Miscarriage
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225595516
2008-07-14T13:54:34Z
Adoniscik
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url to article with broken doi, two column refs in std appendix order
{{Infobox_Disease |
Name = Miscarriage |
Image = |
Caption = |
DiseasesDB = |
ICD10 = {{ICD10|O|03||O|00}} |
ICD9 = {{ICD9|634}} |
ICDO = |
OMIM = |
MedlinePlus = 001488 |
eMedicineSubj = search |
eMedicineTopic = miscarriage |
MeshID = D000022 |
}}
'''Miscarriage''' or ''spontaneous abortion'' is the natural or spontaneous end of a [[pregnancy]] at a stage where the [[prenate]] is incapable of surviving, generally defined in humans at prior to 20 weeks of [[gestation]]. Miscarriage is the most common complication of early pregnancy.<ref>{{cite web | last = Petrozza | first = John C | title = Early Pregnancy Loss | work = eMedicine | publisher = WebMD | date = [[August 29]] [[2006]] | url = http://www.emedicine.com/med/topic3241.htm | accessdate = 2007-07-20 }}<br>
{{cite web | title = Early Pregnancy Loss (Miscarriage) | work = Pregnancy-bliss.co.uk | publisher = The Daily Telegraph | year = 2007 | url = http://www.pregnancy-bliss.co.uk/miscarriage.html | accessdate = 2007-07-20 }}</ref> The medical term "spontaneous abortion" is used in reference to miscarriages because the medical term "abortion" refers to any terminated pregnancy, deliberately induced or spontaneous, although in common parlance it refers specifically to active termination of pregnancy.
==Terminology==
Very early miscarriages - those which occur before the sixth week [[gestational age|LMP]] (since the woman's Last Menstrual Period) are medically termed ''early pregnancy loss''<!--
--><ref name="paternal smoking">{{cite journal | author=Venners S, Wang X, Chen C, Wang L, Chen D, Guang W, Huang A, Ryan L, O'Connor J, Lasley B, Overstreet J, Wilcox A, Xu X | title=Paternal smoking and pregnancy loss: a prospective study using a biomarker of pregnancy. | journal=Am J Epidemiol | volume=159 | issue=10 | pages=993–1001 | year=2004 | pmid=15128612 | url=http://aje.oxfordjournals.org/cgi/content/full/159/10/993 | doi=10.1093/aje/kwh128}}</ref> or ''chemical pregnancy''.<!--
--><ref>{{cite web | title = What is a chemical pregnancy? | url = http://www.babyhopes.com/articles/chemical-pregnancy.html | publisher = Baby Hopes | accessdate = 2007-04-27 }}</ref> Miscarriages that occur after the sixth week LMP are medically termed ''clinical spontaneous abortion''.<ref name="paternal smoking" />
In medical contexts, the word "[[abortion]]" refers to any process by which a pregnancy ends with the death and removal or expulsion of the fetus, regardless of whether it's spontaneous or intentionally induced. Many women who have had miscarriages, however, object to the term "abortion" in connection with their experience, as it is generally associated with induced abortions. In recent years there has been discussion in the medical community about avoiding the use of this term in favor of the less ambiguous term "miscarriage."<ref>{{cite journal |author=Hutchon D, Cooper S |title=Terminology for early pregnancy loss must be changed |journal=BMJ |volume=317 |issue=7165 |pages=1081 |year=1998 |pmid=9774309}}<br>
{{cite journal |author=Hutchon D |title=Understanding miscarriage or insensitive abortion: time for more defined terminology? |journal=Am. J. Obstet. Gynecol. |volume=179 |issue=2 |pages=397–8 |year=1998 |pmid=9731844 |doi=10.1016/S0002-9378(98)70370-9}}</ref>
