Hoekstra, S.T. (2012) Placental volume measurements:Does the first trimester placental volume predict second trimester volume? thesis, Medicine.
Full text available on request.Abstract
Background: Previous studies using 3D ultrasound showed a strong correlation between small placental volumes (PV) in second trimester and perinatal complications. To improve maternal and perinatal outcome, we investigated whether small PV earlier in pregnancy may be predictive of reduced volume in the second trimester, which could possibly lead to earlier intervention in these cases. The objective of this study was to see if 1st trimester PV could predict 2nd trimester volumes. While we know from previous studies that an increased impedance of flow in the uterine vessels is associated with increased risk for pre-eclampsia and IUGR, the secondary aim of this study was to find out if the uterine artery resistance index is related to placental development. Methods: In a prospective design, 80 pregnant women were included in this study at 11 - 14 weeks gestation. Assessment of the PV was done in-vivo by using a multi-planar technique on 3D ultrasound images at both 1st and 2nd trimester. Uterine artery resistance index was calculated using the systolic and diastolic blood flow velocity of three subsequent cardiac cycles on a Doppler waveform. Resistance indices were calculated by peak systolic flow minus end diastolic flow divided by peak systolic flow. Placental dimensions were measured after delivery to see if these measurements could be related to the placental volume measurements in utero. Results- We found a strong significant correlation between 1st and 2nd trimester PV, p=0.007. The uterine artery resistance index did not show significant correlations between first and second trimester. No correlations could be found when we compared both 1st and 2nd trimester PV with the resistance index. PV and weight after delivery were strongly correlated with each other and with birthweight. Discussion: By the increasing focus of antenatal care in first trimester, PV measurements might have a predictive value for at risk pregnancies seen the significant correlation between 1st and 2nd trimester placental volumes. No significant correlation was found between the uterine artery resistance index in 1st and 2nd trimester. We would have expected a negative correlation, due to the enlargement of the vascular placental bed. Neither was found a significant correlation between placental volumes and the resistance indices in both trimester. This is possible due to the high biological variation in placental development. Other reasons for this outcome could be (physiological) factors that affect the perfusion to the placental. Conclusion: If our results were to be confirmed in larger prospective study linking change in placental volume size between first and second trimester with birthweight, then placental volume measurements may become a useful means of detecting risk of IUGR. Also, further research would be needed to establish the discrepancy between the placental volumes and resistance indices.
| Item Type: | Thesis (Thesis) |
|---|---|
| Supervisor name: | Facultair supervisor: and Kappelle, J.W. |
| Supervisor name: | Host supervisor: and Macklon, Prof. dr. N.S. and Research institute: Princess Anne Hospital, Department of Ob |
| Faculty: | Medical Sciences |
| Date Deposited: | 25 Jun 2020 11:07 |
| Last Modified: | 25 Jun 2020 11:07 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/2653 |
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