OG10.1-2,OG11.1 | Late Pregnancy Complications — Glossary

Evidence-based protocol using oxytocin 10 IU IM immediately after delivery of the anterior shoulder to prevent postpartum haemorrhage; not directly related to APH but part of the same haemorrhage-prevention framework.

Potentially fatal immune reaction from ABO incompatibility; causes haemolysis, haemoglobinuria, shock, DIC; precipitated by clerical errors; first action is immediate cessation of transfusion.

Serial aspiration of excess amniotic fluid from the recipient twin sac in TTTS to reduce polyhydramnios, preterm labour risk, and intrauterine pressure; used in centres without laser or as bridging therapy.

Bleeding from the genital tract after 20 weeks of gestation and before delivery; classified as placental, extraplacental, or indeterminate.

Alkali denaturation test to distinguish fetal haemoglobin (HbF, alkali-resistant — stays pink) from adult maternal haemoglobin (HbA, alkali-sensitive — turns brown) in vaginal blood; used when vasa praevia rupture is suspected.

Corticosteroid given 12 mg IM × 2 doses 24 hours apart before 34 weeks of gestation to accelerate fetal lung maturity (surfactant production) when preterm delivery is anticipated.

Continuous electronic recording of fetal heart rate and uterine contractions; abnormal CTG patterns (late decelerations, prolonged bradycardia, sinusoidal pattern) indicate fetal compromise.

Intraoperative autotransfusion — surgical blood loss is collected, washed, and re-infused to reduce allogeneic transfusion; used in planned procedures with expected major blood loss (e.g., CS in PAS).

The number of chorions (placentas) in a twin pregnancy; dichorionic = two separate placentas; monochorionic = one shared placenta. Chorionicity is the single most important prognostic determinant.

Hypocalcaemia from chelation of calcium by citrate anticoagulant in stored blood products; relevant in massive transfusion; treated with calcium gluconate 10 mL IV after every 4–6 units PRBCs.

Placental abruption where the retroplacental haematoma does not track externally; the visible bleeding is minimal or absent, leading to underestimation of true haemorrhage and disproportionate shock.

Incomplete separation of MZ twins with shared body parts; arises from disc-stage splitting >13 days; extremely rare (1 in 50,000–100,000 deliveries); delivered by CS.

Specific complication of MCMA twinning — both fetuses share one amniotic sac; their umbilical cords entwine and can compress acutely, causing fetal bradycardia or death; requires inpatient CTG monitoring and elective CS.

Extravasation of blood throughout the myometrium in severe abruption, giving the uterus a bruised purple appearance; impairs uterine contractility and may necessitate hysterectomy.

Blood product derived from FFP on slow thawing; rich in fibrinogen, factor VIII, XIII, and von Willebrand factor; used to replace fibrinogen in DIC (each unit contains ~250 mg fibrinogen).

Strategy of simultaneous administration of red cells, clotting factors, and platelets in fixed ratio from the outset of major haemorrhage, rather than reactive replacement guided only by lab results.

Twin pregnancy with two separate chorions and two amnions — either DZ (always) or MZ split ≤3 days; lowest risk category; surveillance every 4 weeks, delivery at 38 weeks.

Coagulopathy from dilution of clotting factors and platelets by large volumes of crystalloid, colloid, or red cells alone; prevented by the 1:1:1 MTP ratio.

Consumption of clotting factors and platelets triggered by massive release of thromboplastin from the decidua in severe abruption; manifests as uncontrollable haemorrhage and oozing.

Twinning arising from fertilisation of two separate ova by two sperms; always produces dichorionic-diamniotic twins; more common than MZ; influenced by maternal age, family history, parity, and ART.

Fever (≥1°C rise) and rigors during transfusion due to antibodies against donor leucocytes or storage cytokines; commonest transfusion reaction; reduced by pre-storage leucodepletion.

Fetoscopic procedure to photocoagulate arteriovenous anastomoses on the equatorial surface of a monochorionic placenta; treatment of choice for TTTS Stages II–IV; reduces perinatal mortality vs amnioreduction.

Frozen plasma containing all clotting factors; used to reverse coagulopathy in DIC and massive haemorrhage; dose 10–15 mL/kg.

Haemolysis, Elevated Liver enzymes, Low Platelets — a severe variant of pre-eclampsia; platelet transfusion indicated for count <50 × 10⁹/L before operative delivery.

The internal opening of the cervical canal at the junction of the cervix and uterine cavity; the anatomical landmark used to classify placenta praevia types and vasa praevia.

Obstetric manoeuvre to convert a transverse or non-cephalic twin 2 presentation to a breech presentation by internal manipulation, allowing breech extraction; used after delivery of twin 1 during vaginal twin birth.

Acid elution test that detects fetal red blood cells in the maternal circulation; used to quantify fetomaternal haemorrhage and guide anti-D immunoglobulin dosing in Rh-negative mothers.

