SARS-CoV-2 Infection in Pregnancy: Placental Histomorphological Patterns, Disease Severity and Perinatal Outcomes

Controversies in chronic histiocytic intervillositis

Understanding the"paradox" of pregnancy remains a challenging field of investigation especially when immunological dysregulation is suspected in pathological pregnancies. Chronic histiocytic intervillositis (CHI) is an example of a rare placental inflammatory disease that can occur during any trimester of pregnancy. The pathogenesis of CHI involves an abnormal immune response characterized by an inflammatory infiltrate of maternal CD68+ mononuclear immune cells in the intervillous space. CHI may be associated with villous and intervillous fibrinoid deposits. The precise immunological mechanism is not yet fully understood; it probably relies on an allo-immune of graft rejection rather than an auto-immune mechanism, although it has been described in several autoimmune diseases. CHI has also been described in COVID19 infected pregnant women. The recurrence rate is high and complications are severe: CHI is strongly associated with fetal growth restriction, miscarriage and stillbirth. The management of these patients remains an issue lacking of -standardized guidelines. The aim of this narrative review is to focus on the knowledge, pathogenesis, diagnosis and treatment of CHI over the last 5 years.

Placenta a potential gateway of prenatal SARS-CoV-2 infection: A review

SARS-CoV-2, the causative agent of COVID-19, can infect various tissues in the body apart from the lungs. Although placental infection remains controversial, COVID-19-associated placental abnormalities have been reported worldwide. Therefore, COVID-19 poses a significant risk for fetal distress as well. Scientists are currently debating whether such distress results from direct viral induced assault or placental damage caused by the mother's immune response. The placenta develops different histopathological lesions in response to maternal SARS-CoV-2 infection. While some studies support both theories, the transmission rate through the placenta remains low. Therefore, a more in-depth study is necessary to determine the primary cause of maternal SARS-CoV-2-induced fetal distress. This comprehensive review is aimed to shed light on the possible reasons towards fetal distress among mothers with COVID-19. This review describes the various mechanisms of viral entry along with the mechanisms by which the virus could affect the placenta. Reported cases of placental abnormalities and fetal distress symptoms have been collated to provide an overview of the current state of knowledge on vertical transmission of COVID-19.

Evaluation of the effect of SARS-CoV-2 infection on Doppler ultrasound and placental findings of pregnant women: a systematic review and meta-analysis

PURPOSE

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can infect the human placenta and has been shown to have an adverse effect on Doppler ultrasound parameters and placental features. However, the specific effects of the SAS-CoV-2 infection on the fetal-placental unit in pregnant women remain unclear. The aim of this systematic review and meta-analysis was to evaluate the impact of SARS-CoV-2 infection on Doppler ultrasound and placental findings in pregnant women.

METHODS

A systematic search was conducted using four electronic databases (PubMed, Embase, Scopus, and Cochrane Library) to select publications published in peer-reviewed journals written in English. Odds ratios (ORs) were calculated, along with their 95% confidence intervals (CIs). Heterogeneity was assessed using Cochrane Q and I2 statistics and the appropriate P-value. The analysis used RevMan 5.3.

RESULTS

This meta-analysis included 1,210 pregnant women from 10 case-control studies. SARS-CoV-2-infected pregnant women exhibited higher likelihoods of placental abnormalities (OR, 2.62; 95% CI, 1.66 to 4.13), aberrant Doppler values (OR, 1.95; 95% CI, 1.16 to 3.27), an abnormal cerebroplacental ratio (OR, 2.68; 95% CI, 1.52 to 4.75), altered fetoplacental circulation (OR, 1.56; 95% CI, 1.07 to 2.28), and increased placental thickness and placental venous lakes (OR, 1.85; 95% CI, 1.25 to 2.72).

CONCLUSION

According to this meta-analysis, pregnant women infected with SARS-CoV-2 are more likely to experience altered Doppler ultrasonography parameters and placental abnormalities, including increased placental thickness, placental venous lakes, altered fetoplacental circulation, and cerebroplacental ratio. However, the limited number of case-control studies requires larger sample sizes to validate and enhance the evidence.

Maternal and neonatal outcomes in women with COVID-19: A retrospective cohort study

Background

Considering the conflicting evidence that exists regarding the effect of the coronavirus disease 2019 (COVID-19) on pregnancy and newborn outcomes, it is necessary to conduct this research during the first year in the north of Iran, a highly visited and trafficked place, which increases the possibility of contracting the virus and severity of the infection.

