Management of suspected primary Toxoplasma gondii infection in pregnant women in Norway: twenty years of experience of amniocentesis in a low-prevalence population

Abstract

BackgroundPrimary infection with Toxoplasma gondii during pregnancy may pose a threat to the fetus. Women infected prior to conception are unlikely to transmit the parasite to the fetus. If maternal serology indicates a possible primary infection, amniocentesis for toxoplasma PCR analysis is performed and antiparasitic treatment given. However, discriminating between primary and latent infection is challenging and unnecessary amniocenteses may occur. Procedure-related fetal loss after amniocentesis is of concern. The aim of the present study was to determine whether amniocentesis is performed on the correct patients and whether the procedure is safe for this indication.MethodsRetrospective study analysing data from all singleton pregnancies (n = 346) at Oslo University Hospital undergoing amniocentesis due to suspected maternal primary toxoplasma infection during 1993–2013. Maternal, neonatal and infant data were obtained from clinical hospital records, laboratory records and pregnancy charts. All serum samples were analysed at the Norwegian Institute of Public Health or at the Toxoplasma Reference Laboratory at Oslo University Hospital. The amniocenteses were performed at Oslo University Hospital by experienced personnel. Time of maternal infection was evaluated retrospectively based on serology results.Results50% (173) of the women were infected before pregnancy, 23% (80) possibly in pregnancy and 27% (93) were certainly infected during pregnancy. Forty-nine (14%) women seroconverted, 42 (12%) had IgG antibody increase and 255 (74%) women had IgM positivity and low IgG avidity/high dye test titre. Fifteen offspring were infected with toxoplasma, one of them with negative PCR in the amniotic fluid. Median gestational age at amniocentesis was 16.7 gestational weeks (GWs) (Q1 = 15, Q3 = 22), with median sample volume 4 ml (Q1 = 3, Q3 = 7). Two miscarriages occurred 4 weeks after the procedure, both performed in GW 13. One of these had severe fetal toxoplasma infection.ConclusionsHalf of our study population were infected before pregnancy. In order to reduce the unnecessary amniocenteses we advise confirmatory serology 3 weeks after a suspect result and suggest that the serology is interpreted by dedicated multidisciplinary staff. Amniocentesis is safe and useful as a diagnostic procedure in diagnosing congenital toxoplasma infection when performed after 15 GW.

WITHDRAWN: Sero-epidemiology of Toxoplasma gondii and risk factors among pregnant women in Africa

“…T. gondii infection during pregnancy results in mental retardation, premature birth, low birth weight, blindness, epilepsy, and death [9]. Moreover a number of published studies have shown that T. gondii infection in pregnancy is associated with increased risk of miscarriages, hearing loss, hematological abnormalities and death as a major determinant of infant mortality and increased risk of maternal morbidity and mortality [51][52][53].…”

Acute Perinatal Infection and the Evidenced-Based Risk of Intrauterine Diagnostic Testing: A Structured Review

“…The majority of diagnostic procedures are limited to amniocentesis and, in selected infections such as CMV, cordocentesis (Table 3) [48][49][50][51][52][53][54][55][56]. The total fetal risk related to amniocentesis in infected cohorts is estimated at 1.5%.…”

“…The possibility of an increased preterm birth mechanism associated with intrauterine viral infection in the late second and third trimester alone has limited data to support this perinatal risk [19,46,47]. Table 3 summarizes the published literature for maternal infection cohorts and the outcomes for unintended fetal loss and evaluations to determine the possibility of fetal VT [48][49][50][51][52][53][54][55][56]. The "pooled" procedure-related fetal loss risk estimate for infectious diagnostic amniocentesis procedures is estimated at 1.5% (18/1,187) -0.8% from varicella (1/127), 0% from HCMV (0/458), and 2.8% from toxoplasmosis (17/602).…”

“…In a retrospectively analyzed amniocentesis cohort with suspected toxoplasmosis infection, a spontaneous transplacental VT rate of 4.5% (15/332) was associated with a positive amniotic fluid viral PCR result (14/15 cases) [56]. Amniocentesis was not associated with an increased VT risk [48,49,[52][53][54]56]. Varicella infection and VT risks has been analyzed.…”

“…Prenatal diagnostic procedures in infected maternal pregnant cohorts[48][49][50][51][52][53][54][55][56] Reference Infection cohort Study, time period, location Unintended pregnancy loss and VT summary Weisz et al [48], 2011 varicella retrospective study (2001-2007), Israel AC in 19/20 cases at a mean of 22.2 ± 1.7 weeks with a mean infection age of 11 ± 3.5 weeks; no postprocedural losses reported; no VT reported Mouly et al [49], 1997 varicella prospective cohort, 1989-1994, France; congenital varicella 2.8% (3/107); postnatal varicella zoster infection 3.8% (3/78) AC 107; FBS 82; procedures at 21-26 weeks of gestation; AC with positive viral AF PCR was identified in 9/107 (8.4%) with maternal infection at <24 weeks; single IUD after AC (negative prenatal testing); no procedure-related VT STOP, surgical termination of pregnancy; TOP, termination of pregnancy; US, ultrasound; VT, vertical transmission.…”