The effect of unrestricted oral carbohydrate intake on labor progress. Eating in labour. A randomised controlled trial assessing the risks and benefits. An evaluation of isotonic "sport drinks" during labor. A comparison of the effectiveness, tolerability and safety of high and low carbohydrate diets in women with gestational diabetes. A carbohydrate-rich drink reduces preoperative discomfort in elective surgery patients. Effect of food intake during labour on obstetric outcome: randomised controlled trial. Advice that includes food sources of unsaturated fat supports future risk management of gestational diabetes mellitus. A randomised controlled trial of dietary energy restriction in the management of obese women with gestational diabetes. (Patho)physiological implications of chronic dietary sodium restriction during pregnancy; a longitudinal prospective randomized study.
To determine if unrestricted oral carbohydrate intake during labor reduced the incidence of dystocia in low-risk nulliparous women.
                A randomized clinical trial at a university-affiliated hospital in southeastern Ontario. Low-risk nulliparous women were randomized between 30 and 40 weeks gestation to either an intervention or usual care group.
                Women in the intervention group received, prenatally, guidelines about food and fluid intake during labor and were encouraged to eat and drink as they pleased during labor. Women in the usual care group received no prelabor information and were restricted to ice chips and water during labor in the hospital.
                The incidence of dystocia, defined as a cervical dilatation rate of less than 0.5 cm/hr for a period of 4 hrs after a cervical dilatation of 3 cm.
                Three hundred twenty-eight women were randomized to the intervention (n = 163) or usual care (n = 165) groups. Women in the intervention group reported a significantly different pattern of oral intake during early labor in the hospital (chi(2) = 40.7, p < .001). The incidence of dystocia was 36% (n = 58) in the intervention group and 44% (n = 72) in the usual care group and was not significantly different (OR = 0.71, 95% CI = 0.46, 1.11). There were no significant differences in the other secondary outcomes or in the incidence of adverse maternal or neonatal complications.
                Eating and drinking early in labor had no significant impact on the incidence of dystocia and/or adverse maternal or neonatal outcomes. The aim of this study was to determine whether permitting women in labour to eat a light diet would: (i) alter their metabolic profile, (ii) influence the outcome of labour, and (iii) increase residual gastric volume and consequent risk of pulmonary aspiration. Women were randomised to receive either a light diet (eating group, n = 48) or water only (starved group, n = 46) during labour. The light diet prevented the rise in plasma beta-hydroxybutyrate (p = 2.3 x 10(-5)) and nonesterified fatty acids (p = 9.3 x 10(-7)) seen in the starved group. Plasma glucose (p = 0.003) and insulin (p = 0.017) rose in the eating group but there was no difference in plasma lactate (p = 0.167) between the groups. There were no differences between the groups with respect to duration of first or second stage of labour, oxytocin requirements, mode of delivery, Apgar scores or umbilical artery and venous blood samples. Relative gastric volumes estimated by ultrasound measurement of gastric antral cross-sectional area were larger (p = 0.001) in the eating group. This was supported by the observation that those from this group who vomited, vomited significantly larger volumes than those in the starved group (p = 0.001). We conclude that eating in labour prevents the development of ketosis but significantly increases residual gastric volume. We compared the metabolic effects of allowing women isotonic "sport drinks" rather than water to drink during labor. The effect of these drinks on gastric residual volume was also evaluated. Sixty women in early labor (cervical dilation <5 cm) were randomized to receive either isotonic sport drinks or water only. Plasma beta-hydroxybutyrate, nonesterified fatty acids, and glucose were measured in early labor and at the end of the first stage of labor. Residual gastric volume was assessed within 45 min of delivery by use of an ultrasound scanner. The incidence and volume of vomiting was recorded. At the end of the first stage of labor, plasma beta-hydroxybutyrate (P = 0.000) and nonesterified fatty acids (P = 0.000) had increased and plasma glucose (P = 0.007) had decreased significantly in the Water-Only group. Gastric antral cross-sectional area after delivery was similar in the two groups. The incidence of vomiting and the volume vomited during labor and within the hour of delivery were also similar. There was no difference between the groups in any maternal or neonatal outcome of labor. In conclusion, isotonic drinks reduce maternal ketosis in labor without increasing gastric volume.