Objective

This study aimed to compare maternal and neonatal outcomes in pregnant women with and without COVID-19.

Materials and Methods

In this retrospective cohort study, data from 160 pregnant women referred to 3 hospitals in Mazandaran, Iran from April 2020 to March 2021 were extracted from their medical records using checklists. Participants were divided into 2 groups: group A) 80 pregnant women with COVID-19 and group B) 80 noninfected pregnant women. All information related to maternal and neonatal outcomes were extracted and compared from the files of the 2 groups. The results obtained from comparing 2 groups of pregnant women from the result of the reverse-transcription polymerase chain reaction test were analyzed.

Results

The most common symptoms in the COVID-19 group were fever and cough. Pregnancy complications such as abortion, pre-eclampsia, and premature birth were not significant between groups (p = 0.4, 0.45, 0.45, respectively). No statistically significant difference was observed between groups regarding maternal and neonatal outcomes.

Conclusion

Despite the peak and severity of the COVID-19 disease in the first year of the pandemic, it seems that it had no effect on maternal and neonatal outcomes in each trimester of pregnancy in affected women.

Safety and Efficacy of Antiviral Drugs and Vaccines in Pregnant Women: Insights from Physiologically Based Pharmacokinetic Modeling and Integration of Viral Infection Dynamics

Addressing the complexities of managing viral infections during pregnancy is essential for informed medical decision-making. This comprehensive review delves into the management of key viral infections impacting pregnant women, namely Human Immunodeficiency Virus (HIV), Hepatitis B Virus/Hepatitis C Virus (HBV/HCV), Influenza, Cytomegalovirus (CMV), and SARS-CoV-2 (COVID-19). We evaluate the safety and efficacy profiles of antiviral treatments for each infection, while also exploring innovative avenues such as gene vaccines and their potential in mitigating viral threats during pregnancy. Additionally, the review examines strategies to overcome challenges, encompassing prophylactic and therapeutic vaccine research, regulatory considerations, and safety protocols. Utilizing advanced methodologies, including PBPK modeling, machine learning, artificial intelligence, and causal inference, we can amplify our comprehension and decision-making capabilities in this intricate domain. This narrative review aims to shed light on diverse approaches and ongoing advancements, this review aims to foster progress in antiviral therapy for pregnant women, improving maternal and fetal health outcomes.

Non-hypertensive gestational diabetes mellitus: Placental histomorphology and its association with perinatal outcomes

INTRODUCTION

Gestational diabetes mellitus (GDM) exerts a great impact on the placenta and reflects changes on placentas both morphological and functionally. The aims of this study are to evaluate the prevalence of placental histopathological lesions in pregnancies complicated by GDM compared to gestational age-matched controls, and their association with maternal and fetal complications.

METHODS

Fifty-four singleton GDM-complicated pregnancies were recruited and compared to 33 consecutive normal pregnancies. Two pathologists, blinded to all clinical data, reviewed and evaluated all histological samples of the placentas in accordance with Amsterdam criteria. Relevant demographic, clinical data and primary birth outcomes were recorded.

RESULTS

A myriad of histomorphological abnormalities, including chronic inflammation (n = 9/54, p = 0.031), histological chorioamnionitis (n = 23/54, p < 0.001), umbilical/chorionic vasculitis (n = 9/54, p = 0.031), changes related to maternal vascular malperfusion (n = 22/54, p = 0.003), chorangiosis (n = 10/54, p = 0.046) and villous dysmaturity (n = 9/54, p = 0.012) were observed more frequently in the GDM placentas compared to the controls. Additionally, GDM significantly increased the risk of fetal complications, including macrosomia/fetal growth restriction (n = 13/54, p = 0.004).

DISCUSSION

Histoarchitectural abnormalities were observed more frequently in placentas of GDM pregnancies compared to the controls. Our findings support the hypothesis that diabetic-induced damage in the placental function may be associated with the increased in fetal growth disorders in GDM-complicated pregnancies.

The impact of gestational weeks of Coronavirus disease 2019 (COVID-19) infection on perinatal outcomes

BACKGROUND

To evaluate the relationship between coronavirus disease 2019 (COVID-19) infection at different time points during pregnancy and perinatal outcomes.

