Miscarriage is the common, everyday term for what physicians call spontaneous abortion or sometimes merely abortion. It means the unintentional loss, without human intervention, of a pregnancy during the first twenty weeks (counting from the first day of the last menstrual period).

How common is spontaneous abortion during the first trimester?

Spontaneous abortion during the early stages of pregnancy is quite common. Estimates range from 15 to 20 percent of pregnancies, and those figures refer to recognized pregnancies — those that have been confirmed through a test or strongly suspected because of a missed menstrual period. There are probably many more instances where an egg and a sperm get together but the fertilized egg does not implant properly in the uterus, and the miscarriage occurs before a menstrual period is missed.

The very commonness of spontaneous abortion shows that even in this age of great technological advances, some very basic things remain beyond our control. It is a hard lesson. I consider it something of a miracle that miscarriage does not happen more often. So many things must go right once fertilization takes place: the fertilized egg must correctly make its initial divisions and begin to develop, it must travel down the fallopian tube into the uterus, and it must implant appropriately in the uterine lining and continue to grow there. It is amazing that 80-85 percent of pregnancies do result in the birth of a child and that only 15-20 percent end in miscarriage.

Box: Medical Terms for Miscarriage

Threatened abortion: A miscarriage that may or may not happen. It is characterized by vaginal bleeding, with or without cramps, but the cervix remains closed.

Inevitable abortion: A miscarriage that is sure to happen because the fetus is no longer viable. Symptoms include vaginal bleeding, with or without cramps; the cervix opens.

Incomplete abortion: A miscarriage in which not all of the fetal tissue is expelled from the uterus. Symptoms include vaginal bleeding, sometimes heavy, for several days and continued cramping.

Complete abortion: A miscarriage during which all the fetal tissue is expelled from the uterus. Bleeding and cramping will gradually decrease and cease on their own.

Missed abortion: The fetus is not viable but has not yet been expelled.

In the majority of miscarriages, the pregnancy would not have produced a healthy child because the fetus was genetically abnormal. This may seem cold comfort when you are dealing with the loss, but many women find some consolation in realizing that a child with severe genetic abnormalities would have no normal life, or perhaps no life at all — unable to survive outside the uterus. It is crucial, I think, to focus on the potential quality of life.

If I have a miscarriage, should a genetic study be done on the tissue?

About 99 percent of the time there is no valid reason to do so. Learning that the fetus was genetically abnormal has no bearing on subsequent pregnancies. The tests are very expensive and the results will not influence your future health care. Basically what your caregiver can say to you is, Try again; you had bad luck.

Who is at risk for miscarriage?

Older women are at higher risk than younger ones; an older woman has older eggs, which are more likely to have some genetic abnormality. Some women do not produce adequate progesterone to support a pregnancy and are at increased risk for miscarriage: they become pregnant but miscarry early on.

A woman whose mother took diethylstilbestrol (diethylstilbestrol) while she was pregnant is at increased risk. Some conditions of the uterus (multiple polyps or fibroids, or structural abnormalities) can cause spontaneous abortions, but many women with these conditions go on to have successful pregnancies. Some research has suggested that, in rare instances, immune factors play a role in spontaneous abortion.

Certain diseases or chronic illnesses may increase risk, but the details are not fully known. Nor is the role of environmental toxins, radiation, or drugs.

Does a genetically abnormal pregnancy happen because one or both parents are genetically abnormal?

Sometimes, but quite rarely, parental genetic abnormalities can cause repeated miscarriages, but in my career I have only taken care of three patients with this kind of problem. Usually a specific egg and a specific sperm meet up and do not develop properly.

The most frequent genetic abnormality in the parents is something called a balanced translocation. People who have this condition have all the right chromosomes, but one of the chromosomes is “backward” — in the sense that when the chromosomes duplicate themselves, which they do when eggs and sperm are being produced, they produce genetically defective cells. People who have balanced translocations look perfectly normal, and they are perfectly normal except that their eggs or sperm can be defective. However, about one quarter of these eggs or sperm are not abnormal and can produce a normal pregnancy.

Cassie had her first baby when she was 27. Everything went well and she had a healthy, normal child. Then Cassie had two spontaneous losses, so we decided to do a workup to see what was wrong. Her genetic tests showed that she had a balanced translocation. There was absolutely nothing I could tell her except, “Don’t give up. The odds are that at some point things will work out well.” Cassie was fortunate, because her next two pregnancies were perfectly normal and she had two more healthy children.

