Placental cytomegalovirus infection without fetal involvement following primary infection in pregnancy

Oral hexadecyloxypropyl-cidofovir therapy in pregnant guinea pigs improves outcome in the congenital model of cytomegalovirus infection

Cytomegalovirus (CMV) infection is the leading cause of congenital infection, producing both sensorineural hearing loss and mental retardation. We evaluated the in vivo efficacy of an orally bioavailable analog of cidofovir, hexadecyloxypropyl-cidofovir (HDP-CDV), against guinea pig CMV (GPCMV) in a guinea pig model of congenital CMV infection. HDP-CDV exhibited antiviral activity against GPCMV with a 50% effective concentration (EC(50)) of 0.004 μM ± 0.001 μM. To evaluate in vivo efficacy, pregnant Hartley guinea pigs were inoculated with GPCMV during the late second/early third trimester of gestation. Animals were administered 20 mg HDP-CDV/kg body weight orally at 24 h postinfection (hpi) and again at 7 days postinfection (dpi) or administered 4 mg/kg HDP-CDV orally each day for 5 days or 9 days. Virus levels in dam and pup tissues were evaluated following delivery, or levels from dam, placenta, and fetal tissues were evaluated following sacrifice of dams at 10 dpi. All HDP-CDV regimens significantly improved pup survival, from 50 to 60% in control animals to 93 to 100% in treated animals (P ≤ 0.019). Treatment with 20 mg/kg HDP-CDV significantly reduced the viral load in pup spleen (P = 0.017) and liver (P = 0.029). Virus levels in the placenta were significantly reduced at 10 dpi following daily treatment with 4 mg/kg HDP-CDV for 5 or 9 days. The 9-day treatment also significantly reduced the viral levels in the dam spleen and liver. Although the 4-mg/kg treatment improved pup survival, virus levels in the fetal tissues were similar to those in control tissues. Taken together, HDP-CDV shows potential as a well-tolerated antiviral candidate for treatment of congenital human CMV (HCMV) infection.

Pathology of the placenta and cord in ascending and in haematogenous infection

The two main patterns of inflammatory response in the placenta and its adnexae are: (1) amniotic infection, usually bacterial ascending, with acute chorioamnionitis and funisitis; (2) haematogenous villitis, usually viral, with early necrotizing lesions and vasculitis and, later, chronic infiltrates and obliterative vasculitis. In amniotic infection most cells in the exudate are maternal. These leucocytes participate in antibacterial defence of the amniotic cavity in conjunction with substances such as zinc polypeptide and lysozyme and may contribute directly to fetal defence. Immunoglobulins may be produced in the cord of placenta only in protracted lesions such as 'healed' funisitis. Individual variations in the resistance of the membranes to bacterial penetration are possible. In viral infections a massive multifocal production by plasmacytes of immunoglobulins M, G and A is seen in affected villi. The secretion of non-specific antiviral substances in the infected placenta is possible. In all affected villi there is an activation of fixed macrophages (Hofbauer cells) that remain partly 'immature', i.e. are lysozyme-negative. Multifocal lymphoplasmacytic villitis is uncommon and has helped to focus the diagnosis on prenatal infection. In contrast, non-specific lymphocytic villitis is common; since there is no morphological difference between cases known to be associated with an infection, e.g. varicella, and the others, many cases may well be due to silent infection, although a graft-versus-host reactions remains a distinct possibility.

Cytomegalovirus and the role of interferon in the expression of tumor necrosis factor-related apoptosis-inducing ligand in the placenta

OBJECTIVE

Cytomegalovirus infection causes adverse outcomes during pregnancy. Our objective was to determine the role of cytomegalovirus in modulating tumor necrosis factor (TNF)-related apoptosis-inducing ligand expression in the placenta.

STUDY DESIGN

TNF-related apoptosis-inducing ligand messenger RNA and protein were quantified in cytomegalovirus-infected placental fibroblasts by polymerase chain reaction and enzyme-linked immunosorbent assays, respectively. Blocking antibodies against interferon and type I interferon receptor were applied to culture medium to characterize the role of type I interferon in cytomegalovirus-induced TNF-related apoptosis-inducing ligand upregulation.