Labour resulting in live birth before the 37th week of pregnancy is termed "[[premature birth]]," even if the infant dies shortly afterward. The [[limit of viability]] at which 50% of [[fetus]]/[[infant]]s survive longterm is around 24 weeks, with moderate or major neurological disability dropping to 50% only by 26 weeks.<ref name="pmid16396856">{{cite journal |author=Kaempf JW, Tomlinson M, Arduza C, ''et al'' |title=Medical staff guidelines for periviability pregnancy counseling and medical treatment of extremely premature infants |journal=Pediatrics |volume=117 |issue=1 |pages=22–9 |year=2006 |pmid=16396856 |doi=10.1542/peds.2004-2547 |url=http://pediatrics.aappublications.org/cgi/content/full/117/1/22}} - in particular see [http://pediatrics.aappublications.org/cgi/content-nw/full/117/1/22/T1 TABLE 1 Survival and Neurologic Disability Rates Among Extremely Premature Infants]</ref> Although long-term survival has never been reported for infants born from pregnancy shorter than 21 weeks and 5 days,<ref name="titlePowell's Books - Guinness World Records 2004 (Guinness Book of Records) by">{{cite web |url=http://www.powells.com/biblio?show=0553587129&page=excerpt? |title=Powell's Books - Guinness World Records 2004 (Guinness Book of Records) by |accessdate=2007-11-28 |format= |work=}}</ref> infants born as early as the 16th week of pregnancy may sometimes live for some minutes after birth.<!--
--><ref>{{cite paper | author = Patricia Lee June | title = A Pediatrician Looks at Babies Late in Pregnancy and Late Term Abortion | publisher = Presbyterians Pro-Life | date = November 2001 | url = http://www.ppl.org/PJune_PostViability_2001.html | accessdate = 2006-12-24 }}</ref>
A fetus that dies while in the uterus after about the 20-24th week of pregnancy is termed a "[[stillbirth]]"; the precise gestational age definition varies by country. Premature births or stillbirths are not generally considered miscarriages, though usage of the terms and causes of these events may overlap.
[[Image:Miscarriage-Pregnancy timeline.png|800px|center]]
==Forms and types==
The clinical presentation of a ''threatened abortion'' describes any bleeding seen during pregnancy prior to viability, that has yet to be assessed further. At investigation it may be found that the fetus remains viable and the pregnancy continues without further problems. It has been suggested that [[bed rest]] improves the chances of the pregnancy continuing when a small subchorionic [[hematoma]] has been found on ultrasound scans.<!--
--><ref name="pmid12841015">{{cite journal |author=Ben-Haroush A, Yogev Y, Mashiach R, Meizner I |title=Pregnancy outcome of threatened abortion with subchorionic hematoma: possible benefit of bed-rest? |journal=Isr. Med. Assoc. J. |volume=5 |issue=6 |pages=422–4 |year=2003 |pmid=12841015 |doi=}}</ref>
Alternatively the following terms are used to describe pregnancies that do not continue:
* An [[Anembryonic gestation|empty sac]] is a condition where the gestational sac develops normally, while the embryonic part of the pregnancy is either absent or stops growing very early. Other terms for this condition are ''blighted ovum'' and ''anembryonic pregnancy''.
* An ''inevitable abortion'' describes where the fetal heart beat is shown to have stopped and the cervix has already dilated open, but the fetus has yet to be expelled. This usually will progress to a complete abortion.
* A ''complete abortion'' is when all products of conception have been expelled. ''Products of conception'' may include the [[trophoblast]], [[chorionic villi]], [[gestational sac]], [[yolk sac]], and [[fetal pole]] ([[embryo]]); or later in pregnancy the [[fetus]], [[umbilical cord]], [[placenta]], amniotic fluid, and [[amniotic sac|amniotic membrane]].
* An ''incomplete abortion'' occurs when [[biological tissue|tissue]] has been passed, but some remains ''[[in utero]]''.<!--
--><ref name="MedlinePlus">{{cite web |author=MedlinePlus | authorlink =MedlinePlus | date = [[2004-10-25]] | url=http://www.nlm.nih.gov/medlineplus/ency/article/000904.htm | title =Abortion - incomplete | work =Medical Encyclopedia | accessdate =2006-05-24}}</ref>
* A ''missed abortion'' is when the embryo or fetus has died, but a miscarriage has not yet occurred. It is also referred to as ''delayed miscarriage''.
The following two terms consider wider complications or implications of a miscarriage:
* A ''septic abortion'' occurs when the tissue from a missed or incomplete abortion becomes infected. The infection of the womb carries risk of spreading infection ([[septicaemia]]) and is a grave risk to the life of the woman.
