Our next blog for our series throughout International Multiple Birth Awareness week is highlighting the complication of postpartum haemorrhage and comes from Vicky Mitchell.
This International Multiple Birth Awareness Week, the team at the Elizabeth Bryan Multiple Birth Centre are advocating for more systematic evidence regarding the incidence, management and interventions of anaemia and postpartum haemorrhage (PPH) for women with multifetal pregnancies and birth. Improving our knowledge of these complications is essential to inform evidence-based care to improve the outcomes for this population of women and their babies.
Women with multifetal pregnancies (twins or higher-order multiples such as triplets or quads) undergo significant physical changes with their cardiovascular, hematologic and metabolic systems (Alarfaj et al., 2025; Whittaker et al., 2023). During multifetal pregnancies, the circulatory blood volume increases by around 50-70% by 20 weeks of pregnancy (Goodnight and Newman, 2009). This requires greater maternal red blood cell mass and plasma volume expansion to support increased fetal and placental demands, resulting in greater iron and other micronutrient requirements (Shinar et al., 2017).
The prevalence of maternal anaemia (low red blood cell/low haemoglobin levels) is significantly higher in multifetal pregnancies compared to singleton pregnancies (Li et al., 2025). This is clinically significant as maternal anaemia has been associated with outcomes including preterm delivery, low birth weight, and neonatal anaemia (Li et al., 2025). Multifetal pregnancies are associated with higher rates of caesarean delivery, which may correspond to an increases risk of maternal PPH (Abdulsalam et al., 2024).
Rates of PPH (defined as a blood loss of over 1500ml) are higher for twins (11.6%) and triplets/quads (33.3%) compared to singletons (3.4%) (NMPA Project Team, 2026). Factors contributing to higher chance of PPH include uterine atony (where the uterine muscles fail to effectively contract following delivery) (Abdulsalam et al., 2024), and higher rates of preeclampsia and caesarean birth, compared with singleton births (NMPA Project Team, 2026).
The International Council of Multiple Birth Organisation (ICOMBO) promotes the unique needs of multiple birth families. It’s Declaration of rights and statement of needs of twins and higher order multiples advocates appropriate management throughout a multiple pregnancy, including care by professionals who are knowledgeable in managing potential complications (ICOMBO, 2022). It also recognises the importance of women having access to prenatal resources and care which are designed to foster their health and their baby’s development, including information about the increased risks of pre-and postnatal complications (ICOMBO, 2022).
However, awareness must be underpinned by evidence. While national audit data provides important insights (NMPA Project Team, 2026), further primary research is needed to understand not just the incidence, but optimal intervention and management of anaemia and PPH. Robust evidence could inform population-specific screening, prevention or management pathways for women with multifetal pregnancies. The team at the Elizabeth Bryan Multiple Birth Centre calls for greater recognition of the specific maternal needs associated with multiple pregnancies and for more systematic research to ensure clinical guidance and maternity decision-making are informed by evidence relevant to women with multifetal pregnancies and births, and their babies.