OMSB Obstetrics and Gynecology (OEOG) key terms

A five-part obstetric history notation: total pregnancies, term births, preterm births, abortions (spontaneous or induced), and living children. It summarises a woman's reproductive history quickly and guides risk assessment in the current pregnancy.

New hypertension after 20 weeks' gestation with proteinuria or maternal organ dysfunction such as renal, hepatic, haematological, or neurological involvement. It is a leading cause of maternal and perinatal morbidity and mandates close surveillance and timely delivery.

The occurrence of generalised tonic-clonic seizures in a woman with preeclampsia, without another identifiable cause. It is an obstetric emergency requiring airway support, magnesium sulfate, blood pressure control, and planning for delivery.

A severe variant of preeclampsia defined by haemolysis, elevated liver enzymes, and low platelets. It may present with right upper quadrant pain, nausea, or malaise and can progress rapidly, so prompt recognition and delivery planning are essential.

A parenteral drug used for seizure prophylaxis and treatment in preeclampsia and eclampsia, and for fetal neuroprotection before preterm birth. Toxicity is monitored through reflexes, respiratory rate, urine output, and serum levels; calcium gluconate is the antidote.

Low-dose aspirin (typically 75-150 mg nightly) started before 16 weeks in women at high risk of preeclampsia. It reduces the incidence of early-onset preeclampsia and associated fetal growth restriction through antiplatelet and anti-inflammatory effects.

Failure of a fetus to reach its genetically determined growth potential, usually identified by estimated fetal weight below the 10th centile plus abnormal Doppler or growth trajectory. It increases risks of stillbirth, hypoxia, and neonatal morbidity.

Ultrasound assessment of blood flow velocity waveforms in fetal and maternal vessels, commonly the umbilical artery, middle cerebral artery, and ductus venosus. Abnormal resistance patterns help time delivery in growth-restricted fetuses and detect fetal anaemia.

An amniotic fluid volume below the expected range for gestational age, commonly defined as deepest vertical pocket under 2 cm or amniotic fluid index under 5 cm. Causes include ruptured membranes, placental insufficiency, and fetal renal anomalies.

Excess amniotic fluid, usually defined as deepest vertical pocket over 8 cm or amniotic fluid index over 24 cm. It is associated with maternal diabetes, fetal swallowing disorders, gastrointestinal obstruction, and aneuploidy, and predisposes to preterm labour and cord prolapse.

Birth before 37 completed weeks of gestation. It is the leading cause of neonatal mortality and morbidity worldwide, with causes including infection, cervical insufficiency, multiple gestation, and uterine overdistension.

Betamethasone or dexamethasone given to women at risk of preterm delivery between roughly 24 and 34 weeks. They accelerate fetal lung maturation and reduce respiratory distress syndrome, intraventricular haemorrhage, and neonatal death.

Neonatal respiratory failure caused by surfactant deficiency, most common in preterm infants. It presents with tachypnoea, grunting, retractions, and ground-glass chest radiograph, and is reduced by antenatal corticosteroids and postnatal surfactant.

Painless cervical dilatation and shortening in the second trimester leading to recurrent pregnancy loss or preterm birth, in the absence of contractions or infection. It is managed with cerclage, vaginal progesterone, or expectant surveillance.

A surgical suture placed around the cervix to reinforce it in cervical insufficiency. McDonald and Shirodkar techniques are common; the procedure is considered in women with history of mid-trimester loss or short cervix.

Rupture of the fetal membranes before 37 weeks and before the onset of labour. Management balances risks of infection, cord prolapse, and pulmonary hypoplasia against those of prematurity, with antibiotics and corticosteroids usually indicated.

Infection and inflammation of the fetal membranes and amniotic fluid, usually ascending from the vagina. It presents with maternal fever, uterine tenderness, foul discharge, and fetal tachycardia, and requires broad-spectrum antibiotics and prompt delivery.

Blood loss of 500 mL or more after vaginal birth or 1000 mL or more after caesarean birth, or any loss causing haemodynamic instability. Causes follow the four Ts: tone, trauma, tissue, and thrombin.

Failure of the uterus to contract effectively after delivery, the most common cause of postpartum haemorrhage. Management includes uterine massage, uterotonics such as oxytocin, ergometrine, carboprost, and misoprostol, and surgical measures if bleeding persists.