* ''[[Habitual abortion|Recurrent pregnancy loss]]'' (RPL) or ''recurrent miscarriage'' (medically termed ''habitual abortion'') is the occurrence of three consecutive miscarriages. If the proportion of pregnancies ending in miscarriage is 15%,<!--
--><ref name="rcog2003">{{cite journal | author = Royal College of Obstetricians and Gynaecologists | authorlink = Royal College of Obstetricians and Gynaecologists | year = 2003 | month = May | title =The Investigation and Treatment of Couple with Recurrent Miscarriage | journal = Guideline | volume = No 17 |url=http://www.rcog.org.uk/resources/Public/pdf/Recurrent_Miscarriage_No17.pdf | format = PDF | accessdate = 2006-05-24}}</ref> then the probability of two consecutive miscarriages is 2.25% and the probability of three consecutive miscarriages is 0.34%. The occurrence of recurrent pregnancy loss is 1%. <!--
--><ref name="rcog2003">{{cite journal | author = Royal College of Obstetricians and Gynaecologists | authorlink = Royal College of Obstetricians and Gynaecologists | year = 2003 | month = May | title =The Investigation and Treatment of Couple with Recurrent Miscarriage | journal = Guideline | volume = No 17 |url=http://www.rcog.org.uk/resources/Public/pdf/Recurrent_Miscarriage_No17.pdf | format = PDF | accessdate = 2006-05-24}}</ref> A large majority (85%) of women who have had two miscarriages will conceive and carry normally afterwards.
==Causes==
Miscarriages can occur for many reasons, not all of which can be identified.
===First trimester===
Most clinically apparent miscarriages (two thirds to three-quarters in various studies) occur during the first trimester.<ref name="webmd">{{cite web | last = Rosenthal | first = M. Sara | title = The Second Trimester | work = The Gynecological Sourcebook | publisher = WebMD | date = 1999 | url = http://www.webmd.com/content/article/4/1680_51802.htm | accessdate = 2006-12-18 }}</ref><ref name="pmid12336441">{{cite journal |author=Francis O |title=An analysis of 1150 cases of abortions from the Government R.S.R.M. Lying-in Hospital, Madras |journal=J Obstet Gynaecol India |volume=10 |issue=1 |pages=62–70 |year=1959 |pmid=12336441 |doi=}}</ref>
Chromosomal abnormalities are found in more than half of embryos miscarried in the first 13 weeks. A pregnancy with a genetic problem has a 95% chance of ending in miscarriage. Most chromosomal problems happen by chance, have nothing to do with the parents, and are unlikely to recur.<!--
--><ref name="PDR Family Guide 1994">{{cite web |author= |year= |title=Miscarriage: Causes of Miscarriage |url=http://www.healthsquare.com/fgwh/wh1ch27p3.htm |publisher=[http://www.healthsquare.com/about.htm HealthSquare.com] |accessdate=2007-09-18}}<br> taken word-for-word from pp. 347-9 of: <br>
{{cite book |author= |year=1994 |title=The PDR Family Guide to Women's Health and Prescription Drugs |location=Montvale, NJ |publisher=Medical Economics |isbn=1-56363-086-9 |chapter=Chapter 27. What To Do When Miscarriage Strikes |pages=pp. 345-50}}</ref> Genetic problems are more likely to occur with older parents; this may account for the higher miscarriage rates observed in older women.<!--
--><ref>{{cite web | title = Pregnancy Over Age 30 | work = MUSC Children's Hospital | url = http://www.musckids.com/health_library/hrpregnant/over30.htm | accessdate = 2006-12-18 }}</ref>
Another cause of early miscarriage may be [[progesterone]] deficiency. Women diagnosed with low progesterone levels in the second half of their menstrual cycle ([[luteal phase]]) may be prescribed progesterone supplements, to be taken for the first trimester of pregnancy.<ref name="PDR Family Guide 1994" /> However, no study has shown that general first-trimester progesterone supplements reduce the risk of miscarriage,<ref name="Cochrane">{{cite journal |author=Wahabi HA, Abed Althagafi NF, Elawad M |title=Progestogen for treating threatened miscarriage |journal=Cochrane database of systematic reviews (Online) |volume= |issue=3 |pages=CD005943 |year=2007 |pmid=17636813 |doi=10.1002/14651858.CD005943.pub2 |accessdate = 2007-11-12 }}</ref> and even the identification of problems with the luteal phase as contributing to miscarriage has been questioned.<ref>{{cite journal |author=Bukulmez O, Arici A |title=Luteal phase defect: myth or reality |journal=Obstet. Gynecol. Clin. North Am. |volume=31 |issue=4 |pages=727–44, ix |year=2004 |pmid=15550332 |doi=10.1016/j.ogc.2004.08.007}}</ref>
