OG9.1-6 | Early Pregnancy Complications — Glossary

Termination of pregnancy before 20 completed weeks of gestation or when the fetal weight is <500 g, whether spontaneous or induced.

The genetic mechanism of complete molar pregnancy in which chromosomes are entirely of paternal origin, arising from fertilisation of an ovum that has lost its nuclear DNA.

Antibody preparation given to Rh-negative women after any abortion (spontaneous or induced) to prevent Rh isoimmunisation; 50 µg if <12 weeks, 300 µg if ≥12 weeks.

Autoimmune condition characterised by antibodies against phospholipid-binding proteins (anticardiolipin, anti-β2-glycoprotein-I, lupus anticoagulant); causes placental thrombosis and is the single most important treatable cause of recurrent pregnancy loss.

Autoimmune condition with antiphospholipid antibodies (lupus anticoagulant, anticardiolipin, anti-β2-glycoprotein-I) causing placental thrombosis; the most important treatable cause of RPL. Requires two positive tests ≥12 weeks apart.

Intrauterine adhesions (synechiae) resulting from endometrial damage, most commonly after aggressive sharp curettage; causes secondary amenorrhoea and recurrent pregnancy loss.

A parental chromosomal rearrangement in which genetic material is exchanged between chromosomes without net gain or loss; the carrier is phenotypically normal but produces a proportion of unbalanced gametes, causing RPL or abnormal offspring.

A gestational sac in the uterus with no embryo or a mean sac diameter ≥25 mm on TVS without an embryo; represents an early form of missed abortion where the embryo never developed properly.

A purse-string suture placed around the cervix at 12–14 weeks to prevent premature dilatation in women with cervical incompetence; McDonald and Shirodkar are two surgical techniques.

Pain elicited by moving the cervix during pelvic examination; indicates adnexal pathology (fallopian tube or ovary); a key physical sign in ectopic pregnancy.

Structural or functional weakness of the cervix causing painless progressive dilatation in the second trimester, typically leading to loss at 14–24 weeks; treated by prophylactic cervical cerclage.

Softening and dilating the cervix before surgical evacuation to reduce trauma; achieved with misoprostol 400 µg sublingual 2–3 hours before the procedure, or with osmotic dilators (laminaria/Dilapan) placed the night before for later gestations.

A highly malignant form of GTN characterised by absence of chorionic villi, sheets of malignant trophoblastic cells, and early haematogenous metastasis to lungs, brain, liver; highly chemosensitive (>95% cure).

Finger-like projections of placental trophoblast; the structure of a normal early pregnancy placenta; identified in the tissue bowl after evacuation as fluffy, floating pink-white material — their absence mandates exclusion of ectopic pregnancy.

Total expulsion of all products of conception; the cervical os is closed, uterus involuted, bleeding settled, and USG confirms an empty uterine cavity.

A molar pregnancy with 46,XX diploid karyotype entirely of paternal origin (androgenetic), no fetal tissue, marked trophoblastic proliferation, and 15-20% risk of progressing to GTN.

Ectopic implantation in the intramural segment of the fallopian tube within the uterine wall; the most dangerous site due to dual blood supply (uterine + ovarian arteries); ruptures late (10–14 weeks) with massive haemorrhage.

Surgical evacuation technique used at 13–20 weeks; requires wider cervical dilatation (osmotic dilators placed the night before), larger-bore suction cannula, and forceps for fetal parts; performed under anaesthesia in an operating theatre.

The serum β-hCG threshold above which an intrauterine gestational sac should be visible on TVS (approximately 1,500–2,000 IU/L); empty uterus above this level strongly suggests ectopic pregnancy.

The serum β-hCG threshold above which an intrauterine gestational sac should be visible on USG; approximately 1500–2000 IU/L on TVS; absence of intrauterine sac above this level raises strong suspicion for ectopic pregnancy.

The combination of doxylamine (antihistamine) 10 mg and pyridoxine (vitamin B6) 10 mg; the established first-line pharmacological antiemetic for nausea and vomiting of pregnancy and mild-to-moderate HG with the most reassuring fetal safety data.

Implantation of the fertilised ovum outside the uterine cavity; 95–98% in the fallopian tube; the ampullary segment is the most common site (~70%). A life-threatening emergency if the containing structure ruptures.