Failure to deliver the placenta within a defined interval after birth, or incomplete expulsion of placental tissue. It causes haemorrhage and infection and may require manual removal, curettage, or surgical exploration.

A systemic coagulation disorder with widespread activation of clotting and secondary fibrinolysis, causing both thrombosis and bleeding. In obstetrics it complicates abruption, amniotic fluid embolism, sepsis, and severe postpartum haemorrhage.

Premature separation of a normally implanted placenta before delivery, presenting with painful vaginal bleeding, uterine hypertonicity, and fetal distress. It risks maternal haemorrhage, coagulopathy, and fetal death, and often requires urgent delivery.

Implantation of the placenta over or near the internal cervical os. It causes painless antepartum bleeding and is a contraindication to vaginal delivery; caesarean section is usually required.

Fetal blood vessels running through the membranes over the cervix, unprotected by placental tissue or Wharton's jelly. Rupture of membranes can cause rapid fetal exsanguination, so antenatal diagnosis prompts planned caesarean delivery.

Glucose intolerance first recognised during pregnancy. It increases risks of macrosomia, shoulder dystocia, preeclampsia, and neonatal hypoglycaemia, and is managed with diet, exercise, and insulin or oral agents when needed.

Excessive fetal birth weight, commonly defined as 4000 g or more or above the 90th centile for gestational age. It increases the risk of prolonged labour, shoulder dystocia, obstetric anal sphincter injury, and caesarean delivery.

Failure of the fetal shoulders to deliver after the head, requiring additional manoeuvres such as McRoberts positioning, suprapubic pressure, or internal rotation. It is an obstetric emergency associated with brachial plexus injury and neonatal hypoxia.

Perineal trauma involving the anal sphincter complex, classified as third degree (sphincter) or fourth degree (sphincter plus anal epithelium). Recognition and primary repair by an experienced clinician reduce risk of faecal incontinence.

Inflammation or infection of the uterine lining, most commonly postpartum or after instrumentation. It presents with fever, lower abdominal pain, and abnormal discharge and is treated with broad-spectrum antibiotics.

Infection of the upper female genital tract, often due to Chlamydia trachomatis or Neisseria gonorrhoeae ascending from the cervix. It causes pelvic pain and can lead to tubal factor infertility, ectopic pregnancy, and chronic pelvic pain.

Implantation of a pregnancy outside the uterine cavity, most often in the fallopian tube. It can present with pain and bleeding, and rupture causes life-threatening haemorrhage; management is surgical or medical with methotrexate.

Infertility caused by damage, obstruction, or dysfunction of the fallopian tubes, often from pelvic infection, endometriosis, or prior surgery. Diagnosis uses hysterosalpingography or laparoscopy, and treatment may involve surgery or assisted reproduction.

Assisted reproduction in which oocytes are retrieved, fertilised outside the body, and embryos transferred to the uterus. It is used for tubal factor infertility, severe male factor infertility, and other causes unresponsive to simpler treatments.

An iatrogenic complication of controlled ovarian stimulation characterised by ovarian enlargement, capillary leak, ascites, and haemoconcentration. Severe cases risk thrombosis and renal failure and require fluid management and thromboprophylaxis.

A common endocrine disorder diagnosed by oligo-ovulation, hyperandrogenism, and polycystic ovarian morphology after excluding other causes. It causes irregular menses, hirsutism, and subfertility and is associated with insulin resistance.

Overgrowth of the endometrial glands relative to stroma, usually due to unopposed oestrogen. It causes abnormal uterine bleeding and, when atypical, carries a significant risk of progression to endometrial carcinoma.

A malignant tumour arising from the endometrial lining, typically presenting with postmenopausal bleeding. Most are oestrogen-driven endometrioid tumours with a favourable prognosis when detected early; staging is surgical.

An autosomal dominant mismatch repair gene defect causing hereditary non-polyposis colorectal cancer and a markedly increased lifetime risk of endometrial and ovarian cancer. It warrants genetic testing and risk-reducing gynaecological surgery after childbearing.