===Second trimester===
Up to 15% of pregnancy losses in the second trimester may be due to [[uterine malformation]], growths in the uterus ([[fibroids]]), or [[Cervical incompetence|cervical problems]].<ref name="PDR Family Guide 1994" /> These conditions may also contribute to [[premature birth]].<ref name="webmd" />
One study found that 19% of second trimester losses were caused by problems with the [[umbilical cord]]. Problems with the [[placenta]] may also account for a significant number of later-term miscarriages.<!--
--><ref>{{cite journal | author = Peng H, Levitin-Smith M, Rochelson B, Kahn E | title = Umbilical cord stricture and overcoiling are common causes of fetal demise. | journal = Pediatr Dev Pathol | volume = 9 | issue = 1 | pages = 14–9 | year = 2006| pmid = 16808633 | doi = 10.2350/05-05-0051.1}}</ref>
===General risk factors===
Pregnancies involving more than one fetus are at increased risk of miscarriage.<ref name="PDR Family Guide 1994" />
Uncontrolled diabetes greatly increases the risk of miscarriage. Women with controlled diabetes are not at higher risk of miscarriage. Because diabetes may develop during pregnancy ([[gestational diabetes]]), an important part of [[prenatal care]] is to monitor for signs of the disease.<ref name="PDR Family Guide 1994" />
[[PCOS|Polycystic ovary syndrome]] is a risk factor for miscarriage, with 30-50% of pregnancies in women with PCOS being miscarried in the first trimester. Two studies have shown treatment with the drug [[metformin]] to significantly lower the rate of miscarriage in women with PCOS (the metformin-treated groups experienced approximately one-third the miscarriage rates of the control groups).<ref>{{cite journal |author=Jakubowicz DJ, Iuorno MJ, Jakubowicz S, Roberts KA, Nestler JE |title=Effects of metformin on early pregnancy loss in the polycystic ovary syndrome |journal=J. Clin. Endocrinol. Metab. |volume=87 |issue=2 |pages=524–9 |year=2002 |pmid=11836280 |url=http://jcem.endojournals.org/cgi/content/full/87/2/524 |accessdate=2007-07-17 |doi=10.1210/jc.87.2.524}}<br>
{{cite journal |author=Khattab S, Mohsen IA, Foutouh IA, Ramadan A, Moaz M, Al-Inany H |title=Metformin reduces abortion in pregnant women with polycystic ovary syndrome |journal=Gynecol. Endocrinol. |volume=22 |issue=12 |pages=680–4 |year=2006 |pmid=17162710 |doi=10.1080/09513590601010508}}</ref> However, a 2006 review of metformin treatment in pregnancy found insufficient evidence of safety and did not recommend routine treatment with the drug.<ref>{{cite journal |author=Lilja AE, Mathiesen ER |title=Polycystic ovary syndrome and metformin in pregnancy |journal=Acta obstetricia et gynecologica Scandinavica |volume=85 |issue=7 |pages=861–8 |year=2006 |pmid=16817087 |doi=10.1080/00016340600780441 |doi_brokendate=2008-06-26}}</ref>
[[Hypertension|High blood pressure]] and certain illnesses (such as [[rubella]] and [[Chlamydia infection|chlamydia]]) increase the risk of miscarriage.<ref name="PDR Family Guide 1994" />
Tobacco (cigarette) smokers have an increased risk of miscarriage.<!--
--><ref name="x">{{cite journal | author=Ness R, Grisso J, Hirschinger N, Markovic N, Shaw L, Day N, Kline J | title=Cocaine and tobacco use and the risk of spontaneous abortion. | journal=N Engl J Med | volume=340 | issue=5 | pages=333–9 | year=1999 | pmid=9929522 | doi=10.1056/NEJM199902043400501}}</ref> An increase in miscarriage is also associated with the father being a cigarette smoker.<!--
--><ref name="paternal smoking" /> The husband study observed a 4% increased risk for husbands who smoke less than 20 cigarettes/day, and an 81% increased risk for husbands who smoke 20 or more cigarettes/day.
