From the Guidelines
A blighted ovum, also known as anembryonic pregnancy, is diagnosed when an ultrasound shows a gestational sac without an embryo after 6-7 weeks of pregnancy, and management typically involves either expectant, medical, or surgical approaches. The diagnosis of a blighted ovum is based on the absence of an embryo in a gestational sac with a mean sac diameter (MSD) of 25 mm or larger, or the absence of embryonic cardiac activity in an embryo with a crown-rump length (CRL) of 7 mm or larger 1.
Diagnosis
The following criteria are used to diagnose a blighted ovum:
- Absence of an embryo in a gestational sac with an MSD of 25 mm or larger
- Absence of embryonic cardiac activity in an embryo with a CRL of 7 mm or larger
- Absence of a yolk sac in a gestational sac with an MSD of 8 mm or larger
Management
Management options for a blighted ovum include:
- Expectant management: waiting for natural miscarriage, which occurs in about 65-80% of cases within 2-6 weeks
- Medical management: using misoprostol, typically 800 mcg vaginally or 600 mcg sublingually, which may be repeated after 24 hours if needed
- Surgical management: dilation and curettage (D&C) provides immediate resolution and tissue for genetic testing but carries risks of infection, uterine perforation, and scarring
Monitoring and Follow-up
Patients should be monitored for excessive bleeding, severe pain, fever, or foul-smelling discharge, which warrant immediate medical attention 1. Emotional support is essential as this represents pregnancy loss, and most women can expect normal fertility afterward, with no increased risk of recurrence in subsequent pregnancies unless multiple losses occur.
Key Considerations
It is essential to use the recommended lexicon terms, such as "anembryonic pregnancy" instead of "blighted ovum," to ensure clear and respectful communication with patients and healthcare providers 1. Additionally, the decision to treat should be based on clinical factors or a persistent gestational sac, rather than the presence of "retained" products of conception 1.
From the Research
Diagnosis of Blighted Ovum
- A blighted ovum is typically diagnosed using ultrasound examination, which can confirm the absence of an embryo or fetal development 2.
- Serum β-hCG measurement can also be used to predict complete abortion after medical induction, and is as effective as ultrasound in confirming a successful medically induced abortion in early pregnancy 3.
Management of Blighted Ovum
- Medical management of blighted ovum is a valid option for those women seeking an alternative to traditional surgical management, with a success rate of 83.3% 4.
- Mifepristone combined with oral misoprostol is an effective treatment for first trimester miscarriage, including blighted ovum, with a success rate of 70.5% and 66.7% for different doses of mifepristone 5.
- Surgical therapy may also be used to manage blighted ovum, especially in cases where there is a simultaneous ectopic pregnancy 2.
- The choice of management depends on various factors, including the woman's preferences, medical history, and the presence of any complications.
Complications and Risk Factors
- Higher beta-hCG values 14 days after the procedure and the absence of evacuation of products of conception during hospitalisation are associated with a higher complication rate 4.
- Complications that may occur after medical management of blighted ovum include bleeding, pain, nausea, and diarrhoea, with a complication rate of 9% 4.
- A high index of suspicion is necessary to diagnose and manage blighted ovum and any potential complications, especially in low-income settings 2.