The “one size fits all” approach to prescribing medication during pregnancy may put low birth weight babies at risk for the rest of their lives, according to a new study published in Placenta.

Smaller fetuses metabolize medication taken by the mother in a less efficient way than normal weight babies, which may cause long term health consequences, according to the study. Growth-restricted babies may be exposed to a higher concentration of some prescribed and OTC medications during pregnancy.  

One in 7 babies are born under 2500 grams due to the placenta failing to deliver adequate nutrients and oxygen to the fetus, according the study. Low birth weight can be linked to pre-eclampsia, poor placental development, and smoking. 

Intrauterine growth restricted babies are at an increased risk of diabetes, heart disease, lower immunity, and metabolic disease throughout their life, and many require drug treatment themselves during adulthood, according to the study; however, it is not known whether they metabolize these drugs differently. 

"If the fetus is smaller and a mother takes 20 milligrams of a drug, it may effectively be a higher dose than in a normal sized baby…The actual drug doesn't make the fetus smaller, but if it is already smaller, the fetus may be less able to metabolize the drug and get rid of it," professor Janna Morrison, PhD, said in a press release. 

More work is still needed in order to understand the interaction between pregnancy, fetal growth, and drug metabolization, which will help better determine the right dosage for both the mother and unborn child, according to the study.  

Reference:
'One size fits all' medication approach doesn't work in pregnancy [News Release] September 8, 2020; Adelaide, Australia. https://www.eurekalert.org/pub_releases/2020-09/uosa-sf090820.php. Accessed September 23, 2020.