Severe cases of [[hypothyroidism]] increase the risk of miscarriage. The effect of milder cases of hypothyroidism on miscarriage rates has not been established. Certain immune conditions such as [[Autoimmunity|autoimmune disease]]s greatly increase the risk of miscarriage.<ref name="PDR Family Guide 1994" />
Cocaine use increases miscarriage rates.<ref name="x" /> Physical trauma, exposure to environmental toxins, and use of an [[IUD]] during the time of conception have also been linked to increased risk of miscarriage.<ref name=health.am>{{cite web | title =Miscarriage: An Overview | publisher=Armenian Medical Network | url=http://www.health.am/pregnancy/more/miscarriage_an_overview/ | year = 2005 | accessdate=2007-09-19}}</ref>
===Correlations===
Several factors have been correlated with higher miscarriage rates, but whether they cause miscarriages is debated. No causal mechanism may be known, the studies showing a correlation may have been retrospective (beginning the study after the miscarriages occurred, which can introduce bias) rather than prospective (beginning the study before the women became pregnant), or both.
Nausea and vomiting of pregnancy (NVP, or [[morning sickness]]) are associated with a decreased risk of miscarriage. Several mechanisms have been proposed for this relationship, but none are widely agreed on.<ref>{{cite journal |author=Furneaux EC, Langley-Evans AJ, Langley-Evans SC |title=Nausea and vomiting of pregnancy: endocrine basis and contribution to pregnancy outcome |journal=Obstet Gynecol Surv |volume=56 |issue=12 |pages=775–82 |year=2001 |pmid=11753180|doi=10.1097/00006254-200112000-00004}}</ref> Because NVP may alter a woman's food intake and other activities during pregnancy, it may be a confounding factor when investigating possible causes of miscarriage.
One such factor is [[exercise]]. A study of over 92,000 pregnant women found that most types of exercise (with the exception of swimming) correlated with a higher risk of miscarriage prior to 18 weeks. Increasing time spent on exercise was associated with a greater risk of miscarriage: an approximately 10% increased risk was seen with up to 1.5 hours per week of exercise, and a 200% increased risk was seen with over 7 hours per week of exercise. High-impact exercise was especially associated with the increased risk. No relationship was found between exercise and miscarriage rates after the 18th week of pregnancy. The majority of miscarriages had already occurred at the time women were recruited for the study, and no information on nausea during pregnancy or exercise habits prior to pregnancy was collected.<ref>{{cite journal |author=Madsen M, Jørgensen T, Jensen ML, ''et al'' |title=Leisure time physical exercise during pregnancy and the risk of miscarriage: a study within the Danish National Birth Cohort |journal=BJOG |volume=114 |issue=11 |pages=1419–26 |year=2007 |pmid=17877774 |doi=10.1111/j.1471-0528.2007.01496.x}}</ref>
[[Caffeine]] consumption has also been correlated to miscarriage rates, at least at higher levels of intake. A 2007 study of over 1,000 pregnant women found that women who reported consuming 200 mg or more of caffeine per day experienced a 25% miscarriage rate, compared to 13% among women who reported no caffeine consumption. 200 mg of caffeine is present in 10 oz (300 mL) of coffee or 25 oz (740 mL) of tea. This study controlled for pregnancy-associated nausea and vomiting (NVP or morning sickness): the increased miscarriage rate for heavy caffeine users was seen regardless of how NVP affected the women. About half of the miscarriages had already occurred at the time women were recruited for the study.<ref>{{cite journal |author=Weng X, Odouli R, Li DK |title=Maternal caffeine consumption during pregnancy and the risk of miscarriage: a prospective cohort study |journal=Am J Obstet Gynecol |volume= |issue= |pages= |year=2008 |pmid=18221932 |doi=10.1016/j.ajog.2007.10.803}}<br>
{{cite news | last = Grady | first = Denise | title = Study Sees Caffeine Possibly Tied to Miscarriages | work = The New York Times | date = [[January 20]] [[2008]] | url = http://www.nytimes.com/2008/01/20/health/20cnd-caffeine.html?_r=1&bl&ex=1201150800&en=0019b93b4bb1c219&ei=5087%0A | accessdate = 2008-01-23 }}</ref> A second 2007 study of approximately 2,400 pregnant women found that caffeine intake up to 200 mg per day was ''not'' associated with increased miscarriage rates (the study did not include women who drank more than 200 mg per day past early pregnancy).<ref>{{cite journal |author=Savitz DA, Chan RL, Herring AH, Howards PP, Hartmann KE |title=Caffeine and miscarriage risk |journal=Epidemiology |volume=19 |issue=1 |pages=55–62 |year=2008|month=January |pmid=18091004 |doi=10.1097/EDE.0b013e31815c09b9 |doi_brokendate=2008-06-26|url=http://www.cafeesaude.com.br/downloads/caffeine%20miscarriage%202008%20A.pdf}}<br>
