Blood pressure during pregnancy, neonatal size and altered body composition: the Healthy Start study

Body composition in term neonates of mothers with hypertensive disorders of pregnancy

BACKGROUND

Neonates of gravidas with hypertensive disorders of pregnancy (HDP) are at increased lifelong risk of cardiometabolic complications. Neonatal adiposity measured by body composition (BC) is a better surrogate of nutritional status than birth weight. Data comparing BC in term neonates of hypertensive and normotensive pregnant patients is lacking. Our objective was to compare body composition in both groups of neonates.

METHODS

This was a retrospective cohort study from March 2018 to June 2019 at our tertiary institution where term neonatal BC are routinely measured. Neonates of patients with HDP and matched controls were included. Skin fold thickness (SFT) and percent body fat (PBF) were calculated using a validated anthropometric formula and compared using Mann-Whitney U and chi-square tests.

RESULTS

One hundred and forty-two neonates of patients with HDP were compared to 150 controls. Demographic characteristics were similar except for higher pre-pregnancy BMI (29.7 ± 8.4 vs 26.75 ± 7.1, p = <0.01) in the HDP group. SFT was not significantly different (4.6 vs 4.4 mm, p = 0.09) but PBF was higher in the hypertensive group (13.15 vs 11.72, p = 0.01).

CONCLUSIONS

PBF is higher in neonates of mothers with HDP, which may contribute to an increased risk of cardiometabolic complications later in life.

IMPACT

Birth weight percentiles do not explain the predisposition to cardiovascular complications in offspring of hypertensive mothers. Body composition estimation may provide an explanation for this increased risk. Percent body fat is higher in term neonates of mothers with hypertensive disorders of pregnancy than neonates of normotensive mothers. Body composition is different in term neonates of mothers with hypertensive disorders of pregnancy.

Prevalence and Risk Factors of QTc Prolongation During Pregnancy

Background

Prolonged QT intervals have been observed in pregnant women, which predispose them to a higher risk of potentially lethal ventricular arrhythmias. This study was designed to evaluate the prevalence of QTc prolongation in Chinese hospitalized parturient women with single and twin pregnancies, and to explore potential risk factors associated with QTc prolongation.

Methods

This retrospective study included 1,218 patients from a large Chinese population between January 2014 and October 2020. Data from parturient women with single and twin pregnancies without pre-pregnancy cardiac diseases were collected. QTc was corrected by the Fridericia formula [QTc = QT/RR(1/3)], and QTc ≥ 460 ms for females was defined as prolonged QTc, QTc ≥ 500 ms was defined as severely prolonged QTc. The prevalence and common risk factors of QTc prolongation during pregnancy were analyzed in this cohort. Uni- and multivariable logistic regression analysis were performed to identify clinical parameters associated with QTc prolongation in this population.

Results

The prevalence of QTc prolongation was 48.19% among this population, 10.56% in single pregnancy, 89.44% in twin pregnancies. The prevalence of severely prolonged QTc was 23.48% among the total cohort, 0.49% in single pregnancy, and 46.47% in twin pregnancies. The mean QTc interval was significantly longer in twin pregnancies than in single pregnancy (498.65 ± 38.24 vs. 424.96 ± 27.67 ms, P < 0.001). Systolic blood pressure, diastolic blood pressure, total cholesterol, serum uric acid, gestational hypertension and twin pregnancies were associated with QTc prolongation in parturient women.

Conclusion

This is the first study to assess the prevalence and risk factors of QTc prolongation between single and twin pregnancies. QTc prolongation is more prevalent, and QTc intervals are significantly longer in twin pregnancies as compared to single pregnancy.

Parameterization of the mid-trimester drop in blood pressure trajectory during pregnancy and its utility for predicting preeclampsia

OBJECTIVES

The purpose of this study was to parameterize mid-trimester drop in blood pressure (BP) trajectory during pregnancy and to evaluate its utility for predicting preeclampsia.

METHODS

To develop parametric models for BP trajectory during pregnancy, we used data from 7923 Chinese pregnant women with 24 810 routine antenatal care visits. Then, we evaluated the utility of BP trajectory parameters for predicting clinician-diagnosed preeclampsia in a separate sample of 3524 pregnant women from a randomized controlled trial of prenatal vitamin supplementation conducted in the same area. We focused on parameters related to the mid-trimester BP drop, including the gestational age and BP value at the nadir (lowest point), change in BP, velocity, and area under curve during two periods (from 12 weeks of gestation to the nadir and from the nadir to 33 weeks of gestation).

