Hi, my name is Allison Schaaf, my own fertility journey, including 5 miscarriages, inspired me to create this website to help YOU navigate your own fertility journey.
Here are my main takeaways I would share with you as a friend:
- Blighted ovum is the most common type of miscarriage
- Miscarriage has both physical and emotional aspects, both need to be considered
- Any miscarriage is difficult to endure, but a healthy pregnancy after is very possible
Of course, I also recommend you work with your doctor and do your own research! I have coordinated these articles with the nitty-gritty details and links to research so you can decide what works best for you, read on for more. And don’t miss my Action Steps at the bottom of the article!
Table of Contents
What is a Blighted ovum?
What causes Blighted ovum?
Symptoms of blighted ovum
How does blighted ovum affect the next pregnancy?
Diagnosis of blighted ovum
Treatment for blighted ovum
When to contact your fertility specialists and when to try again?
Blighted ovum (anembryonic pregnancy) is a leading type of early miscarriages. It happens after the fertilized egg implants and starts to become visible on the ultrasound, but does not develop further. 1 You may already have missed a period or two, tested positive on a pregnancy test, and started to feel pregnant.
If you have been anticipating a pregnancy, a blighted ovum can be devastating. The good news is that once you have had an early miscarriage, there is a nearly 80% chance of achieving a live birth within a few years. 2 Understanding why and working on addressing potential causes may be helpful. This article will cover what you need to know about blighted ovum and potential causes.
What is a Blighted ovum?
Blighted ovum or anembryonic pregnancy is when a fertilized egg implants but does not develop and a viable embryo is not present. 3 The embryo may never develop or stop developing. It then gets resorbed, leaving an empty gestational sac (large cavity of fluid that envelops the embryo) and the intact placenta. 4 Blighted ovum typically result in a miscarriage between weeks 8 – 13. 5
During a blighted ovum pregnancy, the pregnancy hormone, ꞵHCG, should already be detectable. However, depending on when the embryo stops developing, you may or may not feel pregnancy symptoms.
A transabdominal ultrasound can typically detect a pregnancy on the 5th gestational week, when the yolk sac starts being visible. When blighted ovum occurs, by this time, the yolk sac is visible but no other embryonic features are visible in the ultrasound.
It is possible to be completely unaware of a blighted ovum. You might experience a miscarrage that looks exactly like normal menstruation, or have what is called missed miscarriage, a pregnancy loss without any signs of miscarriage. In the worst case scenario, a woman might experience prolonged vaginal bleeding, pain, or lower abdomen discomfort that represents a typical presentation of early pregnancy loss. 6
What causes Blighted ovum?
The most common cause of blighted ovum is genetic abnormalities in the embryo that are severe enough to prevent further development. These are found in approximately 70% of miscarried embryos. Other factors include infections, immunologic, and hormonal factors that contribute to implantation failure.
Genetic factors
Most early pregnancy losses are due to chromosomal abnormalities, especially when other causes of recurrent miscarriages have been ruled out. 7 23 pairs of chromosomes hold our genes, so chromosome breakages can disrupt embryonic growth and lead to miscarriage. In addition, mistakes in the cell division process can result in an extra or missing chromosome. Other types of DNA damages, such as due to oxidative stress and toxins, may also trigger blighted ovum.
