Clinical overview
Medical disorders complicating pregnancy are a leading cause of maternal death in South Africa. The Saving Mothers reports of the NCCEMD consistently identify non-pregnancy-related infections (dominated by HIV and its sequelae — pneumonia, tuberculosis), obstetric haemorrhage, and hypertension as the top contributors, with medical and surgical disorders forming a substantial avoidable fraction. Many deaths are judged avoidable: late presentation, failure to recognise the sick pregnant woman, delayed referral up the levels of care, and substandard monitoring recur as themes. The registrar's task is to anticipate decompensation, because pregnancy lowers physiological reserve and masks early warning signs — a tachycardia or breathlessness that would alarm in a non-pregnant patient is too easily dismissed as "normal pregnancy".
This chapter is deliberately broad: a survey of the common medical complications named in the objective, each treated to the depth a registrar needs to triage, stabilise, and refer correctly within the South African four-tier system (clinic/CHC → district → regional → tertiary). Several of these conditions are full emergencies — DKA, thyroid storm, eclampsia/HELLP, severe pneumonia, massive PE — and the drills for those are flagged explicitly. The unifying principle is the National Integrated Maternal and Perinatal Care Guideline (NDoH, 2024): risk-stratify at booking, manage the mother first (a dead mother delivers no live baby), and escalate early.
Core knowledge
Physiological pregnancy adaptations that change interpretation
- Plasma volume rises ~40–50% more than red-cell mass, producing a dilutional fall in haemoglobin (physiological anaemia of pregnancy).
- Cardiac output rises ~30–50%, heart rate climbs, and a mild resting tachycardia is normal.
- Respiratory alkalosis (progesterone-driven hyperventilation) is the baseline; a "normal" PaCO₂ in an asthmatic or septic woman may signal impending failure.
- Hypercoagulability (rising fibrinogen, factors VIII/IX/X, falling protein S, venous stasis) raises VTE risk several-fold.
- Renal plasma flow and GFR rise, lowering normal creatinine and urea; relative glycosuria and ureteric dilatation predispose to UTI/pyelonephritis.
- Insulin resistance rises across gestation (human placental lactogen, cortisol, progesterone), unmasking gestational and worsening pre-existing diabetes.
Figure J24.1 — Pregnancy adaptations that change interpretation of common symptoms and tests.
Condition-specific essentials
Anaemia is haemoglobin below the trimester-specific threshold; iron deficiency dominates, but in SA also consider HIV, chronic infection, and haemoglobinopathy. The classical WHO/standard cut for anaemia in pregnancy is Hb <11 g/dL, with severe anaemia conventionally taken as Hb <7 g/dL — verify the exact threshold and trimester adjustment against the NDoH guideline.
UTI spans asymptomatic bacteriuria, cystitis, and pyelonephritis. Asymptomatic bacteriuria matters in pregnancy because it progresses to pyelonephritis far more often than outside pregnancy and is associated with preterm birth and low birthweight — hence screening and treatment.
VTE (DVT and pulmonary embolism) is a leading direct cause of maternal death in well-resourced settings. Risk is present from the first trimester and is highest postpartum. RCOG GTG 37a/37b frame risk assessment and acute management.
Diabetes is either pre-existing (type 1/2) or gestational (GDM). Pre-existing diabetes carries congenital-anomaly and miscarriage risk tied to periconceptional glycaemia; GDM is a disorder of glucose tolerance first recognised in pregnancy (NICE NG3).
Asthma often runs a "rule of thirds" course (a third improve, worsen, or stay the same). Poorly controlled asthma — not the inhalers — harms the fetus.
Pneumonia and TB: pregnancy is relatively immunosuppressed; in SA, TB and HIV co-infection drive maternal morbidity and feature heavily in Saving Mothers.
Epilepsy: seizure control and teratogenicity must be balanced (RCOG GTG 68). Sodium valproate is highly teratogenic and broadly contraindicated in women of childbearing potential.
Hypertensive disorders / HELLP: HELLP (Haemolysis, Elevated Liver enzymes, Low Platelets) is a severe variant of pre-eclampsia — covered fully in pre-eclampsia-and-hellp and hypertension-in-pregnancy; managed per NICE NG133 and the NDoH guideline.
Obesity (RCOG GTG 72) amplifies almost every other risk: GDM, pre-eclampsia, VTE, anaesthetic difficulty, shoulder dystocia, wound sepsis, stillbirth.
Depression and perinatal mental illness are common, under-detected, and a recognised contributor to maternal death (including suicide) — see gbv-mental-health-pregnancy.
