First trimester pregnancy volumes and subsequent small for gestational age fetuses

Does a Caesarean Section Scar Affect Placental Volume, Vascularity and Localization?

Caesarean section is associated with an increased risk of abnormal placental implantation and adverse pregnancy outcomes in subsequent pregnancies. Besides the placenta accrete spectrum, only a few of the previous studies focused on other placental development alterations in the scarred uterus. We assessed placental development deviations in the uterus with a Caesarean section scar by evaluating placental volume (PV) and vascular flow indexes. From 1 January 2021 until 31 March 2022, placental volumes and vascularization indexes (VI, FI, VFI) were prospectively measured by 3D power Doppler and VOCAL techniques in 221 patients attending the first trimester screening program. We also calculated the placental quotient to standardize PV to the gestational age. No statistically significant differences in the values of placental volume, placental quotient and placental vascularization indexes were detected between women with previous Caesarean section delivery or women with vaginal delivery. FI was significantly lower in nulliparous in the first trimester. The results of our study suggest that 3D placental evaluation was not able to detect placental development alteration in the uterus with a Caesarean section scar. Future research needs to verify whether 3D power Doppler and Vocal techniques can provide more information if used in an earlier gestational age.

Combination of three-dimensional placental vascular indices and volume and uterine artery pulsatility index at 10-13 weeks of gestation could improve the prediction of adverse pregnancy outcomes

AIM

To evaluate whether three-dimensional (3D) placental vascular indices and volumes during the first trimester of pregnancy can be used as predictors of subsequent adverse outcomes.

METHODS

This was a prospective cohort study including women with singleton pregnancies between 10 and 13 weeks. 3D placental volume and vascular indices and uterine artery pulsatility index (UtA-PI) were measured. Adverse outcomes were defined whether there was any of the following complications: small for gestational age pregnancy, preterm delivery, and preeclampsia. The serum pregnancy-associated plasma protein-A (PAPP-A) and free beta-human chorionic gonadotropin (β-hCG) levels were also compared. We analyzed the screening performances of these parameters for prediction of any of adverse outcomes.

RESULTS

Of 348 women screened, 300 women were completed follow-up. Overall, 57 (19.0%) of 300 women developed any of adverse pregnancy outcomes. Multiple logistic regression analysis demonstrated that gestational age-adjusted z-scores of log₁₀ placental volume (odds ratio [OR], 0.572; 95% confidence interval [CI], 0.416-0.788), log₁₀ placental vascularization flow index (VFI; OR, 0.676; 95% CI, 0.496-0.921), and log₁₀ UtA-PI (OR, 1.910; 95% CI, 1.335-2.731) were significantly associated adverse pregnancy outcomes. The multivariate model combining placental VFI, placental volume, UtA-PI, and underweight or obese body mass index exhibited the highest screening performances (AUC = 0.77) and PAPP-A and β-hCG did not add any significance to multivariate model.

CONCLUSIONS

Placental volume and vascular indices at 10-13 weeks of gestation are significantly associated with adverse pregnancy outcomes. Combination of these placental indices and UtA-PI could improve the screening performance for adverse outcomes.

Comparison of Placental Three-Dimensional Power Doppler Vascular Indices and Placental Volume in Pregnancies with Small for Gestational Age Neonates

This prospective observational study aimed to compare the changes in placental vascular indices and placental volume using three-dimensional power Doppler (3DPD) ultrasound in pregnancies with small for gestational age (SGA) neonates. We enrolled 396 women with singleton pregnancies from September 2013 to June 2016. Placental vascular indices, including the vascularization index (VI), flow index (FI), and vascularization flow index (VFI), and placental volume were obtained using 3DPD ultrasound in the first and second trimesters. Of the enrolled women, 21 delivered SGA neonates and 375 did not. In the first trimester, the SGA group had a significantly lower mean FI (25.10 ± 7.51 versus 33.10 ± 10.97, p < 0.001) and VFI (4.59 ± 1.95 versus 6.28 ± 2.35, p = 0.001) than the non-SGA group. However, there was no significant difference in the placental volume between the two groups during the first trimester. In the second trimester, the SGA group also had a significantly lower mean FI (27.08 ± 7.97 versus 31.54 ± 11.01, p = 0.022) and VFI (6.68 ± 1.71 versus 8.68 ± 3.09, p < 0.001) than the non-SGA group. In addition, a significantly smaller placental volume was noted in the SGA group (104.80 ± 24.23 cm³ versus 122.67 ± 26.35 cm³, p = 0.003) than in the non-SGA group during the second trimester. The results showed that a decreased placental VFI occurred earlier than a decreased placental volume in SGA pregnancies.

Placental volume at 11 to 14 gestational weeks in pregnancies complicated with fetal growth restriction and preeclampsia

OBJECTIVE

The study aims to evaluate the predictive value of first trimester placental volume in pregnancies destined to develop fetal growth restriction (FGR) and preeclampsia (PE).

METHODS

Prospective observational study including placentas from 34 FGR, 12 PE, 15 GH (gestational hypertension) pregnancies, and 265 controls. Placental volume (PV) was obtained using VOCAL technique, and a z score was calculated (z-PV). The association of PV with other first trimester variables and maternal characteristics was assessed with Spearman's correlation.