Are you at increased risk for miscarriage if your mother had one (or several) miscarriages?

Unless your mother had some genetic problem, like a balanced translocation (which is statistically very rare), you are not at increased risk.

What are the symptoms of miscarriage?

Ordinarily, the first symptom is vaginal bleeding. It can be light — just spotting or staining. Or it can be quite heavy. It may occur with or without uterine cramps and may go on for several days.

Bleeding and abdominal pain can also be signs of an ectopic pregnancy (a pregnancy that is developing in the fallopian tubes or elsewhere outside the uterus). Since such a pregnancy is dangerous, you should report bleeding to your caregiver so that the possibility can be ruled out.

Can your doctor tell whether you are miscarrying?

Sometimes it is very difficult to tell whether a miscarriage is in progress, because women often spot or bleed during the first weeks of pregnancy without actually having a miscarriage. Many women bleed at the time the embryo implants in the uterine lining, which normally takes place at about the time of the first missed menstrual period, and some women continue to bleed on the monthly “anniversaries” of their regular periods (though no one knows why). Bleeding may be a sign of a threatened miscarriage orofoneof these other events.

You cannot hear a fetal heartbeat with a Doppler stethoscope until nine or ten weeks of gestational life (four or five weeks after your missed period), so if the bleeding starts earlier, it is difficult to determine from a physical exam whether the fetus is still viable. The size of the uterus is not much help, since during the first and second months of pregnancy it is still quite small. If a woman has a great deal of body fat, it is especially difficult to assess the size of the uterus by a physical examination. About the only thing your caregiver can tell is whether or not your cervix is open.

For this reason, and because there is very little either you or your doctor can do to prevent a miscarriage that is about to happen, a threatened abortion is not a medical emergency — though understandably it may seem so if you are going through it.

Box: Ultrasound Technology

Ultrasound is one of the tools used to assess the condition of a pregnancy. It can show the size of the uterus and the health of the pregnancy, help confirm a due date, reveal the presence of twins (or a larger multiple pregnancy) or an ectopic pregnancy, and disclose certain fetal abnormalities.

Ultrasound bounces high-frequency sound waves off internal body tissues. A sensor (transducer) produces the sound waves, which bounce back according to the different densities of the tissues they encounter. The transducer senses the patterns of these reflections or echoes, which are then processed by a computer to create a moving image. The image can be projected onto a monitor and photographed to create a permanent record.

How can your caregiver find out whether your pregnancy is going well?

Although a physical exam in the early weeks of pregnancy will not give much information, there are two ways of testing to see how things are going. One is ultrasound imaging, which can be done either abdominally, by placing the sensor on the abdomen above the uterus, or vaginally, by inserting into the vagina a probe containing the sensor.

With either type of ultrasound procedure, your doctor is looking for the size of the fetus and the development of a fetal heart. Early in the pregnancy the vaginal probe will probably give more information, but by the seventh or eighth week of gestational life an abdominal ultrasound will supply the information you need. At about seven weeks an abdominal ultrasound will reveal a little sac and possibly a fetal heart. A vaginal ultrasound probe may give the same information as early as six weeks. If a heart is beating in the sac, the odds are in your favor. Only occasionally does a fetus develop far enough to have a heart and then cease growing.

A second test, a blood test that can be used earlier in pregnancy, is called quantitative beta preg levels — or just quants or beta preg testing. This test, which was a research tool in the mid-1970s and became available for clinicians later in that decade, measures blood levels of the beta subunit of human chorionic gonadotropin, the same substance used in a simple test for pregnancy. In fact, this test is very similar to a pregnancy test, except that it measures the amount of human chorionic gonadotropin instead of merely looking for its presence.

We do the quants test by taking blood samples every couple of days. If we get a level of 200 one day and two or three days later get a 400 level, and then 800, it looks as if things are going well. If the levels of human chorionic gonadotropin do not double every few days during the first trimester, it does not necessarily mean that something is terribly wrong, but a steadily rising level is encouraging. Once the pregnancy has developed far enough, we can do an ultrasound and see how the visual image correlates with the beta preg quants.

Is there any foolproof method to tell exactly when you became pregnant?

Every pregnancy is different, even different pregnancies in the same woman. Urine testing will reveal that you are pregnant when the quantitative level of human chorionic gonadotropin is only about 50. Most women reach this level at about the time they miss their menstrual period. But women vary. Some may reach that detectable level a few days earlier, some a few days later. You cannot automatically say that when your quant is 1,500 you are five weeks and two days pregnant.