RESULTS

Expression of TNF-related apoptosis-inducing ligand messenger RNA and protein was increased in cytomegalovirus-infected placental fibroblasts, compared with uninfected controls. The cytomegalovirus-induced TNF-related apoptosis-inducing ligand messenger RNA upregulation was demonstrated across gestation, occurred in the absence of viral gene expression, and required cellular protein synthesis. TNF-related apoptosis-inducing ligand messenger RNA upregulation was markedly attenuated by inactivation of either type I interferon or its receptor.

CONCLUSION

One mechanism by which cytomegalovirus infection causes unfavorable pregnancy outcomes may involve placental upregulation of TNF-related apoptosis-inducing ligand via an interferon-mediated pathway.

Correlates of placental infection with cytomegalovirus, parvovirus B19 or human herpes virus 7

Vertical transmission of viruses is an important cause of morbidity in the fetus and neonate. Placental viral infection indicates risk of vertical transmission, but not always transmission to, or disease of the fetus. Specimens from mothers and babies from three groups-two prospective and one retrospective cohort-were tested for pathogens of teratogenic potential using multiplex PCR. Placental infection was present in 13% of the 105 samples collected. Assessment of the prospective cohorts showed cytomegalovirus (CMV) detected in 4% of placentae from unselected women, parvovirus B19 in 1% and Ureaplasma parvum in 1% of placentae. In a retrospective cohort of women at high risk of transmitting congenital infection due to seroconversion during pregnancy, miscarriage or stillbirth, CMV was detected in 64% and human herpes virus type 7 in 9% of placentae. Of 14 PCR-positive placentae, two were associated with the birth of a living symptomatic infant, two with stillbirth, one with miscarriage, and two with elective terminations of pregnancy. Directed laboratory assessment of women at high risk of transmitting congenital infection, on the basis of clinical or laboratory markers, is important for accurate diagnosis of adverse outcomes of pregnancy. However, routine screening for viruses in the placentae from women with a low-risk serological profile for transmitting congenital infection is unlikely to result in significant numbers of additional diagnoses and is confounded by inadequacy of current diagnostic methods. The major pathogen detected in all cases of placental infection associated with fetal death was human CMV.

Human Cytomegalovirus-Induced Inhibition of Cytotrophoblast Invasion in a First Trimester Extravillous Cytotrophoblast Cell Line

Human cytomegalovirus (HCMV) is the leading cause of congenital viral infection in the United States and intrauterine transmission of HCMV occurs in approximately 40% of pregnant women with primary HCMV infection. Although HCMV infection during pregnancy clearly may be detrimental to fetal development, its consequences on placentation remain largely unexplored. In this study, the effects of HCMV infection on cytotrophoblast (CTB) invasion were investigated utilizing the first trimester extravillous CTB cell line SGHPL-4. HCMV infection significantly inhibited SGHPL-4 proliferation, epidermal growth factor (EGF)- and hepatocyte growth factor (HGF)-induced migration and invasion, as well as the secretion of matrix metalloproteinase (MMP)-2 and MMP-9. Both HCMV and EGF activated the EGF receptor (EGFR), inducing receptor tyrosine phosphorylation at specific residues. Of interest, EGFR was differentially activated by HCMV, and viral gene transcription was not required for the observed inhibitory effect on CTB invasiveness. These findings demonstrate that HCMV infection impairs CTB differentiation along the invasive pathway and that the differential regulation of EGFR by HCMV may contribute to impaired CTB function. Elucidating the mechanisms by which HCMV impairs placentation may be key in understanding fetal and maternal pathologies associated with intrauterine HCMV infection.

Comparison of cytomegalovirus polymerase chain reaction and serology for screening umbilical cord blood components

BACKGROUND

Recipients of umbilical cord blood (UCB) transplants are susceptible to opportunistic infections, including cytomegalovirus (CMV). To prevent CMV transmission from UCB donors, most laboratories perform serology on corresponding maternal samples and quarantine units when the mother has immunoglobulin M (IgM) anti-CMV.

