Miscarriage and recurrent pregnancy loss

• Miscarriage is the spontaneous loss of a pregnancy before it reaches viability; the WHO and CDC define it as loss before 20 weeks or at a fetal weight of 500 g or less, while local viability-based definitions vary. ^[5]
• Most single first-trimester losses are caused by random chromosomal abnormalities in the embryo, which is why miscarriage is common and usually not anyone's fault. Aneuploidy is behind roughly half of all early pregnancy losses. ^[5][4]- Miscarriage can present as threatened bleeding with a viable pregnancy, or as an incomplete, complete, missed, or septic loss; accurate transvaginal ultrasound, sometimes repeated a week later, is what separates these and prevents treating a pregnancy that is still viable. ^[1][5]
• For a confirmed miscarriage, first-line management is expectant for 7 to 14 days; medical management uses mifepristone and misoprostol for a missed miscarriage and misoprostol alone for an incomplete miscarriage; surgical aspiration under local or general anaesthesia is equally valid and should be offered as a choice. ^[1]
• Recurrent pregnancy loss affects about 1 to 2 percent of couples. Definitions differ: ESHRE considers two or more pregnancy losses, while RCOG usually reserves the term recurrent miscarriage for three or more first-trimester losses, although investigation after two is reasonable if a pathological cause is suspected. ^[2][3][4]

By the end of this page you should be able to:

1. Define miscarriage and recurrent pregnancy loss and use the clinical classification correctly.
2. Explain why miscarriage occurs and which risk factors are modifiable.
3. Interpret a transvaginal scan for viability or pregnancy location, including the safety rules for making the diagnosis.
4. Choose between expectant, medical and surgical management for a confirmed miscarriage and quote the drug doses.
5. Recognise and manage a septic miscarriage as an emergency.
6. Plan an evidence-based recurrent pregnancy loss work-up (genetic, thrombophilia/antiphospholipid, anatomical, endocrine, male factors).
7. Explain which treatments are supported, which are not, and where guidelines disagree.
8. Provide supportive, psychologically informed care and correct anti-D immunoglobulin management.

The older phrase "spontaneous abortion" is still found in records, but patients prefer "miscarriage" or "pregnancy loss", and professional organisations now recommend those terms. ^[5]

Early pregnancy loss means loss before 13 weeks of gestation, and an "early miscarriage" usually means a loss before 10 to 13 weeks. ^[5]

• Threatened miscarriage: bleeding and cramping in an otherwise viable pregnancy before 20 weeks. ^[5]
• Inevitable miscarriage: a historical term for bleeding with an open cervical os but no tissue passed yet. Many clinicians avoid it, because an apparently inevitable loss sometimes still continues. ^[5]
• Incomplete miscarriage: some products of conception have been passed but retained tissue remains, usually with ongoing bleeding and cramping and an open cervix. ^[5]
• Complete miscarriage: all products have been passed, bleeding settles, and the uterus is empty on scan. ^[1]
• Missed miscarriage (missed abortion): the embryo or fetus has died (or an anembryonic "blighted ovum" sac has formed) but nothing has been passed; the cervix is usually closed and bleeding is absent or only slight. ^[1]
• Septic miscarriage: any pregnancy loss complicated by intrauterine infection, which can be life-threatening. ^[5][6]
• Anembryonic pregnancy: a gestational sac grows but no embryo develops. It is one cause of missed miscarriage. ^[5]
• Biochemical pregnancy loss: a positive urinary or serum beta-hCG that resolves before it can be seen on ultrasound. ^[5]
• Clinical pregnancy loss: a loss after ultrasound has confirmed an intrauterine pregnancy. ^[5]

An ordinary single miscarriage is usually sporadic. Recurrent pregnancy loss means repeated losses.