Suppose you measure your quant the day you miss your period (which is day 28 of your pregnancy, if you have twenty-eight-day cycles) and your level is 50; then you measure it three days later and it is 200, and in another two days it comes in at 400. At this rate by the time you are five weeks pregnant you will be at a level of about 800 and in five and a half weeks at 1,600. Now, five and a half weeks is about when something starts showing up on ultrasound: not necessarily a fetus with a heartbeat, but a gestational sac with a fetus forming. So beta quant testing in conjunction with ultrasound can give you a general idea of the date of conception, but it will not give you an exact date.

Nor can you yourself tell, unless you only had sex one time that month — or maybe only one time in two months, since occasional women have bleeding around the time of their expected period when the fertilized egg is being implanted. Perhaps what you thought was a period was actually bleeding at implantation.

Some women believe that they know intuitively when they get pregnant, and perhaps they do. I cannot vouch for the value of intuition one way or the other, since sometimes my patients’ intuitive knowledge has turned out to be wrong.

Is it worthwhile to do an ultrasound three or four days after a missed menstrual period?

No, an ultrasound done that early will not reveal anything useful. Before six weeks gesta-tional age (about a month after conception) an ultrasound would, except in special circumstances, be a waste of time and money.

If an ultrasound does not reveal a heart or other fetal parts by seven weeks, does that mean that there is no pregnancy?

Not necessarily Remember that it is very difficult to determine exactly when conception occurred, and often it is worth waiting another week and doing another test. More than once I have had a patient ready to despair at not being pregnant, when a test a week later showed a fetal sac. The woman just got pregnant a week later than she thought. If the ultrasound does not show a fetal sac, there is nothing medically that your caregiver can do to improve the pregnancy.

What can you do to stop a threatened miscarriage?

There really is not much that you can do, nor is there much that your caregiver can do for you. While this is distressing, it does make some sense. First of all, since many of the fetuses that spontaneously abort have serious genetic defects, miscarriage is nature’s way of recognizing that the fetus is not healthy.

Second, we have learned from experience that it is dangerous to try to deal hormon-ally with threatened miscarriage. Forty or fifty years ago, if you had gone to your physician with vaginal bleeding during early pregnancy, he or she might have prescribed diethylstilbestrol, a synthetic estrogen that was frequently given to prevent miscarriage, premature labor, and other complications of pregnancy, even though there was not much evidence that it was effective. Unfortunately, diethylstilbestrol turned out to cause birth defects and reproductive disorders in the daughters of women who had taken it during pregnancy. The medical profession learned through that tragedy that it is a mistake to give hormonal medications (unless they have been thoroughly tested) during the first months of pregnancy.

For that reason there is not much your doctor can do to prevent a spontaneous abortion. If your cervix has opened, the miscarriage is inevitable. If your cervix has not opened and the miscarriage is only threatened, there still is not much that can be done.

Will bed rest help prevent a miscarriage?

Bed rest is often prescribed for women later in pregnancy who have a condition in which the cervix threatens to dilate too soon, but bed rest will not help prevent a first-trimester miscarriage. There is no posture, even standing on your head, that will prevent it.

Will stress, sexual activity, dietary habits, or environmental factors cause a miscarriage?

Ordinary activities, even emotionally stressful ones, cannot bring about a miscarriage. Fighting with your mother-in-law or worrying about your work will not cause a miscarriage. Nor will normal exercise, though common sense suggests that you probably should not run or do rigorous aerobics. At least if you go on to miscarry, you will not need to say to yourself, “Oh, if only I hadn’t done kickboxing last week, I wouldn’t be miscarrying.”

Some women worry about having intercourse when they are spotting or having vaginal bleeding. Although I generally advise patients who are threatening to miscarry that they should abstain from sex, the reasons are again psychological. I don’t want anyone to blame herself for losing a baby because she had sex.

Some women who are threatening to miscarry wonder whether changes in diet and environment will keep the miscarriage from happening. While it is a good idea to lead a healthy life, clean air and a diet rich in vegetables will not prevent a miscarriage. Nor is there evidence that exposure to video display terminals (computers and TV sets) or microwave ovens will cause a miscarriage.

Does vaginal bleeding in the first trimester mean you wont be able to carry the pregnancy to completion?

