Adding to the spectrum of medical and surgical pathologies, obesity is also associated with an increased incidence of antenatal disorders. A thorough understanding of physiology, pathophysiology, associated conditions, their complications and the implications for analgesia and anaesthesia should place the anaesthetist in a better position to care for these patients. As a result, increasing number of obese patients is being presented to critical care units for various indications. The attending intensivist has to face numerous challenges during management of such patients. Consequently, the anaesthetist is increasingly confronted with the problems of anaesthetising obese patients, and even more so the obstetric anaesthetist.

Obesity has been identified as a significant risk factor for anaesthesia-related maternal mortality [4, 5]. The increased incidence of operative procedures, both elective and emergency, and the concurrent medical and antenatal problems may contribute to the risk. Postoperative complications such as wound infection, deep vein thrombosis, atelectasis and chest infection are more prevalent [5–7]. In addition to the associated medical problems, the anaesthetist is challenged by these patients with technical difficulties of airway management and insertion of regional blocks. No anaesthetic technique is without special hazards in grossly obese patients.

The incidence of failed tracheal intubation is approximately 1 in 280 in the obstetric population compared to 1 in 2230 in the general surgical population [8–10]. This is in contrast with an incidence of difficult intubation in an obese population as high as 15.5%.

So it is evident that difficult or failed tracheal intubation in obese parturients is very high, and optimal assessment and management of the airway cannot be overemphasised in this population.

Though there are no bony differences between the pregnant and non-pregnant population, obese and nonobese patients, fat deposition in obese and soft tissue changes during pregnancy do influence the airway. Operational factors such as poor head positioning, cricoid pressure and anxiety contribute to the difficulty on occasion [11, 12]. In addition, pregnancy-induced hypertension, upper respiratory tract infection, stridor and voice changes may suggest the presence of airway oedema. Weight gain in excess of 15 kg during pregnancy has been shown to be associated with an increase in suboptimal laryngoscopic views [13].

Anaesthesia for both emergency and elective scenarios should be planned in advance. It is appropriate to involve patients in the decision-making process for safe delivery of the foetus.

The likelihood of obstructive sleep apnoea (OSA) has been alluded to, but it is often under-diagnosed in women of childbearing age [14]. It is possible that, in as much as complaints of difficulty in sleeping and daytime fatigue are common, women suffering from OSA are not identified. Careful history taking may help diagnose OSA. Prompt diagnosis by polysomnography and treatment with continuous positive airway pressure may be beneficial. Pulmonary hypertension and right heart failure need to be excluded in parturients with OSA [15, 16]. Measurement of oxygen saturation by pulse oximetry, both in sitting and supine positions, may provide evidence of airway closure during normal tidal volume ventilation, thereby identifying candidates for postoperative oxygen administration.

Cardiovascular co-morbidities such as hypertension, ischaemic heart disease and heart failure dominate the clinical picture in the obese population, and these can coexist in obese parturients. Nearly 40% of the obese population experience angina without demonstrable coronary artery disease [17]. Hence, routine electrocardiograph recording may be useful. Cardiologists should be involved early in the care of symptomatic morbidly obese parturients to investigate and optimise the disease status wherever appropriate.