• ESHRE defines RPL as the loss of two or more pregnancies. The definition includes losses after spontaneous conception and after assisted reproduction, but excludes ectopic and molar pregnancies. ESHRE keeps "recurrent miscarriage" for cases where all losses have been confirmed as intrauterine. ^[2][3]
• ASRM defines RPL as two or more failed clinical pregnancies (the older RCOG-reported wording), while its 2026 committee opinion defines RPL as the spontaneous loss of two or more pregnancies before 22 completed weeks, including those diagnosed only by urinary or serum hCG. Evaluation is recommended in that group. ^[4]
• RCOG defines recurrent miscarriage as three or more first-trimester miscarriages, but encourages clinicians to begin extensive evaluation after two when there is suspicion of a pathological rather than sporadic cause, and allows non-consecutive losses and losses with different partners. ^[4]

ESHRE reports that whichever definition is used, RPL affects roughly 1 to 2 percent of couples. ^[2][3]

Miscarriage is common but under-counted, because many very early losses are never recognised. ^[5]

• Roughly 10 to 15 percent of clinically recognised pregnancies end in spontaneous loss (some sources cite 10 to 20 percent). ^[5]
• Older estimates include around 26 percent of all pregnancies, which reflects the large number of losses before a pregnancy is recognised. ^[5]
• Loss is overwhelmingly a first-trimester event: an early miscarriage is defined as loss before 10 to 13 weeks. ^[5]
• About half of early pregnancy losses are due to embryonic chromosomal abnormalities (estimates range from about 50% to 60%, and rise to roughly two-thirds of losses between 6 and 10 weeks). ^[4][5]
• RPL affects 1 to 2 percent of couples. ^[2][3]
• Aneuploidy is more likely as maternal age rises; RPL is more common over the age of 40 years. ^[2][3]

A single miscarriage usually happens by chance and is not a sign of poor health. About half of first-trimester losses are due to chromosomal error in the embryo, most of them random aneuploidies. ^[5]

Recognised risk factors for miscarriage and for RPL include:

• Maternal age: risk is lowest between 20 and 35 years and rises rapidly after 40. ^[3][2]
• Multiple previous losses: the risk of a further miscarriage increases with each successive loss. ^[4]
• Paternal age over 40 years, especially when the woman is 35 or older. ^[2][3]
• Modifiable factors: smoking, obesity or significant underweight, and excessive alcohol; ESHRE recommends stopping smoking, aiming for a healthy BMI, and limiting alcohol. Caffeine and exercise have insufficient evidence as direct causes. ^[3]
• Stress is associated with RPL, but there is no evidence that stress directly causes pregnancy loss. ^[3]
• Uterine anatomy: congenital (Mullerian) anomalies, intrauterine adhesions, polyps, and submucosal fibroids. ^[3]
• Antiphospholipid syndrome: persistent antibodies (lupus anticoagulant, anticardiolipin, and anti-beta2 glycoprotein I) that predispose to placental thrombosis. ^[3]
• Endocrine: overt hypothyroidism, thyroid autoimmunity, and uncontrolled diabetes; PCOS markers themselves do not predict loss. ^[3]
• Infection: pelvic infection, and the rare but dangerous septic miscarriage. ^[5][6]
• Genetic carriership: balanced chromosomal translocations or inversions in a parent. ^[3]
• Hereditary thrombophilia: a contested contributor; ESHRE suggests screening only with additional risk factors. ^[3]
• Male factors: lifestyle (smoking, alcohol, weight, age) and possibly sperm DNA fragmentation. ^[2][3]

How a viable pregnancy fails depends on the cause.

• Chromosomal error: aneuploidy triggers failed embryonic development and bleeding; this explains the steep rise with age. ^[5]
• Failed implantation or placentation: defective decidualisation or endometrial receptivity prevents stable attachment.
• Uterine malformation or adhesions: reduce cavity surface, distort vascular supply, or restrict growth.
• Antiphospholipid antibodies: cause placental vascular thrombosis and decidual failure, explaining recurrent loss rather than sporadic loss.
• Infection: bacterial ascent causes chorioamnionitis, tissue necrosis and sepsis.
• Endocrine or thyroid dysfunction: alters the endometrial milieu in early gestation.