Actually about one third of women bleed during the first three months of pregnancy, although we are not always sure why it happens. More than half of these women continue to carry perfectly normal pregnancies. We do know that some women bleed a little at the time of implantation and that other women become pregnant with two eggs, fraternal twins, and miscarry one.

If you start to bleed, don’t panic; talk to your caregiver. If the bleeding is heavy, say heavier than a normal menstrual period, it is likely that you will have a miscarriage. On the other hand, occasionally even heavy bleeding does not result in a miscarriage.

Kelly came in to the emergency room bleeding so heavily that she had a towel between her legs. We used ultrasound to try to determine what was happening. We could see a fetus developing with a normal heartbeat, but we couldn’t see any reason why she would be bleeding so heavily. One or two days later the bleeding stopped and Kelly continued her pregnancy. Her baby was completely normal.

What is an incomplete abortion?

If the miscarriage takes place early in the pregnancy, before six or seven weeks gestation, chances are that the miscarriage will be complete. Nothing will be left behind in the uterus. However, if you are nine or ten weeks pregnant, a little piece of placenta or other tissue may be left behind.

The appropriate therapy is to scrape out the lining of the uterus in a procedure similar to a D&C, except that the cervix is probably already dilated because of the miscarriage. If there is even a fragment of placental tissue left in the uterus, it will not contract effectively, and it is the contraction of the uterus that stops the bleeding.

If possible, we do the procedure with a general anesthetic. But sometimes circumstances allow only local anesthesia, which numbs the cervix but does not deaden feeling in the uterus itself. If someone comes in to the office bleeding very heavily, we do not have general anesthesia available. Some women even request that they not have general anesthesia. The procedure is painful, but it only lasts a few minutes.

What is a missed abortion?

A missed abortion is one in which the fetus dies but is not expelled for as long as several months. Women become aware of the possibility because after the symptoms of early pregnancy have been present for a while, perhaps confirmed by a pregnancy test, the signs diminish or go away.

A missed abortion can be diagnosed by a lack of the signs of a continuing, healthy pregnancy. If the uterus is not enlarging (or has shrunk since the last examination), if there is no fetal heartbeat by eight to ten weeks of gestational age, then missed abortion is a possibility.

What is the treatment for a missed abortion?

The treatment can be watchful waiting, allowing the body to expel the fetus in its own good time, or the contents of the uterus can be removed through a suction D&C.

Lianne missed a period two months ago and had a blood pregnancy test that was positive. In the meantime, she had a little vaginal bleeding and some cramping, but did not actually have a miscarriage. Perhaps she had a threatened abortion that never actually happened.

We did some quantitative blood pregnancy tests and the results were not encouraging. Her human chorionic gonadotropin levels were not rising rapidly. An ultrasound did not showed a fetus forming in her uterus. We repeated the quants and did a backup ultrasound at about eight or nine weeks from the time Lianne thought she had conceived. The backup ultrasound still did not show a fetal heartbeat.

Testing showed she no longer had a viable fetus and sooner or later would miscarry on her own. One of her choices was to wait and let her body deal with the situation in its own way. She decided instead to schedule a D&C and have the fetal tissue removed from her uterus.

The advantage of a D&C is that the procedure can be done under controlled conditions. The patient can go to an operating room, have a general anesthetic, and have her own physician there to perform the procedure. If she comes in to the emergency room at 10:00 p.m. hemorrhaging heavily, she may be unable to have a general anesthetic because she had dinner only two hours earlier. Her own doctor may not be available. Or she may come in at 2:00 a.m. and find that the emergency room is crowded with patients who have been waiting all day.

Some women react to an ultrasound showing that the fetus has ceased to develop by wanting an immediate D&C. They know that a miscarriage will occur sooner or later and are very unhappy with the idea of harboring dead tissue until that time comes. Other women want to let nature take care of the problem in its own way and feel uncomfortable with the idea of a D&C even though the fetus is no longer viable.

What are the risks of a D&C to resolve a missed abortion?

The risks of a D&C for any purpose are bleeding and infection. There is also a remote chance that the uterus will be perforated during the surgery. Women who have several miscarriages and subsequent D&Cs have the risk of scarring the lining of the uterus, a condition called Asherman’s syndrome. Even though the risk is small, infertility can result later on.

What is the recuperation time after a miscarriage and D&C?

I tell my patients to rest and take it easy the day of the procedure. You can go back to work in a day or so if you feel like it. I recommend that you not have intercourse for a week, though some physicians advise waiting two weeks. Take it easy on aerobic activity for a week or two.

Is there any risk to waiting for the body to expel a fetus that has died?

