The contraction and expansion of the uterus following childbirth are known to cause postpartum cramps (Dashe et al., 2018), with more than 80% of women experiencing after-pains following vaginal delivery (Evcili and Didem, 2019). After-pain is also prevalent among multiparous women (77%) (Jangsten et al., 2011) due to increased central nerve sensitivity, decreased uterine muscle strength following multiple deliveries, or an enlarged uterus (Betts, 2005). After-pain can be significant within the first 12–24 hours during the first four days (Evcili and Didem, 2019). In general, 95% of women experience after-pain on the first day after delivery, while 65% of them tolerate pain until the tenth day (Holdcroft, 1999). Postpartum pain and discomfort have negative effects on women’s self-care, functional ability, breastfeeding and infant care, as well as the emotional bond between mother and baby (Rezaeean et al., 2017, Perry et al., 2019). Mothers may also experience anxiety, sleep and emotion disorders, and depression (Yerby, 2000, Madineh and Ghaheri, 2005, Shohani et al., 2013). Evcili and Didem (2019) reported that the severity of postpartum after-pain influenced breastfeeding self-efficacy.

The uterus contracts through the activation of oxytocin produced in the hypothalamus or prostaglandins generated by cyclooxygenase (Marifah and Suryantini, 2017). The main cause of after-pain is the production and release of prostaglandins (Grant et al., 2019). Uterine contractions release chemical mediators of pain, such as bradykinin, leukotriene, prostaglandin, serotonin, and lactic acid (Kheiriyat et al., 2016).

Nonsteroidal anti-inflammatory drugs (NSAIDs) (Ogunfowokan and Babatunde, 2010) such as Mefenamic acid inhibit the cyclooxygenase enzyme and reduce the action of inflammatory mediators such as prostaglandins (Yeh et al., 2005), making them effective for pain relief (Deussen et al., 2020). However, these treatments may lead to side effects such as headache, dizziness, heartburn, constipation, drowsiness, and gastrointestinal bleeding. Increased postpartum haemorrhage is the most serious adverse effect associated with NSAIDs (Huang et al., 2002). A portion of the drug (approximately 1% of the total) enters breast milk and may have negative effects on newborns (Vahidi and Eranmanesh, 2011). Therefore, the use of medicinal plants for pain relief has received considerable attention in recent years (Rezaeean et al., 2017).

Sesame, scientifically known as Sesamum indicum, is a plant in the Pedaliaceae family that is laxative, diuretic, milk-enhancing, and anti-anaemic (Hadad et al., 2006). Palmitic acid, oleic acid, linoleic acid, and lecithin are all available in sesame oil. Lecithin is an acetylcholine precursor that reduces pain by synthetising acetylcholine and activating nicotinic receptors. The fatty acids in diets containing sesame oil inhibit prostaglandin E synthase, which mediates the conversion of cyclooxygenase-1 and cyclooxygenase-2 to prostaglandin E2, thereby increasing the pain perception threshold (Ji et al., 2010). Sesame oil is also rich in polyunsaturated and monounsaturated fatty acids, as well as vitamin E, which regulate inflammatory and immunological mediators (Haidari et al., 2012). Sesame oil contains 39.7 g of monounsaturated fatty acids and 41.7 g of polyunsaturated fatty acids per 100 g (Vermeer, 2012). A study conducted by Askari et al. (2016) evaluated the impact of back massage with sesame oil on childbirth pain and time in nulliparous women. It was found that sesame oil reduced pain during the first, second, and third stages of labour. Additionally, Haidari et al. (2012) suggested that sesamin and alpha tocopherol in sesame reduce the severity of dysmenorrhoea pain by modifying the biosynthesis of eicosanoids.

Abdalla (2014) reported that the daily consumption of 100 g of sesame increased haemoglobin levels in pregnant women during their second and third trimesters but had no negative side effects, such as increased bleeding during pregnancy or after childbirth. In one study, it was reported that sesame seeds were effective in reducing dysmenorrhoea (Mohammadian et al., 2017). Existing data support the hypothesis that sesame seeds may possess antioxidant and anti-inflammatory properties (Hirata et al., 1996).

Johnson et al. (2011) reported no specific contraindications for the use of sesame or its products, except for individuals with a history of sesame allergy. Healthcare providers are mandated to address and alleviate patients’ pain, enhance their physical comfort, improve their quality of life, and minimise their length of hospital stay (Perry et al., 2019). After-pains can have a negative impact on the health of mothers, infants, and families (Dastjerdi et al., 2019), and as no study has investigated the effect of sesame oil on after-pains, the present study aimed to investigate the impact of sesame soft gels on after-pains in multiparous women.