Overview
Miscarriage is the result of pregnancy conditions. There are about 43 conditions that can lead to miscarriages. Sometimes, a patient can have multiple conditions resulting in her miscarriages. Hence, thorough diagnosis is important to prevent miscarriages in subsequent pregnancies, especially if you have a history of recurrent pregnancy loss.
There are two general categories for miscarriages, which are early and late miscarriages. An early miscarriage happens in the first 12 weeks of pregnancy. A late miscarriage happens after 13 weeks of pregnancy. Apart from the gestational week, if the gender is still unidentifiable, then it indicates an early miscarriage. The weight of the embryo/fetus can also determine how far along the pregnancy was.
Causes of Early Miscarriages
- Reproductive Immunity disorder
Reproductive immunity disorder accounts for 70% of all unexplained recurrent miscarriages. An embryo is made of 50% maternal genes and 50% paternal genes. However, a woman with reproductive immunity disorder will detect the paternal genes as a foreign protein and produce anti-embryonic antibodies as a natural immunity reaction. During subsequent pregnancies, the placenta’s fibronectin layer, which serves as an immunological barrier for the embryo, will be attacked by the anti-embryonic antibodies.
It is a very big indicator that you might have anti-embryonic antibodies if you have a history of induced abortion(s) and unexplained recurrent early miscarriages that occurred around the same gestational week. It is important to note that most recurrent chemical losses are a result of anti-embryo antibodies.
The diagnosis and treatment are simple, and it is recognized with international patent rights. Currently, only Antai hospital diagnoses and treats reproductive immunity disorder caused by anti-embryonic antibodies.
- Low progesterone levels
Progesterone is a “pregnancy hormone” that is essential in the first trimester of the pregnancy, before the placenta is formed. The progesterone is responsible for secure implantation and creating a stable environment for the embryo to develop. Hence, low progesterone levels create a very high risk of an early miscarriage. Progesterone is produced by the corpus luteum and some conditions will result in a corpus luteum defect where it is unable to produce sufficient levels of progesterone.
Conditions that can lead to low progesterone levels are:
- Endometriosis
- Primary ovarian insufficiency
- Polycystic ovarian syndrome
- Ovarian dermoid cyst
- Pelvic adhesions
- Hyperthyroidism
- Hypothyroidism
- Hyperemesis
- Insufficient uterine blood flow (low hCG levels)
Insufficient uterine blood flow will affect the development of the embryo because it inhibits the transportation of nutrients essential for growth. An important point to note is that in initial stages, your hCG level will be lower than expected if you have a condition that directly affects the embryo’s development, despite normal progesterone levels. Of course, your progesterone level will eventually fall, too, since hCG is responsible for progesterone production.
The conditions that lead to insufficient blood flow in the uterus can be classified into two types; the first is congenital conditions, and the second is acquired conditions.
Congenital conditions:
- Septate uterus
- Uterine hypoplasia (Infantile uterus)
- Unicornuate uterus (with or without rudimentary horn)
- Double uterus
Acquired conditions:
- Intrauterine adhesions
- Uterine fibroids
- Uterine polyps
- Post-surgical intrauterine scarring
Note that some doctors may prescribe anti-coagulant drugs for conditions that can lead to insufficient uterine blood flow. However, this medication is not effective and insufficient to maintain the pregnancy to full term because it does not treat the underlying cause. Even if the pregnancy is sustained to second or third trimester, patients may still suffer from a late miscarriage.
- Abnormal Embryo Implantation
Abnormal embryo implantation can lead to early miscarriages when the embryo is not implanted into the endometrial basal layer. Sometimes, the embryo can even be implanted on areas without uterine lining, such as the fallopian tube (ectopic pregnancy).
Conditions such as uterine anomalies can also lead to abnormal embryo implantation.
With abnormal embryo implantation, the embryo is not in a position ideal to receive blood and nutrients supply that are essential for embryo’s development. This results in an early miscarriage.
- Embryonic Chromosomal abnormalities
Embryonic chromosomal abnormalities happen when there is an error during cell division. There are different types of abnormalities, and they will either lead to embryonic demise or the baby will have birth defects/disorders.
There is no way to save a pregnancy if the abnormality is fatal. However, please keep in mind that fatal chromosomal abnormalities are by no means the fault of the parents. If you are experiencing recurrent miscarriages, it is most likely caused by other pregnancy conditions.
Causes of Late Miscarriages
- Cervical Insufficiency
Cervical insufficiency is also known as cervical incompetency. Having cervical insufficiency will lead to late miscarriages because the cervix dilates prematurely. Depending on the severity of the cervical insufficiency, it will either lead to late miscarriages or preterm births.
Congenital Cervical Insufficiency
- The cervix naturally has more muscles than connective tissues. As a result, there will be a lot of elasticity in the cervix, and it will open easily with the slightest pressure from a growing fetus.
Acquired Cervical Insufficiency
- Some women will suffer from cervical insufficiency after a vaginal birth, where their cervix got damaged in the process. As a result, the cervix is not able to handle the pressure of a growing fetus in subsequent pregnancies.
- Short Cervix
Having a short cervix will lead to late miscarriages because it does not have the length and strength to withstand the pressure of a growing fetus. Depending on the severity of the cervical insufficiency, it will either lead to late miscarriages or preterm births.
Congenital Short Cervix
- The length of the cervix is far smaller than the uterus. A normal cervix is around 3.5 cm to 4.5 cm. However, the length of a congenital short cervix is about 2 cm.
Acquired Short Cervix
- Women will have an acquired short cervix after a conization. Conization is a procedure that removes a part of the cervix to prevent cervical cancer.
- Insufficient uterine space
Insufficient uterine space will lead to late miscarriages because it will come to a point where the uterus can no longer accommodate the fetus and inhibits its growth instead.
Conditions that can lead to insufficient uterine space include:
- Uterine anomalies
- Singular, large ovarian cyst
- Singular, large uterine fibroid
- Abdominal/Uterine Pressure
Insufficient uterine space and abdominal/uterine pressure are closely linked, because insufficient uterine space can add on to the pressure. Having abdominal or uterine pressure can trigger premature labor contractions. In a pregnancy, labor contractions should only happen when the baby reaches full term and is ready for delivery. Hence, premature labor contractions will either lead to late miscarriages or preterm births.
Conditions that can lead to abdominal/uterine pressure include:
- Uterine anomalies
- Singular, large ovarian cyst
- Singular, large fibroid
- Hyperemesis
Importance of Thorough Diagnosis
Many times, women suffering from a miscarriage or recurrent miscarriages are a result of various conditions.
Multiple-factor miscarriage: miscarriage caused by two conditions.
Complex-factor miscarriage: miscarriage caused by three or more conditions.
The longer a thorough diagnosis is delayed, the higher the possibility for the pregnancy to become more complicated because one condition can lead to another. Many women suffer from recurrent miscarriages because they have undiagnosed underlying conditions. It is essential to receive treatment for all conditions to have a successful pregnancy.
Antai hospital specialises in the diagnosis and treatment of recurrent miscarriages. Our doctors are experts in reproductive immunology. So far, we have helped over 34,000 to finally have their rainbow baby.