These chromosomal abnormalities, typically resulting from mistakes in the cell division process that produce the sperm or the egg, may include: 8
- Trisomy – The presence of an extra chromosome being the most commonly found one, which may contribute to about 30% of cases
- Translocation – When a piece of a chromosome breaks off and attached to another chromosome
- Monosomy – Missing of one chromosome (monosomy)
- Polyploidy – Multiplication of an entire set of chromosome
Factors that contribute to these DNA damages in the eggs and sperms may include:
- Parental age, over 36 for men and in the 40s for women 910
- Sperm DNA fragmentation 11
- Reduced ability to neutralize oxidative stress, such as reduced antioxidant enzymes 1213
- Toxin and radiation exposure
Some parents are carriers of genetic factors in all cells in their bodies, which don’t cause disease for them but prevents them from having a successful pregnancy. For example, they may have a “balanced translocation,” where the broken pieces of two chromosomes switch places. Because this doesn’t cause any significant gene loss, these translocations don’t cause problems in the parents. However, making a baby requires combining half the chromosomes from one parent with another half from another parent. When the baby might receive the broken off chromosome or the chromosome with the extra piece, which can disrupt development and lead to a blighted ovum. This is found in about 4.5% of couples with recurrent miscarriages. 14 Also, balanced translocations can be more problematic in couples who are genetically related (68.5% versus 31.5%). 15
Other types of genetic mutations, such as single nucleotide changes and changes in copy numbers of genes may also contribute to early miscarriages. 16
Implantation problems
Each of the following factors can contribute to a minority of blighted ovum cases. The evidence related to these factors so far have been mostly limited to small clinical studies. Therefore, we need more studies to understand how these factors cause blighted ovum.
- Infections, such as untreated urinary tract infections may cause blighted ovum, although these are rare in developed countries. 17
- Tubal pregnancies – the environment in the fallopian tube is typically not conducive for embryonic implantation and growth. 18 Tubal pregnancies are more common in women over 35 years old.
- Hormonal factors, such as variation in prolactin levels, thyroid disorders, low progesterone, and polycystic ovarian syndrome. 192021
- Immunologic factors, such as natural killer cell dysfunctions in the womb could contribute to a blighted ovum. 222324
IVF and blighted ovum
IVF is not a risk factor for chromosome anomaly in miscarriages. Rather, rates of chromosomal abnormalities may actually be lower in pregnancies achieved by IVF because IVF selects for the best embryo. 25
Symptoms of blighted ovum
In some cases, blighted ovum pregnancies can have no symptoms. If the woman wasn’t aware that she was pregnant, she might lose the pregnancy in bleeding that resembles menstruation.
Couples who are trying to conceive might be aware of pregnancy due to a positive pregnancy test. In addition, at this stage of pregnancy (6 weeks), you may already feel early pregnancy symptoms, such as nausea and fatigue. In that case, when the blighted ovum pregnancy loss happens, it might appear as: 2627
- Without any symptoms of miscarriage, also known as missed miscarriage
- Low abdominal pain and cramping
- Vaginal bleeding, which may include spotting or menstrual bleeding
How does blighted ovum affect the next pregnancy?
You may need some time to grieve after such early loss before trying again. 28 However, a normal pregnancy is totally possible after a blighted ovum. 29
Diagnosis of blighted ovum
Diagnosing a blighted ovum involves clinical signs, pregnancy test, and ultrasound exam.
Many couples suspect a miscarriage if there are ongoing pregnancy symptoms but declining HCG levels. You may still feel the early pregnancy symptoms, including fatigue, nausea, vomiting, breast tenderness, and increased appetite. However, a beta-HCG blood test may drop below 25 mIU/mL. An hCG level between 6 and 24 mIU/mL is considered a grey area, and should be correlated with ultrasound findings. 30
Home urine pregnancy tests are less reliable than blood tests, so a fading line on these tests are not conclusive. You may need a blood test to confirm that the hCG level is really going down. 31
Your doctor will diagnose the blighted ovum with an endovaginal ultrasound exam based on the following observations: 32
- when there is no embryo in a gestational sac with mean sac diameter (MSD) ≥25 mm
OR
- there is no embryo on the follow-up scan
- ≥11 days after a scan showing gestational sac with a yolk sac, but no embryo
- ≥ 2 weeks after a scan showing gestational sac without a yolk sac or embryo
Treatment for blighted ovum
There is no medical intervention that can stop such an early miscarriage. 33 Possibly, working with your physician to understand potential causes and addressing them may improve your chance for the next pregnancy.
