[Ultrasonic evaluation of the uterus during puerperium]

The aim of this study was to evaluate morphological and volumetric changes in the uterus during the first eight days postpartum in a sample of 229 patients using ultrasonography. Both pregnancies and postpartum were physiological in all the women examined. Fifty patients underwent cesarean section. A sectorial 3.5 MHz probe was used to measure the longitudinal, antero-posterior and latero-lateral diameter of the uterus and its volume. Involution was gradual both in relation to the diameters and uterine volume up until day 8 and was most evident during days 1-4. Longitudinal and antero-posterior diameter reduced more quickly in relation to the latero-lateral diameter. Uterine volume, calculated by considering the uterus as an ellipsoid, diminished 42% from 730 cc to 421 cc. No differences were observed between uterine diameters in primiparas and those in pluriparas, nor between patients undergoing cesarean section and those after normal childbirth. However, there was a clear difference between those patients who breastfed immediately after birth and those who resorted to artificial methods; uterine volume diminished more rapidly in the former, especially between days 1-4, confirming that early breastfeeding plays an important role in uterine involution in the very early days of postpartum. The physiological characteristics of the postpartum uterus were useful in formulating a medical or surgical treatment strategy in the few cases of postpartum metrorrhagia observed during the study.