Women describe bleeding of any amount from spotting to heavy flow, cramping pelvic pain, passage of tissue or clots, fading pregnancy symptoms (nausea, breast tenderness), and sometimes shoulder-tip pain if bleeding is intra-abdominal. ^[1]

• Threatened: bleeding with a closed cervix and a potentially viable pregnancy.
• Incomplete or inevitable: heavy bleeding, stronger cramps, open cervix, tissue in the vagina or cervical canal.
• Complete: bleeding tapers off, cramps settle, and tissue has been passed.
• Missed: slight brown discharge, loss of pregnancy symptoms, a closed cervix; the diagnosis is made on scan.
• Septic: fever, chills, abdominal pain, offensive discharge, uterine tenderness, tachycardia or hypotension.

Blood pressure, pulse and temperature come first. Abdominal tenderness, peritoneal signs and a rigid abdomen suggest rupture or sepsis. A pelvic (speculum) examination identifies open or closed cervix, tissue in the canal, and bleeding; bimanual examination estimates uterine size and tenderness. Always exclude an ectopic pregnancy. ^[1]

Bleeding in early pregnancy has many causes. The key distinction is between a continuing intrauterine pregnancy, a miscarriage, and an ectopic pregnancy or gestational trophoblastic disease. ^[1]

Every woman of reproductive age with pain, bleeding, dizziness or collapse needs a pregnancy test. ^[1]

NICE's safe-diagnosis rules are designed to avoid calling a viable pregnancy non-viable. ^[1]

• Transvaginal ultrasound is first-line; use a second scan before diagnosis when early. ^[1]
• Crown-rump length under 7.0 mm with no heartbeat: scan again after at least 7 days. ^[1]
• Crown-rump length 7.0 mm or more with no heartbeat: seek a second opinion and/or repeat scan after at least 7 days.
• Mean sac diameter under 25.0 mm with no fetal pole: scan again after at least 7 days.
• Mean sac diameter 25.0 mm or more with no fetal pole: seek a second opinion and/or repeat scan after at least 7 days.
• With transabdominal scanning, allow at least 14 days between scans.
• Last menstrual period alone must not decide whether a heartbeat should be visible; the cycle may be irregular. ^[1]
• If a complete miscarriage is diagnosed on scan without a previous scan proving an intrauterine pregnancy, always consider pregnancy of unknown location and arrange follow-up. ^[1]
• Give a 24-hour telephone number for any woman who may still be miscarrying. ^[1]

If serum hCG falls by more than 50 percent over 48 hours, the pregnancy is unlikely to continue, but is not proven ended; provide written follow-up instructions. If hCG falls by less than 50 percent or rises by less than 63 percent, review within 24 hours. ^[1]

ESHRE provides the most detailed evidence-based scheme. It is a work-up after RPL, not after a single loss. ^[3]

Genetic

• Genetic analysis of pregnancy tissue is not routine but could be done for explanatory purposes; use array-based comparative genomic hybridisation because maternal contamination is lower. ^[3]
• Parental (peripheral) karyotyping is not routine but can follow individual risk assessment; carriers of a balanced translocation need genetic counselling. ^[3]

Antiphospholipid and thrombophilia

• Screen for antiphospholipid antibodies - lupus anticoagulant and anticardiolipin IgG and IgM - after two pregnancy losses; beta2 glycoprotein I antibodies can be considered. ^[3]
• Do not screen for hereditary thrombophilia unless there are additional risk factors or it is research, because evidence for antithrombotic benefit in RPL is lacking. ^[3]
• ESHRE 2023 maintains the APS screening advice and adds adenomyosis assessment (below). ^[2]

Anatomical

• All women with RPL need an assessment of uterine anatomy. ^[3]
• Transvaginal three-dimensional ultrasound is preferred; sonohysterography or hysterosalpingography can be used if 3D ultrasound is unavailable or tubal patency must be checked. ^[3]
• MRI is not first line. If a Mullerian anomaly is found, consider renal and urinary tract imaging. ^[3]
• ESHRE 2023 adds 2D ultrasound to look for adenomyosis in women with RPL. ^[2]

