Exposure of ambient PM2.5 during gametogenesis period affects the birth outcome: Results from the project ELEFANT

Various environmental and behavioural factors influence neonatal health. Gamete formation (gametogenesis) is a crucial period which affects embryo development and neonatal health and ambient air pollution exposure at this stage may lead to an adverse birth outcome. Previous epidemiological and toxicological research demonstrated a strong association between maternal ambient air pollution exposure and adverse birth outcomes. However, the joint exposure-outcome of paternal exposure (76 days before the last menstruation and 14 days after the last menstruation) and maternal exposure (14 days after the last menstruation) when exploring the mechanism of the influence of air pollutants on pregnancy outcome and neonatal health remains unexplored. Here, in the Project Environmental and LifEstyle FActors iN metabolic health throughout life-course Trajectories (ELEFANT), we collected the data of 10,960 singleton pregnant women with 24-42 completed gestational weeks and included them in this study. A multinominal logistic regression model was applied to investigate the association between adverse birth outcomes and ambient PM_2.5 exposure levels during spermatogenesis and oogenesis. Results from the binary classification of ambient PM_2.5 exposure showed that the risk of abnormal birthweight was significantly greater when ambient PM_2.5 exposure was both higher during spermatogenesis and oogenesis, with RRs of 1.86 (95% CI: 1.02, 3.39). The risk of macrosomia (RR: 1.88 (95% CI: 1.13, 3.12)) increased significantly when ambient PM_2.5 levels were higher during spermatogenesis. Primiparity and primigravity are more likely to be influenced by higher ambient PM_2.5 levels during spermatogenesis. In conclusion, more attention should be paid to higher exposure level of ambient PM_2.5 during spermatogenesis.

First-trimester maternal haemodynamic adaptation to pregnancy and placental, embryonic and fetal development: the prospective observational Rotterdam Periconception cohort

Objective

To investigate whether first‐trimester maternal haemodynamic adaptation impacts placental, embryonic and fetal development as well as birth outcomes in pregnancies with and without placenta‐related complications.

Design

Prospective observational cohort.

Setting

A Dutch tertiary hospital.

Population

Two hundred and fourteen ongoing pregnancies.

Methods

At 7, 9 and 11 weeks of gestation, we assessed maternal haemodynamic adaptation (mean arterial blood pressure [MAP], uterine artery [UtA] blood flow) and placental development (placental volume [PV], uteroplacental vascular volume [uPVV]) using three‐dimensional power Doppler ultrasound volumes, and embryonic development (crown–rump length, embryonic volume). At 22 and 32 weeks of gestation, fetal development was assessed by estimated fetal weight. Birth outcomes (birthweight, placental weight) were extracted from medical records. Linear mixed modelling and linear regression analyses were applied.

Main outcome measures

Birthweight centile and placental weight.

Results

In placenta‐related complications (n= 55, 25.7%), reduced haemodynamic adaptation, i.e. higher UtA pulsatility index (PI) and resistance index (RI) trajectories, was associated with smaller increase in PV (β = −0.559, 95% CI −0.841 to −0.278, P< 0.001; β = −0.579, 95% CI −0.878 to −0.280, P< 0.001) and uPVV trajectories (UtA PI: β = −0.301, 95% CI −0.578 to −0.023, P= 0.034). At birth, reduced haemodynamic adaptation was associated with lower placental weight (UtA PI: β = −0.502, 95% CI −0.922 to −0.082, P= 0.022; UtA RI: β = −0.435, 95% CI −0.839 to −0.032, P= 0.036). In pregnancies without placenta‐related complications, higher MAP trajectories were positively associated with birthweight centile (β = 0.398, 95% CI 0.049–0.748, P= 0.025).

Conclusions

Reduced first‐trimester maternal haemodynamic adaptation impacts both placental size and vascularisation and birthweight centile, in particular in pregnancies with placenta‐related complications.

Tweetable abstract

Reduced first‐trimester maternal haemodynamic adaptation to pregnancy impairs early placental development.

First-trimester miscarriage rate decreases with hydralazine therapy in pregnancies with early uterine vascular insufficiency: a cohort study

BACKGROUND

Miscarriage is the most frequent cause of pregnancy loss, affecting 15-20% of clinically recognized pregnancies. Early uterine vascular insufficiency (EUVI), defined as abnormal uterine artery (UA) Doppler impedance indices in early pregnancy, is present in two-thirds of pregnancies ending in miscarriage after embryonic cardiac activity has been detected. There is currently no available therapy for reducing the risk of miscarriage in these cases.

