Neurological outcome in school-age children after in utero exposure to coumarins

The effect of prenatal exposure to coumarins (acenocoumarol, phenprocoumon) on neurological outcome was assessed in a cohort of 306 children aged 7-15 years. Findings were compared with those in a non-exposed cohort of 267 children, matched for sex, age, and demographic region. We used a neurological examination technique which pays special attention to minor neurological dysfunction (MND). None of the children was found to be neurologically abnormal. However, exposure to coumarins during gestation increases the risk for MND in children of school age, odds ratio (OR) 1.9 (CI(95) 1.1-3.4), predominantly after exposure in the second or third trimester, odds ratio 2.1 (CI(95) 1.2-3.8). We found a dose-response relationship with an odds ratio of 1.2 (CI(95) 1.0-1.5) per mg coumarin derivative prescribed per day. The results suggest that coumarins have an influence on the development of the brain which can lead to mild neurological dysfunctions in children of school age.

Coumarins during pregnancy: long-term effects on growth and development of school-age children

Anticoagulation during pregnancy is complicated because of potential risks for mother and foetus. Unfractionated or low-molecular-weight heparin is used for most anticoagulant indications. Its efficacy, however, in pregnant women with prosthetic heart valves is questioned, therefore coumarins are preferred for this indication. We studied long-term effects of prenatal coumarin-exposure on growth and on neurological, behavioural and cognitive development in 274 school-age children in comparison with 231 age-matched non-exposed controls. No major abnormalities were found. The exposed children had an increased risk for minor neurological dysfunction and for a low intelligence quotient (IQ below 80). The risk for a combination of two or more (minor) abnormalities was higher for the exposed children, RR = 7.6. We conclude that prenatal exposure to coumarins is associated with an increased risk for disturbances in development in school-age children. However, for the vast majority of children there is no clinical significant effect on growth and long-term development.

Coumarins during Pregnancy: Long-term Effects on Growth and Development of School-age Children

Anticoagulation during pregnancy is complicated because of potential risks for mother and foetus. Unfractionated or low-molecular-weight heparin is used for most anticoagulant indications. Its efficacy, however, in pregnant women with prosthetic heart valves is questioned, therefore coumarins are preferred for this indication.

We studied long-term effects of prenatal coumarin-exposure on growth and on neurological, behavioural and cognitive development in 274 school-age children in comparison with 231 age-matched non-exposed controls. No major abnormalities were found. The exposed children had an increased risk for minor neurological dysfunction and for a low intelligence quotient (IQ below 80). The risk for a combination of two or more (minor) abnormalities was higher for the exposed children, RR = 7.6. We conclude that prenatal exposure to coumarins is associated with an increased risk for disturbances in development in school-age children. However, for the vast majority of children there is no clinical significant effect on growth and long-term development.

Growth until puberty after in utero exposure to coumarins

Anticoagulation with coumarins is an effective therapy during pregnancy. Fetal exposure to coumarin derivatives during the first trimester, however, is associated with skeletal anomalies (warfarin or coumarin embryopathy). Information about long-term effects of prenatal coumarin exposure on the skeletal development is not available. We investigated growth and body proportions at school age of children exposed to coumarins in utero. A blind population-based cohort study was conducted on 307 exposed children and 267 non-exposed controls ages 8-15 years. The exposed cohort was based on a prospective registry of coumarin-treated pregnant women. Anthropometric data included height, weight, head circumference, and measurements to evaluate body proportions. The mean height of exposed children did not differ from that of the non-exposed children (mean difference 0.01 SD). In addition, no differences were found for the proportional measures. As a group, children exposed in the first trimester showed no evidence of growth impairment. Two children in this group, however, were born with signs of coumarin embryopathy and one of these displayed a deficit in height at school age. Long-term growth was not affected by a high cumulative dosage or exposure after the first trimester. We conclude that, when exposure during the first trimester is avoided, coumarin therapy during pregnancy has no demonstrable risk for the child's skeletal development.

Late neurological, cognitive and behavioural sequelae of prenatal exposure to coumarins: a pilot study

Neurological, cognitive and behavioural development were assessed in a group of 21, 8- to 10-year old children whose mothers took coumarins during pregnancy. Findings were compared with those in a group of 17 control children. The study was performed to test whether it is feasible to carry out a reliable retrospective study of late effects of prenatal exposure to coumarins. This turned out to be the case. In this small pilot study, no statistical significant differences were found between the study and control group, nevertheless a few findings were remarkable. One child showed severe neurological abnormalities, which may be due to prenatal exposure to oral anticoagulants. The children with the lowest scores on the neurological assessment and the lowest IQ-scores, were found in the exposed group. Obviously, the number of children in this study is too small to conclude if there has been definite effects from coumarin, but these results indicate that a large follow-up study is required. In the present paper, we have shown that such a study is feasible.