Endocrine and immunological

• Thyroid screening (TSH and TPO antibodies) is recommended, with T4 follow-up for abnormal results. ^[3]
• Overt hypothyroidism is treated with levothyroxine. ESHRE 2023 states levothyroxine should not be used in euthyroid women with thyroid antibodies. Subclinical hypothyroidism is a judgement call with conflicting evidence. ^[2][3]
• Testing that ESHRE does not recommend: PCOS/fasting insulin and glucose, prolactin (unless symptomatic), ovarian reserve, luteal phase, androgens, LH, homocysteine, cytokines, NK cells, HLA (except Scandinavian secondary RPL prognostic subset) and anti-HLA antibodies. Antinuclear antibody testing could be considered for explanation. ^[3]

Male factors

• Assess lifestyle in the male partner (age, smoking, alcohol, exercise, weight); ESHRE 2023 upgraded this from good practice to a strong recommendation. ^[2][3]
• Sperm DNA fragmentation testing can be considered for diagnostic purposes. ^[2][3]

NICE provides the formal viability thresholds above, which are the operational criteria used in UK early pregnancy units. ^[1]

For recurrent loss, ESHRE's clinical conclusion is that RPL can be considered after two losses, because of the limits on evidence for a stricter cut-off and the wishes of patients and clinicians. ^[3] ASRM's older phrasing used two or more failed clinical pregnancies, while its 2026 committee opinion uses two or more pregnancies lost before 22 weeks (including hCG-only pregnancies); RCOG usually advises investigation after three first-trimester losses, with discretion after two. ^[4]

• Any woman who is shocked, septic, bleeding heavily or has severe pain needs resuscitation, senior review and a plan to empty the uterus.
• Haemorrhage from retained or incomplete products may be controlled temporarily, but definitive management is needed; if the woman cannot have a transfusion or has a coagulopathy, delay worsens outcomes.
• Septic miscarriage requires broad-spectrum antibiotics given intravenously immediately, urgent evacuation of the uterus and transfer to a unit that can perform surgery if the patient is in septic shock. An RCOG example regimen from post-abortion care is ampicillin 0.5 to 1 g every 6 hours plus metronidazole 500 mg every 8 hours and gentamicin 120 mg daily before transfer, with monitoring. ^[6][7]
• RCOG GTG64 (2024) covers sepsis up to and after pregnancy, including post-abortion sepsis, emphasising early diagnosis, rapid antibiotics and senior review; maternal sepsis accounts for a substantial share of maternal deaths worldwide. ^[6]

• NICE advises women whose bleeding stops that routine antenatal care continues, and to return if bleeding worsens or persists beyond 14 days. ^[1]
• RCOG/ESHRE-informed NICE: offer vaginal micronised progesterone 400 mg twice daily to women with vaginal bleeding and a previous miscarriage after a scan confirms a live intrauterine pregnancy; if a fetal heartbeat is confirmed, continue to 16 completed weeks of pregnancy. ^{[1] [4]}
• RCOG adds that progesterone should be considered for women with recurrent miscarriage who bleed in early pregnancy (for example 400 mg micronised vaginal progesterone twice daily from the bleeding until 16 weeks), while noting insufficient evidence for asymptomatic unexplained RPL. ^[4]
• ESHRE 2023 says vaginal progesterone may improve live birth rate in women with three or more losses who also have bleeding in the next pregnancy. ^[2]

NICE: expectant management for 7 to 14 days is first-line for a confirmed miscarriage, unless there is higher haemorrhage risk (late first trimester), a previous traumatic experience of pregnancy, coagulopathy or inability to transfuse, or evidence of infection, in which case another method is explored. ^[1]

If expectant management is not acceptable, offer medical management. ^[1]

Other practical points from NICE: if bleeding has not started within 48 hours after misoprostol, contact the team to decide further care; provide pain relief and antiemetics for medical management; tell women what to expect (bleeding, pain, diarrhoea, vomiting) and when and how to seek help; provide a urine pregnancy test to take at home 3 weeks after medical management; an advancing pregnancy test at 3 weeks should prompt review for retained pregnancy, molar pregnancy or ectopic pregnancy; and advise return if heavy bleeding or fever persists despite a negative test. ^[1]

