Omeprazole (Losec®) and Esomeprazole (Nexium®)

Last Update: 18 Nov 2024

Medication

Table of content

1. What Are They? 2. Risks 3. Benefits 4. Breastfeeding 5. Key Takeaways 6. Research limits

Welcome to our Fact Sheet on Omeprazole (Losec®) and Esomeprazole (Nexium®) during pregnancy and breastfeeding. The information given is based on current research and may be updated with new scientific knowledge. This information does not replace personalized advice from healthcare professionals.

1. What Are Omeprazole and Esomeprazole?

Omeprazole (e.g. Losec®, Olex®) and esomeprazole (e.g. Nexium®) are medications known as proton pump inhibitors (PPIs). They are commonly used to reduce the production of stomach acid, leading to discomfort and conditions like:

heartburn
gastroesophageal reflux disease (GERD)
ulcers of the stomach
inflammation of the stomach lining.

The hormonal changes and the growing baby during pregnancy often increases stomach acidity and slow the digestive system. By lowering acid levels, omeprazole and esomeprazole can provide relief and promote healing of the stomach.

In the stomach, specialised cells with tiny “pumps” called proton pumps release acidity essential for digestion. When this acid is produced in excess it can lead to discomfort. PPIs medications work by blocking these tiny “pumps” in the stomach and reduce the amount of acid released into the stomach. This way, omeprazole and esomeprazole help relieve and prevent issues associated with excess of stomach acid.

Can I Take Omeprazole or Esomeprazole During My Pregnancy?

If you‘re pregnant and currently taking omeprazole or esomeprazole, or considering starting these medications, studies show these medications do not appear to increase the risk of adverse pregnancy or birth outcomes. However, it remains important to consult with your healthcare provider before making any changes to your medication regimen. They can help you weigh the benefits, and any potential risks based on your personal history, ensuring the best treatment plan for both you and your baby.

2. What Are the Risks of Omeprazole and Esomeprazole Associated with Pregnancy?

As with any medication, it’s important to talk to your healthcare team to evaluate the advantages and potential risks so that you and your baby can get the best care.

Miscarriages, congenital malformations tooltip, premature births and other complications can occur in any pregnancy for many different reasons. This is known as the background risk. Here, we compare this background risk with the risks associated with taking the medication.

Pregnant women can take omeprazole or esomeprazole. These medications are generally compatible with pregnancy, but as with any medications, there are a number of things to consider when balancing risks and benefits.

Studies involving thousands of pregnant women have shown that taking these medications does not increase the risk of congenital malformations or premature birth (before 37 weeks) when compared with the background risk in the general population.

While the available research is reassuring, more research is needed to fully understand the impact of omeprazole and esomeprazole on fertility tooltip, miscarriage, or impact on the baby’s health. No research has been done yet on the development of the baby’s brain when a person takes omeprazole or esomeprazole during pregnancy.

The table below summarizes the potential risks based on current evidence. Remember, these risks are relative and can be influenced by factors like the mother’s age, genetics, ethnicity, lifestyle, and other medical conditions.

Table 1. Risks associated with omeprazole or esomeprazole during pregnancy.

For who?	What?	What does research say?
For the pregnant person	Fertility	Not enough research to tell if there’s an increased risk.
For the pregnant person	Miscarriages	Not enough research to tell if there’s a risk above the background risk.
For the unborn child	Congenital Malformations	Studies have not found an increased risk compared to the background risk tooltip.
	Growth	No increased risks of having a baby with low birth weight (less 5 pounds 8 ounces or [2,500 grammes]) was found tooltip.
	Premature Birth	No increased risk of premature birth (< 37 weeks) was found tooltip. More research is needed to confirm this risk.
For future child/ adult	Long-term health issues	Not enough research to tell if there’s a risk.

* The risks that increased when compared to the background chance in the population are in bold.

3. What Are the Benefits of Omeprazole and Esomeprazole?

While there are risks, there’s also benefits taking omeprazole and esomeprazole. They are often prescribed during pregnancy as they relieve heartburn and acid reflux, preventing and healing ulcers, and omeprazole and esomeprazole offer other benefits for pregnant women:

Management of Acid-Related Nausea: can help manage nausea and vomiting by reducing acid production.

Reduction of Acid-Related Inflammation: can help reduce inflammation in the esophagus and stomach lining caused by acid reflux.

Preventing Complications from Severe Acid Reflux: can help prevent serious conditions associated with severe acid reflux like esophagitis (inflammation of the esophagus) or Barrett’s esophagus (a condition that increases the risk of esophageal cancer).

These benefits make omeprazole and esomeprazole useful for managing various gastrointestinal issues during pregnancy, promoting both maternal comfort and health.

Nausea can be challenging during pregnancy, here's a few tips to help.

Learn more

4. Will I Be Able to Breastfeed?

Breastfeeding is a personal choice. Remember, if you have questions about your situation, you can seek help from your healthcare professional (doctor, nurse, pharmacist) or a lactation consultant.