                Solid foods may endanger a woman's life if consumed during labor. Isotonic sport fluids were evaluated as a nutritional alternative. Results demonstrate that mothers who have not received parenteral opioids can safely drink isotonic drinks in active labor. Nutrition therapy is an integral part of the management of gestational diabetes mellitus (GDM). Most women with GDM are treated by nutritional management alone. The goal of our study was to compare low and high carbohydrate diets in their effectiveness, safety and tolerability in women with GDM.
                The study group consisted of 30 Caucasian women newly diagnosed with GDM, with a mean age of 28.7 +/- 3.7 years and pregnancy duration of 29.2 +/- 5.4 weeks. The patients were randomised into two groups: those on a low and those on a high carbohydrate diet (45% vs. 65% respectively of energy supply coming from carbohydrates). The presence of urine ketones was controlled every day. After two weeks daily glucose profiles and compliance with the recommended diets were analysed.
                Glucose concentration before implementation of the diet regimen did not differ between groups. No changes in fasting blood glucose were noticed in the group that had followed a low carbohydrate diet, although a significant decrease in glucose concentration was observed after breakfast (102 +/- 16 vs. 94 +/- 11 mg/dl), lunch (105 +/- 12 vs. 99 +/- 9 mg/dl) and dinner (112 +/- 16 vs. 103 +/- 13 mg/dl) (p < 0.05). In the high carbohydrate diet group fasting and after-breakfast glucose concentration did not change. A significant decrease in glycaemia was noticed after lunch (106 +/- 15 vs. 96 +/- 7 mg/dl) and dinner (107 +/- 12 vs. 97 +/- 7 mg/dl) (p < 0.05). Ketonuria was not observed in either group. Obstetrical outcomes did not differ between groups.
                Both high and low carbohydrate diets are effective and safe. A diet with carbohydrate limitation should be recommended to women who experience the highest glycaemia levels after breakfast. We studied the effects of different preoperative oral fluid protocols on preoperative discomfort, residual gastric fluid volumes, and gastric acidity. Two-hundred-fifty-two elective abdominal surgery patients (ASA physical status I-II) were randomized to preparation with a 12.5% carbohydrate drink (CHO), placebo (flavored water), or overnight fasting. The CHO and Placebo groups were double-blinded and were given 800 mL to drink on the evening before and 400 mL on the morning of surgery. Visual analog scales were used to score 11 different discomfort variables. CHO did not increase gastric fluid volumes or affect acidity, and there were no adverse events. The visual analog scale scores in a control situation were not different between groups. During the waiting period before surgery, the CHO-treated group was less hungry and less anxious than both the other groups (P < or = 0.05). CHO reduced thirst as effectively as placebo (P < 0.0001 versus Fasted). Trend analysis showed consistently decreasing thirst, hunger, anxiety, malaise, and unfitness in the CHO group (P < 0.05). The Placebo group experienced decreasing unfitness and malaise, whereas nausea, tiredness, and inability to concentrate increased (P < 0.05). In the Fasted group, hunger, thirst, tiredness, weakness, and inability to concentrate increased (P < 0.05). In conclusion, CHO significantly reduces preoperative discomfort without adversely affecting gastric contents.
                Discomfort during the period of waiting before elective surgery can be reduced if patients are prepared with a carbohydrate-rich drink, compared with preoperative oral intake of water or overnight fasting. Visual analog scales can provide useful information about preoperative discomfort in elective surgery patients. To investigate the effect of feeding during labour on obstetric and neonatal outcomes.
                Prospective randomised controlled trial.
                Birth centre in London teaching hospital.
                2426 nulliparous, non-diabetic women at term, with a singleton cephalic presenting fetus and in labour with a cervical dilatation of less than 6 cm.
                Consumption of a light diet or water during labour.
                The primary outcome measure was spontaneous vaginal delivery rate. Other outcomes measured included duration of labour, need for augmentation of labour, instrumental and caesarean delivery rates, incidence of vomiting, and neonatal outcome.