STUDY DESIGN AND METHODS

UCB units and associated samples (UCB plasma and red cell pellet; maternal whole blood and serum) from two cord blood banks were tested with two validated CMV polymerase chain reaction assays (UL54 and UL93 targets). Results were compared with maternal CMV serology (IgG and IgM).

RESULTS

Only 4 of 48 (8.3%) quarantined CMV IgM-positive units were also CMV nucleic acid testing (NAT)-positive (651-68,600 copies/mL). In contrast, 1 of 200 "CMV-safe" UCB units (CMV IgM-equivocal or -negative) had CMV DNA (0.5%). The corresponding maternal samples were CMV NAT-negative. Positive maternal IgM serology demonstrates only modest sensitivity (80%) and specificity (82%) and poor positive predictive value (8%), when correlated with the presence of CMV DNA in UCB units.

CONCLUSION

CMV NAT may be a useful adjunct to serologic screening, potentially reducing wastage of IgM-positive and NAT-negative units while also detecting potentially infectious units that would pass serologic screening. A prospective clinical trial to further evaluate the role of CMV NAT in UCB transplantation appears warranted.

Permissive human cytomegalovirus infection of a first trimester extravillous cytotrophoblast cell line

Human cytomegalovirus (HCMV) is the leading cause of congenital viral infection in the United States and Europe. Despite the significant morbidity associated with prenatal HCMV infection, little is known about how the virus infects the fetus during pregnancy. To date, primary human cytotrophoblasts (CTBs) have been utilized to study placental HCMV infection and replication; however, the minimal mitotic potential of these cells restricts experimentation to a few days, which may be problematic for mechanistic studies of the slow-replicating virus. The aim of this study was to determine whether the human first trimester CTB cell line SGHPL-4 was permissive for HCMV infection and therefore could overcome such limitations. HCMV immediate early (IE) protein expression was detected as early as 3 hours post-infection in SGHPL-4 cells and progressively increased as a function of time. HCMV growth assays revealed the presence of infectious virus in both cell lysates and culture supernatants, indicating that viral replication and the release of progeny virus occurred. Compared to human fibroblasts, viral replication was delayed in CTBs, consistent with previous studies reporting delayed viral kinetics in HCMV-infected primary CTBs. These results indicate that SGHPL-4 cells are fully permissive for the complete HCMV replicative cycle. Our findings suggest that these cells may serve as useful tools for future mechanistic studies of HCMV pathogenesis during early pregnancy.

Frequency of human cytomegalovirus-specific T cells during pregnancy determined by intracellular cytokine staining

The characteristics of cytomegalovirus (CMV)-specific T-cell immunity was investigated in pregnant women with primary, latent, or reactivated CMV infection, and in a comparative group of non-pregnant women. Forty-six pregnant and 8 non-pregnant women were examined based on the presence of serum antibody activity against CMV and viral excretion in urine. The frequency of CMV-specific CD4(+) T cells in peripheral blood lymphocytes was determined by staining for intracellular cytokines, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha. There was no change in the frequencies of CMV-specific CD4(+) T cells in CMV-seropositive normal non-pregnant and pregnant women at any gestation. However, the frequency of CMV-specific CD4(+) T cells in pregnant women associated with CMV reactivation or reinfection was significantly higher than in CMV-seropositive normal pregnant and non-pregnant women. There were no CMV transmissions to the infants of all these women. These CMV-specific T cells responses in pregnant women may contribute some to block the intrauterine CMV infection in their infants.

Diagnosis and management of human cytomegalovirus infection in the mother, fetus, and newborn infant

