The Effect of Aspirin Administration on Fetal Cardiovascular Function Between 18 to 24 Weeks of Gestation: A New Perspective on ASA Indication in Obstetrics.

BACKGROUND

Low-dose aspirin (ASA) is used in obstetrics for different indications, mainly to prevent preeclampsia. This study investigated the underlying mechanism of ASA's effect on the fetus's cardiovascular functions.

METHODS

42 pregnant women at 18-24 weeks of gestation, identified as high-risk for preeclampsia, received 160 mg of ASA daily. Fetal Doppler ultrasound was performed before and three weeks after ASA treatment, assessing ductus venosus, middle cerebral, umbilical, and uterine arteries pulsatility indices as well as pulmonary, aorta, and superior vena cava (SVC) diameters in the three-vessel view, including pulmonary/aorta and SVC/aorta ratios. All analyses were performed using SPSS software version 27, with a significance threshold set at p<0.05. A paired t-test was used to assess differences in means. The Chi-square and Fisher's exact test analyzed nominal variables.

RESULTS

Post-intervention analysis revealed significant improvements in abnormal uterine artery resistance (p<0.001) and abnormal pulsatility index of the umbilical artery, middle cerebral artery, and ductus venosus (p<0.001 for all). Moreover, 160 mg/day aspirin administration significantly increased mitral E/A (early filling velocity/atrial contraction velocity: 0.397±0.029; p<0.001), diameters of aorta (4.390±0.852; p<0.001), pulmonary artery (4.895±1.087; p<0.001), and SVC (2.511±0.535; p<0.001), while significantly decreasing left ventricular myocardial performance index (p<0.05).

CONCLUSION

Daily administration of 160 mg of aspirin enhances fetal vascular and cardiac function. Evaluating fetal cardiovascular parameters beyond routine uterine artery Doppler, especially in high-risk pregnancies, and initiating ASA therapy in cases of insidious abnormalities, may help delay or prevent fetal complications such as intrauterine growth restriction (IUGR) by improving cardiovascular function.