Do such factors as parity or BMI affect the placental volume and placental quotient in the first trimester?

It is well known that parity and high BMI are associated with increased birthweight and placental weight. The aim of our study was to evaluate whether parity and BMI affects placental volume and placental quotient in the first trimester. During the first trimester screening Placental volume was obtained in 64 pregnant woman with VOCAL software (Voluson E8, GE). The off-line analysis was performed using VOCAL option (30°). All cases of fetal anomalies were excluded. Informed consent was signed before enrolment. Placental quotient (PQ) was calculated by dividing PV by the foetal crown–rump length (CRL). Body mass index (BMI) was calculated (k/m2) and recorded. To assess parity influence on the placental volume, patients were divided in two subgroups - there were 25 patients in nullipara and 39 in multipara subgroup. Spearman’s correlation coefficient ( ρ ) was used to study the relationships between all the studied variables. P < 0.05 was considered statistically significant. The median PV in nullipara group was 56,93mm and 66,51mm3 in multipara group, a non statistically significant difference (P=0.36). The median PQ in both groups were not significant different with 0,223 in nulliparous vs. 0.195 for the multipara group (P=0.36). On the average BMI was 22.54 (range 17.08–35.75) kg/m2. BMI did not correlate with PV( ρ = 0.096, P = 0.45) or PQ( ρ = 0.053, P = 0.67) The results of our study suggest that placental volume does not correlate with parity or BMI. The limitation of current study was the small number of patients. Further studies are needed to evaluate the influence of parity and obesity on placental volume.