A multi-agent chemotherapy regimen for high-risk GTN: Etoposide, Methotrexate, Actinomycin-D / Cyclophosphamide, Vincristine (Oncovin); detailed in OG34.3.

Randomised controlled trial (Mol 2014) comparing salpingostomy versus salpingectomy for ectopic pregnancy in women with a patent contralateral tube; found no significant difference in cumulative ongoing pregnancy rates at 3 years (61% vs 56%), supporting salpingectomy as standard when the other tube is normal.

The International Federation of Gynecology and Obstetrics anatomical staging system for gestational trophoblastic neoplasia (Stages I–IV based on localisation and metastatic sites); paired with the WHO prognostic scoring system to determine treatment intensity. Covered in OG34.3.

Biochemical thyroid overactivity (suppressed TSH, elevated fT4) occurring in up to 60% of women with HG, caused by β-hCG cross-reacting with TSH receptors; self-limiting, resolves as hCG falls, and does NOT require antithyroid treatment.

A spectrum of disorders arising from abnormal trophoblastic tissue, ranging from hydatidiform moles (benign) through gestational trophoblastic neoplasia (malignant), all sharing the marker β-hCG.

A post-evacuation β-hCG level that does not fall by more than 10% over three consecutive weekly assays, meeting the RCOG criterion for gestational trophoblastic neoplasia requiring oncologic referral.

A post-evacuation β-hCG increase of more than 10% over two consecutive weekly assays at any point after evacuation, also meeting the criterion for GTN referral.

Blood in the peritoneal cavity; in the context of ectopic pregnancy, results from rupture of the ectopic site; may cause shoulder-tip pain (diaphragmatic irritation), abdominal guarding, and haemodynamic instability.

A balanced crystalloid solution preferred over dextrose-containing fluids in HG management; it provides volume replacement without the risk of worsening thiamine depletion that dextrose carries in a malnourished patient.

A graded series of double-ended metal rods used to dilate the cervical os to a size appropriate for the intended cannula; passed sequentially from smaller to larger to avoid traumatic dilatation.

Simultaneous intrauterine and ectopic pregnancy; rare naturally (~1 in 30,000) but significantly more common after IVF (~1 in 100); the presence of an IUP on USG does not exclude a simultaneous ectopic.

Severe, pathological nausea and vomiting of pregnancy characterised by weight loss exceeding 5% of pre-pregnancy body weight, ketonuria ≥2+, and electrolyte disturbance requiring hospitalisation; a diagnosis of exclusion after secondary causes are ruled out.

Serum potassium <3.5 mEq/L; a common electrolyte disturbance in HG caused by vomiting-related losses and secondary hyperaldosteronism; severe hypokalaemia (<2.5 mEq/L) risks cardiac arrhythmias and muscle weakness.

Partial expulsion of the products of conception; characterised by an open cervical os, retained tissue in the uterus, and ongoing bleeding.

Abortion in which the cervical os is open and expulsion of the products of conception is certain; distinguishable from incomplete by the absence of expelled tissue.

Failure of the fetus to achieve its genetic growth potential, defined as estimated fetal weight below the 10th centile; occurs in severe prolonged HG due to maternal nutritional depletion, but is uncommon with adequate management.

A locally invasive form of GTN in which trophoblastic villi penetrate the myometrium; does not metastasise haematogenously but can cause haemorrhage; responds well to chemotherapy.

A flexible plastic suction cannula with two openings near the tip; available in sizes 4–12 mm corresponding to weeks of gestation; used in MVA for atraumatic uterine evacuation.

The presence of ketone bodies in urine, reflecting starvation ketosis; detected on urine dipstick as 2+ or 3+; a key marker of metabolic decompensation in hyperemesis gravidarum.

A chronic amnesic syndrome characterised by irreversible short-term memory impairment and confabulation, representing the untreated late stage of Wernicke's encephalopathy; prevented by early thiamine replacement.

Anticoagulant used in APS-associated RPL (e.g. enoxaparin 40 mg SC daily); prevents placental thrombosis; combined with aspirin 75 mg daily as first-line treatment for obstetric APS.

An antiphospholipid antibody detected by clotting-time assays (DRVVT, aPTT); paradoxically named — it causes thrombosis in vivo but prolonged clotting times in vitro. One of three APS antibodies.

