Australian Birth Defects Society

A Society devoted to the study of birth defects

Quick round-up of interesting articles that have passed my desk this month.

Journal Club

December 2016

Prenatal cannabis exposure - The “first hit” to the endocannabinoid system Neurotoxicology and Teratology xxx (2016) xxxxxx

An interesting review of cannabis exposure during pregnancy. The authors concede that is no evidence of structural, cognitive, behavioural or functional abnormalities due to exposure during pregnancy. However marijuana use during pregnancy is hypothesised to perturb the fetal endogenous cannabinoid signalling system which is important in regulating cardiovascular processes. Thus they propose a two-hit hypothesis with prenatal exposure predisposes exposed offspring to abnormalities in cognition and altered emotionality.

 

Pregnancy outcomes after maternal varenicline use; analysis of surveillance data collected by the European Network of Teratology Information Services. Reproductive Toxicology 67 (2017) 26–34.

 Varenicline (Champix) is a smoking cessation aid. This ENTIS study compared 89  Varenicline first-trimester-exposed pregnancies with 267 control and 78 nicotine-replacement or bupropion replacement pregnancies. There was no increase in major malformation rate.

Assessment of YouTube videos as a source of information on medication use in pregnancy. Pharmacoepidemiology and drug safety 2016; 25: 3544

The internet is already a large source of information for mothers but YouTube also videos also discuss drug use in pregnancy. This study viewed 314 videos finding the majority were from law firms (67%). The most common class of drug was SSRIs (72%) with 88% of these claiming SSRIs were unsafe for use on pregnancy in contrast to TERIS which rates this drug class as a “minimal” or “unlikely” risk. 

October 2016

Page updated 6 February 2017

Ondansetron Use in Pregnancy and Birth Defects
A Systematic Review.
Obstet Gynecol 2016;127:878-83

Ondansetron has become one of the most prescribed antiemetics for treating nausea and vomiting in pregnancy. Despite its apparent safety, concerns have been raised regarding its safety. This paper is a metanalysis of 8 studies concluding that whil ethe overall risk is very low there is also inconsistent evidence of a small increase in cardiac defects.

Prospective Study of Pregnancy and Newborn Outcomes in Mothers with West Nile Illness during Pregnancy. Birth Def Res A (2016): 106:716–723.

Western Nile virus has yet to hit the headlines as Zika but it can cause acute encephalitis in the mother and concern has also been raised that it might induce neurologic abnormalities in the newborn. This paper reports a prospective longitudinal cohort study of  28 patients. While the study is small, there appeared to be no increased risk of adverse outcomes despite the higher incidence of febrile illness and medication use in infected mothers.

Evaluation of pregnancy outcomes from the Tysabri® (natalizumab) pregnancy exposure registry: a global, observational, follow-up study. BMC Neurology (2016) 16:150.

Natalizumab can be used in the treatment of multiple sclerosis and Crohns disease. It is unclear from animal studies whether it crosses the placenta and there are few human studies. This paper reports on the 369 patients enrolled in the Tysabri  pregnancy registry. To date, the spontaneous abortion rate was similar to general population. Overall rate of birth defects, while slightly higher than control population, showed no consistent pattern suggestive of a drug effect.