First Trimester Miscarriage


First-trimester miscarriage (before 12 weeks) is the most common type of pregnancy loss; about 80% of miscarriages happen before the end of the first trimester. Many women have questions about what causes first-trimester miscarriage and whether it can be prevented, not to mention concerns about which miscarriage symptoms may occur.

Types of First-Trimester Pregnancy Loss
The term miscarriage is fairly general for the spontaneous loss of a pregnancy in the first trimester, but some subtypes exist (note that some of these can also be diagnosed in the second trimester). Some miscarriages will not fall into any of these categories.
  1.        Chemical Pregnancy
  2.        Missed Miscarriage
  3.        Blighted Ovum

Signs of Early Miscarriage
Most miscarriage symptoms are not definitive indicators of pregnancy loss, but possible signs include vaginal bleeding in pregnancy, cramping, and loss of pregnancy symptoms.

Signs and symptoms of an early miscarriage (or chemical pregnancy) would generally be spotting or vaginal bleeding similar to a menstrual period, and possibly some abdominal cramping. The bleeding might have more clots than a menstrual period; the clots would look like tiny lumps in the vaginal discharge.

If you have had a positive pregnancy test and are now having miscarriage symptoms, call your doctor for advice. Your doctor will most likely run some diagnostic tests (such as serial hCG blood tests or an early ultrasound) to determine whether or not you are having a miscarriage. Bleeding in pregnancy does not always mean a miscarriage, but your doctor should be able to figure out what is going on after analyzing the results from the tests.

Remember that bleeding or spotting accompanied by severe abdominal pain or dizziness could mean an ectopic pregnancy, so treat these symptoms as an emergency.

In most first trimester miscarriages, the baby stops developing at some point early in the pregnancy. The woman's body then recognizes that the pregnancy is not viable and begins to shed the uterine lining, leading to mild cramping alongside vaginal bleeding -- the most common signs of miscarriage.

The woman's body does not always recognize immediately that the pregnancy is not viable, however, and weeks can pass before miscarriage symptoms appear. If an ultrasound takes place during this time period, the doctor will usually diagnose a missed miscarriage or a blighted ovum(depending on the exact circumstances and assuming the doctor is confident in the dating of the pregnancy).

Threatened Miscarriages
Most of the time, the baby's heart has stopped beating before the miscarriage symptoms appear -- but in some cases, the heartbeat may still be detectable when the miscarriage symptoms appear. If the woman is still in the first trimester, this will most likely be diagnosed as a threatened miscarriage.

Sometimes the bleeding stops in these cases and the pregnancy is still viable, meaning the bleeding was for some other reason than a miscarriage (but if the heartbeat has stopped after having previously been detected, the pregnancy is definitely no longer viable). If a miscarriage does occur, what happens is that the body appears to trigger the uterine lining to shed for some reason. Doctors do not understand why this happens and usually cannot stop the process if it happens in the first trimester -- although they may advise bed rest as a precaution

First-Trimester Miscarriage Causes
Doctors believe most first-trimester miscarriages happen because of factors outside anyone's control, and rarely can anyone pinpoint the cause of a specific miscarriage. Doctors do have some ideas about possible causes, however

Preventing First-Trimester Miscarriage
Most of the time, you cannot prevent a miscarriage from happening. Most miscarriages happen for reasons out of anyone's control. That said, occasionally some lifestyle modifications can put you in a lower risk category. Find out about what does and doesn't decrease your risk.

A lot of people wonder about risk factors for miscarriages. The truth is that risk factors are a complicated subject. A lot of women who miscarry will have no risk factors beforehand, and others might have every possible risk factor for pregnancy loss but still end up with a normal pregnancy. Except for avoiding known lifestyle factors that increase miscarriage risks, usually you cannot do much to affect the outcome of your pregnancy.

Let’s differentiate miscarriage risk factors from miscarriage symptoms, because the distinction might be confusing. After all, a person with symptoms of miscarriage is at risk for a miscarriage too, since most symptoms are not definitive. For the purposes of this article, we’ll consider miscarriage symptoms to be factors in an existing pregnancy that might indicate a miscarriage is already happening. We’ll use the term risk factors to indicate factors present before and during pregnancy that might be correlated with higher odds of a future miscarriage.

Again, remember that not everyone who has risk factors for pregnancy loss will miscarry and also that a person can miscarry even in the absence of any known risk factors. Also, in most cases, even a person with increased risk of miscarriage is more likely to have a normal pregnancy than to miscarry.
Medical Conditions Correlated with Increased Miscarriage Risk

Most miscarriages are the result of random chromosomal abnormalities, and the risk for conceiving a baby with chromosomal abnormalities is higher as the mother gets older. In other cases, certain medical conditions in the mother might mean a greater than average risk of pregnancy loss, stillbirth, or recurrent miscarriages.

  1.        Mother’s age (younger than 15 or older than 35)
  2.        Problems in earlier pregnancies
  3.        Conceiving after infertility
  4.        Being very overweight or underweight
  5.        Chronic medical conditions
  6.        Sexually transmitted diseases
  7.        Certain viral and bacterial infections during pregnancy
  8.        Having a known recurrent miscarriage cause, such as a septate uterus

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