A longitudinal mucosal laceration at the gastro-oesophageal junction caused by repeated forceful retching; presents as haematemesis in severe HG; most are self-limiting.

Preferred surgical method for uterine evacuation in incomplete and missed abortion up to 13 weeks; uses a hand-operated syringe attached to a cannula to evacuate retained products.

A folic acid antagonist used medically to treat unruptured ectopic pregnancy in haemodynamically stable women meeting strict criteria (β-hCG <5000 IU/L, no cardiac activity, mass ≤3.5 cm); given as single-dose 50 mg/m² IM.

A dopamine D2-receptor antagonist antiemetic used in HG; effective but limited to short courses (<5 days) due to the risk of extrapyramidal side effects including acute dystonia and akathisia.

A bioidentical vaginal progesterone preparation (400 mg twice daily from positive pregnancy test) used in women with unexplained RPL and early pregnancy bleeding; PRISM trial demonstrated significant reduction in miscarriage rate.

An antiprogestogen that sensitises the uterus to prostaglandins; given 24–48 hours before misoprostol to improve efficacy in medical management of missed abortion and MTP.

A prostaglandin E1 analogue used medically to manage missed and incomplete abortion; promotes cervical ripening and uterine contractions leading to expulsion of retained products.

Intrauterine fetal death with retained products of conception and a closed cervical os; often diagnosed incidentally on USG with absent cardiac activity.

Indian legislation governing medical termination of pregnancy; amended in 2021 to extend the gestational limit to 24 weeks for specified categories, with approval of a State Medical Board required beyond 24 weeks for substantial fetal abnormality.

The physiological nausea and vomiting affecting up to 80% of pregnant women in the first trimester, typically onset 4–6 weeks, peak 8–12 weeks, resolution by 16 weeks; does not cause significant weight loss or dehydration.

A selective 5-HT3 (serotonin-3) receptor antagonist antiemetic used as second-line therapy in HG; carries debated first-trimester safety data (small oral cleft risk in some studies) and risk of QTc prolongation at high doses.

Local anaesthetic injection at the cervicovaginal junction (4 and 8 o'clock positions) using 1% lignocaine to reduce pain during cervical manipulation and uterine evacuation.

A molar pregnancy with triploid karyotype (69,XXX or 69,XXY), often with abnormal fetal tissue present, less dramatic clinical features, and ~0.5-1% GTN risk.

Pre-Conception and Pre-Natal Diagnostic Techniques Act; prohibits the use of any diagnostic technique (including USG) for sex determination of the fetus; violation is a criminal offence.

Residual viable trophoblastic tissue remaining in the fallopian tube after salpingostomy (~5–8% of cases); detected by persistently elevated or rising post-operative β-hCG; treated with a single dose of methotrexate.

A pregnancy in which the serum β-hCG is positive but TVS shows neither intrauterine nor ectopic pregnancy; requires serial β-hCG monitoring at 48 hours to determine the likely location and trajectory.

Embryo biopsy during IVF to identify chromosomally balanced embryos for transfer; used in couples where one partner carries a balanced translocation, to reduce risk of miscarriage and abnormal offspring.

Randomised controlled trial (Coomarasamy 2019) of vaginal progesterone vs placebo in women with unexplained RPL and first-trimester bleeding; showed significant reduction in miscarriage rates, particularly in the subgroup with ≥3 previous losses.

The tissues that form as a result of conception: gestational sac, chorionic villi, decidua, and embryo/fetus; also called 'products of pregnancy'.

Pregnancy-Unique Quantification of Emesis — a validated 3-item severity score for NVP/HG measuring hours of nausea, number of vomiting episodes, and number of retching episodes per day; total 3–15: mild ≤6, moderate 7–12, severe ≥13.

Three or more consecutive pregnancy losses before 20 weeks (RCOG/ESHRE definition); the ASRM threshold is two or more clinical losses. Requires systematic investigation to identify treatable causes.

Surgical removal of the affected fallopian tube; preferred when the contralateral tube is normal (eliminates persistent trophoblast risk and future ectopic risk in that tube), and mandatory in ruptured ectopic with uncontrolled bleeding.