For surgery, NICE offers a choice between manual vacuum aspiration under local anaesthetic in an outpatient or clinic setting and surgical management in theatre under general anaesthetic, with full written and verbal information. ^[1]

Expectant management monitoring: if resolution of bleeding and pain suggests completion during 7 to 14 days, give a urine pregnancy test to use after 3 weeks. If bleeding has not started, or is persisting or increasing, repeat the scan and discuss all options again; if expectant management continues, review at a minimum of 14 days after the first follow-up. ^[1]

Septic miscarriage is rare but lethal without prompt treatment. ^[5][6]

• Antibiotics first: start broad-spectrum intravenous antibiotics immediately if infection is severe, and do not wait to complete investigations. ^[7]
• Evacuate the uterus urgently: infection with retained products needs source control; transfer to a unit that can operate if the local unit cannot. ^[7]
• Septic shock: transfer immediately to a specialist unit for uterine evacuation; give intravenous ampicillin 0.5 to 1 g every 6 hours, metronidazole 500 mg every 8 hours and gentamicin 120 mg daily before transfer if available, with appropriate monitoring. ^[7]
• Use RCOG GTG64 principles (early diagnosis, rapid antibiotics, senior review, early critical care/infection specialist involvement). ^[6]

Supportive care is a treatment in its own right.

• ESHRE recommends a dedicated RPL clinic with experienced staff, appropriate listening skills and imaging, where the first visit reviews history, answers questions, gives information and proposes a plan, and where psychological needs are taken into account. ^[3]
• RCOG emphasises informed, empathetic communication, prompt access to services, ultrasound for reassurance and mental-health support. Its graded (progressive) model would start supportive and simple investigations earlier than the third loss; RCOG asks the health system to adopt it. ^[4]
• Most unexplained RPL will end in live birth with supportive care alone; ESHRE's prognostic tools (Kolte and Westergaard) base odds on the woman's age and her complete pregnancy history. ^[2][3]
• After RPL, couples should be counselled about maternal age, smoking, BMI and alcohol, and that stress is not a direct cause of loss. ^[3]

• Offer genetic counselling and information if an abnormal parental or fetal karyotype is found. ^[3]
• Preimplantation genetic testing has no clear benefit in RPL. ^[3]

• For women who meet APS laboratory criteria and have had three or more pregnancy losses, ESHRE suggests low-dose aspirin 75 to 100 mg per day started before conception plus a prophylactic dose of heparin, unfractionated or low-molecular-weight, starting when the pregnancy test is positive, rather than no treatment. ^[3]
• For women with two losses and APS, anticoagulation should be offered only in clinical research. ^[3]
• Women with known hereditary thrombophilia should not receive routine antithrombotic prophylaxis for RPL unless VTE prevention or research applies. ^[3]
• Heparin or aspirin is not effective for unexplained RPL and is not recommended. ^[3]
• RCOG advises testing for acquired thrombophilia, particularly lupus anticoagulant and anticardiolipin antibodies, before pregnancy in recurrent miscarriage. ^[4]

• ESHRE: metroplasty is not recommended for bicorporeal uterus with normal cervix; reconstruction is not recommended for a hemi-uterus; metroplasty for bicorporeal uterus with double cervix has insufficient evidence; hysteroscopic septum resection should be studied in trials, with a 2023 update noting only one small randomised trial showing no benefit; and hysteroscopic removal of polyps or submucosal fibroids has insufficient evidence. ^[2][3]
• By ESHRE 2023, adenomyosis is associated with higher loss rates and women with RPL could have 2D ultrasound to exclude it. ^[2]

• Treat overt hypothyroidism with levothyroxine, but do not treat euthyroid women who simply have thyroid antibodies. ^[2][3]
• Levothyroxine for subclinical hypothyroidism may reduce miscarriage but evidence conflicts, so the benefit must be balanced against harm. ^[3]
• Glucocorticoids, intravenous immunoglobulin (except conditional repeated high-dose very early in four or more unexplained losses) and lymphocyte immunisation are not recommended. ^[2][3]
• Progesterone for unexplained RPL does not improve outcome (PROMISE), but (ESHRE 2023 update) vaginal progesterone may improve live birth in women with 3 or more losses who have bleeding in a subsequent pregnancy. ^[2][3]
• Don't forget G-CSF: ESHRE 2023 says there is no evidence to recommend it in unexplained RPL. ^[2]