Triangular wedge of placental tissue projecting into the base of the inter-twin membrane on first-trimester USS; indicates dichorionic-diamniotic (DCDA) twinning; identified at 11–14 weeks.

Uterine size on palpation exceeding expected gestational age; in early pregnancy, a common clinical clue to multiple pregnancy, polyhydramnios, or gestational trophoblastic disease.

The thin, poorly muscularised lower portion of the uterus formed from the isthmus during the third trimester; develops progressively from 20 weeks onward; placenta praevia implants here.

Pre-activated institutional plan for delivering large volumes of blood products in a 1:1:1 ratio (PRBCs:FFP:platelets) to prevent dilutional coagulopathy in major haemorrhage.

MZ twins sharing one chorion (placenta) with two separate amnions; MZ split at 4–8 days; at risk for TTTS, sIUGR, TAPS; surveillance every 2 weeks from 16 weeks; delivery at 36–37 weeks.

MZ twins sharing one chorion AND one amnion; MZ split at 8–13 days; highest risk — universal cord entanglement; inpatient monitoring from 28–30 weeks; elective CS at 32–34 weeks.

Twinning arising from splitting of a single fertilised ovum; timing of split determines chorionicity — split ≤3 days (DCDA), 4–8 days (MCDA), 8–13 days (MCMA), >13 days (conjoined).

Simultaneous development of more than one fetus in the uterus; twins are most common; higher-order multiples (triplets+) carry escalating maternal and fetal risk.

National Institute for Health and Care Excellence Guideline NG137 (2019) on twin and triplet pregnancy; specifies chorionicity-stratified surveillance schedules: MCDA every 2 weeks from 16 weeks; DCDA every 4 weeks from 20 weeks.

Universal donor red cells (no A, B, or Rh(D) antigens); safe for emergency transfusion before compatibility testing; reserved preferentially for Rh(D)-negative women of childbearing age.

Concentrated red cells with haematocrit ~65–70% in additive solution; one unit raises Hb by ~1 g/dL; stored at 4°C; primary product for restoring oxygen-carrying capacity.

Abnormal invasion of placental trophoblast into or through the myometrium (accreta, increta, percreta); associated with placenta praevia in a scarred uterus and is a leading cause of peripartum hysterectomy.

Implantation of the placenta in the lower uterine segment, wholly or partially overlying the internal os; causes painless recurrent third-trimester bleeding.

Premature separation of a normally sited placenta from its uterine attachment before delivery; causes painful haemorrhage, uterine rigidity, and potentially DIC.

Pooled platelets in plasma or additive solution; must be stored at 20–24°C with continuous agitation — never refrigerated; transfusion trigger <50 × 10⁹/L with active bleeding.

Five-stage classification of TTTS severity: I (discordant fluid volumes, bladder visible), II (absent donor bladder), III (critically abnormal Doppler), IV (hydrops), V (fetal death); Stages II–IV indicate laser ablation.

Placental abruption where blood tracks along the membranes and escapes through the cervix; external blood loss is visible but may still underestimate total loss.

FGR affecting one twin in a monochorionic pregnancy due to unequal placental sharing; diagnosed when one twin is <10th centile with birthweight discordance ≥25%; requires Doppler surveillance.

Four-grade classification of placental abruption (0–III) based on extent of haemorrhage, fetal outcome, and presence of DIC; Grade IIIb includes consumption coagulopathy.

Inter-twin membrane meeting the placental surface perpendicularly without a placental wedge on first-trimester USS; indicates monochorionic twinning (MCDA or MCMA); associated with higher risk of TTTS.

Cardiogenic pulmonary oedema from excessive transfusion volume or rate; distinguishable from TRALI by hypertension, raised JVP, and response to diuretics.

Non-cardiogenic pulmonary oedema occurring within 6 hours of transfusion, caused by donor antibodies activating recipient neutrophils in the pulmonary vasculature; leading cause of transfusion-related death.

Antifibrinolytic agent that inhibits plasminogen activation; 1 g IV within 3 hours of PPH onset reduces maternal death from bleeding (WOMAN trial 2017); a second dose may be given after 30 minutes.

Ultrasound probe placed in the vagina (not the cervix); more accurate than transabdominal USS for measuring the distance between the placental edge and the internal os; safe in placenta praevia.

Imbalance of blood flow via arteriovenous anastomoses in a monochorionic placenta; donor twin (oligo/anuric, growth-restricted) transfuses recipient (polyhydramniotic, hydrops risk); Quintero staging I–V; treated with fetoscopic laser ablation.

Pre-transfusion testing comprising ABO typing and antibody screen without crossmatching a specific unit; appropriate for procedures with low expected transfusion need.

Fetal blood vessels running unprotected in the membranes across the internal os; rupture at membrane rupture causes rapid fetal exsanguination with minimal maternal blood loss.

International randomised trial (2017) demonstrating that tranexamic acid 1 g IV within 3 hours of PPH onset reduces maternal death from bleeding without increasing thromboembolism; enrolled 20,060 women in 21 countries including India.