From the Guidelines
A blighted ovum, also known as an anembryonic pregnancy, is diagnosed when an embryo fails to develop within a gestational sac during early pregnancy, and the most recent and highest quality study recommends avoiding the term 'blighted ovum' and instead using 'anembryonic pregnancy' or 'diagnostic of early pregnancy loss (EPL)' 1.
Diagnosis
Diagnosis typically involves ultrasound showing an empty gestational sac without an embryo, along with blood tests revealing abnormal hormone levels (hCG not rising appropriately) 1. The criteria for diagnosing EPL include an embryonic crown-rump length (CRL) of less than 7 mm and no cardiac activity, a mean sac diameter (MSD) of 16-24 mm and no embryo, or absence of an embryo with cardiac activity 7-13 days after visualization of the gestational sac and no yolk sac 1.
Treatment
Treatment options include:
- Expectant management (waiting for natural miscarriage)
- Medication management, such as misoprostol (800 mcg vaginally, sometimes repeated after 24 hours), often with prior mifepristone (200 mg orally)
- Surgical intervention, such as dilation and curettage (D&C), a brief outpatient procedure The choice between options depends on how far along the pregnancy is, patient preference, and medical history 1.
Key Points
- Most blighted ova result from chromosomal abnormalities that occur randomly during fertilization or early cell division, and having one does not increase the risk for future pregnancy complications 1.
- Emotional support is an important aspect of care, as this represents a pregnancy loss even though an embryo never developed 1.
- The Society of Radiologists in Ultrasound consensus conference recommendations provide a lexicon for first-trimester ultrasound, which includes terms to avoid and recommended terms to use instead 1.
From the Research
Diagnosis of Blighted Ovum
- The diagnosis of blighted ovum can be made through careful ultrasonic examination 2
- Serum human chorionic gonadotropin (beta-hCG), progesterone (P4), and estradiol (E2) levels can be measured, but hormonal levels may be variable and indistinguishable from normal pregnancies 2
- Histopathologic examination of the placenta can reveal findings compatible with blighted ovum criteria, but this is only seen in 50% of cases 2
Treatment of Blighted Ovum
- Medical management of blighted ovum is a valid option, with a success rate of 83.3% 3
- Mifepristone combined with oral misoprostol can be used for medical management, with a success rate of 70.5% to 66.7% depending on the dose of mifepristone 4
- Misoprostol can be used as a single agent for termination of early pregnancy, with a success rate of 92.4% 5
- Surgical management, such as dilation and curettage, is also an option, but medical management can be a safer and more effective alternative 5, 4, 3