                The spontaneous vaginal delivery rate was the same in both groups (44%; relative risk 0.99, 95% confidence interval 0.90 to 1.08). No clinically important differences were found in the duration of labour (geometric mean: eating, 597 min v water, 612 min; ratio of geometric means 0.98, 95% confidence interval 0.93 to 1.03), the caesarean delivery rate (30% v 30%; relative risk 0.99, 0.87 to 1.12), or the incidence of vomiting (35% v 34%; relative risk 1.05, 0.9 to 1.2). Neonatal outcomes were also similar.
                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.
                Current Controlled Trials ISRCTN33298015. Abstract Women with gestational diabetes mellitus (GDM) have a greater risk of developing type 2 diabetes mellitus (DM) and heart disease than pregnant women without GDM. Advice given during the GDM pregnancy provides an opportunity to develop protective dietary patterns for the long-term management of this risk. Dietary guidelines for the prevention and management of type 2 DM support the inclusion of unsaturated fats, but food advice needs to target this outcome. The aim of this study was to compare the dietary intakes of women with GDM given general low-fat advice (control group) to women with GDM given the same advice with additional targets for food sources of unsaturated fats (intervention group). After approximately 6 weeks, the intervention group reported more ideal dietary fatty acid intakes than the control group, with polyunsaturated:saturated fat ratios of 1:1 and 0.4:1, respectively ( P < .001), assessed using repeated measures analysis of variance. These results confirm the need to include food sources of unsaturated fats in advice strategies to assure optimal protective eating habits in this at-risk group. A randomised controlled trial was designed to determine the effect of moderate 30% maternal dietary energy restriction on the requirement for maternal insulin therapy and the incidence of macrosomia in gestational diabetes. Although the control group restricted their intake to a level similar to that of the intervention group (6,845 kiloJoules (kJ) versus 6,579 kJ), the resulting cohort could not identify any adverse effect of energy restriction in pregnancy. Energy restriction did not alter the frequency of insulin therapy (17.5% in the intervention group and 16.9% in the control group). Mean birthweight (3,461 g in the intervention group and 3,267 g in the control group) was not affected. There was a trend in the intervention group towards later gestational age at commencement of insulin therapy (33 weeks versus 31 weeks) and lower maximum daily insulin dose (23 units versus 60 units) which did not reach statistical significance. Energy restriction did not cause an increase in ketonemia. To study the possible pathophysiological implications of long continued dietary sodium restriction in pregnancy.
                Longitudinal prospective randomized study of the effects of a low sodium diet compared with unrestricted sodium intake in pregnancy.
                Academic Department of Obstetrics and Gynaecology at Sint Radboud Hospital, Nijmegen, The Netherlands.
                42 healthy nulliparous women.
                A low sodium diet (20 mmol sodium daily) started in the 14th week of pregnancy and stopped after delivery.
                Maternal weight gain, food intake, blood pressure, cardiac output, systemic vascular resistance, haematocrit and birthweight.
                Total maternal weight gain and dietary energy intake during pregnancy and weight at 1 and 6 weeks postpartum were significantly lower in the low sodium group. Blood pressure during pregnancy did not show major differences. Stroke volume and cardiac output during pregnancy were significantly lower in the low sodium group whereas systemic vascular resistance was significantly higher. Haematocrit values in the low sodium group tended to be lower during pregnancy, but were significantly lower at 1 and 6 weeks postpartum than in the unrestricted group. Placental and birthweights were not significantly different between the two groups.
                Chronic dietary sodium restriction during pregnancy is characterized by a diminished body fat accumulation and a reduction in circulating volume, due to a decrease in both plasma and red cell volume, in combination with a high systemic vascular resistance without major effects on blood pressure and birthweight.
Since the evidence shows no benefits or harms, there is no justification for the restriction of fluids and food in labour for women at low risk of complications. No studies looked specifically at women at increased risk of complications, hence there is no evidence to support restrictions in this group of women. Conflicting evidence on carbohydrate solutions means further studies are needed and it is critical in any future studies to assess women's views.