METHODS

This retrospective study included 611 women who hospitalized for delivery between December 7 and April 30, 2023. Based on the different pregnancy weeks infected with COVID-19, the participants were divided into four groups: Group 1 (14-27+6 weeks gestation), Group 2 (28-36+6 weeks gestation), Group 3 (37-39+6 weeks gestation), and Group 4 (≥ 40 weeks gestation). Data including maternal demographic characteristics, clinical profiles, and perinatal outcomes were analyzed.

RESULTS

There were no significant differences in maternal demographic characteristics among the four groups (P > 0.05). Compared to Groups 3 and 4, a higher rate of fever was noted in Groups 1 and 2 (P < 0.05). The frequency of preeclampsia and gestational diabetes mellitus showed a decreasing trend as pregnancy progressing (P < 0.05). Preterm delivery and neonatal intensive care unit admission were more frequently observed in Groups 1 and 2 than in Groups 3 and 4 (P < 0.05). Multivariate logistic regression analysis demonstrated that the timing of gestation in which COVID-19 was infected was not associated with preterm delivery and neonatal intensive care unit admission (P > 0.05), whereas gestational age at COVID-19 infection was negatively associated with the occurrence of preeclampsia and gestational diabetes mellitus (P < 0.05).

CONCLUSIONS

Gestational age at COVID-19 infection is a simple parameter that predicts adverse perinatal outcomes to aid clinicians in determining to provide early enhanced prenatal care and increased monitoring to reduce maternal complications.

SARS-CoV-2-Placental effects and association with stillbirth

SARS-CoV-2 has had a significant impact on pregnancy outcomes due to the effects of the virus and the altered healthcare environment. Stillbirth has been relatively hidden during the COVID-19 pandemic, but a clear link between SARS-CoV-2 and poor fetal outcome emerged in the Alpha and Delta waves. A small minority of women/birthing people who contracted COVID-19 developed SARS-CoV-2 placentitis. In many reported cases this was linked to intrauterine fetal death, although there are cases of delivery just before imminent fetal demise and we shall discuss how some cases are sub-clinical. What is surprising, is that SARS-CoV-2 placentitis is often not associated with severe maternal COVID-19 infection and this makes it difficult to predict. The worst outcomes seem to be with diffuse placental disease which occurs within 21 days of COVID-19 diagnosis. Poor outcomes are often pre-dated by reduced fetal movements but are not associated with ultrasound changes. In some cases, there has also been maternal thrombocytopenia, or coagulation abnormalities, which may provide a clue as to which pregnancies are at risk of fetal demise if a further variant of concern is to emerge. In future, multidisciplinary collaboration and cross-boundary working must be prioritised, to identify quickly such a phenomenon and provide clinicians with clear guidance for reducing fetal death and associated poor outcomes. While we wait to see if COVID-19 brings a future variant of concern, we must focus on appropriate future management of women who have had SARS-CoV-2 placentitis. As a placental condition with an infectious aetiology, SARS-CoV-placentitis is unlikely to recur in a subsequent pregnancy and thus a measured approach to subsequent pregnancy management is needed.

An Update on COVID-19-Associated Placental Pathologies

COVID-19 pregnancies are associated with increased rates of premature delivery and stillbirths. It is still a matter of debate whether there is a COVID-19-associated pattern of placenta pathology. We updated our previously published results on a systematic literature review and meta-analysis of COVID-19 pregnancies. In total, 38 reports on 3677 placentas were evaluated regarding histopathological changes. Maternal vascular malperfusion (32%), fetal vascular malperfusion (19%), acute and chronic inflammation (20% and 22%) were frequent pathologies. In non-COVID-19 pregnancies, placentas show similar histologic patterns and mainly similar frequencies of manifestation. It has to be taken into account that there might be an observation bias, because some findings are diagnosed as a "pathology" that might have been classified as minor or unspecific findings in non-COVID-19 placentas. COVID-19 placentitis occurs in 1-2% of cases at the most. In conclusion, this updated meta-analysis indicates that COVID-19 infection during pregnancy does not result in an increased rate of a specific placenta pathology and COVID-19 placentitis is rare.