{{cite web | title = Studies Examine Effects Of Caffeine Consumption On Miscarriage Risk | work = Medical News Today | date = 2008-01-23 | url = http://www.medicalnewstoday.com/articles/94764.php | accessdate = 2008-02-16}}</ref>
==Prevalence==
Determining the [[prevalence]] of miscarriage is difficult. Many miscarriages happen very early in the pregnancy, before a woman may know she is pregnant. Treatment of women with miscarriage at home means medical statistics on miscarriage miss many cases.<!--
--><ref name="bmj1997">{{cite journal | author=Everett C | title=Incidence and outcome of bleeding before the 20th week of pregnancy: prospective study from general practice. | journal=BMJ | volume=315 | issue=7099 | pages=32–4 | year=1997 | pmid=9233324 | url=http://bmj.bmjjournals.com/cgi/content/full/315/7099/32}}</ref> Prospective studies using very sensitive early pregnancy tests have found that 25% of pregnancies are miscarried by the sixth week [[gestational age|LMP]] (since the woman's Last Menstrual Period).<!--
--><ref name="implantation">{{cite journal | author=Wilcox AJ, Baird DD, Weinberg CR | title=Time of implantation of the conceptus and loss of pregnancy. | journal=New England Journal of Medicine | volume=340 | issue=23 | pages=1796–1799 | year=1999 | pmid=10362823 | doi=10.1056/NEJM199906103402304}}</ref><!--
--><ref name="epl">{{cite journal | author = Wang X, Chen C, Wang L, Chen D, Guang W, French J | title = Conception, early pregnancy loss, and time to clinical pregnancy: a population-based prospective study. | journal = Fertil Steril | volume = 79 | issue = 3 | pages = 577–84 | year = 2003 | pmid = 12620443 | doi = 10.1016/S0015-0282(02)04694-0}}</ref> Clinical miscarriages (those occurring after the sixth week LMP) occur in 8% of pregnancies.<ref name="epl" />
The risk of miscarriage decreases sharply after the 10th week LMP, i.e. when the [[fetus|fetal]] stage begins.<ref>[http://news.bbc.co.uk/2/hi/health/2176898.stm Q&A: Miscarriage]. (August 6 , 2002). ''BBC News.'' Retrieved January 17, 2007. Also see [[Lennart Nilsson]], A Child is Born 91 (1990)(At eight weeks, "the danger of a miscarriage . . . diminishes sharply.")</ref> The loss rate between 8.5 weeks LMP and birth is about two percent; loss is “virtually complete by the end of the embryonic period."<ref>Rodeck, Charles; Whittle, Martin. ''[http://books.google.com/books?id=0BY0hx2l5uoC&pg=PA835&lpg=PA835&dq=%22early+pregnancy+loss%22+and+weeks&source=web&ots=RZSIYEWK6N&sig=3v2skknEA6qVVaoMnx03AAN_JpU&hl=en#PPA836,M1 Fetal Medicine: Basic Science and Clinical Practice]'' (Elsevier Health Sciences 1999), page 835.</ref>
The prevalence of miscarriage increases considerably with age of the parents. One study found that pregnancies from men younger than twenty-five years are 40% less likely to end in miscarriage than pregnancies from men 25-29 years. The same study found that pregnancies from men older than forty years are 60% more likely to end in miscarriage than the 25-29 year age group.<!--
--><ref>{{cite journal | author = Kleinhaus K, Perrin M, Friedlander Y, Paltiel O, Malaspina D, Harlap S | title = Paternal age and spontaneous abortion | journal = Obstet Gynecol | volume = 108 | issue = 2 | pages = 369–77 | year = 2006 | pmid = 16880308 | doi = 10.1097/01.AOG.0000224606.26514.3a | doi_brokendate = 2008-06-26}}</ref> Another study found that the increased risk of miscarriage in pregnancies from older men is mainly seen in the first trimester.<!--
--><ref>{{cite journal | author = Slama R, Bouyer J, Windham G, Fenster L, Werwatz A, Swan S | title = Influence of paternal age on the risk of spontaneous abortion. | journal = Am J Epidemiol | volume = 161 | issue = 9 | pages = 816–23 | year = 2005 | pmid = 15840613 | doi = 10.1093/aje/kwi097}}</ref> Yet another study found an increased risk in women, by the age of forty-five, on the order of 800% (compared to the 20-24 age group in that study), 75% of pregnancies ended in miscarriage.<!--
