Losartan pregnancy
Pro Research Analysisby 
Searched over 200M research papers for "losartan pregnancy"
Consensus Meter
Losartan Use During Pregnancy: Risks and Outcomes
Fetal Toxicity and Developmental Effects
Losartan and Fetal Toxicity: Losartan, an angiotensin II receptor blocker (ARB), has been associated with significant fetal toxic effects when used during pregnancy. Documented cases have shown that exposure to losartan can lead to oligohydramnios (decreased amniotic fluid), fetal pulmonary hypoplasia, hypoplastic skull bones, and even fetal death . These adverse outcomes are similar to those observed with angiotensin-converting enzyme (ACE) inhibitors, suggesting a class effect of drugs that interfere with the renin-angiotensin system.
Case Studies and Observations: In one case study, a pregnant woman with nephrotic syndrome who continued losartan therapy experienced persistent oligohydramnios, which normalized after discontinuation of the drug and replacement with nifedipine. Another report highlighted a case where losartan-induced oligohydramnios was reversed, but the fetus subsequently developed inferior vena cava thrombosis, indicating potential complications even after drug withdrawal.
Animal Studies and Mechanisms
Animal Model Insights: Studies in pregnant rats have provided further insights into the effects of losartan. Administration of losartan to pregnant rats resulted in decreased maternal body weight gain and increased serum urea nitrogen levels, with no direct evidence of fetal malformations but significant postnatal developmental delays and increased pup mortality. Additionally, losartan was shown to transfer slowly into fetal tissues, with higher concentrations observed in fetal blood, liver, and kidney compared to maternal plasma.
Renal and Cardiovascular Effects: Research on fetal sheep demonstrated that losartan administration reduced fetal systolic and diastolic blood pressure, indicating significant impacts on fetal cardiovascular function. Moreover, losartan treatment in diabetic pregnant rats reduced proteinuria and renal hypertrophy, but its use is contraindicated due to potential fetal risks.
Clinical Recommendations and Conclusions
Clinical Implications: Given the documented risks, ARBs like losartan are contraindicated during pregnancy. Pregnant women requiring antihypertensive treatment should be switched to safer alternatives, such as nifedipine, to mitigate risks to the fetus. Healthcare providers must inform patients about the potential dangers and closely monitor pregnancies where ARBs have been used.
Conclusion: The use of losartan during pregnancy poses significant risks to fetal development, including oligohydramnios, developmental delays, and potential fetal death. Both clinical case studies and animal research underscore the importance of avoiding losartan and similar ARBs during pregnancy to ensure better maternal and fetal outcomes.
Sources and full results
Most relevant research papers on this topic