Third Trimester Umbilical Artery Doppler in Low-Risk Pregnancies and its Correlation to Estimated Fetal Weight and Birthweight

Value of foetal umbilical vein standardised blood flow volume in predicting weight gain in the third trimester: a prospective case-cohort study

Objective

This study aims to establish a prediction model of foetal umbilical vein standardised blood flow volume (sQuv) on estimated foetal weight (EFW) in the third trimester.

Methods

A case-cohort study involving 200 eligible normal foetuses was conducted at the Ultrasound Department of Longquanyi District of Maternity and Child Healthcare Hospital between June 1, 2020 and December 31, 2021. Ultrasound measurements were taken at two separate intervals to assess EFW and the rate of EFW (rEFW) [first: between 28 w and 33 w6d of gestational age (GA); second: after 4-6 weeks]. Umbilical vein blood flow volume (Quv) and sQuv (normalised with EFW) were calculated only during the initial measurement. Using general linear regression, a prediction model for EFW based on GA and sQuv was developed, with the gestational week employed as a calibration scalar and validated using linear regression cross-validation.

Results

In the third trimester, EFW exhibited significant correlations with GA, abdominal circumference (AC), head circumference (HC) and Quv (all ρ > 0.6, P < 0.001). Furthermore, the rEFW showed significant correlations with Quv and sQuv (all ρ > 0.6, P < 0.001). A linear regression equation was established using a general linear regression model: rEFW = 0.32689 × sQuv. Additionally, a foetal weight prediction model (EFW = -2,554.6770 + 0.9655 × sQuv + 129.6916 × GA) was established using sQuv. The above two formulas were cross-validated by intra-group linear regression and proved to be of good efficacy.

Conclusions

In the third trimester, EFW displayed significant correlations with GA, AC, HC and Quv. Additionally, the rEFW exhibited significant correlations with Quv and sQuv. The sQuv during the third trimester has predictive value for foetal weight, serving as an early warning indicator.

Nontargeted metabolomics reveals the potential mechanism underlying the association between birthweight and metabolic disturbances

AIMS

The aim of this study was to characterize the metabolites associated with small- and large-gestational-age newborns in maternal and cord blood, and to investigate potential mechanisms underlying the association between birthweight and metabolic disturbances.

RESEARCH DESIGN AND METHODS

We recorded detailed anthropometric data of mother-offspring dyads. Untargeted metabolomic assays were performed on 67 pairs of cord blood and maternal fasting plasma samples including 16 pairs of small-for-gestational (SGA, < 10th percentile) dyads, 28 pairs of appropriate-for-gestational (AGA, approximate 50 percentile) dyads, and 23 pairs of large-for-gestational (LGA, > 90th percentile) dyads. The association of metabolites with newborn birthweight was conducted to screen for metabolites with U-shaped and line-shaped distributions. The association of metabolites with maternal and fetal phenotypes was also performed.

RESULTS

We found 2 types of metabolites that changed in different patterns according to newborn birthweight. One type of metabolite exhibited a "U-shaped" trend of abundance fluctuation in the SGA-AGA-LGA groups. The results demonstrated that cuminaldehyde level was lower in the SGA and LGA groups, and its abundance in cord blood was negatively correlated with maternal BMI (r = -0.352 p = 0.009) and weight gain (r = -0.267 p = 0.043). 2-Methoxy-estradiol-17b 3-glucuronide, which showed enrichment in the SGA and LGA groups, was positively correlated with homocysteine (r = 0.44, p < 0.001) and free fatty acid (r = 0.42, p < 0.001) in maternal blood. Serotonin and 13(S)-HODE were the second type of metabolites, denoted as "line-shaped", which both showed increasing trends in the SGA-AGA-LGA groups in both maternal and cord blood and were both significantly positively correlated with maternal BMI before pregnancy. Moreover, cuminaldehyde, serotonin, 13(S)-HODE and some lipid metabolites showed a strong correlation between maternal and cord blood.

CONCLUSIONS

These investigations demonstrate broad-scale metabolomic differences associated with newborn birthweight in both pregnant women and their newborns. The U-shaped metabolites associated with both the SGA and LGA groups might explain the U-shaped association between birthweight and metabolic dysregulation. The line-shaped metabolites might participate in intrauterine growth regulation. These observations might help to provide new insights into the insulin resistance and the risk of metabolic disturbance of SGA and LGA babies in adulthood and might identify potential new markers for adverse newborn outcomes in pregnant women.