DKA can occur at lower glucose levels in pregnancy ("euglycaemic DKA") and threatens the fetus profoundly; it is an emergency.
Thyroid disease (RCOG GTG 76): hypothyroidism needs prompt replacement; thyroid storm is a rare, lethal decompensation of hyperthyroidism.
Proteinuria is a cardinal sign of pre-eclampsia and renal disease; quantify it, do not eyeball it.
Hyperemesis gravidarum (RCOG GTG 69) is intractable vomiting with weight loss, dehydration, and ketosis/electrolyte disturbance — distinct from ordinary nausea.
Assessment
General approach to the sick pregnant woman
Use a structured ABCDE assessment and a maternal early-warning system (modified obstetric early-warning score, MEOWS-type charts as in the NDoH guideline) to detect deterioration. Always record gestation, obstetric history, HIV status and ART, and recent fetal movements; document the fetal heart but never let it delay maternal resuscitation.
Targeted workups
- Anaemia: full blood count and red-cell indices; ferritin (low confirms iron deficiency); peripheral smear; consider HIV, TB screen, and haemoglobinopathy where indicated. Reticulocytes and haemolysis screen if HELLP suspected.
- UTI: urine dipstick (nitrites/leucocytes are suggestive, not diagnostic) and midstream urine culture — the gold standard, mandatory before treating asymptomatic bacteriuria. In pyelonephritis: bloods, FBC, U&E, and observation for sepsis.
- VTE: clinical probability scores are unreliable in pregnancy; D-dimer is not useful (physiologically raised). Image: compression duplex ultrasound for suspected DVT; for suspected PE, ECG, CXR, and definitive imaging with V/Q scan or CTPA (do not withhold imaging for fear of radiation — the fetal dose is low and a missed PE kills).
- Diabetes: in pre-existing diabetes, HbA1c, retinal and renal review; for GDM screening, the 75 g oral glucose tolerance test is standard (NICE NG3) — confirm the SA fasting/2-hour diagnostic thresholds against the current NDoH guideline rather than quoting from memory.
- Asthma: peak flow, symptom frequency, prior admissions/ICU; in acute attacks, oxygen saturation and ABG (a normalising or rising PaCO₂ is ominous).
- Pneumonia/TB: CXR (with abdominal shielding), sputum for GeneXpert (Xpert MTB/RIF) and culture, HIV test if status unknown, oxygen saturation, CRP/WCC.
- Epilepsy: seizure type/frequency, drug levels where relevant, medication adherence; distinguish epileptic seizures from eclampsia in the third trimester.
- HELLP/proteinuria: BP, urinalysis, protein quantification by spot protein:creatinine ratio (PCR) or 24-hour collection — significant proteinuria classically ≥0.3 g/24 h or PCR ≥30 mg/mmol (verify against NICE NG133/NDoH); FBC (platelets), LDH, transaminases, urate, U&E, coagulation.
- DKA: capillary and venous glucose, venous blood gas (pH, bicarbonate), capillary or blood ketones, U&E (potassium), and a search for the precipitant (infection, missed insulin, steroids, tocolytics).
- Thyroid: TSH and free T4 (interpret against trimester-specific ranges); TSH-receptor antibodies in Graves'; in suspected storm, clinical features dominate over waiting for results.
- Hyperemesis: weight, urine ketones, U&E (hypokalaemia, hyponatraemia, hypochloraemic alkalosis), and exclude other causes of vomiting (UTI, thyroid, molar pregnancy, GI pathology).
Figure J24.2 — ABCDE, MEOWS and targeted investigations for the sick pregnant woman.
Management
Anaemia
Treat the cause. Iron deficiency: oral iron is first-line; parenteral (IV) iron where oral is not tolerated, malabsorbed, or time is short (later gestation). Optimise before delivery to reduce transfusion need. Transfuse for symptomatic or severe anaemia, or when delivery with anticipated blood loss is imminent — follow restrictive, individualised thresholds (RCOG GTG 47, Blood Transfusions in Obstetrics) rather than a fixed number. Co-treat HIV and any concurrent infection.
UTI
Treat asymptomatic bacteriuria and cystitis with a culture-directed antibiotic safe in pregnancy, using the NDoH STG/EML choices, and send a test-of-cure. Pyelonephritis is admitted: IV fluids, IV antibiotics per local sensitivities/EML, antipyretics, and monitoring for sepsis and preterm labour. Recurrent infection may warrant suppressive prophylaxis and renal-tract imaging postnatally.