Mild/asymptomatic COVID-19 in unvaccinated pregnant mothers impairs neonatal immune responses

Maternal SARS-CoV-2 infection triggers placental inflammation and alters cord blood immune cell composition. However, most studies focus on outcomes of severe maternal infection. Therefore, we analyzed cord blood and chorionic villi from newborns of unvaccinated mothers who experienced mild/asymptomatic SARS-CoV-2 infection during pregnancy. We investigated immune cell rewiring using flow cytometry, single-cell RNA sequencing, and functional readouts using ex vivo stimulation with TLR agonists and pathogens. Maternal infection was associated with increased frequency of memory T and B cells and nonclassical monocytes in cord blood. Ex vivo T and B cell responses to stimulation were attenuated, suggesting a tolerogenic state. Maladaptive responses were also observed in cord blood monocytes, where antiviral responses were dampened but responses to bacterial TLRs were increased. Maternal infection was also associated with expansion and activation of placental Hofbauer cells, secreting elevated levels of myeloid cell-recruiting chemokines. Moreover, we reported increased activation of maternally derived monocytes/macrophages in the fetal placenta that were transcriptionally primed for antiviral responses. Our data indicate that even in the absence of vertical transmission or symptoms in the neonate, mild/asymptomatic maternal COVID-19 altered the transcriptional and functional state in fetal immune cells in circulation and in the placenta.

Exploring the impact of COVID-19 on reported maternal and neonatal complications and access to maternal health care in five government health facilities in Blantyre, Malawi

BACKGROUND

There is a dearth of studies assessing the effects of SARS-CoV-2 on the healthcare system and access to care, especially in lower- and middle-income countries such as Malawi. We aimed to assess the impacts of COVID-19 on reported maternal and neonatal complications as well as potential changes in maternal care access to care among five primary care health facilities in Blantyre, Malawi.

METHODS

This retrospective cohort study assessed maternal and neonatal register data from five participating health centers in Blantyre, Malawi using the Malawi District Health Information Software 2 (DHIS2) to compare outcomes from 15 months before COVID-19 emerged, defined as the pre-Covid period (January 2019 -March 2020) with nine months after COVID-19 (April 2020 -December 2020).

RESULTS

There was a significant decrease in reported use of vacuum extraction, which went from <0.01%in the pre-COVID period to 0% in the COVID period (p = 0.01). The proportion of births reporting fetal distress almost tripled from 0.46% to 1.36% (p = 0.001) during the COVID-19 period. Additionally, reported anticonvulsant use significantly increased from 0.01% to 1.2% (p<0.01), and antibiotic use significantly increased from 0.45% to 1.6% (p = 0.01). Asphyxia was the only significant neonatal complication variable reported, increasing from 2.80% to 3.45% (p = 0.01).

CONCLUSION

Our findings suggest that significant outcomes were mainly due to the indirect effects of COVID-19 rather than the virus itself. Based on our findings and the contextual qualitative interviews with two Malawian expert midwives, we concluded that mothers may have been affected more due to understaffing and shortage of skilled personnel in the study health facilities. Therefore, the development of highly skilled health workers may contribute to better outcomes, along with adequate staffing and a streamlined referral process.

Mild/Asymptomatic Maternal SARS-CoV-2 Infection Leads to Immune Paralysis in Fetal Circulation and Immune Dysregulation in Fetal-Placental Tissues

Few studies have addressed the impact of maternal mild/asymptomatic SARS-CoV-2 infection on the developing neonatal immune system. In this study, we analyzed umbilical cord blood and placental chorionic villi from newborns of unvaccinated mothers with mild/asymptomatic SARSCoV-2 infection during pregnancy using flow cytometry, single-cell transcriptomics, and functional assays. Despite the lack of vertical transmission, levels of inflammatory mediators were altered in cord blood. Maternal infection was also associated with increased memory T, B cells, and non-classical monocytes as well as increased activation. However, ex vivo responses to stimulation were attenuated. Finally, within the placental villi, we report an expansion of fetal Hofbauer cells and infiltrating maternal macrophages and rewiring towards a heightened inflammatory state. In contrast to cord blood monocytes, placental myeloid cells were primed for heightened antiviral responses. Taken together, this study highlights dysregulated fetal immune cell responses in response to mild maternal SARS-CoV-2 infection during pregnancy.

