Purpose and Disclaimer
This writeup attempts to cover both the facts and the feelings of this difficult topic. Before we proceed, please note: I am not a medical specialist. My only expertise is that of personal experience, and subsequent attempts to understand what happened. As always, nothing on Everything2 should be considered medical advice. Consult with your own medical doctor before making any decisions about your health. See also the Everything2 medical disclaimer.
Introduction
Miscarriage is a traumatic experience. Most people who experience a miscarriage are completely unprepared to face it. It takes so many people by surprise because it is seldom discussed openly. Western society is increasingly forthright about sex and sexual choices, about childbirth and menopause, but miscarriage remains taboo. We feel that we can't discuss it with even the closest friends and family, and so it is shrouded in mystery and misinformation.
For those experiencing miscarriage, my deepest sympathies. You will find it hard to talk about your loss, and harder to know who you can talk to. Some of your friends and family will have been here, but you probably won't know it. Those who have not won't know what to say, and often will say deeply hurtful things with the best of intentions. Your health care providers have resources for you to fall back on, and you should take advantage of them if you need outside support.
For those who have not experienced miscarriage, or if you might ever become pregnant, please read on. I hope that you never need this information, but if you do, that something here may help you to understand.
Definition
Any pregnancy which terminates before the 20th week of gestation (that is, up to 20 weeks after the last menstrual period) is deemed a miscarriage. This corresponds to the halfway point in a regular pregnancy term. Loss of the pregnancy at or after 20 weeks is called stillbirth.
Miscarriage is not a discrete event. It often starts with the onset of unexpected bleeding (though this alone is not a sure sign) and lasts until the pregnancy is eliminated from the body. This process can take several weeks.
Miscarriage is technically referred to as spontaneous abortion, to distinguish it from a therapeutic abortion. However, the term abortion carries significant emotional baggage for most people, so it is not used in informal conversation.
Causes
Although miscarriage can happen by accident or misadventure, the vast majority of miscarriages occurs because of gestational irregularities -- something that went wrong at the time of conception. These events are totally beyond the parents' control. If you are having or have just had a miscarriage: it is not your fault. It is a common and natural event. Something went amiss in the incredibly complex process of reproduction. It is terribly sad, but it is not unusual, and it is not the end of your dreams of parenthood. In most cases a first or second miscarriage will not harm your chances of a subsequent successful pregnancy in any way.
Most miscarriages occur because the embryo or fetus stopped developing. The pregnancy is "non-viable" and terminates. In some rare cases, the fetus is sound, but the woman's cervix is weakened (due to congenital defect or previous surgery) and is unable to bear the weight of the developing baby. This condition, tactfully called cervical incompetence, is almost inevitably fatal to the fetus unless detected early enough that the woman can be completely restricted to bed rest.
The most commonly diagnosed cause of miscarriage in the first trimester is chromosomal abnormality. Soon after the sperm and the egg meet inside the fallopian tube, their chromosomes match up. The sperm and egg each normally contribute 23 unique chromosomes (via meiosis) to the future embryo. In a small percentage of sperm, and a larger percentage of eggs, an abnormal number of chromosomes present, a condition called aneuploidy. Improper chromosome counts are usually, but not always, fatal to the pregnancy.
50% of chromosome-related miscarriages are found to be due to trisomy, the presence of a third copy of one chromosome. For most chromosomes, trisomy is not survivable. Trisomy 21, known as Down syndrome, is the most common exception. Duplication of chromosome 23, the sex chromosome, is also survivable1. Another 25% of chromosome-related miscarriages are due to monosomy, where only a single copy of a chromosome occurs. Monosomy is usually fatal2. The remainder of chromosome-related miscarriages involve rarer problems such as translocation of chromosomal material. Increasing age is a significant risk factor in chromosomal abnormality, especially for women past age 35.
The end of the first trimester is the point at which it is traditionally "safe" to tell others that you are pregnant. Chances of miscarriage fall off significantly. Risks in the second trimester include serious illness or injury, or structural problems in the reproductive organs. Cervical incompetence, mentioned previously, may be a risk.
Symptoms
The most common symptom of miscarriage is the sudden onset of vaginal bleeding. Some spotting is normal and expected, but any amount of brightly coloured blood is potentially serious, and you should see your health care provider or visit emergency immediately. Your provider will want to know how much bleeding there has been, and if there was any 'tissue'.
(Aside: At no point during our visit to emergency did anyone define 'tissue' for me. I thought it was a euphemism for 'fetus' in some sort of bizarre attempt at delicacy. In fact, the vast majority of 'tissue' shed during an early miscarriage is placental, as the lining of the uterus dissolves and is expelled.)
Though it is enormously difficult to think about, if there is tissue it should be preserved for testing, as it can give vital clues to the cause of the miscarriage.
Note that bleeding also can accompany successful pregnancies! Bleeding occurs in 40% of all pregnancies, and half of those go on to successful completion. A mild tear ('abruption') where the forming placenta attaches to the uterine wall, or an embryo implantation that happens to hit a blood vessel, can cause alarming bleeding that is actually harmless. Heavy vaginal bleeding (soaking more than one pad per hour) is cause for alarm -- immediate medical attention is warranted.
Cramping, either mild or severe, may also be present. Again this symptom is not conclusive. Some cramping is normal may be a result of the womb and other organs adjusting to accommodate the pregnancy. Cramping and bleeding together are cause for serious concern, and immediate medical attention is warranted. This may indicate that the womb is disposing of the embryo, placenta, endometrium, and other materials.