Human cytomegalovirus (HCMV) is the leading cause of congenital viral infection and mental retardation. HCMV infection, while causing asymptomatic infections in most immunocompetent subjects, can be transmitted during pregnancy from the mother with primary (and also recurrent) infection to the fetus. Hence, careful diagnosis of primary infection is required in the pregnant woman based on the most sensitive serologic assays (immunoglobulin M [IgM] and IgG avidity assays) and conventional virologic and molecular procedures for virus detection in blood. Maternal prognostic markers of fetal infection are still under investigation. If primary infection is diagnosed in a timely manner, prenatal diagnosis can be offered, including the search for virus and virus components in fetal blood and amniotic fluid, with fetal prognostic markers of HCMV disease still to be defined. However, the final step for definite diagnosis of congenital HCMV infection is detection of virus in the blood or urine in the first 1 to 2 weeks of life. To date, treatment of congenital infection with antiviral drugs is only palliative both prior to and after birth, whereas the only efficacious preventive measure seems to be the development of a safe and immunogenic vaccine, including recombinant, subunit, DNA, and peptide-based vaccines now under investigation. The following controversial issues are discussed in the light of the most recent advances in the field: the actual perception of the problem; universal serologic screening before pregnancy; the impact of correct counseling on decision making by the couple involved; the role of prenatal diagnosis in ascertaining transmission of virus to the fetus; the impact of preconceptional and periconceptional infections on the prevalence of congenital infection; and the prevalence of congenitally infected babies born to mothers who were immune prior to pregnancy compared to the number born to mothers undergoing primary infection during pregnancy.

Diagnosis and management of human cytomegalovirus infection in the mother, fetus, and newborn infant

Human cytomegalovirus (HCMV) is the leading cause of congenital viral infection and mental retardation. HCMV infection, while causing asymptomatic infections in most immunocompetent subjects, can be transmitted during pregnancy from the mother with primary (and also recurrent) infection to the fetus. Hence, careful diagnosis of primary infection is required in the pregnant woman based on the most sensitive serologic assays (immunoglobulin M [IgM] and IgG avidity assays) and conventional virologic and molecular procedures for virus detection in blood. Maternal prognostic markers of fetal infection are still under investigation. If primary infection is diagnosed in a timely manner, prenatal diagnosis can be offered, including the search for virus and virus components in fetal blood and amniotic fluid, with fetal prognostic markers of HCMV disease still to be defined. However, the final step for definite diagnosis of congenital HCMV infection is detection of virus in the blood or urine in the first 1 to 2 weeks of life. To date, treatment of congenital infection with antiviral drugs is only palliative both prior to and after birth, whereas the only efficacious preventive measure seems to be the development of a safe and immunogenic vaccine, including recombinant, subunit, DNA, and peptide-based vaccines now under investigation. The following controversial issues are discussed in the light of the most recent advances in the field: the actual perception of the problem; universal serologic screening before pregnancy; the impact of correct counseling on decision making by the couple involved; the role of prenatal diagnosis in ascertaining transmission of virus to the fetus; the impact of preconceptional and periconceptional infections on the prevalence of congenital infection; and the prevalence of congenitally infected babies born to mothers who were immune prior to pregnancy compared to the number born to mothers undergoing primary infection during pregnancy.

Human cytomegalovirus infection of placental cytotrophoblasts in vitro and in utero: implications for transmission and pathogenesis

Human cytomegalovirus (CMV) is the leading cause of prenatal viral infection. Affected infants may suffer intrauterine growth retardation and serious neurologic impairment. Analysis of spontaneously aborted conceptuses shows that CMV infects the placenta before the embryo or fetus. In the human hemochorial placenta, maternal blood directly contacts syncytiotrophoblasts that cover chorionic villi and cytotrophoblasts that invade uterine vessels, suggesting possible routes for CMV transmission. To test this hypothesis, we exposed first-trimester chorionic villi and isolated cytotrophoblasts to CMV in vitro. In chorionic villi, syncytiotrophoblasts did not become infected, although clusters of underlying cytotrophoblasts expressed viral proteins. In chorionic villi that were infected with CMV in utero, syncytiotrophoblasts were often spared, whereas cytotrophoblasts and other cells of the villous core expressed viral proteins. Isolated cytotrophoblasts were also permissive for CMV replication in vitro; significantly, infection subsequently impaired the cytotrophoblasts' ability to differentiate and invade. These results suggest two possible routes of CMV transmission to the fetus: (i) across syncytiotrophoblasts with subsequent infection of the underlying cytotrophoblasts and (ii) via invasive cytotrophoblasts within the uterine wall. Furthermore, the observation that CMV infection impairs critical aspects of cytotrophoblast function offers testable hypotheses for explaining the deleterious effects of this virus on pregnancy outcome.

