Further clarification from the trial authors was required from one author. Pregnancy and Childbirth Group’s Trials Register on 1 October 2009 and added the results to the awaiting classification section. Selection criteria Randomised and quasi\randomised controlled trials of women in normal labour assessing the routine administration of drugs (antacids, H2 receptor antagonists, dopamine antagonists and proton\pump inhibitors) compared with placebo/no treatment, and compared with other drugs for reducing gastric aspiration. Data collection and analysis Two review authors independently assessed eligibility, quality, extracted data and performed double\data entry. Main results Three trials were included, involving 2465 women, assessing the effects NSHC of antacids, H2 receptor antagonists and dopamine antagonists. There were no trials on proton\pump inhibitors. None of the trials were of good quality, and none assessed the incidence of gastric aspiration, Mendelsohn’s syndrome or their consequences. All the studies assessed vomiting, and Nicergoline there was limited evidence that vomiting may be reduced by antacids (relative risk (RR) 0.46, 95% confidence interval (CI) 0.27 to 0.77, n = 578, one trial) or by dopamine antagonists given alongside pethidine (RR 0.40, 95% CI 0.23 to 0.68, n = 584, one trial). Comparisons between different drugs showed no significant differences, though the number of participants was small. There was no evidence that H2 receptor antagonists improved outcomes compared with antacids, though only one trial addressed this issue. Authors’ conclusions There is no good evidence to support the routine administration of acid prophylaxis drugs in normal labour to prevent gastric aspiration and its consequences. Nicergoline Giving such drugs to women once a decision to give general anaesthesia is made, is Nicergoline assessed in another Cochrane review. [Note: The four citations in the awaiting classification section of the Nicergoline review may alter the conclusions of the review once assessed.] strong class=”kwd-title” Keywords: Female, Humans, Pregnancy, Labor, Nicergoline Obstetric, Antacids, Antacids/therapeutic use, Antiemetics, Antiemetics/therapeutic use, Histamine H2 Antagonists, Histamine H2 Antagonists/therapeutic use, Obstetric Labor Complications, Obstetric Labor Complications/prevention & control, Pneumonia, Aspiration, Pneumonia, Aspiration/prevention & control, Randomized Controlled Trials as Topic, Vomiting, Vomiting/prevention & control Routine prophylactic drugs in normal labour for reducing gastric aspiration and its effects No good evidence for drugs, like antacids, in normal labour to reduce the small chance of inhaling some stomach contents if general anaesthesia is required. Caregivers are often concerned that some woman in normal labour may go on to have a general anaesthetic, either for a caesarean section in labour, or to remove the placenta after birth should it become retained. The concern occurs because there is a very small risk that the woman might regurgitate and possibly inhale some of the belly contents into the lungs (gastric aspiration or Mendelsohn’s syndrome) during the general anaesthetic. This can cause severe lung and breathing problems, especially if the belly contents are acid (low pH), and extremely rarely (one inside a million) a woman may pass away from an anaesthetic problem. Giving medicines to reduce the volume of the belly contents, or to make them less acidity may help to reduce the problem. The review of tests looked to see whether providing such medicines routinely to all women in normal labour was effective. The evaluate identified three tests involving 2465 ladies but none assessed gastric aspiration, probably because it is definitely a very rare event. Instead the tests all assessed the incidence of vomiting, although there is no proven link between vomiting in labour and gastric aspiration during general anaesthesia. The evaluate found some limited evidence that 1) medicines like antacids may reduce the chance of vomiting in labour, 2) H2 receptor antagonist medicines (like ranitidine) appeared to have a similar impact on results as antacids and 3) dopamine antagonists (like metoclopramide) may reduce the opportunity on vomiting in labour when given alongside pethidine. Overall, there was no evidence that any of these medicines reduced the incidence of gastric aspiration or Mendelsohn’s syndrome. Background Introduction Many women have the ability to give birth without the need for medical interventions (Gaskin.