416-813-6780 (Toronto and GTA)
Alcohol and Substance
Pregnancy & Breastfeeding Resources
Read more in our News Archive
Sick of Morning Sickness?
Get support from the Motherisk Nausea and Vomiting of Pregnancy (NVP) Helpline.
Nausea and vomiting in pregnancy (NVP), also referred to as "morning sickness," is very common. It afflicts up to 80% of pregnant women, to a greater or lesser extent.
Though usually limited to the first 7 to 12 weeks of pregnancy, approximately 20% of women experience NVP for a longer period of time. Some women may suffer from NVP until the end of the pregnancy.
For some, nausea and vomiting can have serious adverse effects. If severe enough, NVP can cause dehydration, with associated salt and vitamin imbalances. These and other effects can be harmful to the health of the woman and the well-being of her baby. The severity of NVP symptoms can also be related to factors such as a multiple pregnancy.
For these and other reasons, it is important to get the right information, care and treatment.
Nausea and vomiting in pregnancy can also impact on personal relationships. That means that partners and family need information, too.
Care based on research
Motherisk researchers have interviewed thousands of women, gathering detailed accounts of their experience with NVP. Many have describe it as a time of acute suffering, worry and frustration.
This and other research have helped us understand the extent of the suffering, determine possible causes and deterrents, and establish recommendations on how to treat the condition.
We continue to collect information about the effects of NVP and its treatment, paying special attention to NVP's impact on the quality of women's lives.
NVP can and should be treated if persistent or disruptive to a woman's physical, mental or social health.
- With a call to the NVP Helpline women can discuss optimal therapies.
- They can also help further Motherisk research by providing information about the effects of NVP on their health and daily lives.
- "I couldn't even keep down a glass of water" © Glow Magazine
- Treatment of nausea and vomiting in pregnancy
Ondansetron Use In Early Pregnancy And The Risk Of Congenital Malformations - A Register Based Nationwide Cohort Study
Jon T Andersen, MD, PhD, Nadia L Andersen, MD, PhD, Henrik E Poulsen, MD, DMSc and Espen Jimenez-Solem, MD, PhD. Department of Clinical Pharmacology, Copenhagen university Hospital Bispebjerg, Copenhagen, Denmark and Copenhagen Mental Health Center, Copenhagen, Denmark. (February 2014)
Scary Science: Ondansetron Safety in Pregnancy - Two Opposing Results from the Same Danish Registry
Gideon Koren, MD (Ther Drug Monit, Volume 36, Number 1, February 2014)
Diclectin for morning sickness: Long-term neurodevelopment.
Irena Nulman, MD, FRCPC and Gideon Koren, MD, FRCPC, FACMT (Free PMC article, February 2011)
Optimal management of nausea and vomiting of pregnancy.
Neda Ebrahimi, Caroline Maltepe, Adrienne Einarson (Free PMC article, August 2010)
Nausea and vomiting of pregnancy: using the 24-hour Pregnancy-Unique Quantification of Emesis (PUQE-24) scale
Neda Ebrahimi, Caroline Maltepe, Facundo Garcia-Bournissen, Gideon Koren.(September 2009)
The safety of histamine 2 (H2) blockers in pregnancy: a meta-analysis.
Gill SK, O'Brien L, Koren G. (September 2009)
The effect of Acid-reducing pharmacotherapy on the severity of nausea and vomiting of pregnancy.
Simerpal Gill, Caroline Maltepe, Kathy Mastali, Gideon Koren. (Free PMC article, July 2009)
The safety of proton pump inhibitors (PPIs) in pregnancy: a meta-analysis.
Gill SK, O'Brien L, Einarson TR, Koren G. (June 2009)
The effect of heartburn and acid reflux on the severity of nausea and vomiting of pregnancy.
Simerpal Gill, Caroline Maltepe C, Gideon Koren (Free PMC article, April 2009)
Pregnancy outcome following use of large doses of vitamin B6 in the first trimester
Alon Shrim, Rada Boskovic, Caroline Maltepe, Yvette Navioz, Facundo Garcia-Bournissen, Gideon Koren. (November 2006)
The safety of ondansetron for nausea and vomiting of pregnancy: a prospective comparative study.
Adrienne Einarson, Caroline Maltepe, Yvette Navioz, Debbie Kennedy, Michael Tan, Gideon Koren.(September 2004)
Pre-emptive therapy for severe nausea and vomiting of pregnancy and hyperemesis gravidarum
Gideon Koren, Caroline Maltepe.(August 2004)
The safety of higher than standard dose of doxylamine-pyridoxine (Diclectin) for nausea and vomiting of pregnancy
Gordana Atanackovic , Yvette Navioz, Myla Moretti, Gideon Koren (August 2001)
Safety of antihistamines during pregnancy and lactation
Miranda So, RPh, Pina Bozzo, Miho Inoue, MD and Adrienne Einarson, RN
Treatment of heartburn and acid reflux associated with nausea and vomiting during pregnancy
Ruth Law, Caroline Maltepe, Pina Bozzo and Adrienne Einarson, RN
Safety of 14C-UBT for diagnosis of Helicobacter pylori infection in pregnancy
Yedidia Bentur, MD, Doreen Matsui, MD and Gideon Koren, MD
Treatment of nausea and vomiting in pregnancy - an updated algorithm
Adrienne Einarson, RN, Caroline Maltepe, Rada Boskovic, MD and Gideon Koren, MD FRCPC
Preventing recurrence of severe morning sickness
Gideon Koren, MD, FRCPC, Caroline Maltepe
Use of proton pump inhibitors during pregnancy and breastfeeding
Alejandro A. Nava-Ocampo, MD, Elvia Y. Velazquez-Armenta, MSC, Jung-Yeol Han, MD, Gideon Koren, MD, FRCPC,