Malformation Risk (malformation + risk)

Distribution by Scientific Domains


Selected Abstracts


Congenital malformations in infants whose mothers reported the use of folic acid in early pregnancy in Sweden.

CONGENITAL ANOMALIES, Issue 4 2007
A prospective population study
ABSTRACT The use of folic acid prior to conception is generally recommended for the prevention of birth defects, notably neural tube defects. In a previous study from Sweden, based on interviews of women in early pregnancy, no such effect was found on the general malformation rate, but data for neural tube defects were scarce. Using data from the Swedish Medical Birth Register for the years 1995,2004, 20 891 women were identified who reported the use of folic acid in early pregnancy, but not of anticonvulsants. These women were compared to all other women who gave birth during the study period. Malformations in the infants born were identified from multiple sources. No reduction in the general malformation rate was seen among infants born to women who reported the use of folic acid (OR = 1.09, 95% CI 1.02,1.17) and no effect of neural tube defect rate was seen (RR = 1.35, 95% CI 0.82,2.22), based on 16 infants with neural tube defect whose mother reported the use of folic acid. No effect was seen on the rates of other malformations except for cardiac defects, where a statistically significant increased risk (notably for severe defects) was found (OR = 1.19, 95% CI 1.05,1.35). The effect of various deficiencies in data collection is discussed, but is unlikely to explain the lack of protective effect noticed. So far, it has not been possible to demonstrate a beneficial effect of folic acid supplementation on malformation risk in Sweden. A more complete ascertainment and detailed timing and dosage of folic acid use in a prospective study is recommended. [source]


The teratogenic risk of antiepileptic drug polytherapy

EPILEPSIA, Issue 5 2010
Frank J. E. Vajda
Summary Purpose:, To compare the risks of fetal malformation during pregnancy associated with antiepileptic drug (AED) polytherapy and monotherapy. Methods:, Statistical analysis of malformation rate and antiepileptic drug exposure data from the Australian Register of Antiepileptic Drugs in Pregnancy, and from the literature. Results:, The calculated relative risk (RR) value for AED polytherapy compared with monotherapy was below 1.0 in only 3 of 14 literature publications. In the register, at 1 year postnatally there were fetal malformations in 5.32% of 282 AED polytherapy pregnancies, and in 7.84% of 791 AED monotherapy pregnancies, an RR of 0.68 [95% confidence interval (CI) 0.39,1.17). For pregnancies exposed to valproate, the RR of fetal malformation (0.39, 95% CI 0.20,0.89) was lower in polytherapy (7.26%) than in monotherapy (17.9%); the difference did not depend on valproate dosage. The RR values for fetal malformation were not significantly different for AED polytherapy and monotherapy when valproate was not involved. Logistic regression suggested that coadministration of lamotrigine may have reduced the malformation risk from valproate. Discussion:, The fetal hazard of AED polytherapy relative to monotherapy may depend more on the degree of exposure to valproate than on the fact of polytherapy per se. Coadministration with lamotrigine may lower the fetal risk of valproate therapy. [source]


Valproate teratogenicity and epilepsy syndrome

EPILEPSIA, Issue 12 2008
Edward B. Bromfield
Summary Maternal valproate (VPA) use is associated with a significant risk for congenital malformations in the exposed fetus. Since VPA is commonly used in epilepsy syndromes with a presumed genetic cause (idiopathic epilepsies), it is possible that maternal genetic background contributes to this outcome. We reviewed responses to telephone questionnaires and medical records, when available, of enrollees in the North American Antiepileptic Drug Pregnancy Registry, classifying reason for treatment as idiopathic generalized epilepsy (IGE), partial epilepsy (PE), nonclassifiable epilepsy (NCE), or not epilepsy (NE). Of 284 VPA-exposed pregnancies, 30 (11.0%) were associated with malformations: IGE = 15/126 (12%), PE = 4/28 (14%), NCE = 9/105 (9%), NE = 2/25 (8%) (p > 0.7 for all comparisons). There was a trend toward increased malformation risk with higher VPA doses (p = 0.07). VPA, and not the underlying genetic syndrome, seems to be associated with the elevated risk for malformations in the drug-exposed fetus. [source]


Data collected on maternal dietary exposures in the Danish National Birth Cohort

PAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 1 2007
Sjúrdur Fródi Olsen
Summary Recent research suggests that the diet consumed in, or shortly before, pregnancy can potentially lead to maldevelopment and diseases in the offspring, which may become apparent at any time from the embryonic stage until old age. For example, maternal diet may affect the chance of twinning (and associated complications), malformation risk, brain development, and the offspring's fecundity and risk of contracting cardiovascular dieases and cancer in adult life. Prospectively designed longitudinal studies with sufficient size and data quality are much needed to substantiate or refute these hypotheses. At present, the Danish National Birth Cohort is likely to be the largest epidemiological database containing extensive information on maternal dietary exposures. By October 2002, 100 000 women had been recruited in early pregnancy, for long-term follow-up of themselves and their offspring. The present paper details the information available in the database on early nutritional exposures with emphasis on maternal dietary intake. We also present distributions of selected nutritional exposures. [source]


Congenital malformations in infants born after in vitro fertilization in Sweden

BIRTH DEFECTS RESEARCH, Issue 3 2010
Bengt Källén
Abstract BACKGROUND: The risk for congenital malformations is increased in infants born after in vitro fertilization (IVF). Some specific malformations appear to be more affected than others. METHODS: The presence of congenital malformations in 15,570 infants born after IVF with an embryo transfer between April 1, 2001, and the end of 2006 were compared with all infants born in Sweden during 2001 to 2007 (n = 689,157). Risk estimates were made after adjusting for year of birth, maternal age, parity, smoking, and body mass index. The risks of specific malformations were compared with data from a previous study (1982 to March 31, 2001) of 16,280 infants born after IVF. Different IVF methods were compared to respect to malformation risk. RESULTS: Increased risks of a similar magnitude were found for most cardiovascular malformations and limb reduction defects for both study periods. For neural tube defects, cardiac septal defects, and esophageal atresia, there was still an increased risk, but it was lower during the second than during the first period. For small bowel atresia, anal atresia, and hypospadias, the risk increase observed during the first study period had disappeared during the second period. An increased risk was seen for some syndromes that have been associated with imprinting errors. No difference in malformation risk according to IVF method was apparent. CONCLUSIONS: A slightly increased risk for congenital malformations after IVF persists. A decreasing risk is seen for some specific malformations, either true or the result of multiple testing. Birth Defects Research (Part A), 2010. © 2010 Wiley-Liss, Inc. [source]