Characterization of the placental barrier to murine enterovirus infection

We performed studies to characterize the mechanisms responsible for development during gestation of a placental barrier to Theiler's murine encephalomyelitis virus (TMEV) in a murine model of gestational enterovirus infection. Electron microscopy of placentae infected in early gestation revealed TMEV-induced changes in the decidua, giant cell, spongiotrophoblast, and labyrinth layers; in contrast, placentae infected in middle and late pregnancy demonstrated degenerative changes in the decidua, giant cell, and spongiotrophoblast layers but not in the labyrinth. Immunohistochemistry and in situ hybridization of placentae infected in early or late gestation demonstrated accumulation of monocytes/macrophages in infected, histologically damaged labyrinths, but no infiltration of immune cells into infected but histologically normal placental regions. Silver staining of placentae from dams inoculated in late gestation with inert gold beads the size of TMEV virions revealed beads within the decidua, giant cell, and spongiotrophoblast layers, but restriction of beads from labyrinths, similar to the usual distribution of TMEV in placentae infected in late pregnancy. These experiments suggest that anatomical relationships, and not systemic immune response, appear to be a major contributor to the murine placental barrier to TMEV.

Placental morphology in cytomegalovirus infection

Three groups of placentae from 27 cases of cytomegalovirus infection were examined morphologically and by specific immunofluorescence. Placentae in Group 1 (four cases) had a mean gestational age of 24.5 +/- 2.5 weeks; those in Group 2 (11 cases) had a mean gestational age of 36.4 +/- 2.7 weeks; those in Group 3 (12 cases) had a mean gestational age of 40 +/- 1.8 weeks. A tendency towards increased placental weight was observed. In 23 cases, a haematogenous placentitis was suspected on gross examination. Some specific features were detected on light microscopy. In Group 1 the lesions were represented by pronounced dysmaturity of villous structures, diffuse reparative villitis and intervillitis allied to an abundance of cytomegalic cells and areas of necrosis and calcification. In Group 2 a chronic active process was indicated by the presence of vascular involvement, proliferative-necrotic and reparative villitis and fresh villous necrosis; cytomegalic cells were scarce. In Group 3 placentae there was a predominance of villous plate lesions similar to those found in the septicaemic phase of maternal infections; necrotizing, proliferative and, rarely, reparative villitis was present; cytomegalic cells were rare. We may conclude that placental morphology needs to be substantiated by special laboratory techniques for the detection of cytomegalovirus infection.

Maternal cell-mediated cytolysis of CMV-infected fetal cells and the outcome of pregnancy in the guinea pig

Cytolytic recognition of CMV-infected syngeneic fetal guinea pig cells by maternal peripheral blood mononuclear cells (PBMC) was suppressed late in pregnancies of uninfected guinea pig breeders with less than 25% conceptus loss. A small subset of less successful uninfected pregnancies with greater than or equal to 50% fetal wastage exhibited only partial suppression of cytolytic activity against CMV-infected fetal cells. Primary CMV infection of dams extending into early pregnancy induced augmented cytolysis of CMV-infected fetal cells, but not MA104 NK cell targets, throughout gestation and resulted in 70% loss of conceptus. Decreased suppression of cytolytic activity against CMV-infected fetal cells in uninfected pregnancy was also associated with runting of newborn pups, which was not as severe as that observed in congenitally CMV-exposed or CMV-infected pups. Congenitally infected pups were affected more than their exposed but uninfected litter mates. Lack of suppression of cytolysis of CMV-infected syngeneic fetal cells, whether spontaneous or CMV-infection-induced, appears to be associated with poor pregnancy outcome.