• Folic acid is advised preconceptionally to prevent neural tube defects but has not been shown to prevent loss in unexplained RPL. Multivitamins should be advised on safety grounds. ^[3]
• Women with APS after two losses should, under current ESHRE advice, receive anticoagulant treatment only in clinical research. ^[3]

NICE's 2026 anti-D update for miscarriage (for women, trans men and non-binary people) is: ^[1]

• No anti-D up to and including 11 weeks plus 6 days after an ectopic pregnancy, miscarriage or threatened miscarriage. ^[1]
• At 12 weeks 0 days to 12 weeks 6 days, offer anti-D at a dose of at least 250 IU (50 micrograms) to RhD-negative people having medical or surgical management of a miscarriage or ectopic pregnancy. ^[1]
• Consider anti-D at the same dose for threatened miscarriage with heavy or recurrent bleeding at that gestation.
• Do not use a Kleihauer test to quantify fetomaternal haemorrhage in this setting. ^[1]

• Give every woman a urine pregnancy test to take at home 3 weeks after a complete (expectant) or medical miscarriage; a positive test needs review to exclude retained products, molar or ectopic pregnancy. ^[1]
• If the test is negative but bleeding, pain or fever persists, assess again. ^[1]
• NICE asks units to provide 24-hour access to someone experienced in early pregnancy complications. ^[1]
• Provide psychological support and information about further options; NICE explicitly aims to limit the psychological impact of loss and notes the value of good support. ^[1]

• Haemorrhage from incomplete evacuation or coagulopathy.
• Sepsis and septic shock, usually with retained products.
• Retained products of conception causing prolonged bleeding or infection.
• Intrauterine adhesions after surgical evacuation (the main long-term gynaecological concern after instrumented procedures).
• Psychological morbidity: grief, anxiety and post-traumatic symptoms are common, particularly after recurrent loss, and should be screened for. ^[4]
• Rh alloimmunisation in RhD-negative women without correct anti-D. ^[1]
• Undiagnosed molar pregnancy with persistent hCG.
• Asherman-syndrome-type scarring especially after multiple procedures.

• Most women who miscarry once go on to have a successful pregnancy; an occasional loss is a normal reproductive event.
• RPL prognosis depends on maternal age and the complete pregnancy history (losses, live births and their sequence). ^[2]
• RCOG 2023 notes that recurrent miscarriage affects about 1 percent of women and raises the graded model of care; prognosis improves with age-adjusted counselling, and ESHRE bases prognosis on age and the full pregnancy history. ^[4][2]
• Age is the strongest outlook factor: women over 40 have a markedly higher per-loss rate. ^[2][3]
• Unexplained RPL carries a good prognosis with specialist supportive care. ^[3]

• There is no true primary prevention for sporadic miscarriage.
• Modifiable factors: stop smoking, maintain a healthy weight, limit alcohol, and manage chronic conditions such as diabetes and thyroid disease before conception. ^[3]
• Systems: early pregnancy assessment services, timely transvaginal ultrasound, clear written follow-up and 24-hour access reduce ruptured/late presentations and psychological harm. ^[1]
• Infection prevention: treat pelvic infection early (especially chlamydia) to protect tubes and endometrium. ^[1]
• Graded care: support after a first or second loss, not only after three, improves experience and is endorsed by RCOG. ^[4]

• Adolescents: pregnancy testing is non-negotiable in lower abdominal pain; outcomes and mental-health support need attention. ^[1]
• Women over 40: counsel early about rising aneuploidy and loss rates; consider chromosomal screening discussions. ^[2]
• RhD-negative women: follow the 2026 NICE anti-D rules above. ^[1]
• Women with assisted reproduction: heterotopic and non-tubal losses occur more often; early scanning matters.
• Thyroid disease: treat overt hypothyroidism; do not treat thyroid antibodies alone. ^[3]
• APS and SLE: multidisciplinary management in pregnancy. ^[3]
• Mental health: recurrent loss is a major negative life event; screen and support both partners. ^[3][4]

