the mother-to-be is over age 35 (advanced maternal age)
alcohol use – since no definite safe limit is known, no alcohol should be consumed during pregnancy
heavy caffeine use – drinking more than two cups of caffeinated beverages per day
exposure to anesthetic gas, such as nitrous oxide
cigarette smoking - smoking is not recommended during pregnancy and for many other health reasons
cocaine use – never use an illegal drug
previous miscarriage – spontaneous abortion
abnormality of the uterus
chronic disease in the mother-to-be, such as celiac disease, poorly controlled diabetes, or an autoimmune disease (especially anti-phospholipid antibody syndrome)
pregnancy beginning within three to six months of a previous delivery
many previous abortions
exposure to toxins, including lead, ethylene glycol, heavy metals, or organic solvents
use of an intra-uterine device (IUD)
certain infections, such as some sexually transmitted diseases
use of some medications – misoprostol, retinoids, methotrexate, NSAIDs
taking long hot tub or whirlpool baths during early pregnancy
excess weight – obesity is linked to a higher risk of miscarriage in the first trimester, and with recurring miscarriage.

The following do not lead to miscarriage although once thought to do so:

sexual activity, as long as the pregnancy is normal
stress
using marijuana – since there is no proof of marijuana’s safety in pregnancy, it should be avoided for both health and legal reasons
moderate exercise.

Although up to a quarter of women have some bleeding in pregnancy, not all miscarry. About half go on to have a normal, full-term pregnancy. Remember, bleeding does not always signal a miscarriage. If a woman has a small amount of painless bleeding, her doctor should watch her closely.

What causes a miscarriage?

With most miscarriages, the actual cause is either unknown or can’t be determined. Of the known causes, the most common (49 per cent) is random abnormality of the chromosomes. These are genetic mistakes that do not run in families, and are not likely to happen again. They do not allow the pregnancy to progress normally.

Lacking certain hormones can also cause miscarriage. For instance, progesterone is important during early pregnancy. If there is not enough, this can lead to miscarriage.

Pregnancy loss after 13 weeks is sometimes caused by the cervix opening earlier than it should. The cervix is the opening of the uterus, where the unborn baby (fetus) develops.

What can be done?

Keep in mind that it can take about two weeks after a pregnancy stops developing before bleeding begins. By the time bleeding starts, miscarriage is unavoidable and no medical therapy can stop it.

If bleeding starts during the first 13 weeks, contact your family doctor first. An emergency room visit is usually unnecessary for bleeding in the first trimester, but women may go there believing it is an emergency.

If it is not certain whether the pregnancy will be lost, keep in touch with your doctor until the outcome is certain. If bleeding is quite heavy and there is cramping pain, it is probably a miscarriage. At this time, an explanation of treatment options, benefits and risks should be given.

What are the choices?

Expectant management involves watching and waiting, as miscarriage often happens on its own.
Medications can be prescribed to hasten the miscarriage.
A short surgical procedure may be needed to empty the uterus if bleeding is heavy or does not stop.

Sometimes a combination of these options must be used.

All pregnant women who are bleeding need to have a blood test done to determine their blood type and Rh status. A medication called Rhogam can prevent an Rh negative mother from developing antibodies to the Rh positive blood of her fetus. This can happen when the baby’s blood and the mother’s blood mix. If the woman does develop antibodies, this can harm any Rh-positive fetus in future pregnancies.

Should I go to emergency?

Go to your doctor’s office or emergency department if:

you have severe pain (more than cramping) in your lower abdomen.
you have severe pain more on one side of the abdomen than the other, signaling an ectopic pregnancy. (The pregnancy is lodged in one of the fallopian tubes between the ovaries and the uterus, rather than in the uterus itself.)
you have had a prior ectopic pregnancy or surgery on a fallopian tube.
an IUD is in place.
there is a lot of bleeding, soaking a maxi-pad each hour, for at least three hours in a row.

A watch-and-wait approach

Expectant management means the woman stays at home or follows her usual routine, including work if she wishes, until the miscarriage ends. Many miscarriages in the first 13 weeks finish safely on their own. Avoiding the hospital may be easier, both emotionally and in a practical sense.

Using this approach in the first trimester is safe and almost always ends without complications (up to 96 per cent of the time). One study showed that women who choose expectant management have better overall mental health 12 weeks after a miscarriage.

What happens during a miscarriage?

Over time, from hours to days, bleeding becomes bright red and cramping begins. When cramping becomes severe, bleeding generally becomes quite heavy. If the miscarriage is uncomplicated, the cramping and heavy bleeding (which may include tissue or clots) will last two to four hours. If it continues for more than four hours, contact a doctor.

After this period of heavy bleeding and cramping, bleeding usually becomes lighter and there is less pain. Light bleeding or spotting may continue for up to two weeks. If there are no complications, most miscarriages end within 72 hours.

Generally, it is safe to remain reasonably active and follow up with your doctor regularly. Bed rest does not change (or help) what will happen.

More on medications

Certain medications can be used to complete miscarriages. They include mifepristone (which blocks the action of progesterone) and misoprostol (which makes the uterus contract). They can only be used after a proper assessment by a doctor, and under certain circumstances. These include a pregnancy under 13 weeks, or a natural miscarriage that has not started after the fetus has died. (This is called a missed abortion.)

Is surgery necessary?

Up to half of women still require surgical treatment. Usually, this is because tissue from the pregnancy is still in the uterus or there is severe bleeding. Surgery may be needed if:

there is fever or signs of infection
pregnancy loss happens in the second trimester of the pregnancy (after 13 weeks)
expectant management or medications to complete the miscarriage have not worked
there is very severe pain
there is a large amount of bleeding
some tissue remains in the opening of the cervix.

Some women prefer surgery to the inconvenience and emotional trauma of a long miscarriage.

A dilatation and curettage, or D&C, is a brief procedure that empties the uterus. It is done under anesthetic. If there are no complications, women can go home within hours.

After a miscarriage

After a miscarriage, it is important to discuss feelings about the pregnancy loss. Early miscarriages can leave women feeling isolated. Many family members and friends may not have known about the pregnancy. Some may not realize the extent of this loss. Others may make well-meaning comments that make it seem unimportant.

Adjusting to a miscarriage is similar to the grieving process that follows the death of a loved one. Grief is part of a healing process that helps us let go of the past and adjust to the future.

Women and their partners often grieve, and may feel anxious or depressed. Many women feel guilty that some habit, stress, or negative feeling about the pregnancy caused the miscarriage. This is simply not true.

When speaking with children, be careful in explaining the loss. Using phrases such as, “The baby went to sleep,” “God took the baby,” or “The baby was very sick,” can make kids confused and scared. Siblings also experience their own feelings of guilt and loss.

Connecting with a counsellor who has experience in helping people cope with pregnancy loss may be helpful. Many hospitals and community agencies offer support programs that can provide follow-up care and information.

Understanding Miscarriage Coping with a sad reality

Can miscarriage be avoided?