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.

PREVIOUS Journal Clubs

August 2016

Pregnancy outcome following maternal exposure to pregabalin may call for concern.

Neurology 86:2251-2257

This observational cohort study found a significantly higher major birth defect rate among women  exposed to pregabalin  through pregnancy (OR 3.0, 1.2-7.9). Data was ascertained through TIS.

 

Maternal use of oral contraceptives and risk of birth defects in Denmark: prospective, nationwide cohort study

BMJ 2016;352

Large observational cohort study of contraceptive use and major birth defects collected from 880000 live births from Danish registries. There was with recent contraceptive use (0-3 months).

The Brazilian Zika virus strain causes birth defects in experimental models.

Nature 2016

This paper gives a good description of the history of Zika virus from in first description in 1947 to its appearance in Brazil in 2013. The authors have developed a mouse model which shows how Zika crosses the placenta and causes microcephaly by targeting cortical progenitor cells.

Occurrence of pregnancy and pregnancy outcomes during isotretinoin therapy.

CMAJ 2016

Of 60,000 female patients receiving isotretinoin, 24.3% - 32.9% of participants received prescriptions for oral contraceptives. By 42 weeks after treatment, there were 1473 pregnancies (24.9/1000 users). Of these, 90% terminated spontaneously or were terminated by medical intervention. Among the 118 live births were 11 (9.3%) cases of congenital malformation.

June 2016

Page updated 10 October 2016

Self-reported and laboratory evaluation of late pregnancy nicotine exposure and drugs of abuse.

J Perinatol doi: 10.1038/jp.2016.100

In this retrospective study, self-reported smoking status was compared to maternal urine results.  Only about half of women with high nicotine levels (15.8%) during the last days of their pregnancies reported that they were still smoking cigarettes. An additional 7.5% had low-level nicotine readings, indicative of second-hand smoke exposure.

 

Stillbirths: rates, risk factors, and acceleration towards 2030. Lancet doi:10.1016/S0140-6736(15)00837-5

The Every Newborn Action Plan has the target of 12 or fewer stillbirths per 1000 births in every country by 2030. Mainly high-income countries and upper middle-income countries have already met this target. Most counties where the target has not been met are in low-income and middle-income countries. Congenital abnormalities account for only 7.4% of stillbirths. Diseases such as malaria 8.0% and syphilis 7.7% are preventable causes. Prolonged pregnancies contribute to 14.0% of stillbirths.

Teratogenic effects of the Zika virus and the role of the placenta. Lancet

doi:10.1016/S0140-6736(16)00650-4

Two hypotheses regarding the role of the placenta are possible: one is that the placenta directly conveys the Zika virus to the early embryo or fetus. Alternatively, the placenta itself might be mounting a response to the exposure; this response might be contributing to or causing the brain defect. This distinction is crucial to the diagnosis of fetuses at risk and the design of therapeutic strategies to prevent Zika-induced teratogenesis.