• Diagnosis relies on urine hCG, bedside or ward ultrasound if available, and clinical findings; ultrasound can be performed by trained clinicians even in emergency departments. ^[1]
• A ruptured or septic loss is a surgical emergency; if laparoscopy is unavailable, urgent laparotomy with evacuation and transfusion (with infectious-disease screening of blood) is standard, with transfer to a comprehensive emergency obstetric centre where local surgery is not possible. ^[7]
• Where surgery cannot be provided safely, medical management can be used only in carefully selected women (stable, small mass, low hCG, no heartbeat) with reliable follow-up.
• Broad-spectrum antibiotics, evacuation and monitoring for sepsis are essential; source control (emptying the uterus) must not be delayed. ^[6][7]
• Anti-D is given according to national protocol; in settings where it is scarce, its use must be prioritised by gestation and route of management as per the national guideline.
• Send all pregnancy tissue for histopathology when available to confirm the diagnosis and to exclude molar pregnancy. ^[5]

• Miscarriage is the spontaneous loss of a pregnancy before viability; WHO/CDC and UK definitions differ slightly in gestational cut-off. ^[4][5]
• About 10 to 15 percent of clinically recognised pregnancies end in miscarriage (some sources cite 10 to 20 percent), and roughly half to 60 percent of early losses are due to embryonic chromosomal abnormalities. ^[5][4]
• Recurrent pregnancy loss affects 1 to 2 percent of couples: ESHRE uses two or more losses; ASRM evaluates after two failed clinical pregnancies; RCOG defines recurrent miscarriage as three or more first-trimester losses but may investigate after two. ^[2][3][4]
• Types are threatened, inevitable (historical term), incomplete, complete, missed/anembryonic, biochemical, clinical and septic. ^[5]
• Transvaginal ultrasound with safety thresholds (7.0 mm crown-rump length, 25.0 mm sac) protects viable pregnancies from misdiagnosis. ^[1]
• First-line management for a confirmed miscarriage is expectant for 7 to 14 days, with medical (mifepristone 200 mg plus misoprostol 800 micrograms, or misoprostol 600/800 micrograms) or surgical options if not suitable. ^[1]
• Septic miscarriage is an emergency requiring immediate intravenous antibiotics and urgent uterine evacuation. ^[6][7]
• Threatened miscarriage with prior loss may benefit from vaginal progesterone 400 mg twice daily to 16 weeks; unexplained recurrent loss does not benefit from hormones. ^[1][4]
• RPL work-up includes fetal tissue array-CGH when used, parental karyotype by risk, antiphospholipid antibodies after two losses, uterine anatomy (preferably 3D ultrasound), thyroid screening, and lifestyle assessment in both partners. ^[2][3]
• Do not recommend hereditary thrombophilia screening, routine immunological testing, IVIG, glucocorticoids, or aspirin/heparin for unexplained RPL. ^[3]
• APS-related RPL is managed with low-dose aspirin 75 to 100 mg per day before conception plus prophylactic heparin from a positive pregnancy test, after three or more losses. ^[3]
• Anti-D in the UK is not offered up to 11 weeks 6 days; at 12 to 12+6 weeks RhD-negative people having medical or surgical miscarriage or ectopic management should receive at least 250 IU; threatened miscarriage with heavy bleeding is a consideration. ^[1]
• Supportive care, psychological support and clear follow-up (home urine pregnancy test after 3 weeks) are core treatment. ^[1][4]

Miscarriage management and counselling; early pregnancy assessment services; ectopic pregnancy; pregnancy of unknown location; gestational trophoblastic disease; antepartum haemorrhage; pelvic inflammatory disease and tubal damage; pregnancy diagnosis and physiology; contraception after pregnancy loss; mental health and bereavement after pregnancy loss.