This is the case with the two local hospitals I recently toured, although there are ways to get around this rule. In one hospital, you need to do it on the sly when the nurses aren't watching. In the other, they said they'd document that they discussed their policy of nothing but water/ice chips, then it would be up to the woman to decide if she wished to eat or drink. Still, most women are probably not aware that they do not have to follow hospital policies.
The study, Effect of Food Intake During Labour on Obstetric Outcome: Randomised Controlled Trial, concluded that:
Consumption of a light diet during labour did not influence obstetric or neonatal outcomes in participants, nor did it increase the incidence of vomiting. Women who are allowed to eat in labour have similar lengths of labour and operative delivery rates to those allowed water only.For a more thorough look at the historical restriction on eating and drinking during labor, visit the Cochrane Database's review (PDF). Below is the background information from the review:
Restricting oral food and fluid intake of women in active labour in hospitals is a strongly held obstetric tradition. A survey of labour ward policies in England in 1985 revealed that over a third of consultant maternity units allowed no fluids whatsoever during labour (Garcia 1985). In a more recent survey of 351 units in England and Wales, one third allowed some form of food and drink and over ninety per cent allowed some form of oral intake, usually water (Michael 1991). Restriction of oral intake is not a common practice in home births or birth centers (Rooks 1989) nor is the practice consistent across hospital sites (Haire 1991). Few if any centers have policies that are reflective of women's preferences (Pengelley 1998). Most are based on historical, but important concerns, related to the risks of gastric content regurgitation and aspiration into the lungs during general anaesthesia, a risk first identified by Mendelson in the 1940s. Though rare with modern anaesthetic techniques, the syndrome is potentially fatal.
The rationale for withholding food and fluid during labour is to decrease the risk of maternal morbidity and mortality from Mendelson's syndrome if a general anaesthetic is required, as fasting will ensure small gastric volumes. Recent reviews suggest that there is no evidence to support this belief (O'Sullivan 1994). Interventions to reduce stomach contents or the acidity of the content, both by pharmacological means and by restriction of oral intake, have not proved successful (Taylor 1975). Gastric emptying is delayed during labour (Davidson 1975). Irrespective of whether a woman has been starved or not during labour, anaesthetic precautions are necessary to reduce the risk of gastric content aspiration. These include reducing unnecessary operative interventions; using regional rather than general anaesthesia; and using rapid sequence induction with airway protection for general anaesthesia (Am Soc Anesth 1999). With modern techniques, particularly the use of regional analgesia, the risk of gastric content aspiration has become extremely small (McKay 1988).
Fluid and nutrient needs during labour are not well studied. Glucose metabolism and need are accelerated during pregnancy and labour. Many believe that elevated levels of ketone bodies, which accumulate during exercise or starvation (Williamson 1971), is a physiological response with little clinical significance. However, associations between ketone levels and longer labours and maternal psychological stress have been reported (Chang 1993; Foulkes 1985). It is difficult to determine whether ketone production contributes to the longer labour or whether it is a consequence. The presence of ketonuria should be considered a signal for metabolic imbalance, though the effect of the imbalance is not known (Johnson 1991).
Intravenous therapy instead of oral hydration is common practice during labour. Historically, practitioners administered high dose glucose solutions to combat the development of ketones (Ketteringham 1939). More commonly now, intravenous fluids are isotonic or low dose glucose as high dose glucose solutions are associated with increased incidence of neonatal hypoglycemia (low blood sugar levels) (Mendiola 1982; Grylack 1984). Dextrose only solutions cause a fall in serum osmolality and sodium concentration (hyponatraemia) (Begum 1999). Regardless of solution type, intravenous therapy predisposes women to immobilization, stress, increased risk of fluid overload, and does not ensure a nutrient and fluid balance for the demands of labour (Simkin 1986a; Simkin 1986b). The value and safety of routine intravenous fluid therapy has been questioned (Begum 1999).
Despite these risks, and lack of evidence of benefit, routine restriction of foods and fluids in labour has persisted. This policy is not reflective of women's preferences or cultural expectations (Broach 1988a; Broach 1988b). This systematic review may assist in resolving the clinical uncertainty, which is currently apparent.
O’Sullivan G, Liu B, Hart D, et al. Effect of food intake during labour on obstetric outcome: randomised controlled trial. Br Med J 2009; 338:b784.