HbA1c at term delivery and adverse pregnancy outcome

Background

There are no obvious thresholds at which the risk of adverse pregnancy outcomes increases as a result of maternal hyperglycemia. HbA1c level which is representative of average blood glucose levels over the last 2–3 months is not as strongly predictive of adverse outcome compared to blood glucose values of oral glucose tolerance test. Data is sparse on the predictive value of HbA1c at term just prior to delivery on adverse outcome. We sought to evaluate HbA1c taken on admission for delivery at term on adverse outcomes of Cesarean delivery and large (≥ 90^th centile) for gestational age (LGA) infants.

Methods

A prospective cross-sectional study was conducted in a university hospital in Malaysia from December 2017-August 2018. 1000 women at term whose deliveries were imminent were enrolled. Blood were drawn and immediately sent for HbA1c analysis at our hospital laboratory. Primary outcomes were Cesarean delivery and LGA.

Results

On crude analyses, Cesarean births (vs. vaginal births) were associated with significantly higher HbA1c (%) levels 5.4[5.2–5.7] vs. 5.3[5.1–5.6] P =  < 0.001 but not for LGA vs. non-LGA 5.4[5.1–5.6] vs. 5.3[5.1–5.6] P = 0.17. After controlling for significant confounders identified on crude analysis (diabetes in pregnancy, parity, ethnicity, body mass index (BMI), previous cesarean, labor induction, Group B streptococcus (GBS) carriage and birth weight), HbA1c is independently predictive of Cesarean birth, adjusted odds ratio (AOR) 1.47 95% CI 1.06–2.06 P = 0.023 per HbA1c 1% increase. Following adjustment for significant confounders (BMI, predelivery anemia [hemoglobin < 11 g/dl] and GBS carriage), the impact of raised HbA1c level on LGA is AOR 1.43 95% CI 0.93–2.18 P = 0.101 per HbA1c 1% increase and non-significant.

Conclusion

Raised HbA1c level at term births in the general pregnant population is independently predictive of Cesarean delivery after adjustment for potential confounders including diabetes in pregnancy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-05000-7.

Amniotic-Umbilical-to-Cerebral Ratio - A Novel Ratio Combining Doppler Parameters and Amniotic Fluid Volume to Predict Adverse Perinatal Outcome in SGA Fetuses At Term

PURPOSE

 Introduction of a novel ratio - the amniotic-umbilical-to-cerebral ratio (AUCR) - to predict adverse perinatal outcome in SGA fetuses at term and comparison of its predictive accuracy with established parameters.

MATERIALS AND METHODS

 This retrospective cohort study included 165 singleton pregnancies with SGA fetuses (birth weight < 10^th percentile) at term. Cases with planned vaginal delivery and documented pulsatility indices (PI) of the umbilical artery (UA), middle cerebral artery (MCA), and single deepest pocket (SDP) were included. CPR was calculated as the ratio between MCA PI and UA PI, UCR as the ratio between UA PI and MCA PI. AUCR was defined as follows: SDP/(UA PI/MCA PI). Adverse perinatal outcomes were defined as operative intervention (OI), OI due to fetal distress, admission to the neonatal intensive care unit (NICU), and composite adverse perinatal outcome (CAPO). Associations between Doppler parameters and these outcomes were estimated using regression analyses.

RESULTS

 OI was statistically significantly associated with UCR, SDP, and AUCR, whereas no association was observed for UA PI, MCA PI, and CPR. Fetuses requiring OI due to fetal distress revealed a significantly higher UA PI and UCR as well as a lower MCA PI, CPR, and AUCR. With regard to NICU admission and CAPO, a significantly higher UA PI and lower CPR were found. Furthermore, a significant association was shown for SDP, UCR, and AUCR. AUCR achieved the best area under the curve for all outcome parameters.

CONCLUSION

 AUCR leads to an improvement in the prediction of unfavorable outcome in SGA fetuses at term. Furthermore, results of our study show that UCR might be superior to CPR.