The windsor definition for hyperemesis gravidarum: A multistakeholder international consensus definition

To develop an international definition for hyperemesis gravidarum to assist in clinical diagnosis and harmonize hyperemesis gravidarum definition for study populations.

A mixed-methods approach was used to identify potential hyperemesis gravidarum definition criteria (i.e. systematic review, semi-structured interviews and closed group sessions with patients and Project Steering Committee input). To reach consensus on the definition we used a web-based Delphi survey with two rounds, followed by a face-to-face consensus development meeting, held in Windsor UK, and a web-based consultation round, in which the provisional hyperemesis gravidarum definition was fed back to the stakeholders. Four stakeholder groups were identified 1) researchers; 2) women with lived experience of hyperemesis gravidarum and their families; 3) obstetric health professionals (obstetricians, gynecologists, midwives); and 4) other health professionals involved in care for women with hyperemesis gravidarum (general practitioners, dieticians, nurses). To reflect the opinions of the international community, stakeholders from countries in all global regions were invited to participate.

Twenty-one identified potential criteria entered the Delphi survey. Of the 277 stakeholders invited, 178 completed round one, and 125 (70%) also completed round two. Twenty stakeholders attended the consensus development meeting, representing all stakeholder groups. The consultation round was completed by 96 (54%) stakeholders, of which 92% agreed with the definition as presented. The consensus definition for hyperemesis gravidarum consisted of: start of symptoms in early pregnancy (before 16 weeks gestational age); nausea and vomiting, at least one of which severe; inability to eat and/or drink normally; strongly limits daily living activities. Signs of dehydration were deemed contributory for the definition for hyperemesis gravidarum.

The proposed definition for hyperemesis gravidarum will help clinical studies to achieve more uniformity, and ultimately increasing the value of evidence to inform patient care.