Impact of COVID-19 during pregnancy on placental pathology, maternal and neonatal outcome - A cross-sectional study on anemic term pregnant women from a tertiary care hospital in southern India

Background

SARS-CoV-2 infection during pregnancy may cause adverse maternal, neonatal and placental outcomes. While tissue hypoxia is often reported in COVID-19 patients, pregnant women with anemia are suspected to be more prone to placental hypoxia-related injuries.

Methods

This hospital-based cross-sectional study was conducted between August-November 2021, during COVID-19 second wave in India. Term pregnant women (N=212) admitted to hospital for delivery were enrolled consecutively. Since hospital admission mandated negative RT-PCR test for SARS-CoV-2 virus, none had active infection. Data on socio-demography, COVID-19 history, maternal, obstetric, and neonatal outcomes were recorded. Pre-delivery maternal and post-delivery cord blood samples were tested for hematological parameters and SARS-CoV-2 IgG. Placentae were studied for histology.

Results

Of 212 women, 122 (58%) were seropositive for SARS-CoV-2 IgG, but none reported COVID-19 history; 134 (63.2%) were anemic. In seropositive women, hemoglobin (p=0.04), total WBC (p=0.009), lymphocytes (p=0.005) and neutrophils (p=0.02) were significantly higher, while ferritin was high, but not significant and neutrophils to lymphocytes (p=0.12) and platelets to lymphocytes ratios (p=0.03) were lower. Neonatal outcomes were similar. All RBC parameters and serum ferritin were significantly lower in anemic mothers but not in cord blood, except RDW that was significantly higher in both, maternal (p=0.007) and cord (p=0.008) blood from seropositive anemic group compared to other groups. Placental histology showed significant increase in villous hypervascularity (p=0.000), dilated villous capillaries (p=0.000), and syncytiotrophoblasts (p=0.02) in seropositive group, typically suggesting placental hypoxia. Maternal anemia was not associated with any histological parameters. Univariate and multivariate logistic regression analyses of placental histopathological adverse outcomes showed strong association with SARS-CoV-2 seropositivity but not with maternal anemia. When adjusted for several covariates, including anemia, SARS-CoV-2 seropositivity emerged as independent risk factor for severe chorangiosis (AOR 8.74, 95% CI 3.51-21.76, p<0.000), dilated blood vessels (AOR 12.74, 95% CI 5.46-29.75, p<0.000), syncytiotrophoblasts (AOR 2.86, 95% CI 1.36-5.99, p=0.005) and villus agglutination (AOR 9.27, 95% CI 3.68-23.32, p<0.000).

Conclusion

Asymptomatic COVID-19 during pregnancy seemed to be associated with various abnormal placental histopathologic changes related to placental hypoxia independent of maternal anemia status. Our data supports an independent role of SARS-CoV-2 in causing placental hypoxia in pregnant women.

Sialylation status in placentas from pregnancies with SARS-CoV-2 infection

INTRODUCTION

Recent investigations suggest the potential negative impact of SARS-CoV-2 infection on pregnant women and pregnancy outcome. In addition, some studies have described pathological changes in the placental tissue of SARS-CoV-2-positive mothers, which are related or not to the infection severity and/or infection trimester. Among the various molecules involved in the normal structure and functionality of the placenta, sialic acids (Sias) seem to play an important role. Hence, we aimed to investigate possible changes in the distribution and content of Sias with different glycosidic linkages, namely α2,3 and α2,6 Galactose- or N-acetyl-Galactosamine-linked Sias and polymeric Sia (PolySia), in placentas from pregnant women infected by SARS-CoV-2 during the three different pregnancy trimesters.

METHODS

α2,3 and α2,6 Galactose-linked Sias were evaluated by lectin histochemistry (Maackia amurensis agglutinin (MAA) and Sambucus nigra agglutinin (SNA), respectively), while immunohistochemistry was used for PolySia detection.

RESULTS

Data showed lower levels of α2,3 Galactose-linked Sias in the trophoblast and underlying basement membrane/basal plasma membrane in placentas from women infected during the second and third infection trimester compared with uninfected cases and those infected during first trimester. On the other hand, higher levels of PolySia were detected in the trophoblast during the second and third infection trimester.

CONCLUSIONS

Our findings suggest that changes in the sialylation status of trophoblast and its basement membrane/basal plasma membrane, together with other concomitant factors, could be at the basis of the most common placental histopathological alterations and gestational complications found especially in pregnancies with SARS-CoV-2 infection during the second and third trimester.