RESULTS

All participants in our analysis had a mid-pregnancy drop in their SBP, DBP, and mean arterial pressure (MAP) trajectories. There were high correlations (|r| > 0.90) among trajectory parameters of the same BP measure. The final prediction model included selective parameters of SBP, DBP, and MAP trajectories, prepregnancy BMI and gestational age at the first antenatal care visit. The area under the receiver-operating curve for predicting preeclampsia was 0.886 (95% confidence interval 0.846--0.926) in the training dataset and 0.802 (0.708--0.895) in the validation dataset.

CONCLUSION

Our novel BP trajectory parameters are informative and can predict preeclampsia at a clinically acceptable level.

Population reference and healthy standard blood pressure range charts in pregnancy: findings from the Born in Bradford cohort study

Women who develop gestational hypertension are at increased risk of adverse perinatal and longer-term outcomes. Reference charts may aid early detection of raised blood pressure (BP) and in doing so reduce adverse outcome risk. We used repeated BP measurements to produce ‘reference’ (whole population) and ‘standard’ (healthy pregnancies only) gestational-age-specific BP charts for all pregnant women (irrespective of ethnicity) and for White British (WB) and Pakistani (P) women. We included 9218 women recruited to the Born in Bradford study with 74,770 BPs. 19% of the whole population, 11% and 25% of WB and P women respectively were defined as healthy pregnancies. For reference and standard charts, for all women and each ethnic group, SBP/DBP at 12 and 20 weeks gestation was similar before rising at 37 weeks. DBP/SBP of reference charts for all women and for each ethnic group were higher than those of the corresponding standard charts. Compared to WB, P women had lower SBP/DBP at 12, 20 and 37 weeks gestation. To conclude; maternal population BP reference charts are higher compared to standard charts (healthy pregnancies) and are influenced by ethnicity.

Combined environmental and social exposures during pregnancy and associations with neonatal size and body composition: the Healthy Start study

BACKGROUND

Prenatal environmental and social exposures have been associated with decreased birth weight. However, the effects of combined exposures in these domains are not fully understood. Here we assessed multi-domain exposures for participants in the Healthy Start study (Denver, CO) and tested associations with neonatal size and body composition.

METHODS

In separate linear regression models, we tested associations between neonatal outcomes and three indices for exposures. Two indices were developed to describe exposures to environmental hazards (ENV) and social determinants of health (SOC). A third index combined exposures in both domains (CE = ENV/10 × SOC/10). Index scores were assigned to mothers based on address at enrollment. Birth weight and length were measured at delivery, and weight-for-length z-scores were calculated using a reference distribution. Percent fat mass was obtained by air displacement plethysmography.

RESULTS

Complete data were available for 897 (64%) participants. Median (range) ENV, SOC, and CE values were 31.9 (7.1-63.2), 36.0 (2.8-75.0), and 10.9 (0.4-45.7), respectively. After adjusting for potential confounders, 10-point increases in SOC and CE were associated with 27.7 g (95%CI: 12.4 - 42.9 g) and 56.3 g (19.4 - 93.2 g) decreases in birth weight, respectively. SOC and CE were also associated with decreases in % fat mass.

CONCLUSIONS

Combined exposures during pregnancy were associated with lower birth weight and % fat mass. Evidence of a potential synergistic effect between ENV and SOC suggests a need to more fully consider neighborhood exposures when assessing neonatal outcomes.

Air displacement plethysmography (pea pod) in full-term and pre-term infants: a comprehensive review of accuracy, reproducibility, and practical challenges

Air displacement plethysmography (ADP) has been widely utilised to track body composition because it is considered to be practical, reliable, and valid. Pea Pod is the infant version of ADP that accommodates infants up to the age of 6 months and has been widely utilised to assess the body composition of full-term infants, and more recently pre-term infants. The primary goal of this comprehensive review is to 1) discuss the accuracy/reproducibility of Pea Pod in both full- and pre-term infants, 2) highlight and discuss practical challenges and potential sources of measurement errors in relation to Pea Pod operating principles, and 3) make suggestions for future research direction to overcome the identified limitations.