Most times, a missed period is the first sign of pregnancy, and depending on a woman’s situation, this may either be really good news, or not.
However for some women, they may miss a period, do a pregnancy test that comes out positive and then after a few days, Aunt Flow shows up like GOTCHA! This is sometimes a type of very early miscarriage known as a blighted ovum.
A blighted ovum usually occurs early in pregnancy — between about week 8 and week 13 — sometimes before you even know you’re pregnant.
For a normal pregnancy to occur, a sperm fertilizes an egg. Within hours, this fertilized egg starts dividing. By about 10 days later, the growing clump of cells has formed an embryo and, inside a gestational sac, implanted itself in the uterus. Implantation spurs the placenta to start developing, and hormone levels (including those detected on a home pregnancy test) to start surging. Over the next few weeks, the embryo keeps growing and — by week 6 of pregnancy, or about a month after ovulation and fertilization — it can be seen as a few-millimeter speck on an ultrasound.
In some cases, however, something stops development during these first few weeks. Either a fertilized egg never develops into an embryo but implants into the uterus anyway. Or something causes an embryo to stop growing in those first days after it implants in the uterus. This is what is referred to as a blighted ovum.
A diagnosis of blighted ovum is made by a doctor if they can only see an empty gestational sac and no embryo (or no fetal pole — the first sign of an embryo) on an ultrasound by week 7 of pregnancy.
What Causes a Blighted Ovum?
Miscarriages from a blighted ovum are usually as a result of problems with chromosomes, (i.e the structures that carry genes.) This may be from a poor-quality sperm or egg. Or, it may occur due to abnormal cell division. Regardless, the body stops the pregnancy because it recognizes this abnormality.
For women who experience this, It’s important to understand that you have done nothing to cause this miscarriage and you almost certainly could not have prevented it. For most women, a blighted ovum occurs only once.
SYMPTOMS OF BLIGHTED OVUM
A blighted ovum feels similar to a normal pregnancy, even after the fertilized egg has stopped growing. This happens because the body — sensing something has implanted into the uterus — can keep acting like there’s a growing embryo there, producing hormones and causing early pregnancy symptoms. That means many people who eventually find out they have an anembryonic pregnancy are still getting positive pregnancy tests and experiencing symptoms like morning sickness, sore breasts and bloating. But a few less normal signs can point toward a possible blighted ovum:
Heavy bleeding, similar to your period (some bleeding can be normal early in pregnancy, but heavy bleeding is worth a visit to the doctor)
Severe cramping (this can also point to other pregnancy complications, including an ectopic pregnancy, so be sure to get checked out)
An ultrasound at 7 weeks gestation showing an amniotic sac but no embryo
HOW IS IT DIAGNOSED?
A blighted ovum can only be diagnosed with an ultrasound, which can reveal that a fertilized egg hasn’t developed into an embryo. Since the general definition of a blighted ovum is that there’s no fetal pole visible on a 7-week ultrasound, this kind of miscarriage can often be misdiagnosed.
TREATING A BLIGHTED OVUM
Most cases of blighted ovum do not require any treatment. The body is sometimes able to recognize that the embryo isn’t growing and spontaneously expel the contents of the uterus including the embryo which isn’t growing, and this presents as vaginal bleeding similar to a heavy period.
This happens fairly commonly and most women don’t even know it has occurred. For some women who have already done a pregnancy test which came back positive it’s completely normal for them to grieve as this is still a loss and their feelings should not be dismissed.
These women subsequently go on to have very normal pregnancies, so a blighted ovum really doesn’t cause any future complications.
