the treatment centre.
Women are assessed before chemotherapy using the FIGO 2000 scoring system (see Table 1 in the original guideline document). Women with scores ≤6 are at low risk and are treated with single-agent intramuscular methotrexate alternating daily with folinic acid for 1 week followed by 6 rest days. Women with scores ≥7 are at high risk and are treated with intravenous multi-agent chemotherapy, which includes combinations of methotrexate, dactinomycin, etoposide, cyclophosphamide and vincristine. Treatment is continued, in all cases, until the hCG level has returned to normal and then for a further 6 consecutive weeks.
When Can Women Whose Last Pregnancy Was a Complete or Partial Hydatidiform Molar Pregnancy Try to Conceive in the Future and What Is the Outcome of Subsequent Pregnancies?
D - Women should be advised not to conceive until their follow-up is complete.
D - Women who undergo chemotherapy are advised not to conceive for 1 year after completion of treatment.
What Is the Long-term Outcome of Women Treated for GTN?
D - Women who receive chemotherapy for GTN are likely to have an earlier menopause.
D - Women with high-risk GTN who require multi-agent chemotherapy which includes etoposide should be advised that they may be at increased risk of developing secondary cancers.
What Is Safe Contraception Following a Diagnosis of GTD and When Should It Be Commenced?
D - Women with GTD should be advised to use barrier methods of contraception until hCG levels revert to normal.
D - Once hCG level have normalised, the combined oral contraceptive pill may be used. There is no evidence as to whether single-agent progestogens have any effect on GTN.
Classification of Evidence Levels
1++ High-quality meta-analyses, systematic reviews of randomised controlled trials or randomised controlled trials with a very low risk of bias
1+ Well-conducted meta-analyses, systematic reviews of randomised controlled trials or randomised controlled trials with a low risk of bias
1- Meta-analyses, systematic reviews of randomised controlled trials or randomised controlled trials with a high risk of bias
2++ High-quality systematic reviews of case–control or cohort studies or high-quality case–control or cohort studies with a very low risk of confounding, bias or chance and a high probability that the relationship is causal
2+ Well-conducted case–control or cohort studies with a low risk of confounding, bias or chance and a moderate probability that the relationship is causal
2- Case–control or cohort studies with a high risk of confounding, bias or chance and a significant risk that the relationship is not causal
3 Non-analytical studies; e.g., case reports, case series
4 Expert opinion
Grades of Recommendations
A - At least one meta-analysis, systematic review or randomised controlled trial rated as 1++, and directly applicable to the target population; or
A systematic review of randomised controlled trials or a body of evidence consisting principally of studies rated as 1+, directly applicable to the target population and demonstrating overall consistency of results.
B - A body of evidence including studies rated as 2++ directly applicable to the target population, and demonstrating overall consistency of results; or
Extrapolated evidence from studies rated as 1++ or 1+
C - A body of evidence including studies rated as 2+ directly applicable to the target population and demonstrating overall consistency of results; or
Extrapolated evidence from studies rated as 2++
D - Evidence level 3 or 4; or
Extrapolated evidence from studies rated as 2+
Good Practice Point - Recommended best practice based on the clinical experience of the guideline development group