Surgical procedure in which a linear incision is made over the ectopic pregnancy in the fallopian tube, the ectopic is removed, and the tube is left to heal without suture; tube-conserving; preferred when the contralateral tube is absent or damaged.

Any type of abortion complicated by intrauterine infection; presents with fever, uterine tenderness, and offensive discharge; a life-threatening emergency.

The characteristic pelvic ultrasound appearance of a complete molar pregnancy: a uterine cavity filled with a heterogeneous echogenic mass containing multiple small anechoic cystic spaces, with no identifiable fetal pole.

Paternal factor in RPL; excessive DNA strand breaks in sperm reduce fertilisation quality and increase embryonic arrest; assessed by TUNEL assay or comet assay; treated with antioxidant therapy or varicocele repair where applicable.

The surgical method of choice for evacuating molar pregnancy, using negative pressure through a cannula; preferred over sharp curettage because the trophoblastic uterine wall is friable and at risk of perforation.

Bilateral multicystic ovarian enlargement caused by β-hCG-driven stimulation of theca-lutein cells; a sign of β-hCG excess, they resolve spontaneously after evacuation.

A water-soluble B-vitamin essential for pyruvate dehydrogenase complex and the pentose phosphate pathway; depleted within 2–3 weeks of poor oral intake in HG; its deficiency causes Wernicke's encephalopathy.

Bleeding in the first half of pregnancy with a closed cervical os and a viable intrauterine fetus demonstrable on USG; approximately 50% resolve with ongoing pregnancy.

Prevention of venous thromboembolism using low-molecular-weight heparin (LMWH, e.g. enoxaparin 40 mg SC daily) and compression stockings; indicated in women admitted with HG due to dehydration, immobility, and baseline pregnancy hypercoagulability.

Autoantibody against the enzyme thyroid peroxidase; positive in autoimmune thyroiditis; independently associated with increased pregnancy loss risk even without overt hypothyroidism; indicates need for levothyroxine therapy in RPL.

A rare but potentially fatal peri-operative complication of molar evacuation in which trophoblastic cells enter the pulmonary circulation; risk is minimised by avoiding pre-evacuation oxytocin and vigorous uterine contraction before the cavity is decompressed.

Ultrasound appearance of an unruptured tubal ectopic: a hyperechoic ring-like structure (trophoblastic ring) in the adnexa separate from the ovary; distinct from the decidual cyst of a corpus luteum.

RPL in which a full standardised investigation identifies no treatable cause, occurring in approximately 50% of investigated couples; prognosis with supportive care and progesterone is approximately 70–75% live birth rate.

Inadvertent penetration of the uterine wall by an instrument during evacuation; recognised by sudden loss of resistance, clear fluid in the syringe, and soft uterus; requires immediate cessation of procedure and surgical assessment.

A fibromuscular partition of the uterine cavity arising from incomplete resorption of the Müllerian septum; the most common Müllerian anomaly associated with RPL; treated by hysteroscopic resection.

A thin graduated metal probe passed through the cervical canal to measure the depth of the uterine cavity before cannula insertion during MVA; confirms cavity length and uterine position before a wider instrument is inserted.

An acute neurological emergency caused by thiamine (vitamin B1) deficiency, presenting with the triad of confusion, ophthalmoplegia (lateral rectus palsy/nystagmus), and gait ataxia; preventable in HG by giving thiamine 100 mg IV before any dextrose infusion.

A risk score (0–12+) incorporating prior pregnancy type, interval since index pregnancy, β-hCG level, largest tumour size, metastatic sites, number of metastases, and prior chemotherapy failure; score ≤6 = low-risk (single-agent chemotherapy), ≥7 = high-risk (multi-agent). Covered in OG34.3.

A glycoprotein hormone produced by trophoblastic tissue, which peaks at 8–10 weeks of gestation; high hCG levels are the primary driver of hyperemesis and are the basis of gestational transient thyrotoxicosis.

Glycoprotein hormone produced by the syncytiotrophoblast; doubles every ~48 hours in viable early pregnancy; used to monitor pregnancy viability and ectopic exclusion.

The trophoblast-derived heterodimeric glycoprotein hormone used as the diagnostic and surveillance marker for all gestational trophoblastic disease; normalisation after evacuation is the key surveillance endpoint.