Hello doctor, My husband uses Diclofenac solution (topical) for his neck pain. I am 28 weeks pregnant. He also uses a neck pillow after applying it. Will it affect my unborn baby? How long will it take for the solution to be fully absorbed in his body? I am scared that the Diclofenac solution will be absorbed in my body and will hurt the baby. Also if we have sex and he touches that hand in my vagina, will the Diclofenac solution spread into my body? Should I be worried? Please give me some advice as I am scared.
Hi.  You are in the last trimester (7-9 month) of pregnancy. Most of the organs in the fetus might have developed and now it is growing. Thus, care should be taken in food and lifestyle. The rate of absorption of Diclofenac solution into blood from skin is very very less. Even if you apply the solution on your own body skin for long hours, the absorption will be less. If it is absorbed, it stays in the blood for 2 hours. At the end of 2 hours, 50 % of the drug from the blood gets excreted through urine. Remaining 25 % will get excreted in fourth hour. Remaining 12.5 % gets excreted in sixth hour. It means, if the solution reaches blood at 8 AM, it gets completely excreted at 4 PM. Note the point that the external solution does not get absorbed through skin into blood. Thus, need not to worry.  Be careful with your vagina or oral. Because the vagina or oral is made by mucus membrane containing rich minute blood vessels. Vagina is different from skin. In vaigna, the absorption rate is higher and the Diclofenac drug may reaches the blood. Better to avoid, direct applying of Diclofenac solution to vagina or nearby vagina or touching (hands) solution to vagina. This carries some (less) risk to fetus. If the solution is less, no issues. If the solution applied is more, then little amount enters into your blood. If more drug reaches fetus, it inhibits prostaglandins in fetus heart, which lead to unwanted problems in the heart. You can involve in sexual activity, then your husband can apply the drug. Or wash the hands with soap thoroughly before involving in sex. I hope you could understand what I want to say.