Current research suggests that breastfeeding while taking omeprazole or esomeprazole is generally safe. While research is limited, studies have shown that the amount of these medications that passes into breast milk is very low and is not likely to cause harm to a nursing infant.

However, it’s always best to consult with your healthcare provider before starting any new medication while breastfeeding to ensure it’s the right choice for you and your baby.

To ensure the safety of your baby, discuss your situation with your healthcare provider. They can help you weigh the benefits of breastfeeding against potential risks and decide on the best approach for both your health and your baby’s well-being.

Key Takeaways

Omeprazole (e.g. Losec®, Olex®) and esomeprazole (e.g. Nexium®) are two medications from the group of proton-pumps inhibitors (PPIs) to reduce stomach acid-related issues such as acid reflux.

Hormonal changes and the growing baby can increase stomach acid. PPIs can help reduce this acid, easing discomfort and promoting healing.

Current research suggest that omeprazole or esomeprazole are not likely to increase the risk of birth defects or major pregnancy complications.

The amount of omeprazole or esomeprazole that passes into breast milk is very low and unlikely to harm a nursing baby.

6. Research Is Great, But It Is Not Perfect

Making informed health decisions also involves considering the current state of scientific knowledge. Here are some considerations on omeprazole and esomeprazole during pregnancy that limit the ability to draw definitive conclusions about their safety and efficacy:

Retrospective and Observational Nature: Many studies look back at existing data rather than conducting controlled trials. This can introduce biases and confounding factors that affect the results.

Lack of Long-Term Data: Few long-term research on child development, including potential subtle neurodevelopmental or health outcomes.

Variability in Dosing and Duration: Studies often vary widely in terms of the dosages and duration of medication use, making it difficult to establish standardized safety guidelines or recommendations.

Insufficient Reporting on Outcomes: Insufficient reporting on specific pregnancy outcomes, such as congenital anomalies, preterm birth, or low birth weight, which are critical for assessing the overall risk profile of these medications during pregnancy.

These limitations highlight the importance of consulting healthcare providers for personalized medical advice and relying on up-to-date, comprehensive reviews of the available evidence when considering the use of omeprazole or esomeprazole during pregnancy.

References

Banhidy Peptic ulcer disease with related drug treatment in pregnant women and congenital abnormalities in their offspring. Congenit Anom (Kyoto) 2011; 51:26-33 10.1111/j.1741-4520.2010.00290.x
Bor S 2017. The levels of pantoprazole in human breast milk and plasma: two compartment model. Neurogastroenterol Motil; 29:79-80.
Choi A. JAMA Netw Open 2023; 6:e2250366 Association Between Proton Pump Inhibitor Use During Early Pregnancy and Risk of Congenital Malformations.
Cluver Esomeprazole to treat women with preterm preeclampsia: a randomized placebo controlled trial. Am. J. Obstet. Gynecol. 2018; 219:388.e1-388.e17 10.1016/j.ajog.2018.07.019 [PMID: 30055127]
Diav-Citrin. Aliment. Pharmacol. Ther. 2005; 21:269-75 The safety of proton pump inhibitors in pregnancy: a multicentre prospective controlled study.
Kallen Use of omeprazole during pregnancy–no hazard demonstrated in 955 infants exposed during pregnancy. Eur. J. Obstet. Gynecol. Reprod. Biol. 2001; 96:63-8 10.1016/s0301-2115(00)00388-2 [PMID: 11311763]
Lalkin The safety of omeprazole during pregnancy: a multicenter prospective controlled study. Am. J. Obstet. Gynecol. 1998; 179:727-30 [PMID: 9757979]
Marshall JK 1998. Omeprazole for refractory gastroesophageal reflux disease during pregnancy and lactation. Can J Gastroenterol. 1998 Apr;12(3):225-7.
Matok The safety of fetal exposure to proton-pump inhibitors during pregnancy. Dig. Dis. Sci. 2012; 57:699-705 10.1007/s10620-011-1940-3 [PMID: 22038541]
Moretti Use of proton pump inhibitors during pregnancy and rates of major malformations (Personal communication). 2002
Pasternak. N. Engl. J. Med. 2010; 363:2114-23 Use of proton-pump inhibitors in early pregnancy and the risk of birth defects. 
Van Gelder. Clin Epidemiol 2022; 14:1229-1240 Associations Between Late-Onset Preeclampsia and the Use of Calcium-Based Antacids and Proton Pump Inhibitors During Pregnancy: A Prospective Cohort Study.
Ruigomez Use of cimetidine, omeprazole, and ranitidine in pregnant women and pregnancy outcomes. Am. J. Epidemiol. 1999; 150:476-81 10.1093/oxfordjournals.aje.a010036[PMID: 10472947]
Saito J. Breastfeed Med. 2020 Sep;15(9):598-601. Esomeprazole During Pregnancy and Lactation: Esomeprazole Levels in Maternal Serum, Cord Blood, Breast Milk, and the Infant’s Serum.

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