VTE
Suspected PE / massive collapse — emergency drill. Resuscitate (high-flow oxygen, IV access, left-lateral tilt), call for senior obstetric and anaesthetic/critical-care help, and start therapeutic low-molecular-weight heparin immediately on clinical suspicion — do not wait for imaging (RCOG GTG 37b). In haemodynamic collapse from massive PE, escalate for consideration of thrombolysis with the multidisciplinary team. If cardiac arrest occurs, follow the maternal-collapse drill in resuscitation-in-pregnancy including left-uterine displacement and perimortem caesarean.
For established VTE, weight-based therapeutic LMWH is the mainstay through pregnancy; warfarin is teratogenic and avoided antenatally. Plan peripartum anticoagulation around delivery and neuraxial anaesthesia. Thromboprophylaxis is assessed at booking, on admission, and after delivery using the GTG 37a risk score; LMWH is given to those above threshold, with mechanical measures as adjuncts. Postpartum is the highest-risk window — do not forget it.
Diabetes (pre-existing and GDM)
Aim for tight, safe glycaemic targets (NICE NG3). Pre-existing diabetes: preconception care, high-dose folic acid, optimise HbA1c before conception, and stop teratogenic agents. GDM: lifestyle first, then metformin and/or insulin if targets are not met. Monitor fetal growth; plan timing/mode of delivery (macrosomia raises shoulder-dystocia and caesarean risk — see macrosomia). Intrapartum, maintain euglycaemia (often a glucose–insulin infusion) and watch for neonatal hypoglycaemia.
DKA — emergency drill. Treat as for any DKA but recognise it can be euglycaemic in pregnancy and arises faster. Resuscitate with IV fluids, fixed-rate IV insulin infusion, and careful potassium replacement, treat the precipitant, monitor venous pH/ketones/electrolytes hourly, and provide continuous fetal monitoring (the CTG often improves as the mother is corrected). Stabilise the mother before delivering — delivering an unstable acidotic mother worsens both. Manage in a high-care/ICU setting (regional/tertiary).
Asthma
Treat exactly as in the non-pregnant patient — the danger is undertreatment from misplaced fear of inhalers. Continue inhaled corticosteroids and bronchodilators; control is protective. Acute severe asthma: high-flow oxygen targeting normal saturations, nebulised bronchodilators, systemic corticosteroids, and escalation to critical care if not responding; a rising PaCO₂ signals impending respiratory failure.
Pneumonia / TB (SA priority)
Community-acquired pneumonia: oxygen, empirical antibiotics per EML, fluids, and admission if severe or hypoxic. Always test HIV status and consider opportunistic infection (e.g. PCP) in the immunocompromised. TB: start standard anti-TB therapy promptly — most first-line agents are used in pregnancy and the risk of untreated TB far outweighs drug risk; coordinate with the HIV programme (ART per the SA HIV/ART guidelines, TLD-based) and screen contacts and the neonate. Low threshold for referral and respiratory isolation.
Epilepsy
The principle is fewest drugs, lowest effective dose, avoid valproate (RCOG GTG 68). Continue the controlling drug; counsel on adherence and seizure-safety; prescribe folic acid. Do not stop antiepileptics abruptly for fear of teratogenicity — uncontrolled tonic-clonic seizures endanger mother and fetus. In a third-trimester seizure, treat eclampsia until excluded: magnesium sulphate is the drug for eclampsia, not for known epilepsy. Plan delivery with seizure precautions.
HELLP and significant proteinuria
HELLP / eclampsia — emergency drill. This is severe pre-eclampsia. Magnesium sulphate for seizure prophylaxis/treatment, control severe hypertension (labetalol/nifedipine), restrict fluids, correct coagulopathy/transfuse as needed, and expedite delivery once the mother is stabilised (NICE NG133; NDoH 5th ed). Manage at the appropriate level of care with senior, anaesthetic, and neonatal input. Full detail in pre-eclampsia-and-hellp.
Proteinuria itself is quantified and interpreted in context: new significant proteinuria with hypertension defines pre-eclampsia and triggers the pathway above; isolated proteinuria warrants renal assessment.
Obesity
Manage proactively (RCOG GTG 72): appropriate gestational weight gain, GDM screening, pre-eclampsia prophylaxis with aspirin where indicated, VTE risk assessment and prophylaxis, anaesthetic referral antenatally, and planning for safe delivery (equipment, manual handling, theatre access). Anticipate shoulder dystocia and PPH.
Depression / perinatal mental health
Screen routinely (the NDoH guideline integrates mental-health screening). Mild–moderate illness: psychological therapy and social support. Moderate–severe: consider antidepressants weighing risk/benefit, and refer. Always ask about self-harm, suicidal ideation, thoughts of harming the baby, and psychosis — these are red flags for urgent psychiatric referral. Link with social services where GBV or substance use co-exists (gbv-mental-health-pregnancy, substance-use-in-pregnancy).
