Possible Causes of Miscarriage
the possible causes of mis carriage: Miscarriage, also known in medical terms as a spontaneous abortion and pregnancy loss, is the natural loss of an embryo or fetus before it is able to survive independently. Some use the cutoff of 20 weeks of gestation, after which fetal death is known as a stillbirth. The most common symptom of a miscarriage is vaginal bleeding with or without pain. Sadness, anxiety and guilt may occur afterwards. Tissue and clot-like material may leave the uterus and pass through and out of the vagina. Recurrent miscarriage may also be considered a form of infertility.
POSSIBLE CAUSES OF MISCARRIAGES
Miscarriage may occur for many reasons, not all of which can be identified. Risk factors are those things that increase the likelihood of having a miscarriage but don’t necessarily cause a miscarriage. Described below are some possible causes of miscarriage.
First trimester: Most clinically apparent miscarriages (two-thirds to three-quarters in various studies) occur during the first trimester. About 30% to 40% of all fertilized eggs miscarry, often before the pregnancy is known. The embryo typically dies before the pregnancy is expelled; bleeding into the decidua basalis and tissue necrosis causes uterine contractions to expel the pregnancy. Early miscarriages can be due to a developmental abnormality of the placenta or other embryonic tissues. In some instances an embryo does not form but other tissues do. This has been called a “blighted ovum”.
Second trimester: Second trimester losses may be due to maternal factors such as uterine malformation, growths in the uterus (fibroids), or cervical problems. These conditions also may contribute to premature birth. Unlike first-trimester miscarriages, second-trimester miscarriages are less likely to be caused by a genetic abnormality; chromosomal aberrations are found in a third of cases.
Third trimester: Infection during the third trimester can cause a miscarriage.
The age of the pregnant woman is a significant risk factor. Miscarriage rates increase steadily with age, with more substantial increases after age 35. In those under the age of 35 the risk is about 10% while it is about 45% in those over the age of 40. Risk begins to increase around the age of 30. Paternal age is associated with increased risk.
The effects of surgery on pregnancy are not well-known including the effects of bariatric surgery. Abdominal and pelvic surgery are not risk factors for miscarriage. Ovarian tumours and cysts that are removed have not been found to increase the risk of miscarriage. The exception to this is the removal of the corpus luteum from the ovary. This can cause fluctuations in the hormones necessary to maintain the pregnancy.
EATING DISORDERS AND CAFFEINE
Not only is obesity associated with miscarriage; it can result in sub-fertility and other adverse pregnancy outcomes. Recurrent miscarriage is also related to obesity. Women with bulimia nervosa and anorexia nervosa may have a greater risk for miscarriage. Nutrient deficiencies have not been found to impact miscarriage rates but hyperemesis gravidarum sometimes precedes a miscarriage. Caffeine consumption also has been correlated to miscarriage rates, at least at higher levels of intake. However, such higher rates are statistically significant only in certain circumstances.
Medicines that increase the risk of miscarriage include: retinoids, nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, misoprostol, methotrexate, and statins.
Disorders of the thyroid may affect pregnancy outcomes. Related to this, iodine deficiency is strongly associated with an increased risk of miscarriage. The risk of miscarriage is increased in those with poorly controlled insulin-dependent diabetes mellitus. Women with well-controlled diabetes have the same risk of miscarriage as those without diabetes.
TREATMENTS FOR CANCER
Ionizing radiation levels given to a woman during cancer treatment cause miscarriage. Exposure can also impact fertility. The use of chemotherapeutic drugs used to treat childhood cancer increases the risk of future miscarriage.
Several pre-existing diseases in pregnancy can potentially increase the risk of miscarriage, including diabetes, polycystic ovary syndrome (PCOS), hypothyroidism, certain infectious diseases, and autoimmune diseases. PCOS may increase the risk of miscarriage.
Tobacco (cigarette) smokers have an increased risk of miscarriage. There is an increased risk regardless of which parent smokes, though the risk is higher when the gestational mother smokes.
ANATOMICAL DEFECTS AND TRUAMA
Fifteen per cent of women who have experienced three or more recurring miscarriages have some anatomical defect that prevents the pregnancy from being carried for the entire term. The structure of the uterus affects the ability to carry a child to term. Anatomical differences are common and can be congenital. In some women, cervical incompetence or cervical insufficiency occurs with the inability of the cervix to stay closed during the entire pregnancy. It does not cause first trimester miscarriages. In the second trimester, it is associated with an increased risk of miscarriage. It is identified after a premature birth has occurred at about 16–18 weeks into the pregnancy. During the second trimester, major trauma like fatal accidents can result in a miscarriage.
Autoimmunity is a possible cause of recurrent or late-term miscarriages. In the case of an autoimmune-induced miscarriage, the woman’s body attacks the growing fetus or prevents normal pregnancy progression. Autoimmune disease may cause abnormalities in embryos, which in turn may lead to miscarriage. As an example, Celiac disease increases the risk of miscarriage by an odds ratio of approximately 1.4. A disruption in normal immune function can lead to the formation of antiphospholipid antibody syndrome. This will affect the ability to continue the pregnancy, and if a woman has repeated miscarriages, she can be tested for it.
Ingesting food that has been contaminated with listeriosis, toxoplasmosis, and salmonella is associated with an increased risk of miscarriage.
Alcohol increases the risk of miscarriage. Cocaine use increases the rate of miscarriage. Some infections have been associated with miscarriage. These include Ureaplasma urealyticum, Mycoplasma hominis, group B streptococci, HIV-1, and syphilis. Infections of Chlamydia trachomatis, Camphylobacter fetus, and Toxoplasma gondii have not been found to be linked to miscarriage. Subclinical infections of the lining of the womb, commonly known as chronic endometritis are also associated with poor pregnancy outcomes, compared to women with treated chronic endomertitis or no chronic endometritis.