PGIM MD ObGyn cheat sheet

Estimated due date: Naegele rule = first day of LMP + 280 days; adjust for cycle length, and use crown-rump length at 8–13+6 weeks as the most accurate dating scan.

Gestational diabetes screening: 75 g 2-hour OGTT; IADPSG thresholds are fasting ≥5.1 mmol/L, 1 hour ≥10.0 mmol/L, 2 hours ≥8.5 mmol/L; one abnormal value is diagnostic.

Pre-eclampsia: new hypertension ≥140/90 mmHg after 20 weeks plus proteinuria ≥300 mg/24 h, protein:creatinine ratio ≥30 mg/mmol, or ≥2+ dipstick, or maternal organ dysfunction or uteroplacental insufficiency.

Postpartum haemorrhage: ≥500 mL after vaginal birth or ≥1000 mL after caesarean birth, or any loss causing haemodynamic compromise; remember the four T causes - tone, trauma, tissue, thrombin.

Eclampsia magnesium sulphate: Pritchard regimen = 4 g IV over 20 minutes plus 10 g IM, then 5 g IM every 4 hours; monitor respiratory rate ≥16/min, urine output ≥30 mL/h, and patellar reflexes.

CTG interpretation: normal baseline 110–160 bpm, variability 5–25 bpm, accelerations, and no repetitive decelerations; sinusoidal pattern or absent variability with recurrent decelerations is category III.

Partogram: active-phase cervical dilatation of about 1 cm/hour; prolonged second stage is >3 hours in a nullipara with epidural and >2 hours in a multipara without epidural.

RhD prophylaxis: give anti-D 500–1500 IU to non-sensitised RhD-negative women at 28 weeks and within 72 hours of delivery, and after potentially sensitising events.

Cervical cancer FIGO 2018: stage IB1 ≤2 cm, IB2 >2 to ≤4 cm, IB3 >4 cm; stage IIIC1 = pelvic node metastasis, IIIC2 = para-aortic node metastasis.

Endometrial cancer: the most common gynaecological malignancy in high-income settings; risk factors include unopposed oestrogen, obesity, diabetes, tamoxifen, and Lynch syndrome; postmenopausal bleeding requires endometrial biopsy.

PCOS Rotterdam criteria: two of three - oligo-ovulation or anovulation, clinical or biochemical hyperandrogenism, polycystic ovaries on ultrasound; exclude thyroid disease, hyperprolactinaemia, and non-classic adrenal hyperplasia.

Ectopic pregnancy methotrexate: consider 50 mg/m² IM if haemodynamically stable, hCG <5000 IU/L, no fetal cardiac activity, mass <4 cm, and no significant haemoperitoneum.

Combined oral contraceptive contraindications: migraine with aura, smoking ≥15 cigarettes/day at age ≥35, prior VTE, blood pressure ≥160/100 mmHg, breast cancer, and severe liver disease.

Menopause hormone therapy: use oestrogen alone after hysterectomy; combine oestrogen with a progestogen when the uterus is present; use the lowest effective dose and review annually.

Endometriosis: laparoscopy with visualisation and optional histology is the diagnostic gold standard; medical therapy controls pain but does not improve fertility, so surgery is used for infertility.

Postmenopausal bleeding: transvaginal ultrasound endometrial thickness >4 mm warrants endometrial sampling; approximately 10% of cases are due to endometrial cancer.