A blighted ovum, also known as an anembryonic pregnancy, is a common form of early miscarriage. The fertilized egg implants, and surrounding structures like the gestational sac and placenta begin to develop, but an embryo never forms. Because the body continues to produce pregnancy hormones, the condition presents with initial signs of a healthy pregnancy, even though it is not viable.
Understanding Anembryonic Pregnancy
An anembryonic pregnancy is characterized by an empty gestational sac within the uterus. Following fertilization, the cells that form the placenta and the gestational sac multiply and implant into the uterine wall. However, the cells meant to develop into the embryo fail to progress beyond a very early stage or fail to develop at all, leaving the sac empty.
The continued growth of placental tissue leads to the production of human chorionic gonadotropin (hCG), the hormone detected by pregnancy tests. This hormonal activity causes typical early pregnancy symptoms, such as a missed period, morning sickness, and breast tenderness, delaying the realization that an issue exists.
The failure of the embryo to develop is attributed to chromosomal abnormalities in the fertilized egg. These genetic errors are random occurrences during cell division. The body recognizes that the pregnancy is not developing correctly and initiates the process to stop its progression.
Typical Timeline of Diagnosis and Symptoms
Due to the initial rise in hCG and pregnancy symptoms, a blighted ovum is not discovered until a routine medical scan. Diagnosis is confirmed via transvaginal ultrasound, performed between 7 and 9 weeks of gestation. At this stage, an embryo should be visible; its absence, along with the lack of a fetal pole or yolk sac within a sac of a certain size (often 25 mm or larger), confirms the diagnosis.
If a blighted ovum is left to miscarry naturally, the body eventually recognizes the lack of a developing embryo, and hormone levels decline. The natural miscarriage process, marked by vaginal bleeding and abdominal cramping, occurs in the first trimester, typically between 8 and 13 weeks of gestation. The exact timing is highly variable.
Symptoms of a natural miscarriage include spotting followed by heavier bleeding, similar to a heavy menstrual period, and mild to moderate cramping. The tissue may pass unnoticed in some cases, resembling a heavy period, while in others, the symptoms are more intense. Serial blood tests measuring hCG levels may also indicate a problem, as the levels may plateau or drop instead of continuing to rise.
Management Options After Diagnosis
Once a blighted ovum is diagnosed, three approaches exist for managing the miscarriage, depending on patient preference, medical stability, and physician recommendation. One option is expectant management, which involves waiting for the body to pass the pregnancy tissue naturally. This approach avoids medication or surgery, but the process can take days or several weeks to complete.
Another choice is medical management, which uses prescription medication, most commonly misoprostol, to induce the miscarriage. This medicine causes the uterus to contract and expel the contents, offering a more predictable timeline than expectant management, with the process starting within 24 to 48 hours. Patients receive pain relief medication and instructions, as the process involves significant cramping and heavy bleeding.
The third option is surgical management, a procedure called dilation and curettage (D&C). This brief surgery involves gently opening the cervix and removing the contents of the uterus. A D&C may be preferred for those seeking immediate resolution, experiencing excessive bleeding, or failing to complete the process with other methods. This procedure has a high success rate and provides certainty about the completion of the miscarriage.
Emotional Recovery and Planning
A blighted ovum is a significant loss, and feelings of sadness, confusion, and grief are a normal part of emotional recovery. Emotional healing often takes longer than physical recovery, and there is no standard timeline for working through the loss. Seeking support from a counselor, therapist, or support group can be beneficial for processing these complex emotions.
For those considering future pregnancies, a blighted ovum is usually a one-time event, and most people go on to have successful pregnancies afterward. Physicians advise waiting until after one regular menstrual cycle before trying to conceive, allowing the body to recuperate and the menstrual cycle to normalize. Discussing the specific timeline and any concerns about recurrence with a healthcare provider is important for future planning.