By Rachael Buabeng, Hyperemesis Gravidarum & Maternal health advocate, Ocean Service People Engagement Worker (East London Foundation Trust – Maternal Mental Health Services), Maternity Transformation Programme Service User Voice, Co-chair on the Black and Black-mixed heritage Maternity Voice Partnership for Homerton (City & Hackney), Maternal Health Research Engagement Consultant, Founder of Mummy’s Day Out. @BuabengRachael

and Dr Catriona Jones^, Lecturer in Midwifery, University of Hull, @CatrionaJones6

Nausea and vomiting in pregnancy (NVP) is a common complaint, ranging from mild to moderate nausea, to severe and pathologic vomiting; known as hyperemesis gravidarum (HG)¹. NVP is a normal condition, experienced by 50–80% of pregnant women during the first trimester².  HG on the other hand is considered a rare disorder, distinct from NVP, where nausea and vomiting is persistent with debilitating effects, often resulting in hospitalisation. The impact and consequences of HG include decreased placental blood flow, decreased maternal blood flow and acidosis, threatening the health of the mother and fetus³. The pathophysiology of HG has yet to be fully understood, although endocrine factors are often cited as the main cause⁴.

HG occurs in 0.3 – 3.6% of pregnancies⁵, although prevalence varies on account of different diagnostic criteria, and ethnic variation in study populations⁶. Prevalence estimates are further complicated by the absence of a single accepted definition of HG⁷. Research shows women with NVP have specific risks in relation to their clinical state, with up to 35% of women reporting depression⁵ . HG significantly impacts quality of life for women and their families⁷. Women who have suffered from HG in a previous pregnancy are often unclear if they will have a recurrence in a subsequent pregnancy. Some women with a previous history will avoid pregnancy in the future^{8 9}. Balancing the desire to have more children, alongside the fear of experiencing HG can carry a psychological burden. Commonly, women are concerned about their own health, the health of the unborn baby, the psychological impact of repeated hospitalisations and ongoing illness on other family members and the financial impact of poor health in terms of having to take time off work. Women who have experienced HG in the past have identified that planning for a subsequent pregnancy includes accounting for the prospect of possible financial losses due to absence from work, and financing additional child care needs as a result of ill health.  Consequently, for some women, avoiding pregnancy is the only control left in the scenario, as there is no other way to avoid the ramifications of HG. There is a high recurrence rate and a large percentage of women change their reproductive plans because of their experiences with HG⁹.

Research evidence in relation to birth outcomes for women with HG is complex. Conflicting results can be explained by the differences in the ways research has been conducted, and differences in definitions¹⁰. One study of HG and pregnancy outcomes did not find any negative short-term consequences for the baby, however, the possibility for long-term consequences have barely been studied¹⁰.

HG often requires hospitalisation to correct severe dehydration, electrolyte imbalance, ketonuria and weight loss. However, it is not always diagnosed and is consequently treated in out patient settings. This may be due to the absence of strictly defined criteria for clinical diagnosis. The treatment of intravenous fluids to replenish the lost intravascular volume, highlighting that rehydration along with the replacement of electrolytes in very important, as are antiemetic medication⁶. Ginger acupuncture and hypnosis, have also been shown to decrease the effects for some, but not all women^11. However, most studies of therapeutic options do not consist of randomised controlled trials, and cross study analysis is difficult due to the variation of diagnostic criteria⁶

For the first time, The National Institute for Health and Care Excellence (NICE) (2021) have recommended treatment options for severe pregnancy sickness in draft guidance¹². The new recommendations advise the use of antiemetics, acupressure and intravenous fluids, in line with HG guidance from the RCOG¹³. It is important to remember that pregnant women who are hospitalised in non-maternity environments with severe NVP or HG require a multidisciplinary team approach to their care. Input should be considered from midwifery, and specialist midwifery, and the branches of dietetics and nutrition, pharmacology, endocrinology, gastroenterology and perinatal mental health¹³. In addition to statutory care, peer support has now become a key part of care for HG – and this is a model that needs to be explored further.

Finally, health professionals supporting women with a history of severe HG who are considering their future reproductive plans, should be aware that support can be accessed through charities such as Pregnancy Sickness Support Home (pregnancysicknesssupport.org.uk).  Women who change their reproductive plans because of a history of HG may benefit from counselling, treatment, and risk assessment.

A video produced by blog author Rachael Buabeng on HG can be accessed here Information resource_Video.mp4 – Google Drive

Reference List

1. Lee MM, Saha S. Nausea and vomiting in pregnancy. Gastroenterology Clinics of North America. 2011;40(2): 309 – 334.
2. Hirose M, Tamakoshi K, Takahashi Y et al The effects of nausea, vomiting, and social support on health-related quality of life during early pregnancy: A prospective cohort study. Journal of Psychosomatic Research. 2020;136: 1 – 7.
3. Lamondy A. Managing hyperemesis gravidarum. Available from https://journals.lww.com/nursing/Citation/2007/02000/Managing_hyperemesis_gravidarum.46.aspx [Accessed 3^rd January 2022].
4. Verberg MFG, Gillot DJ, Al-Fardan et al. Hyperemesis gravidarum, a literature review. Human Reproduction Update. 2005;11(5): 527 – 539.
5. Gadsby R, Rawson V, Dziadulewicz et al. Nausea and vomiting of pregnancy and resource implications: the NVP impact study. 2019. Available from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6400600/pdf/bjgpmar-2019-69-680-e217-oa.pdf [Accessed 3^rd January 2022]..
6. London V, Grube S, Shere DM at al. Hyperemesis gravidarum: a review of the literature. Pharmacology. 2017;100: 161 – 171.
7. Jennings LK, Mahdy Hyperemesis gravidarum. (Updated 2021 Aug 25) In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK532917/
8. Poursharif B, Korst LM, Fejzo MS et al. The psychosocial burden of hyperemesis gravidarum. Journal of Perinatology. 2008;28(3): 176 – 181.
9. Fejzo MS, MacGibbon KW, Romero R, et al. Recurrence risk of hyperemesis gravidarum. Reproductive Science. 2010;17: 191 ‐192.
10. Vikanes ÅV, Støer NC, Magnus P. et al.Hyperemesis gravidarum and pregnancy outcomes in the Norwegian mother and child cohort – a cohort study.  Available from https://bmcpregnancychildbirth.biomedcentral.com/track/pdf/10.1186/1471-2393-13-169.pdf [Accessed 3^rd January 2022].
11. Wegrzyniak LJ, Repke JT, Serdar et al. Treatment of hyperemesis gravidarum. Available from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3410506/pdf/RIOG005002_0078.pdf [Accessed 9^th January 2022].
12. National Institute for Health and Care Excellence (NICE). NICE Recommends treatment options for sever pregnancy sickness in new draft guidance. 2021. Available from https://nice.org.uk/news/article/nice-recommends-treatment-options-for-severe-pregnancy-sickness-in-new-draft-guidance [Accessed 13^th January 2022].
13. Royal College of Obstetricians and Gynaecologists (RCOG). The management of nausea and vomiting of pregnancy and hyperemesis gravidarum; Green Top Guideline. 2016. Available from https://rcog.org.uk/globalassets/documents/guidelines/green-top-guidelines/gtg69-hyperemesis.pdf [Accessed 13^th January 2022].