Human parvovirus infections during pregnancy : Special reference to the child-care employees

Human parvovirus B19 (B19V) is known to cause anemia, hydrops fetalis, and fetal death especially during the first half of pregnancy. Women who are in occupational contact with young children are at increased risk of B19V infection. The role of the recently discovered human parvovirus, human bocavirus (HBoV), in reproduction is unknown. The aim of this research project was to establish a scientific basis for assessing the work safety of pregnant women and for issuing special maternity leave regulations during B19V epidemics in Finland. The impact of HBoV infection on the pregnant woman and her fetus was also defined. B19V DNA was found in 0.8% of the miscarriages and in 2.4% of the intrauterine fetal death (IUFD; fetal death after completed 22 gestational weeks). All control fetuses (from induced abortions) were B19V-DNA negative. The findings on hydropic B19V DNA-positive IUFDs with evidence of acute or recent maternal B19V infection are in line with those of previous Swedish studies. However, the high prevalence of B19V-related nonhydropic IUFDs noted in the Swedish studies was mostly without evidence of maternal B19V infection and was not found during the third trimester. HBoV was not associated with miscarriages or IUFDs. Almost all of the studied pregnant women were HboV-IgG positive, and thus most probably immune to HBoV. All preterm births, perinatal deaths, smallness for gestational age (SGA) and congenital anomaly were recorded among the infants of child-care employees in a nationwide register-based cohort study over a period of 14 years. Little or no differences in the results were found between the infants of the child-care employees and those of the comparison group. The annual B19V seroconversion rate was over two-fold among the child-care employees, compared to the women in the comparison group. The seropositivity of the child-care employees increased with age, and years from qualification/joining the trade union. In general, the child-care employees are not at increased risk for adverse pregnancy outcome. However, at the population level, the risk of rare events, such as adverse pregnancy outcomes attributed to infections, could not be determined. According to previous studies, seronegative women had a 5 10% excess risk of losing the fetus during the first half of their pregnancy, but thereafter the risk was very low. Therefore, an over two-fold increased risk of B19V infection among child-care employees is considerable, and should be taken into account in the assessment of the occupational safety of pregnant women, especially during the first half of their pregnancy.

Factor V Leiden as risk factor for pregnancy complications : Epidemiological study of Finnish women

Factor V Leiden (FV Leiden) is the most common inherited thrombophilia in Caucasians increasing the risk for venous thrombosis. Its prevalence in Finland is 2-3%. FV Leiden has also been associated with several pregnancy complications. However, the importance of FV Leiden as their risk factor is unclear. The aim of the study was to assess FV Leiden as a risk factor for pregnancy complications in which prothrombotic mechanisms may play a part. Specifically, the study aimed to assess the magnitude of the risk, if any, associated with FV Leiden for pregnancy-associated venous thrombosis, pre-eclampsia, unexplained stillbirth, and preterm birth. The study was conducted as a nested case-control study within a fixed cohort of 100,000 consecutive pregnant women in Finland. The study was approved by the ethics committee of the Finnish Red Cross Blood Service and by the Ministry of Social Affairs and Health. All participants gave written informed consent. Cases and controls were identified by using national registers. The diagnoses of the 100,000 women identified from the National Register of Blood Group and Blood Group Antibodies of Pregnant Women were obtained from the National Hospital Discharge Register. Participants gave blood samples for DNA tests and filled in questionnaires. The medical records of the participants were reviewed in 49 maternity hospitals in Finland. Genotyping was performed in the Finnish Genome Center. When evaluating pregnancy-associated venous thrombosis (34 cases, 641 controls), FV Leiden was associated with 11-fold risk (OR 11.6, 95% CI 3.6-33.6). When only analyzing women with first venous thrombosis, the risk was 6-fold (OR 5.8, 95% CI 1.6-21.8). The risk was increased by common risk factors, the risk being highest in women with FV Leiden and pre-pregnancy BMI over 30 kg/m2 (75-fold), and in women with FV Leiden and age over 35 years (60-fold). When evaluating pre-eclampsia (248 cases, 679 controls), FV Leiden was associated with a trend of increased risk (OR 1.7, 95% CI 0.8-3.9), but the association was not statistically significant. When evaluating unexplained stillbirth (44 cases, 776 controls), FV Leiden was associated with over 3-fold risk (OR 3.8, 95% CI 1.2-11.6). When evaluating preterm birth (324 cases, 752 controls), FV Leiden was associated with over 2-fold risk (OR 2.4, 95% CI 1.3-4.6). FV Leiden was especially associated with late preterm birth (32-36 weeks of gestation), but not with early preterm birth (< 32 weeks of gestation). The results of this large population-based study can be generalized to Finnish women with pregnancies continuing beyond first trimester, and may be applied to Caucasian women in populations with similar prevalence of FV Leiden and high standard prenatal care.

Substance misuse problems during pregnancy with special emphasis on buprenorphine

Maternal drug abuse during pregnancy endangers the future health and wellbeing of the infant and growing child. On the other hand, via maternal abstinence, these problems would never occur; so the problems would be totally preventable. Buprenorphine is widely used in opioid maintenance treatment as a substitute medication. In Finland, during 2000 s buprenorphine misuse has steadily increased. In 2009 almost one third of clientele of substance treatment units were in treatment because of buprenorphine dependence. At Helsinki Women s Clinic the first child with prenatal buprenorphine exposure was born in 2001. During 1992-2001 in the three capital area maternity hospitals (Women s clinic, Maternity hospital, Jorvi hospital) 524 women were followed at special antenatal clinics due to substance abuse problems. Three control women were drawn from birth register to each case woman and matched for parity and same place and date of the index birth. According to register data mortality rate was 38-fold higher among cases than controls within 6-15 years after index birth. Especially, the risk for violent or accidental death was increased. The women with substance misuse problems had also elevated risk for viral hepatitis and psychiatric morbidity. They were more often reimbursed for psychopharmaceuticals. Disability pensions and rehabilitation allowances were more often granted to cases than controls. In total 626 children were born from these pregnancies. According to register data 38% of these children were placed in out-of-home care as part of child protection services by the age of two years, and half of them by the age of 12 years, the median follow-up time was 5.8 years. The risk for out-of-home care was associated with factors identifiable during the pre- and perinatal period. In 2002-2005 67 pregnant women with buprenorphine dependence were followed up at the Helsinki University Hospital, Department of Obstetrics and Gynecology. Their pregnancies were uneventful. The prematurity rate was similar and there were no more major anomalies compared to the national statistics. The neonates were lighter compared to the national statistics. They were also born in good condition, with no perinatal hypoxia as defined by standard clinical parameters or certain biochemical markers in the cord blood: erythropoietin, S100 and cardiac troponin-t. Almost 80% of newborns developed neonatal abstinence syndrome (NAS) and two third of them needed morphine medication for it. Maternal smoking over ten cigarettes per day aggravated and benzodiazepine use attenuated NAS. An infant s highest urinary norbuprenorphine concentration during their first 3 days of life correlated with the duration of morphine treatment. The average length of infant s hospital stay was 25 days.