There are several approaches to terminate a blighted ovum pregnancy, including the natural expectative approach, medication-induced, and a dilatation & curettage (D&C) surgery.
Expectative approach
Since blighted ovum eventually results in miscarriage, some women choose to wait for the miscarriage to happen naturally. 34 This doesn’t require any medical intervention but can be mentally and physically exhausting since it can take days to weeks for the bleeding to stop. In addition, this approach miscarriage can be painful. It can also be mentally and physically agonizing since it can take days to weeks for the bleeding to stop.
Depending on the stage of the pregnancy, your experience with this approach may be very different. Early on, it may be more like a painful menstrual period. But if you are further along, you may experience contractions similar to birth, which some may find traumatic if they are not prepared.
Medication-induced miscarriage
Mifepristone and oral misoprostol are drugs that can help resolve an early miscarriage. 3536 The dosage and manner of administration will depend on the institution guidelines. The pregnancy loss is therefore resolved faster, but the bleeding can also be uncomfortable.
Dilation and Curettage (D&C) Surgery
D&C is a short surgical procedure to open the cervix and remove the conception materials from the uterine cavity. It takes 15-30 minutes and is performed under general anesthesia. This allows for pathological examinations or genetic testing of the tissues to determine a reason for the miscarriage. Some women feel a D&C procedure helps with closure, mentally and physically. 37 Lastly, sometimes the expectative and medication-induced approaches fail and a D&C becomes necessary.
Like every procedure with general anesthesia, the risks may include nausea, vomiting, pain after the procedure, sore throat, cardiac failure, respiratory failure, allergic reaction and death (rarely). Before the procedure, avoid eating or drinking for 6-12 hours according to your doctor’s instructions. You should consult your doctor if you take blood thinners such as warfarin, aspirin or heparin. 38 Avoid vaginal sex, submerging in water, and tampons until after your next cycle. The bleeding may continue for quite some time for over a week after the procedure.
Some risks specific to D&C are: bleeding, infection, scarring, perforation, and pain after procedure. 39
Read our article on D&C vs natural miscarriage.
Additional treatments for blighted ovum
Genetic Testing and Counseling 40
Genetic testing can help you understand the true reason behind a miscarriage. It may also give you actionable information to improve your chance for the next pregnancy. Consider genetic testing (chromosome analysis) and counseling if there are multiple miscarriages or if miscarriages run in the family. Also, genetic testing may help determine if both partners are genetically similar, such as from marriages between relatives or if they are carriers of mutations that can affect the embryos. 41
You may want to consider genetic testing of the product of conception (POC, the union product of egg and sperm). To get a good quality sample, the lab may provide sample collection instructions for you or your OB/GYN. A new genetic test called chromosomal microarray analysis can identify both chromosome abnormalities and smaller mutations in the product of conception. 42
However, genetic testing is not for everyone and you may not wish to act on the results, so keep in mind that it is totally optional.
When to contact your OB/GYN and when to try again?
If you have had 2 or more miscarriages, especially in a row, you should consult your OB/GYN to investigate potential causes. 43
Many couples need time to time and space to heal emotionally before they are ready to try again. However, physically, your body will recover and become ready for the next pregnancy after 1-3 regular menstrual cycles. 44
Next Steps to Consider
- If you think you are experiencing a blighted ovum miscarriage, contact your doctor immediately
- If you are in the process of going through a blighted ovum miscarriage, give yourself plenty of time and space to heal emotionally
- It is important to work with your doctor to explore potential causes of a blighted ovum miscarriage, but also keep in mind healthy pregnancy is possible after this type of miscarriage
References
I have had multiple blighted ovums. 2 of my 3 were tested and showed up as chromosomal. When meeting with my RE, they said there’s really nothing we can do to improve the chances of having an egg with the right chromosomes pop out. This article states that we can though, when we address possible oxidative stress. Is this correct? Id love to find more specific studies if you have any that note this so I can send this to my RE. Thank you for this article!