--><ref>{{cite journal | author = Nybo Andersen A, Wohlfahrt J, Christens P, Olsen J, Melbye M | title = Maternal age and fetal loss: population based register linkage study | journal = BMJ | volume = 320 | issue = 7251 | pages = 1708–12 | year = 2000 | pmid = 10864550 | doi = 10.1136/bmj.320.7251.1708}}</ref>
==Detection==
The most common symptom of a miscarriage is bleeding;<!--
--><ref name="risk factors">{{cite journal | author = Gracia C, Sammel M, Chittams J, Hummel A, Shaunik A, Barnhart K | title = Risk factors for spontaneous abortion in early symptomatic first-trimester pregnancies | journal = Obstet Gynecol | volume = 106 | issue = 5 Pt 1 | pages = 993–9 | year = 2005 | pmid = 16260517}}</ref> bleeding during pregnancy may be referred to as a ''threatened abortion''. Of women who seek clinical treatment for bleeding during pregnancy, about half will go on to have a miscarriage.<ref name="bmj1997" /> Symptoms other than bleeding are not statistically related to miscarriage.<ref name="risk factors" />
Miscarriage may also be detected during an ultrasound exam, or through serial [[human chorionic gonadotropin]] (HCG) testing. Women pregnant from [[assisted reproductive technology|ART]] methods, and women with a history of miscarriage, may be monitored closely and so detect a miscarriage sooner than women without such monitoring.
Several medical options exist for managing documented nonviable pregnancies that have not been expelled naturally.
==Management==
Blood loss during early pregnancy is the most common symptom of both miscarriage and of [[ectopic pregnancy]]. Pain does not strongly correlate with miscarriage, but is a common symptom of ectopic pregnancy.<ref name="risk factors" /> In the case of concerning blood loss, pain, or both, [[Obstetric ultrasonography|transvaginal ultrasound]] is performed. If a viable intrauterine pregnancy is not found with ultrasound, serial [[human chorionic gonadotropin|βHCG]] tests should be performed to rule out ectopic pregnancy, which is a life-threatening situation.<!--
--><ref name="diagnostic">{{cite journal | author = Yip S, Sahota D, Cheung L, Lam P, Haines C, Chung T | title = Accuracy of clinical diagnostic methods of threatened abortion | journal = Gynecol Obstet Invest | volume = 56 | issue = 1 | pages = 38–42 | year = 2003 | pmid = 12876423 | doi = 10.1159/000072482}}</ref><!--
--><ref name="followHCG">{{cite journal | author = Condous G, Okaro E, Khalid A, Bourne T | title = Do we need to follow up complete miscarriages with serum human chorionic gonadotrophin levels? | journal = BJOG | volume = 112 | issue = 6 | pages = 827–9 | year = 2005 | pmid = 15924545 | doi = 10.1111/j.1471-0528.2004.00542.x}}</ref>
If the bleeding is light, making an appointment to see one's doctor is recommended. If bleeding is heavy, there is considerable pain, or there is a fever, then emergency medical attention is recommended to be sought.
No treatment is necessary for a diagnosis of complete abortion (as long as ectopic pregnancy is ruled out). In cases of an incomplete abortion, empty sac, or missed abortion there are three treatment options:
*With no treatment ([[watchful waiting]]), most of these cases (65-80%) will pass naturally within two to six weeks.<!--
--><ref name="afp">{{cite journal | author = Kripke C | title = Expectant management vs. surgical treatment for miscarriage | journal = Am Fam Physician | volume = 74 | issue = 7 | pages = 1125–6 | year = 2006 | pmid = 17039747 | url= http://www.aafp.org/afp/20061001/cochrane.html#c2 | accessdate = 2006-12-31 }}</ref> This path avoids the side effects and complications possible from medications and surgery.<!--
--><ref>{{cite journal | author = Tang O, Ho P | title = The use of misoprostol for early pregnancy failure. | journal = Curr Opin Obstet Gynecol | volume = 18 | issue = 6 | pages = 581–6 | year = 2006 | pmid = 17099326}}</ref>
*Medical management usually consists of using [[misoprostol]] (a [[prostaglandin]], brand name Cytotec) to encourage completion of the miscarriage. About 95% of cases treated with misoprostol will complete within a few days.<ref name="afp" />
*Surgical treatment (most commonly [[vacuum aspiration]], sometimes referred to as a [[Dilation and curettage| D&C]] or [[Dilation and evacuation| D&E]]) is the fastest way to complete the miscarriage. It also shortens the duration and heaviness of bleeding, and is the best treatment for physical pain associated with the miscarriage.<ref name="afp" /> In cases of repeated miscarriage or later-term pregnancy loss, D&C is also the best way to obtain tissue samples for [[#Pathology|pathology examination]].
