Contribution of fetal blood sampling to determining the prognosis of congenital cytomegalovirus infections: a case-cohort study in Switzerland

BACKGROUND

Cytomegalovirus is responsible for the most common congenital infection, affecting 0.5% to 1.0% of live births in Europe. Congenital cytomegalovirus infection can be diagnosed during pregnancy by viral DNA amplification in the amniotic fluid, but the prognosis of fetuses without severe brain abnormalities remains difficult to establish on the basis of prenatal imaging alone.

OBJECTIVE

To identify predictors of moderate to severe symptomatic cytomegalovirus infection among fetal blood parameters and to propose an algorithm on the basis of these parameters and on prenatal imaging that would provide the best positive and negative predictive values.

STUDY DESIGN

Fetal blood sampling at 21-28 weeks gestation was performed in fetuses with congenital cytomegalovirus infection confirmed by amniocentesis after maternal infection in the first-trimester or periconceptional period. We compared the levels of hemoglobin, thrombocytes, γ-glutamyl transpeptidase, aspartate aminotransferase, alanine aminotransferase, β2-microglobulin, immunoglobulins G and M, and cytomegalovirus DNA viral loads in amniotic fluid and fetal blood between those with moderate to severe symptomatic infection and those with asymptomatic to mild infection (median follow-up of 36 months for live births).

RESULTS

Among 58 fetuses included, 25 (43%) had a moderate to severe symptomatic infection: 16 with severe cerebral abnormalities, 5 with multiple signs or symptoms at birth, 2 with bilateral sensorineural hearing loss, and 2 with neurodevelopmental delay. The values of thrombocytes, aspartate aminotransferase, β2 microglobulin, Immunoglobulin M, and cytomegalovirus viral loads differed significantly between fetuses with moderate to severe symptomatic infection and those with asymptomatic to mild infection. The optimal strategy to predict moderate to severe symptomatic infection was to first perform fetal brain imaging, followed by fetal blood sampling with the following cutoffs: thrombocytes <120,000/mL, viremia ≥5 log10/mL, and β2 microglobulin ≥12 mg/L). This recursive algorithm had a negative predictive value of 100% for moderately to severely symptomatic infection.

CONCLUSION

The combination of thrombocytes, β2-microglobulin, and cytomegalovirus viral load in fetal blood can be used for prognosis determination, particularly in cytomegalovirus-infected fetuses without severe brain abnormalities at the time of prenatal diagnosis. Future studies should evaluate whether these parameters remain useful in infected fetuses who have been treated with valacyclovir before fetal blood sampling.

[First trimester ultrasound: beyond nuchal translucency]

Pregnancy care has gradually evolved over the last two decades, with a trend towards earlier detection and diagnosis of both maternal and fetal pathologies. At the core of this process, antenatal ultrasound allows to identify a large number of congenital malformations as early as the end of the first trimester. It has also become an increasingly specialized procedure, requiring considerable material and human resources. In this article, we review the basic principles of first-trimester ultrasound, focusing on most recent screening recommendations.

Impact of the first wave of the COVID-19 pandemic on birth rates in Europe: a time series analysis in 24 countries

STUDY QUESTION

Did the first wave of the COVID-19 pandemic have an impact on monthly birth rates in Europe?

SUMMARY ANSWER

Using datasets on live births per month in Europe, collected from the Human Fertility Database, we found a -14.1% decline in live births in January 2021 (i.e. 9-10 months after the epidemic peaks and first lockdowns), compared to the average number of live births in January 2018 and 2019.

WHAT IS KNOWN ALREADY

Previous pandemics in the 20th and 21st centuries have been associated with a decline in birth rates 9 months after their peak, and a rebound in births over time. Lockdowns were necessary to control the first wave of the COVID-19 pandemic and may have had an impact on subsequent birth rates.

STUDY DESIGN, SIZE, DURATION

Monthly time series data on live births from January 2018 to March 2021 were extracted to provide a time-series analysis of birthrates during and after the first wave of the COVID-19 pandemic in 24 European countries.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We conducted a random-effect generalized least squares regression to assess the seasonality of births from January 2018 to March 2021, and to identify potential differences in monthly live births after the first wave of the COVID-19 pandemic, considering the seasonality of births. To quantify these potential differences, we estimated the variation rate between the monthly live births observed during 2020 and 2021 and the mean of the 2018-2019 monthly live births in Europe. Factors potentially associated with a variation in monthly birth rates were assessed using univariable and multivariable generalized linear regressions.

MAIN RESULTS AND THE ROLE OF CHANCE

When considering the seasonality of births, January 2021 was the only month with a significant difference in live births. A drop of -14.1% was observed compared to the average number of live births in January 2018 and 2019. At the national level, this drop was observed 9-10 months after the epidemic peaks in 13 countries. The duration of lockdowns was the variable that had the stronger association with this decrease, whereas higher incomes per capita could be a factor limiting this decline. A rebound in births compared to the previous years occurred in March 2021 in 13 countries.

LIMITATIONS, REASONS FOR CAUTION

Our data are based on national data, limiting the power in the multivariable models used and the identification of other potential factors contributing to a decrease or an increase in birth rates. In addition, we collected only live births up to April 2021, which precludes the identification of a difference in births seasonality in 2021.

WIDER IMPLICATIONS OF THE FINDINGS

As with previous pandemics, the COVID-19 outbreak was associated with a decline in births 9 months after its first wave. This trend may be associated with the duration of the lockdowns. Although there was a rebound in births in the following months, it does not seem to compensate for this decline.

STUDY FUNDING/COMPETING INTEREST(S)

The authors receive no external funding and have no conflict of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.