Hello dear, I understand your concern. In my opinion iron supplements are known to cause constipation or hard stools. Constipation is routinely seen complaint in pregnancy. To prevent the constipation:- 1) Change the iron preparation- Certain iron preparations tend to cause gastritis,constipation etc. So changing the brand might be tried. 2)Take adequate fluids upto 3 litres per day. 3)Take high fibre diet daily. 4)Take laxatives if needed. Nothing to worry.It will subside by following the above measures. Coming to vaginal lips swelling check for any infection like white discharge or itching or any high BP. The swelling can also be related to excessive straining at stools. If everything is normal the swelling might be considered physiological as some swelling of vaginal lips might be there in pregnancy and subsides after delivery. But iron preparations might not be associated with swelling of vaginal lips. Anyways nothing to worry as such. Prevention of constipation is important to avoid other problems. Hope this helps. Best regards....Dr. Srilatha