Thyroid disease
Hypothyroidism: replace levothyroxine and increase the dose in pregnancy, monitoring TSH against trimester-specific targets (RCOG GTG 76). Hyperthyroidism: control with antithyroid drugs at the lowest effective dose.
Thyroid storm — emergency drill. A rare, life-threatening decompensation (fever, tachyarrhythmia, agitation/delirium, vomiting, cardiac failure). Manage in ICU with the physicians: supportive cooling and fluids, antithyroid drug, beta-blockade, iodine (given after the antithyroid drug), and corticosteroids, plus treatment of the precipitant and the fetus monitored. Escalate to tertiary care immediately.
Hyperemesis gravidarum
Admit for dehydration/ketosis. IV rehydration with normal saline (not dextrose-first — Wernicke's risk), thiamine supplementation, antiemetics in a stepwise fashion, and correction of electrolytes (especially potassium) (RCOG GTG 69). Thromboprophylaxis while immobile/dehydrated. Exclude UTI, thyroid disease, and molar pregnancy. Most settle; persistent severe disease needs senior input and nutritional support.
Figure J24.3 — Emergency drills for immediately life-threatening medical complications in pregnancy.
Red flags / pitfalls
- Dismissing breathlessness, tachycardia, or "feeling terrible" as normal pregnancy. These are how PE, sepsis, cardiac failure, and DKA announce themselves. Use an early-warning score.
- Waiting for D-dimer or imaging before anticoagulating a clinically likely PE — start LMWH on suspicion; the test that kills is the missed PE.
- Withholding a CXR or CTPA "because of radiation" — fetal doses are low; missing TB or PE is far more dangerous.
- Forgetting euglycaemic DKA — normal glucose does not exclude DKA in a vomiting, acidotic, ketotic pregnant woman.
- Stopping antiepileptics or asthma inhalers out of teratogenicity fear — uncontrolled disease is the greater harm. (But never start/continue valproate in childbearing potential.)
- Treating a third-trimester seizure as epilepsy without excluding eclampsia — give magnesium until eclampsia is ruled out.
- Delivering an unstable mother (DKA, thyroid storm, untreated severe hypertension) before resuscitation — stabilise first; the mother comes first.
- Treating asymptomatic bacteriuria without a culture, or skipping the test-of-cure.
- Not re-assessing VTE risk postpartum — the highest-risk window is after delivery.
- Missing the suicidal or psychotic mother — perinatal mental illness is a recognised, avoidable cause of maternal death; always ask directly.
- Forgetting HIV and TB in the SA context — they underlie a large share of "medical" maternal deaths (Saving Mothers). Test, treat, refer.
- Failing to escalate up the levels of care — district facilities should stabilise and refer; do not attempt definitive critical care without the resources.
Evidence anchors
- National Integrated Maternal and Perinatal Care Guideline (NDoH, 2024), NDoH — the South African obstetric source of truth: risk stratification, early-warning monitoring, levels of care, referral pathways.
- Saving Mothers / NCCEMD reports (latest triennium) — non-pregnancy-related infection (HIV, pneumonia, TB), haemorrhage, and hypertension as leading maternal-death causes; avoidable factors.
- South African EML (Hospital Level, Adults) and NDoH Standard Treatment Guidelines — antibiotic, antiemetic, insulin, and other drug choices.
- South African National HIV/ART Consolidated Guidelines (2023) and SAHCS 2023 Adult ART Guidelines — TLD-based ART, relevant to HIV-associated medical complications.
- RCOG GTG 37a/37b — VTE risk assessment and acute management in pregnancy.
- RCOG GTG 47 — Blood Transfusions in Obstetrics (anaemia/transfusion thresholds).
- RCOG GTG 68 — Epilepsy in pregnancy; GTG 69 — Hyperemesis gravidarum; GTG 72 — Obesity in pregnancy; GTG 76 — Thyroid disorders in pregnancy.
- NICE NG3 — Diabetes in pregnancy (pre-existing and GDM, 75 g OGTT).
- NICE NG133 — Hypertension in pregnancy (substitutes archived GTG 10a): aspirin prophylaxis, antihypertensives, magnesium sulphate, proteinuria quantification; applies to HELLP.
- NICE NG121 — Intrapartum care for women with existing medical conditions or obstetric complications.
Note on hedged facts: trimester-specific Hb and proteinuria cut-offs, the GDM OGTT diagnostic values, and detailed drug doses should be confirmed against the current NDoH guideline/EML before use — they are stated cautiously here and not attached to a specific citation.