The placenta as a site of cytomegalovirus infection in guinea pigs

The development of cytomegalovirus (CMV) infection in the placenta was studied in Hartley guinea pigs inoculated at midgestation, and its role in determining the outcome of fetal CMV infection was assessed. A hematogenous spread of CMV from the mother to the placenta occurred early during the course of the infection. However, the virus remained present in placental tissues long after CMV had been cleared from maternal blood (i.e., 3 and 4 weeks postinoculation). At that time, the virus was able to replicate in placental tissues in the presence of specific maternal antibodies. Viral nucleocapsids were seen within nuclei of trophoblastic cells, and virions were present surrounding infected cells. In addition, typical CMV-induced histopathological lesions bearing CMV antigens were consistently localized at the transitional zone between the capillarized labyrinth and the noncapillarized interlobium. Whenever CMV infection of the fetus occurred, virus was isolated from the associated placenta. Among placental-fetal units with CMV-infected placentas, only 27% of the fetuses were found to be infected. In addition, there was a delay in the establishment of the infection in the fetus in relation to the placenta, although frequencies of virus isolation in placental and fetal tissues peaked at 3 weeks after CMV inoculation. These results suggest that during primary CMV infection of pregnant guinea pigs, the placenta not only serves as a reservoir for CMV but also acts to limit transmission of the virus to the fetus.

Guillain-Barré syndrome and Campylobacter jejuni: a serological study

The association between Campylobacter jejuni infection and Guillain-Barré syndrome was investigated serologically in a retrospective study of 56 patients admitted to this hospital over four years. Evidence of preceding C jejuni infection was found in 21 (38%) of these patients, indicating that C jejuni was the most common single identifiable pathogen precipitating the disease. Among those patients who had presented with preceding diarrhoea the serum antibody response was similar to that in uncomplicated C jejuni enteritis. Patients with serological evidence of preceding C jejuni infection manifested a significantly more severe form of the disease. In cerebrospinal fluid the predominant specific antibody class was IgG, and this was closely related to the serum titres of specific IgG. IgA and IgM specific antibodies were found only in the cerebrospinal fluid of patients with recent C jejuni infection. These findings support the possibility that humoral immune factors are responsible for the neural damage and demyelination seen in Guillain-Barré syndrome.

A prospective study of maternal cytomegalovirus infection and its effect on the fetus

In order to define the effects of maternal cytomegalovirus infection in pregnancy and to identify risk factors associated with delivery of a cytomegalovirus-infected infant, a cohort of 1089 adolescents were prospectively evaluated during pregnancy. One hundred twenty-four subjects (11.4%) manifested cytomegaloviruria during pregnancy. Primary cytomegalovirus infection, defined virologically and serologically, occurred in three subjects. Infants of 119 cytomegalovirus-excreting mothers were cultured at birth, with detection of 12 congenital infections (10%), including one infant delivered of a mother with a third-trimester primary infection. A high titer of urinary virus or a fourfold or greater increase in antibody during the third trimester was significantly associated with delivery of a congenitally infected infant. All maternal and infant infections were asymptomatic. None of the congenitally infected infants manifested adverse effects during the first year of life. Our data demonstrate that pregnant women with cytomegaloviruria are at increased risk of being delivered of congenitally infected infants, particularly if active infection occurs late in pregnancy. If the maternal infection represents reactivation, overall probability of a poor fetal outcome is low.

Pathogenesis of in utero infections with abortogenic and non-abortogenic alphaviruses in mice

The initial stages of infection of pregnant mice at gestation day 11 with either the T48 strain of Ross River virus or avirulent Semliki Forest virus are similar. With both infections, a hematogenous spread of virus to the placenta occurs. The viruses subsequently replicate to high titer in all placentas and are able to persist in the presence of specific maternal antiviral antibodies. There is a delay of at least 1 to 2 days between the initial detection of virus in the placenta and the onset of fetal infection. With Semliki Forest virus, abortion occurred in all mothers and appeared to be preceded by infection of all fetuses. However, when Semliki Forest virus was given at other stages of pregnancy, abortion was less common, and in all non-aborted pregnancies at least one uninfected fetus was observed. This situation was similar to that with Ross River virus, in which abortion was not observed and fetal infection and death were only seen in a proportion of fetuses. Within each pregnancy, the outcome of the two in utero infections appeared to result from similar mechanisms, with the fate of an individual fetus depending upon the timing of the passive transfer of anti-viral immunoglobulin G from the mother relative to the timing of fetal infection by virus from the placenta. Although the passive maternal immunoglobulin G protected susceptible fetuses against infection, antibody did not mediate in utero recovery of infected fetuses or clear placental infection.