OBJECTIVE

To determine whether vasodilator therapy with hydralazine can reduce abnormally high UA impedance indices and miscarriage rates in pregnancies with EUVI when administered from before 9 weeks' gestation until completing 13 weeks' gestation.

METHODS

A total of 253 consecutive singleton pregnancies with a live embryo and scanned before 9 weeks' gestation were included in the study. Ninety-two pregnancies (36.3%) were classified as having EUVI. Hydralazine was administered in daily doses of 50 mg, starting 24-36 h after the initial diagnosis of EUVI and continuing throughout the first trimester. The miscarriage rate in the hydralazine-treated EUVI group was compared with the one observed in our previously reported untreated cohort and the pregnancies with EUVI that declined treatment with hydralazine.

RESULTS

The miscarriage rate among the hydralazine-treated EUVI group was significantly lower than the previously reported untreated cohort (7.8% versus 26.2%, p = .003; odds ratio (OR) = 4.3, 95% confidence interval (CI) = 1.6-11.9). In 15 untreated pregnancies with EUVI, the miscarriage rate was similar to that of the previously reported untreated cohort (26.7% versus 26.2%; p = .603) and higher than the hydralazine-treated group (26.7% versus 7.8%, p = .05; OR = 4.4, 95% CI = 1.1-18.2).

CONCLUSIONS

Hydralazine therapy in pregnancies with EUVI was associated with a significant decrease in the rate of miscarriage. We suggest a sequence of events leading to a higher risk of miscarriage in pregnancies with EUVI and propose a potential mechanism through which hydralazine may reduce this risk.

Comparison of uterine artery Doppler measurements at 6 weeks of pregnancy after IVF between pregnancies that resulted in miscarriage and ongoing pregnancies

OBJECTIVE

To compare uterine artery pulsatility index (UTPI) at 6 weeks of pregnancy following in vitro fertilization (IVF) and embryo transfer (ET) between clinical pregnancies that resulted in a miscarriage and those that were ongoing beyond 12 weeks.

METHODS

A prospective observational study was conducted in an IVF unit at Prince of Wales Hospital, Hong Kong, between December 1, 2017 and December 31, 2019. UTPI was measured at 6 weeks of pregnancy among women who conceived following IVF/ET.

RESULTS

Among 153 participants, 22 (14.4%) had a miscarriage whereas 131 (85.6%) had an ongoing pregnancy beyond 12 weeks. Median UTPI in pregnancies that ended in a miscarriage was significantly lower than those that progressed beyond 12 weeks (2.1, IQR 1.9-2.4 vs 2.50, IQR 2.2-2.9, respectively; P<0.001). The likelihood of the pregnancy ending in a miscarriage when the UTPI was above the 75th percentile (>2.9), between the 25th-75th percentiles (2.2-2.9), and below the 25th percentile (<2.2) was 0%, 13.2%, and 27.7%, respectively (P=0.001).

CONCLUSIONS

IVF pregnancies that resulted in a miscarriage were associated with reduced resistance to uterine artery blood flow at 6 weeks of pregnancy.

Expression and clinical significance of ATP-binding cassette transporter 1 in serum and placental tissue in Chinese patients with preeclampsia

AIM

To investigate the expression and clinical significance of ATP-binding cassette transporter 1 (ABCA1) in pregnant women with preeclampsia (PE).

METHODS

52 pregnant women with PE who were admitted for delivery were enrolled in the study, while 30 normal pregnant inpatients were chosen as controls. Blood lipid and serum ABCA1 concentrations were assayed by enzymatic analysis and ELISA, respectively, and the expression of the ABCA1 gene and its encoded protein were detected and quantified by RT-PCR and Western blotting.

RESULTS

In the study group, blood lipid levels were significantly higher than those in the control group (p < 0.01), while the ABCA1 gene and its encoded protein expression in both serum and placental tissue were lower than that of controls. These differences were highly correlated with disease severity (p < 0.05). In PE patients, serum ABCA1 concentration was positively correlated with ABCA1 protein expression in placental tissue (r = 0.384, p < 0.01) and high-density lipoprotein level (r = 0.318, p < 0.05), but negatively correlated with low-density lipoprotein level (r = -0.279, p < 0.05).

CONCLUSION

In PE women, expression of ABCA1 was decreased, suggesting that ABCA1 may play an important role in onset of PE by altering blood lipid metabolism.