RESULTS

PV increased exponentially with crown-rump length (CRL) and was unrelated to maternal factors (weight, age, parity, and smoking status) as well as first trimester uterine artery Doppler, free β-hCG, nuchal translucency, or fetal heart rate. However, PV was positively associated with maternal height, CRL, PAPP-A, and birth weight. z-PV was a strong predictor for FGR with abnormal fetal Dopplers (AUC = 0.9472, P < 0.001). z-PV provided moderate prediction of FGR with normal fetal Dopplers (AUC = 0.8396, P < 0.001), PE (AUC = 0.8312, P < 0.001), and GH (AUC = 0.7640, P < 0.001). The addition of maternal weight, PAPP-A, β-hCG, and uterine artery Doppler improved our models.

CONCLUSION

At 11 to 14 weeks, PV is an independent predictor of pregnancy complications related to placental insufficiency, and the predictive ability is greater for FGR pregnancies with abnormal fetal Dopplers.

Gestation-Specific Changes in the Anatomy and Physiology of Healthy Pregnant Women: An Extended Repository of Model Parameters for Physiologically Based Pharmacokinetic Modeling in Pregnancy

BACKGROUND

In the past years, several repositories for anatomical and physiological parameters required for physiologically based pharmacokinetic modeling in pregnant women have been published. While providing a good basis, some important aspects can be further detailed. For example, they did not account for the variability associated with parameters or were lacking key parameters necessary for developing more detailed mechanistic pregnancy physiologically based pharmacokinetic models, such as the composition of pregnancy-specific tissues.

OBJECTIVES

The aim of this meta-analysis was to provide an updated and extended database of anatomical and physiological parameters in healthy pregnant women that also accounts for changes in the variability of a parameter throughout gestation and for the composition of pregnancy-specific tissues.

METHODS

A systematic literature search was carried out to collect study data on pregnancy-related changes of anatomical and physiological parameters. For each parameter, a set of mathematical functions was fitted to the data and to the standard deviation observed among the data. The best performing functions were selected based on numerical and visual diagnostics as well as based on physiological plausibility.

RESULTS

The literature search yielded 473 studies, 302 of which met the criteria to be further analyzed and compiled in a database. In total, the database encompassed 7729 data. Although the availability of quantitative data for some parameters remained limited, mathematical functions could be generated for many important parameters. Gaps were filled based on qualitative knowledge and based on physiologically plausible assumptions.

CONCLUSION

The presented results facilitate the integration of pregnancy-dependent changes in anatomy and physiology into mechanistic population physiologically based pharmacokinetic models. Such models can ultimately provide a valuable tool to investigate the pharmacokinetics during pregnancy in silico and support informed decision making regarding optimal dosing regimens in this vulnerable special population.

The correlation between birth weight and insulin-like growth factor-binding protein-1 (IGFBP-1), kisspeptin-1 (KISS-1), and three-dimensional fetal volume

PURPOSE

This study aimed to determine the relationship between birth weight, and maternal serum insulin-like growth factor-binding protein-1 (IGFBP-1) and kisspeptin-1 (KISS-1) levels, and first-trimester fetal volume (FV) based on three-dimensional ultrasonography.

MATERIALS AND METHODS

The study included 142 pregnant women at gestational week 11°-13⁶. All fetuses were imaged ultrasonographically by the same physician. Maternal blood samples were collected at the time of ultrasonographic evaluation and analyzed for IGFBP-1 and KISS-1 levels via enzyme-linked immunosorbent assay (ELISA). Maternal and neonatal weights were recorded at birth. Birth weight ≤10th and the >90th percentiles was defined as small and large for gestational age (SGA and LGA), respectively.

RESULTS

Median crown-rump length (CRL), FV, and maternal serum IGFBP-1 and KISS-1 levels were 58.2 mm (35.3-79.2 mm), 16.3 cm³ (3.8-34.4 cm³), 68.1 ng mL^-1 (3.8-377.9 mL^-1), and 99.7 ng L^-1 (42.1-965.3 ng L^-1), respectively. First-trimester IGFBP-1 levels were significantly lower in the mothers with LGA neonates (p < .05). There was a significant positive correlation between CRL and FV, and between the IGFBP-1 and KISS-1 levels. IGFBP-1 levels and maternal weight at delivery were negatively correlated with neonatal birth weight. There was no correlation between CRL or FV and maternal IGFBP-1 or KISS1 levels (p > .05). The maternal IGFBP-1 level during the first trimester was a significant independent factor for SGA and LGA neonates (Odds ratio (OR): 0.011, 95%CI: 1.005-1.018, p < .001; and OR: 1.297, 95%CI: 1.074-1.566, p = .007, respectively). There was no significant relationship between SGA or LGA, and CRL, FV, or the KISS-1 level.

CONCLUSIONS

As compared to the maternal KISS-1 level, the maternal IGFBP-1 level during the first trimester might be a better biomarker of fetal growth. Additional larger scale studies are needed to further delineate the utility of IGFBP-1 as a marker of abnormal birth weight.