|Care in Normal Birth (WHO, 1996, 60 p.)|
|2. GENERAL ASPECTS OF CARE IN LABOUR|
Views on nutrition during childbirth differ widely across the world. In many developed countries, the fear of aspiration of gastric contents during general anaesthesia (Mendelsons syndrome) continues to justify the rule of no food and drink during labour. For most women in labour the withholding of food poses no problem, as they do not want to eat during labour anyway, although many desperately need to drink. In many developing countries traditional culturally-bound beliefs restrain the food and fluid intake of women in labour.
The fear that eating and drinking during labour will put women at risk of aspirating stomach contents during anaesthesia is real and serious. Keeping a restriction on the food and fluid intake during labour however, does not guarantee reduced stomach content (Crawford 1956, Taylor and Pryse-Davies 1966, Roberts and Shirley 1976, Tettambel 1983, Mckay and Mahan 1988). Several trials on methods to reduce stomach content or the acidity of the content, both by pharmacological means and by restriction of oral intake, have not been able to establish a 100% positive effect of any specific method. The range of pH values found was wide and therefore, a researcher concludes, routine administration of antacids during labour cannot be relied on to prevent Mendelsons syndrome, neither does it affect the volume of gastric contents.
The risk of aspiration is associated with the risk of general anaesthesia. As there is no guarantee against Mendelsons syndrome, the correct approach for normal childbirth should include an assessment of the risk of general anaesthesia. Once categorized, the low risk birth can be managed without administration of antacids.
Labour requires enormous amounts of energy. As the length of labour and delivery cannot be predicted, the sources of energy need to be replenished in order to ensure fetal and maternal well-being. Severe restriction of oral intake can lead to dehydration and ketosis. This is commonly treated by an intravenous infusion of glucose and fluid. The maternal effects of this treatment have been evaluated in a number of randomized trials (Lucas et al 1980, Rutter et al 1980, Tarnow-Mordi et al 1981, Lawrence et al 1982). The rise in mean serum glucose levels appears to be accompanied by a rise in maternal insulin levels (and a reduction in mean levels of 3-hydroxybutyrate). It also results in an increase in plasma glucose levels in the baby and it may result in a decrease in umbilical arterial blood pH. Hyperinsulinism can occur in the fetus when women receive more than 25 grammes of glucose intravenously during labour. This can result in neonatal hypoglycaemia and raised levels of blood lactate. The excessive use of salt-free intravenous solutions can lead to hyponatraemia in both mother and child.
The above mentioned complications, especially dehydration and ketosis, can be prevented by offering oral fluids during labour, and by offering light meals. Routine intravenous infusions interfere with the natural process and restrict womens freedom to move. Even the prophylactic routine insertion of an intravenous cannula invites unnecessary interventions.
In the home birth situation no specific treatment is given; no use of antacids, no restriction of food and fluid intake. Sometimes women are cautioned that eating and drinking during labour can make them nauseous, but as they are in their own home, there is no control over what they eat and drink. When women do decide to eat they tend to eat light foods that are easily digestible. Intuitively they leave heavy meals and beverages alone. It is safe to say that for the normal, low-risk birth in any setting there is no need for restriction of food. However, serious discussion is necessary to determine whether the effects of intervention in maternal nutrition during labour are not worse than the risks of Mendelsons syndrome. And many questions remain, such as: Is there any research on labour with a full stomach? Is there any difference between eating and drinking a little or not at all? Are there any data on the effects of food and fluid restriction during labour in the developing countries, where there are no means of substituting the loss of energy in prolonged labour?
In conclusion, nutrition is a subject of great importance and great variability at the same time. The correct approach seems to be not to interfere with the womens wish for food and drink during labour and delivery, because in normal childbirth there should be a valid reason to interfere with the natural process. However, there are so many die-hard fears and routines all over the world that each needs to be dealt with in a different way.