Malignancy arising from ovarian epithelial, germ cell, or sex cord-stromal tissue. Epithelial tumours often present late with bloating, pelvic pain, and ascites; management combines cytoreductive surgery and platinum-based chemotherapy.

A pathogenic variant in BRCA1 or BRCA2 conferring high lifetime risks of breast and ovarian cancer. Carriers are offered enhanced surveillance, risk-reducing salpingo-oophorectomy, and genetic counselling for family members.

A serum tumour marker commonly elevated in epithelial ovarian cancer and other conditions such as endometriosis and pregnancy. It is used for monitoring treatment response rather than as a stand-alone screening test.

Pre-invasive squamous abnormality of the cervix graded by the proportion of epithelium involved. High-grade lesions are associated with oncogenic human papillomavirus and are treated with excision or ablation to prevent cervical cancer.

A sexually transmitted virus whose oncogenic types, especially 16 and 18, cause most cervical cancers. Vaccination and screening programmes targeting HPV infection and its precursors substantially reduce cervical cancer incidence.

Excision of the cervical transformation zone using a thin wire loop with electrosurgical current. It treats high-grade cervical intraepithelial neoplasia and provides a specimen for histology, with risks of bleeding and future preterm birth.

Malignancy of the cervix, almost always linked to persistent oncogenic human papillomavirus infection. Early disease may be asymptomatic; screening detects precursors, while advanced disease presents with bleeding and is treated with surgery, radiotherapy, or chemotherapy.

Presence of endometrial-like tissue outside the uterine cavity, causing cyclical pelvic pain, dysmenorrhoea, and subfertility. Diagnosis is clinical or laparoscopic, and treatment includes hormonal suppression, analgesia, and surgery.

Presence of endometrial glands and stroma within the myometrium, producing a bulky tender uterus, heavy menstrual bleeding, and dysmenorrhoea. Diagnosis is by imaging or histology, and treatment ranges from hormonal therapy to hysterectomy.

A benign smooth muscle tumour of the uterus, often multiple, causing heavy bleeding, pelvic pressure, and subfertility depending on size and location. Treatment includes observation, hormonal therapy, myomectomy, and hysterectomy.

Bleeding from the uterine corpus that is abnormal in volume, duration, frequency, or regularity. Evaluation follows the PALM-COEIN framework to identify structural and non-structural causes and guide management.

Descent of the anterior vaginal wall, posterior vaginal wall, uterus, or vaginal apex beyond its normal anatomical position. It causes a vaginal bulge, pressure, and urinary or bowel symptoms, and is managed with pessaries or reconstructive surgery.

Involuntary leakage of urine on effort, coughing, or sneezing due to urethral sphincter weakness or hypermobility. It is assessed with urodynamics when needed and treated with pelvic floor exercises, midurethral sling, or bulking agents.

A symptom syndrome of urinary urgency, usually with frequency and nocturia, with or without urgency incontinence, in the absence of infection. First-line management includes bladder training, fluid modification, and antimuscarinic or beta-3 agonist therapy.

A set of tests measuring bladder and urethral function during filling and voiding, including cystometry, pressure-flow studies, and leak point pressures. They help distinguish stress, urgency, and mixed incontinence and identify detrusor overactivity.

Surgical obliteration of the vaginal canal used to correct advanced pelvic organ prolapse in women who no longer desire vaginal intercourse. It is effective and well tolerated in frail or elderly patients.

A silicone device inserted into the vagina to support prolapsed organs or treat incontinence. Ring and Gellhorn types are common; regular follow-up is needed to detect erosion, discharge, or infection.

A folate antagonist used in low, single or multi-dose regimens to treat early unruptured ectopic pregnancy and in some cases of persistent trophoblastic disease. It is contraindicated in hepatic or renal impairment and during breastfeeding.

A spectrum of trophoblastic proliferations ranging from benign hydatiform mole to choriocarcinoma. It typically presents with abnormal bleeding, a markedly elevated beta-hCG, and a snowstorm ultrasound appearance, and is monitored with serial hCG levels.

Abnormal fertilisation producing a complete or partial hydatiform mole, with trophoblastic proliferation and absent or abnormal fetal development. It causes bleeding, hyperemesis, and a very high beta-hCG and requires uterine evacuation and hCG surveillance.