For women in the 6th to 12th weeks of pregnancy, when signs of pregnancy such as nausea and breast tenderness are most common, the sudden loss of these signs is also cause for alarm. Such signs usually start around week 6, are strongest at week 10, and taper off by week 13. A sudden stop may mean that the body has stopped producing HCG, Human Chorionic Gonadotrophin3. This in turn means that the pregnancy has already terminated, though no bleeding or cramping has yet occurred. Again, you should see your health care provider right away.
Even with no symptoms, an early indication of trouble may come from blood tests during the first weeks of pregnancy. There is significant variation in 'normal' HCG levels, and there is no 'right' number. However, the HCG numbers should double every 2-3 days, and quickly mount into the thousands. Numbers that remain in the hundreds and grow much more slowly (as ours did), stay flat, or fall off, indicate that the pregnancy is failing or has failed.
Diagnosis
If a miscarriage is suspected, a physical examination will be conducted to determine the extent of the bleeding and to check for cervical dilation. There will very likely be urine and/or blood tests, including a "beta" blood test for HCG levels. In many cases a blood typing as well. Even if you know your blood type, it will be checked again, in case a shot of RhoGAM is required. Your health care professionals will also check for ectopic pregnancy and molar pregnancy, both of which are very serious and life-threatening conditions which will require immediate surgical action.
If symptoms such as bleeding and cramping were detected early in the pregnancy, all of these tests may be inconclusive. It may be too early to see the developing embryo in an ultrasound. In this case (as it was for us) the medical advice may be to continue blood tests, wait one or two weeks, and have another ultrasound. This was the case for us, and the wait was excruciating. Our "beta" levels were in the low hundreds and not rising, and bleeding continued, so the implication was clear. Nonetheless, successful pregnancies with low betas are not unheard of, and so we waited two weeks, continuing with more disappointing betas and hoping against hope that everything was fine. It wasn't -- two weeks later a second ultrasound confirmed it. There was no embryo, and the endometrium was thinning out.
Process
Most miscarriages occur because the embryo or fetus did not implant properly, did not cause the proper hormones to be generated, or simply stopped developing. The body then ends the pregnancy and breaks down the "products of conception". Many books on miscarriage use the seemingly grisly term "liquify" for the process that breaks down and expels these products. This process can take between one and three weeks. During this entire time the woman must deal with daily bleeding and cramping, both at times quite severe. Even worse, until the levels of HCG return to normal, the hormone continues to send pregnancy signals to the body, resulting in breast discomfort and other 'false' symptoms of pregnancy. This can be particularly heartbreaking -- the woman feels pregnant, yet knows there's no baby.
If the miscarriage does not completely clear on its own, this is an 'incomplete abortion' and medical intervention is required. The most common form of intervention is surgical, the "D&C" or Dilation and curettage. An alternate treatment is the administration of Misoprostol, a drug which makes the uterus contract and expel any remaining products. Both procedures have their risks for future pregnancy, and should be discussed in detail with your health care provider.
Coping
There are many online resources available, and your medical practitioner will be able to recommend support groups and the like. Your hospital chaplain will also be available to discuss any spiritual issues. (And no, it's not punishment. God does not hate you. It's regrettable, but it is not divine vengeance. Not from any God I'm willing to believe in, anyway.)
Sadly, though, the best advice I could find from others who've been here was to support each other and to understand that you can't accept it overnight. It can take a long time to come to terms4.
Sorry I can't offer more than that. If I find something that works better, I'll add it here.
Aftermath
Immediately after a miscarriage, the body has to return to normal. The menstrual cycle must resume, and the pregnancy hormones must dissipate. The cervix must close, if dilated, and the "mucus plug" which prevents infection must reform. In the week immediately following a miscarriage, nothing should be inserted into the vagina (tampons, penes, etc.) in order to prevent infection.
Most experts agree that a normal menstrual cycle should follow before sexual activity is resumed. Studies have shown that chances of successful pregnancy following a miscarriage are no different than chances otherwise. Some studies even suggest a slightly elevated chance of conception in the two or three cycles following a miscarriage.
Emotionally things can be quite difficult, even once past the pain of the miscarriage itself. A subsequent pregnancy can be fraught with concern. Instead of experiencing the joys of pregnancy, couples who have had a miscarriage often spend the months of gestation waiting for something to go wrong. Again, the best advice is that a past miscarriage is no indicator of future difficulties. Each spin of the wheel is independent. You can only wait and hope, and thinking positively is the best remedy for your fears.
Statistics
Most sources put the number of miscarriages in "known" instances of pregnancy at around 20%. One in 5 pregnancies will end in the first or early second trimester due to some problem with the process, as described above. It is felt that significantly more pregnancies fail before the mother even knows she was pregnant. For example, trisomy in all but a few chromosomes will render the embryo non-viable almost immediately after conception. These pregnancies may seem just to be a slightly late and/or unusually heavy period, and often go undetected unless the mother is having a blood test for another reason.
References
My biggest source of information and inspiration was Miscarriage, Why it happens and how to reduce your risk by Henry Lerner, M.D., OB/GYN. This is an excellent and very readable book with a wealth of detail I have omitted here. In addition I read numerous online articles, but I was not as rigorous in tracking them as is my wont. The eMedicine Consumer Health Web Site at http://www.emedicinehealth.com/index.asp was helpful in preparing this entry.
Afterword
Corrections are most welcome, and will be duly recognized.
- Various syndromes such as Klinefelter's syndrome and XYY Syndrome may result.
- On chromosome 23, monosomy is survivable, with Turner's syndrome the result.
- This is the hormone detected by home pregnancy test kits.
- I've been trying to write this entry for weeks.