A study from Denmark shows a link between nicotine exposure during pregnancy, particularly nicotine replacement therapy, and colic. (Popular nicotine replacement therapies, or NRTs, include products like Nicorette gum, patches, etc.)
Babies born to smokers were 1.3 times more likely to be colicky; those born to women using NRT were 1.6 times as likely. Interestingly, women who both smoked and used NRT were no more likely to have colicky babies than women who only smoked.
The reasons for the higher rate of colic from nicotine exposure, and especially the even higher rates for mothers using NRTs, aren’t known. Possibilities (just me guessing here) include a neonatal withdrawal syndrome along the lines with what’s seen with other drugs, or negative effects on the fetal brain from maternal life stresses that may predispose a pregnant woman to smoke in the first place.
The researchers didn’t look at the total amount of nicotine the fetus was exposed to. It’s possible that women trying to quit smoking during pregnancy actually increased their nicotine intake when they switched to an NRT. Pregnancy can be stressful enough by itself–trying to kick an addiction can add to that stress, and perhaps lead to increased nicotine use via NRTs.
Given all the risks of maternal smoking–including SIDS–a few weeks of colic seems a small price to pay for kicking the nicotine habit. But maternity care and pediatric providers (and family members and friends) should be prepared to support a new mother through a rocky period with her fussy baby–a stressful time that may increase the risk of her taking up smoking again.