==Pathology==
When looking for gross or microscopic [[pathology|pathologic]] symptoms of miscarriage, one looks for the products of [[conception]]. Microscopically, these include [[villi]], [[trophoblast]], fetal parts, and background gestational changes in the [[endometrium]]. Genetic tests may also be performed to look for abnormal [[chromosome]] arrangements.
==Psychological aspects==
Although a woman physically recovers from a miscarriage quickly, psychological recovery for parents in general can take a long time. People differ a lot in this regard: some are 'over it' after a few months, others take more than a year. Still others may feel relief or other less negative emotions.
For those who do go through a process of [[grief]], it is often as if the baby had been born but died. How short a time the fetus lived in the womb may not matter for the feeling of loss. From the moment pregnancy is discovered, the parents can start to bond with the unborn child. When the child turns out not to be viable, dreams, fantasies and plans for the future are disturbed roughly.
Besides the feeling of loss, a lack of understanding by others is often important. People who have not experienced a miscarriage themselves may find it hard to [[empathy|empathize]] with what has occurred and how upsetting it may be. This may lead to unrealistic expectations of the parents' recovery. The pregnancy and miscarriage are hardly mentioned anymore in conversation, often too because the subject is too painful. This can make the woman feel particularly isolated.
Interaction with pregnant women and newborn children is often also painful for parents who have experienced miscarriage. Sometimes this makes interaction with friends, acquaintances and family very difficult.<!--
--><ref name="David Vernon">{{cite web |author=David Vernon | authorlink =David Vernon (writer) | date = [[2005]] | url=http://web.mac.com/david.vernon/iWeb/Having%20a%20Great%20Birth%20in%20Australia/Welcome%20-%20Great%20Birth.html | title =Having a Great Birth in Australia | }}</ref>
==ICD10 codes==
{|width=100%
|-valign=top
|width=20%|
*Habitual abortion
*Incomplete abortion
*Missed abortion
*Threatened abortion
|width=80%|
N96<br>
O03.0-O06.4<br>
O02.1<br>
O20.0
|}
==See also==
* [[Childbirth]]
* [[Stillbirth]]
* [[Premature birth]]
* [[Sudden antenatal death syndrome]]
==References==
{{reflist|2}}
== External links ==
* {{dmoz|/Home/Family/Pregnancy/Loss/Support_Groups/|Pregnancy loss support groups}}
* [http://www.nlm.nih.gov/medlineplus/ency/article/001488.htm Spontaneous Abortion]
* [http://news.bbc.co.uk/2/hi/health/3971855.stm Hormones predict miscarriage risk]
* [http://www.emedicinehealth.com/articles/12305-1.asp Miscarriage Overview]
* [http://www.uchospitals.edu/specialties/obgyn/pregnancy-loss/faq.html Frequently asked questions about recurrent miscarriage/recurrent pregnancy loss]
{{Pathology of pregnancy, childbirth and the puerperium}}
{{Pregnancy}}
[[Category:Abortion]]
[[Category:Obstetrics]]
[[cs:Potrat]]
[[da:Spontan abort]]
[[de:Fehlgeburt]]
[[es:Aborto espontáneo]]
[[fr:Fausse couche]]
[[hi:गर्भस्राव]]
[[it:Aborto#Aborto_spontaneo]]
[[he:הפלה טבעית]]
[[lt:Persileidimas]]
[[nl:Miskraam]]
[[ja:流産]]
[[no:Spontanabort]]
[[pl:Poronienie]]
[[pt:Aborto espontâneo]]
[[ru:Самопроизвольный аборт]]
[[sq:Aborti]]
[[sk:Prirodzený potrat]]
[[fi:Keskenmeno]]
[[sv:Missfall]]
[[vi:Hư thai]]
[[tr:Düşük]]
[[zh-yue:流產]]
[[zh:流产]]