Miscarriages are surprisingly common, and they are not always indicative that there will be any problems with future pregnancies or fertility; however, if you have lost two or more clinically documented pregnancies (on ultrasound) before 20 weeks, this is referred to as recurrent pregnancy loss (RPL). “Biochemical pregnancies” are diagnosed by urine or blood testing, but they disappear before anything can be seen on ultrasound. These are not typically included in the diagnosis of recurrent pregnancy loss.
What are the causes of RPL?
Most first-trimester miscarriages result from genetic problems with the fetus. For normal development, an embryo will have 46 chromosomes that contain all the genes to develop into a healthy baby. Sometimes a fetus will have an extra or missing chromosome, typically resulting in a miscarriage. As women age, the risk of a miscarriage increases because the genetics in our eggs get ‘stickier’ over time. This causes extra or missing pieces of chromosomes in our eggs, resulting in imbalanced numbers of chromosomes in the embryos created from these eggs.
Some women are born with a uterine septum, which is a band of tissue inside their uterus. If an embryo happens to implant on this uterine septum, it will lead to a miscarriage. Other abnormalities that take up space inside the uterus, such as fibroids, can increase the risk of a miscarriage if they are near or in the uterine cavity.
Untreated hormone imbalances, such as diabetes, thyroid disease, or hyperprolactinemia, can all increase the risk of a miscarriage.
A condition called antiphospholipid syndrome can increase the risk of blood clot formation in early placental development, which is linked to miscarriage in the first or second trimester.
Smoking and excessive alcohol consumption (over 2 drinks a day) can increase the risk of a miscarriage. Obesity has also been linked with miscarriage and recurrent pregnancy loss.
What testing is done for RPL?
Bloodwork will be done to see if you have a blood clotting abnormality or a hormone imbalance. Occasionally, a chromosome test, called a ‘karyotype’ test, will be done on male and female partners. Sometimes, completely healthy individuals will have differences in the way their chromosomes are arranged, called ‘translocations’. This causes them to have a high occurrence of pregnancies that are genetically imbalanced, resulting in RPL. A study of the uterus will be done to ensure that the inside of the uterine cavity is normal in contour. This evaluation can be done through a procedure called a saline sonogram, or with a hysterosalpingogram. Lastly, we often do genetic testing on the miscarriage tissue to gain important insight into why the miscarriage occurred.
How is RPL treated?
If during the workup a diagnosis is made, then the underlying pathology will be treated. It is important to remember that a specific diagnosis is only made 50% of the time in all couples that suffer from RPL. If the reason for RPL is not clear, we will often recommend empiric and supportive treatment, such as baby aspirin and progesterone supplementation. Some couples will choose to undergo IVF with preimplantation genetic screening (PGS) of the embryos to ensure a genetically ‘balanced’ embryo is carried to the uterus. For some couples, this can markedly reduce the risk of future losses.
If you would like to start receiving personalized care for recurring pregnancy loss in Idaho Falls, Idaho, please call Idaho Fertility Center at 208-529-2019 to set up an appointment with one of our Reproductive Endocrinologists.