There is a slight risk of infection, because the tissue inside the uterus is no longer living and can be infected by the bacteria that normally live in the vagina. But this is a very small risk and is limited by time.

How long should I wait before trying to get pregnant again?

The most conservative physicians say two months. There is certainly no reason to wait longer.

If I have one miscarriage, am I more likely to have another?

When someone has a miscarriage, the first thing I say, before we discuss any other issues, is that it will not impact her future reproductive life. Women who have had one miscarriage often feel very nervous when they become pregnant subsequently, because they fear another miscarriage. Having had one miscarriage does not increase your risk for having another. Large statistical studies have shown you have the same risk of miscarrying that you did the first time, somewhere around 15 percent.

If I’ve had several miscarriages, do I still have a chance to have a healthy child?

If you have one, two, or even three miscarriages, your chances of carrying a pregnancy to term are almost the same as those of a woman who has not had a miscarriage. If you have had two spontaneous abortions, your statistical chances of having a third are not much higher than a woman who has had none, somewhere in the range of 20-25 percent.

Women who have had three or more consecutive abortions are called habitual aborters. That is a term I really dislike, and I hope it will drop from use. If you have had three consecutive miscarriages, your caregiver should recommend a workup to attempt to determine the reason.

What are the causes of repeated miscarriages?

Sometimes, but not always, a workup will reveal a cause for repeated miscarriage. Nowadays there are clinics that specialize in testing and treating women who have repeated miscarriages.

Occasional women have a problem with inadequate luteal phase: they do not produce enough progesterone during the second half of the menstrual cycle to ensure that the fertilized egg will implant properly and be nurtured. There are also occasional anatomical causes, for example a uterine septum that divides the uterus into two parts and causes difficulties with implantation. This can be detected with a hysterogram. A uterus with a septum can usually be surgically corrected, and women with this problem sometimes have successful pregnancies. A fibroid that sticks out into the wall of the uterus can act similarly to a uterine septum. It too can be removed surgically, which may facilitate a successful pregnancy.

Once in a while, women have antibodies to the embryo. The miscarriage is caused by an autoimmune reaction, something like the process that goes on with lupus, in which the body’s immune system produces antibodies that attack its own tissues. Steroid drugs that help block antibody production can be useful.

On rare occasions we find that chronic infections are causing the repeated miscarriages. These infections can be treated with antibiotics, so that a successful pregnancy is possible.

How soon after a miscarriage will the body go back to its prepregnant state?

Bleeding or spotting may continue for several days after the miscarriage, and other signs of pregnancy, for example breast tenderness and abdominal swelling, may continue as long as a week. It is possible that hormonal changes may bring about mood swings, but since the miscarriage itself is usually a depressing event, it is hard to determine whether mood changes are hormonally caused or simply expressions of normal sadness.

What is the psychological impact of miscarriage?

To many women a miscarriage, whether it occurs late or early, means the loss not just of a pregnancy — a potential child — but of a real and complete human being. The intensity of grief varies from woman to woman. Many feel isolation and loneliness, anger, and depression including inability to concentrate, comprehend, or remember. Many women blame themselves, believing if only they had done something differently, the miscarriage would not have happened. Guilt and loss of self-esteem are not uncommon. Nor is anxiety about future pregnancies. Many women feel anger toward their friends who do have children and whose pregnancies seemed easy and happy.

The impact of grief on a marriage can be difficult, since men and women are likely to express loss in different ways. They may have different reactions to sexual intimacy after such a loss and may find that sex is no longer the expression of love and hopefulness that it was before the miscarriage.

Well-meaning but tactless friends and relatives who have not experienced this kind of loss themselves, and do not really know the depth of your feelings, can say painful things intended as comfort. Among these is the suggestion that you have another baby. Women who have had miscarriages know that there is no such thing as a “replacement baby,” and it may help to tell family and friends how important this baby was for you, and to ask them to support you by listening rather than by offering advice.

I expect women to be saddened when miscarriage happens. I expect them to cry. I expect them to have a bad day on their child’s due date, at holidays, and other times. But I hope they will not cry indefinitely. Knowing the clinical cause of the miscarriage (if this is possible) helps some women. Others find solace through support groups, often made up of women who have experienced the same kind of bereavement and know what it is like. If these kinds of assistance are not adequate, professional therapy is also available.


Selections from the book: “The Yale Guide to Women`s Reproductive Health: From Menarche to Menopause”, 2003.

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