The consequences of primary cytomegalovirus infection in pregnancy

Altogether 54 children exposed prenatally to maternal cytomegalovirus (CMV) infection were followed up in a prospective study. Nine had congenital infection with CMV and 37 escaped congenital infection; in 8 congenital CMV could not be confirmed. The birthweight of children with congenital CMV was significantly lower than that of both controls and those who escaped congenital infection. Intrauterine infection was not clinically suspected in any of the children with congenital CMV, although two had head circumferences less than the third centile. Subsequently one child with congenital CMV developed marked psychomotor retardation, and one, in whom congenital CMV was not confirmed, showed mild developmental delay. Speech and language ability was significantly impaired in children with congenital CMV compared with controls and those who escaped congenital infection, suggesting that subtle damage may have occurred. The incidence of intrauterine transmission of CMV after exposure to infection in the first trimester was 20% and in the third trimester 40%, but no congenital infections resulted from exposure in the second trimester. The severity of congenital infection was not related to the time of exposure in utero. Our findings suggest that the risk to an individual fetus from maternal infection in early gestation is so low that termination of pregnancy cannot be recommended; screening of women for primary CMV infection in pregnancy seems therefore to have limited value.

Prevalence of cytomegalovirus and herpes simplex virus in human semen

Cytomegalovirus was isolated from semen in 4 of 170 males seeking evaluation at the Reproductive Medicine Clinic at Prince Henry's Hospital, and from 1 of 40 healthy university students. All initial isolates were from specimens with abnormal semen analysis (P less than 0.01). Herpes simplex virus was not isolated from any sample.

The presumptive diagnosis of primary cytomegalovirus infection in early pregnancy by means of a radioimmunoassay for specific-IgM antibodies

During a 30 month investigation 3633 women were studied when the booked for antenatal care. Complement fixing antibodies against cytomegalovirus (CMV) were detected in 2078 (57 per cent) of the women and these sera were further tested for the presence of specific IgM antibodies by means of a solid-phase radioimmunoassay. Since specific IgM antibodies have previously been shown to persist for up to four months after primary CMV infection, their presence in a booking serum sample (mean gestation 15 weeks) was taken as presumptive evidence of a first trimester primary CMV infection. From theoretical considerations, 11.6 positive CMV-IgM reactions were predicted in these women and 11 were observed. A highly significant (p less than 0.001) excess of fetal death was seen in the infected women since three pregnancies ended in missed abortion (15 weeks), intrauterine death (29 weeks) and spontaneous abortion (24 weeks) whilst the remaining 8 women gave birth to apparently normal babies. Cord sera were available from 5 of the surviving babies and only one contained specific IgM antibodies, showing that transplacental spread of the maternal infections had not occurred in 4 of the 5 survivors.

Maternal immunosuppression and cytomegalovirus infection of the fetus

Prenatal cytomegalovirus (CMV) infection associated with severe brain damage was detected in an infant whose mother had been treated with prednisolone and azathioprine for systemic lupus erythematosus (SLE). Serology showed that maternal CMV infection had been acquired at least four months before pregnancy. Screening for CMV infection in pregnant women receiving immunosuppressive drugs is recommended.

Prospective study of cytomegalovirus infection in pregnancy

In a prospective study of cytomegalovirus infection in 1,040 pregnant women in London 319 (42%) of the white Englishwomen but only 28 (10%) of the immigrant Asian women were without antibodies at the onset of pregnancy. Out of 254 susceptible white women and 16 susceptible Asian women 8 (3%) and 3 (16%) respectively experienced primary infection during the course of pregnancy. The overall incidence of fetal infection after primary infection in the mother was almost 50%, and was higher in early pregnancy. One out of the five infected infants was found to be mentally retarded.Reactivation of latent infection was recognized in 0.7-2.9% of pregnant women; this occurred without involving the fetus.