Three-dimensional sonography of the placental and uterine spiral vasculature: influence of maternal age and parity.

Purpose: : To test the influence of maternal age and parity on placental volume and uterine spiral vasculature volume, their mean gray value, and 3-dimensional power Doppler (3DPD) indices in normal pregnancy.

Methods: : Women with a gestational age of 14-25 weeks were included in the study. Exclusion criteria included posterior placenta, structural or chromosomal anomaly, pregnancy complications, and unknown pregnancy outcome. 3D sonograms of the placenta and uterine spiral vasculature were obtained. Virtual Organ Computer-aided AnaLysis imaging software was used to calculate the volumes, mean gray value, and 3DPD indices.

Results: : The study included 199 women, the majority of whom were Filipino, Japanese, or part Hawaiian. The placental volume, uterine spiral vasculature volume, mean gray value, and 3DPD indices were similar in all women regardless of maternal age. However, uterine spiral vasculature volume was significantly larger in women younger than 25 years, compared with women 35 years of age and older. Parity influenced all placental 3DPD indices, whereas placental volume, uterine spiral vasculature volume, mean gray value, and 3DPD indices remained unaffected.

Conclusion: : Maternal age influenced uterine spiral vasculature volume, whereas parity influenced all placental 3DPD indices.