Placenta of discordant twins: lack of change in histochemically detectable enzyme activities

Prediction of maternal complications and neonatal outcome in dichorionic diamniotic twins with fetal weight discordancy measured by ultrasonography

This study aimed to determine the relationship between estimated fetal weight discordance by ultrasonography and maternal and neonatal outcomes in dichorionic diamniotic twin pregnancies. We conducted a retrospective review of the medical records of 106 twin pregnancies delivered at a single tertiary center between January 2011 and February 2020. At 20–24 and 28–32 weeks of gestation, participants were divided into two groups: discordant twins with an estimated fetal weight difference of more than 20% and concordant twins with a weight difference of less than 20%. Maternal complications and neonatal outcomes were compared between the two groups. Although the incidences of preeclampsia and placenta previa were significantly higher in discordant twins measured between 20 and 24 weeks, no statistical significance was found in neonatal outcomes. Delivery times were earlier, and neonatal weights were lower in discordant twins measured between 28 and 32 weeks. Neonatal outcomes such as ventilator use and neurodevelopment were also significantly different. Discordance in estimated fetal weight measured using ultrasonography between 20 and 24 weeks can be a risk factor for maternal preeclampsia and placenta previa, whereas discordance at 28–32 weeks may predict poor neonatal outcomes.

Reduced amount of cytochrome coxidase subunit I messenger RNA in placentas from pregnancies complicated by preeclampsia

BACKGROUND

Cytochrome c oxidase is a marker enzyme of the mitochondrial inner membrane. A change in the structure and activity of cytochrome c oxidase may alter the electron transport in the inner membrane, leading to insufficient adenosine triphosphate (ATP) production. ATP is essential for maintaining the function of cells. The aim of this study was to compare the expression of cytochrome c oxidase subunit I mRNA in placentas from normal and preeclamptic pregnancies.

METHODS

By means of in situ hybridization, frozen sections of placentas from 23 women with preeclampsia and 29 women with uneventful pregnancies were examined. Digoxigenin (DIG)-labeled probes were used to detect the expression of cytochrome c oxidase subunit I mRNA in the placentas. The expression density was assessed by using an image disposal and analysis system.

RESULTS

Positive expression of cytochrome c oxidase subunit I mRNA was found in the cytoplasm of villous syncytiotrophoblasts. The mean light density of cytochrome c oxidase subunit I mRNA in placental villi of normal pregnant women was 0.2638, and 0.1763 in women with preeclampsia, a statistically significant difference (P < 0.05). The number density of cytochrome c oxidase subunit I mRNA in placental villi was also significantly reduced in preeclamptic women compared with the control group (P < 0.05).

CONCLUSIONS

Our study demonstrates a reduced amount of cytochrome c oxidase subunit I mRNA in preeclamptic placentas compared to control placentas. We hypothesize that a reduced expression may play a role in the pathophysiology of preeclampsia.