Is It Safe To Take Co-trimoxazole During Pregnancy?

Posted on Mon, 13 Jan 2014

Question: Hi Doc. I did a urine test and found out I had an E. coli infection. Susceptibility tests indicated that it was sensitive to cotrimoxazole, so I stopped the blind treatment of Augmentin 625 and started the cotrimoxazole course. However, still feeling a bit unwell, I did a few other tests and tested positive for pregnancy. My question is whether cotrimoxazole would have any teratogenic effects on my 6-week old fetus. Again, I would like to know how gestational ages are calculated. I had my last menses from 18th to 22nd October, 2013. The dimension for the fetus was 6.83 mm. Thank you.

Answered by Dr. Aarti Abraham (1 hour later)

Brief Answer: COTRIMOXAZOLE IS TERATOGENIC. Detailed Answer: Hello Thanks for writing to us with your health concern. Co-trimoxazole should not be used in pregnancy as the safety in pregnancy has not been established. It has been assigned to Pregnancy Category C by the FDA. Co-trimoxazole interferes with folate metabolism and can cause teratogenic effects if given in the first trimester. Its inadvertent use during pregnancy has been linked with the occurrence of multiple congenital abnormalities - including neural tube defects, cardiovascular system anomalies, club foot, urinary tract abnormalities etc. It is best avoided in pregnancy. As you have consumed it, you should now have regular and vigilant ultrasound scans and genetic testing ( double marker in first trimester, quad marker at 16 - 18 weeks, TIFFA and Fetal Echo at 20 - 22 weeks ). You can go through the following link - WWW.WWWW.WW Also regular 5 mg per day folic acid supplements should be taken till term by you. Gestational ages are calculated from the date of the last menstrual period. If your LMP was 18th of October, you would be 4 weeks on 15th of November, 8 weeks on 13th of December and hence, 9 weeks pregnant on the 20th of December. The fetal pole is a mass of cells before the embryo is visible. It grows at a rate of about 1 mm a day, starting from the 6th week of gestational age. Thus, a simple way to "date" an early pregnancy is to add the length of the fetal pole (in mm) to 6 weeks. Thus at 6.83 mm, you would be around 7 weeks pregnant. All the best. Please feel free to ask for further clarifications.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Aarti Abraham (24 hours later)

Thanks Doc. Very useful information. I just want to know which of the two gestational ages to use. I think the fetal pole calculation gives a more accurate gestational age than the LMP but I want to know which one the obs/gyn or pre-natal records would use as my official gestational age. Thanks.

Answered by Dr. Aarti Abraham (31 minutes later)

Brief Answer: DETAILED BELOW Detailed Answer: Thank you for the appreciation ! The fetal pole measurement is accurate, as you rightly surmised. The OB GYN would go with the gestational age as per LMP, unless there is a gross disparity , when the gestational age calculated by first trimester scan is considered. Take care.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Aarti Abraham (14 hours later)

Alright. Thank you.

Answered by Dr. Aarti Abraham (34 minutes later)

Brief Answer: DETAILED BELOW Detailed Answer: All the best to you too. Please feel free to contact me directly anytime using the following link - WWW.WWWW.WW

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar