Continued use of Warfarin in lower dose has safe maternal and neonatal outcomes in pregnant women with Prosthetic Heart Valves

Background and Objective: There has been concerns regarding the safety of Warfarin in pregnant females due to its teratogenic potential. At the same time warfarin provides best anticoagulation in patients with prosthetic valves. Various dosage regimes have been tried to strike a balance between safety of mother and the avoidance of congenital anomalies in the newborn. This study was conducted to observe the effect of Warfarin in pregnant mothers taking different doses of warfarin, and their neonatal outcome, in our outdoor patients.

Methods: This is a cross sectional observational study conducted at the Faisalabad Institute of Cardiology. The pregnant mothers taking warfarin for prosthetic valve replacement who presented to our specialized clinic between November 2016 to April 2017 were included in the study. These included a total of 75 females between the age of 20-35 years. To compare the dose related effect of warfarin, two groups of the patients were formed. One group comprised of patients taking warfarin ≤5mg while the other group consisted of those who were taking >5mg of warfarin daily. These patients were followed till their delivery. The information was collected about the maternal and fetal outcomes. The maternal outcomes including mode of delivery/miscarriage, peripartum bleeding and any valve related thromboembolic complications. The fetal outcomes included birth weight, maturity, embryopathy and congenital anomaly in the baby.

Results: Patient’s mean age was 29.25±3.75 years. The mitral valve replacement was present in 60% patients (n=45) while 25.3% patients (n=19) had aortic valve replacement and 14.7% patients (n=11) had double valve replacement. In this group 30 patients (40%) had taken <5 mg warfarin and 45 patients (60%) had received >5 mg warfarin medicine. Miscarriages, cesarean sections, low birth weight and prematurity were more common in patients receiving warfarin >5 mg with p-values 0.005, 0.046, 0.01 and 0.033 respectively. No case of fetal embryopathy was found in both groups.

Conclusion: No case of embryopathy was found in each group which signifies that warfarin in lower doses is safe anticoagulant in patients with prosthetic valve replacements.