The relationship between ultrasonic findings of postpartum uterus after normal vaginal delivery and the duration of lochia discharge

Lochia is the slight vaginal bleeding between 24 hour to 12 week after delivery. There isnt any standard definition for difference between normal and abnormal lochia in post-partum period. The aim of this study was to determine the relationship between ultrasonic findings of the postpartum uterus after normal vaginal delivery with the duration of lochia discharge.
In this cross-sectional study was done in Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran, from 2014 to 2015. In this study 160 women with non-complicated vaginal delivery were entered. Inclusion criteria were: Term pregnancy with gestational age > 37, singleton fetus with cephalic presentation. Exclusion criteria were pre-term pregnancies, previous Cesarean section or other uterine surgeries and twin fetuses. Transvaginal ultrasound was done in first 48 hours after delivery, endometrial thickness echogenicity and uterine size was evaluated. Maternal age, parity, duration of labor and neonatal weight were evaluated. Then the mothers were followed for 6 weeks. The quality and the quantity of lochia discharge were asked by the phone.
Lochial discharge last more than 6 weeks in 96 out of 160 (60%). One had less than 4 weeks. The uterus length, thickness, height and endometrial length did not show any relationship with the duration of lochial discharge, but endometrial strip thickness significantly correlated with the duration of lochial discharge period (P=0.04). None of clinical variables like the number of gravidity, parity, live birth or child birth weight, were correlated to the duration of lochia discharge period, but the labor time was correlated to the duration of lochia discharge period (P=0.04). Although both endometrial thickness and labor time in univariate analysis were correlated to the lochia duration time but this was true just for endometrial thickness in multivariate analysis.
The endometrial thickness in first 48 hours after normal vaginal delivery could predict the duration of lochia discharge, there wasn’t any correlation between lochia discharge period and other ultrasound parameters.