Parvin Abedi, Shayesteh Jahanfar, Farideh Namvar, Jasmine Lee

Oxytocin and prostaglandin are hormones responsible for uterine contraction during the third stage of labour. Receptors in the uterine muscles are stimulated by exogenous or endogenous oxytocin leading to uterine contractions. Nipple stimulation or breastfeeding are stimuli that can lead to the secretion of oxytocin and consequent uterine contractions. Consequently, uterine contractions can reduce bleeding during the third stage of labour. To investigate the effects of breastfeeding or nipple stimulation on postpartum haemorrhage (PPH) during the third stage of labour. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (15 July 2015) and reference lists of retrieved studies. Randomised and quasi-randomised controlled trials comparing breast stimulation, breastfeeding or suckling for PPH in the third stage of labour were selected for this review. Two review authors independently assessed studies for inclusion in terms of risk of bias and independently extracted data. Disagreements were resolved by a third review author. We included four trials (4608 women), but only two studies contributed data to the review's analyses (n = 4472). The studies contributing data were assessed as of high risk of bias overall. One of these studies was cluster-randomised and conducted in a low-income country and the other study was carried out in a high-income country. All four included studies assessed blood loss in the third stage of labour. Birth attendants estimated blood loss in two trials. The third trial assessed the hematocrit level on the second day postpartum to determine the effect of the bleeding. The fourth study measured PPH ≥ 500 mL. Nipple stimulation versus no treatmentOne study (4385 women) compared the effect of suckling versus no treatment. Blood loss was not measured in 114 women (59 in control group and 55 in suckling group). After excluding twin pregnancies, stillbirths and neonatal deaths, the main analyses for this trial were performed on 4227 vaginal deliveries. In terms of maternal death or severe morbidity, one maternal death occurred in the suckling group due to retained placenta (risk ratio (RR) 3.03, 95% confidence interval (CI) 0.12 to 74.26; one study, participants = 4227; very low quality evidence); severe morbidity was not mentioned. Severe PPH (≥ 1000 mL) was not reported in this study.The incidence of PPH (≥ 500 mL) was similar in the suckling and no treatment groups (RR 0.95, 95% CI 0.77 to 1.16; one study, participants = 4227; moderate quality). There were no group differences between nipple stimulation and no treatment regarding blood loss in the third stage of labour (mean difference (MD) 2.00, 95% CI -7.39 to 11.39; one study, participants = 4227; low quality). The rates of retained placenta were similar (RR 1.01, 95% CI 0.14 to 7.16; one study, participants = 4227; very low quality evidence), as were perinatal deaths (RR 1.06, 95% CI 0.57 to 1.98; one study, participants = 4271; low quality), and maternal readmission to hospital (RR 1.01, 95% CI 0.14 to 7.16; one study, participants = 4227; very low quality). We downgraded the evidence for this comparison for risk of bias concerns in the one included trial (inappropriate analyses for cluster design) and for imprecision (wide CIs crossing the line of no difference and, for some outcomes, few events).Many maternal secondary outcomes (including side effects) were not reported. Similarly, most neonatal secondary outcomes were not reported. Nipple stimulation versus oxytocinAnother study compared the effect of nipple stimulation (via a breast pump) with oxytocin. Eighty-seven women were recruited but only 85 women were analysed. Severe PPH ≥ 1000 mL and maternal death or severe morbidity were not reported.There was no clear effect of nipple stimulation on blood loss (MD 15.00, 95% CI -24.50 to 54.50; one study, participants = 85; low quality evidence), or on postnatal anaemia compared to the oxytocin group (MD -0.40, 95% CI -2.22 to 1.42; one study, participants = 85; low quality evidence). We downgraded evidence for this comparison due to risk of bias concerns in the one included trial (alternate allocation) and for imprecision (wide CIs crossing the line of no difference and small sample size).Many maternal secondary outcomes (including side effects) were not reported, and none of this review's neonatal secondary outcomes were reported. None of the included studies reported one of this review's primary outcomes: severe PPH ≥ 1000 mL. Only one study reported on maternal death or severe morbidity. There were limited secondary outcome data for maternal outcomes and very few secondary outcome data for neonatal outcomes.There was no clear differences between nipple stimulation (suckling) versus no treatment in relation to maternal death, the incidence of PPH (≥ 500 mL), blood loss in the third stage of labour, retained placenta, perinatal deaths or maternal readmission to hospital. Whilst these data are based on a single study with a reasonable sample size, the quality of these data are mostly low or very low.There is insufficient evidence to evaluate the effect of nipple stimulation for reducing postpartum haemorrhage during the third stage of labour and more evidence from high-quality studies is needed. Further high-quality studies should recruit adequate sample sizes, assess the impact of nipple stimulation compared to uterotonic agents such as syntometrine and oxytocin, and report on important outcomes such as those listed in this review.