SARS-CoV-2 Transplacental Transmission: A Rare Occurrence? An Overview of the Protective Role of the Placenta

The outbreak of the coronavirus disease 2019 (COVID-19) pandemic, caused by novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in a global public health crisis, causing substantial concern especially to the pregnant population. Pregnant women infected with SARS-CoV-2 are at greater risk of devastating pregnancy complications such as premature delivery and stillbirth. Irrespective of the emerging reported cases of neonatal COVID-19, reassuringly, confirmatory evidence of vertical transmission is still lacking. The protective role of the placenta in limiting in utero spread of virus to the developing fetus is intriguing. The short- and long-term impact of maternal COVID-19 infection in the newborn remains an unresolved question. In this review, we explore the recent evidence of SARS-CoV-2 vertical transmission, cell-entry pathways, placental responses towards SARS-CoV-2 infection, and its potential effects on the offspring. We further discuss how the placenta serves as a defensive front against SARS-CoV-2 by exerting various cellular and molecular defense pathways. A better understanding of the placental barrier, immune defense, and modulation strategies involved in restricting transplacental transmission may provide valuable insights for future development of antiviral and immunomodulatory therapies to improve pregnancy outcomes.

Changing Laboratory Practice for Early Detection of a Fetal Inflammatory Response: A Contemporary Approach

Neonates born with the fetal inflammatory response (FIR) are at risk of complications such as early-onset neonatal sepsis, meningitis, and pneumonia. Providing an early histopathological diagnosis of FIR is important to guide management but can be a challenge in busy laboratories. This is a retrospective cross-sectional study over a four-month duration recruiting all placental cases with histological chorioamnionitis in our institution. The diagnostic performance of the umbilical cord (UC) section in identifying FIR, relative to the corresponding subsequent placental sections, was assessed. Clinical predictors of umbilical cord FIR were also investigated. A total of 390 UC sections were analyzed, of which 206 (52.8%) were found positive for FIR: 111 cases (53.9%) stage 1, 87 (42.2%) stage 2, and 8 (3.9%) stage 3. Our data revealed a good diagnostic sensitivity, specificity, positive predictive value, and accuracy of 76.2% (95%CI: 68.6-82.7%), 82.4% (95%CI: 65.5-93.2%), 95.0% (95%CI: 90.2-97.6%), and 77.3% (95%CI: 70.6-83.1%) respectively, in cases when clinical chorioamnionitis, fever and/or prolonged rupture of membrane (PROM) were suspected, with the area under the curve of 0.793. A maternal inflammatory response (MIR) was correlated with FIR (p < 0.001). Multivariate logistic regression analysis indicated that the higher the gestational age, clinical suspicion of chorioamnionitis, fever, and/or PROM, and the higher the stage of MIR significantly increased the odds of FIR (p < 0.001). UC section diagnosis of FIR is reasonably accurate in cases with clinical chorioamnionitis, fever, and/or PROM. Changing current laboratory practice to rapid processing of UC ahead of the rest of the other placental sections can be recommended in busy pathology departments.

Clinical Manifestation and Obstetric Outcomes in Pregnant Women with SARS-CoV-2 Infection at Delivery: A Retrospective Cohort Analysis

This retrospective cohort study aimed to analyze the clinical manifestations, complications, and maternal-fetal outcomes in patients affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during delivery. The cohort included 61 pregnant women positive for SARS-CoV-2 infection at the time of delivery. Patients were divided into two groups: symptomatic and asymptomatic. We found a significantly higher rate of leukocytosis (p < 0.00078) and lymphopenia (p < 0.0024) in symptomatic women compared with asymptomatic ones. Other laboratory parameters, such as CRP (p = 0.002), AST (p = 0.007), LDH (p = 0.0142), ferritin (p = 0.0036), and D-dimer (p = 0.00124), were also significantly more often increased in the group of symptomatic pregnant women. Overall, symptomatic pregnant women with SARS-CoV-2 infection at the delivery show more often altered laboratory parameters compared with asymptomatic ones; nevertheless, they have a slightly higher but non-significant rate of preterm delivery, cesarean section, as well as lower neonatal birth weight and Apgar score, compared with asymptomatic women.