<p>Aim To describe reduction as a method using van Manen’s phenomenological hermeneutic research approach.</p> <p>Background Reduction involves several levels that can be distinguished for their methodological usefulness. Researchers can use reduction in different ways and dimensions for their methodological needs.</p> <p>Data sources A study of Finnish multiple-birth families in which open interviews (n=38) were conducted with public health nurses, family care workers and parents of twins.</p> <p>Review methods A systematic literature and knowledge review showed there were no articles on multiple-birth families that used van Manen’s method.</p> <p>Discussion The phenomena of the ‘lifeworlds’ of multiple-birth families consist of three core essential themes as told by parents: ‘a state of constant vigilance’, ‘ensuring that they can continue to cope’ and ‘opportunities to share with other people’.</p> <p>Conclusion Reduction provides the opportunity to carry out in-depth phenomenological hermeneutic research and understand people’s lives. It helps to keep research stages separate but also enables a consolidated view. Social care and healthcare professionals have to hear parents’ voices better to comprehensively understand their situation; they need further tools and training to be able to empower parents of twins.</p> <p>Implications for research/practice This paper adds an empirical example to the discussion of phenomenology, hermeneutic study and reduction as a method. It opens up reduction for researchers to exploit.</p>