Background: Fundal pressure during the second stage of labour (also known as the 'Kristeller manoeuvre') involves application of manual pressure to the uppermost part of the uterus directed towards the birth canal, in an attempt to assist spontaneous vaginal birth and avoid prolonged second stage or the need for operative birth. Fundal pressure has also been applied using an inflatable belt. Fundal pressure is widely used, however methods of its use vary widely. Despite strongly held opinions in favour of and against the use of fundal pressure, there is limited evidence regarding its maternal and neonatal benefits and harms. There is a need for objective evaluation of the effectiveness and safety of fundal pressure in the second stage of labour. Objectives: To determine if fundal pressure is effective in achieving spontaneous vaginal birth, and preventing prolonged second stage or the need for operative birth, and to explore maternal and neonatal adverse effects related to fundal pressure. Search methods: We searched Cochrane Pregnancy and Childbirth's Trials Register (30 November 2016) and reference lists of retrieved studies. Selection criteria: Randomised and quasi-randomised controlled trials of fundal pressure (manual or by inflatable belt) versus no fundal pressure in women in the second stage of labour with singleton cephalic presentation. Data collection and analysis: Two or more review authors independently assessed potential studies for inclusion and quality. We extracted data using a pre-designed form. We entered data into Review Manager 5 software and checked for accuracy. Main results: Nine trials are included in this updated review. Five trials (3057 women) compared manual fundal pressure versus no fundal pressure. Four trials (891 women) compared fundal pressure by means of an inflatable belt versus no fundal pressure. It was not possible to blind women and staff to this intervention. We assessed two trials as being at high risk of attrition bias and another at high risk of reporting bias. All other trials were low or unclear for other risk of bias domains. Most of the trials had design limitations. Heterogeneity was high for the majority of outcomes. Manual fundal pressure versus no fundal pressure Manual fundal pressure was not associated with changes in: spontaneous vaginal birth within a specified time (risk ratio (RR) 0.96, 95% confidence interval (CI) 0.71 to 1.28; 120 women; 1 trial; very low-quality evidence), instrumental births (RR 3.28, 95% CI 0.14 to 79.65; 197 women; 1 trial), caesarean births (RR 1.10, 95% CI 0.07 to 17.27; 197 women; 1 trial), operative birth (average RR 0.66, 95% CI 0.12 to 3.55; 317 women; 2 studies; I2 = 43%; Tau2 = 0.71; very low-quality evidence), duration of second stage (mean difference (MD) -0.80 minutes, 95% CI -3.66 to 2.06 minutes; 194 women; 1 study; very low-quality evidence), low arterial cord pH in newborn babies (RR 1.07, 95% CI 0.72 to 1.58; 297 women; 2 trials; very low-quality evidence), or Apgar scores less than seven at five minutes (average RR 4.48, 95% CI 0.28 to 71.45; 2759 infants; 4 trials; I2 = 89%; Tau2 = 3.55; very low-quality evidence). More women who received manual fundal pressure had cervical tears than in the control group (RR 4.90, 95% CI 1.09 to 21.98; 295 women; 1 trial). No neonatal deaths occurred in either of the two studies reporting this outcome (very low-quality evidence). No trial reported the outcome severe maternal morbidity or death. Fundal pressure by inflatable belt versus no fundal pressure Fundal pressure by inflatable belt did not reduce the number of women havinginstrumental births (average RR 0.73, 95% CI 0.52 to 1.02; 891 women; 4 trials; I2 = 52%; Tau2 = 0.05) or operative births (average RR 0.62, 95% CI 0.38 to 1.01; 891 women; 4 trials; I2 = 78%; Tau2 = 0.14; very low-quality evidence). Heterogeneity was high for both outcomes. Duration of second stage was reported in two trials, which both showed that inflatable belts shortened duration of labour in nulliparous women (average MD -50.80 minutes, 95% CI -94.85 to -6.74 minutes; 253 women; 2 trials; I2 = 97%; Tau2 = 975.94; very low-quality evidence). No data on this outcome were available for multiparous women. The inflatable belt did not make any difference to rates of caesarean births (average RR 0.56, 95% CI 0.14 to 2.26; 891 women; 4 trials; I2 = 70%; Tau2 = 0.98), low arterial cord pH in newborn babies (RR 0.47, 95% CI 0.09 to 2.55; 461 infants; 1 trial; low-quality evidence), or Apgar scores less than seven at five minutes (RR 4.62, 95% CI 0.22 to 95.68; 500 infants; 1 trial; very low-quality evidence). Third degree perineal tears were increased in the inflatable belt group (RR 15.69, 95% CI 2.10 to 117.02; 500 women; 1 trial). Spontaneous vaginal birth within a specified time, neonatal death, andsevere maternal morbidity or death were not reported in any trial. Authors' conclusions: There is insufficient evidence to draw conclusions on the beneficial or harmful effects of fundal pressure, either manually or by inflatable belt. Fundal pressure by an inflatable belt during the second stage of labour may shorten duration of second stage for nulliparous women, and lower rates of operative birth. However, existing studies are small and their generalizability is uncertain. There is insufficient evidence regarding safety for the baby. There is no evidence on the use of fundal pressure in specific clinical settings such as inability of the mother to bear down due to exhaustion or unconsciousness. There is currently insufficient evidence for the routine use of fundal pressure by any method on women in the second stage of labour. Because of current widespread use of the procedure and the potential for use in settings where other methods of assisted birth are not available, further good quality trials are needed. Further evaluation in other groups of women (such as multiparous women) will also be required. Future research should describe in detail how fundal pressure was applied and consider safety of the unborn baby, perineal outcomes, longer-term maternal and infant outcomes and maternal satisfaction.