The study published in JAMA Network Open revealed the number of babies born with birth defects to mothers who had taken the drug during the first trimester was 26.9 per 1,000, reports news-medical.net. For those taking other types of antibiotics, this was between 19.8 and 23.5 per 1,000 – roughly in line with the standard risk in all pregnancies.
Trimethoprim is prescribed about 130,000 times in England per month, according to the Daily Mail.
Dr Caroline Ovadia, an expert in obstetrics at the University of Edinburgh, who was not involved in the study, said previous research suggested trimethoprim blocked a key nutrient in pregnancy, the Daily Mail reports.
She said: “Trimethoprim can block the action of folic acid, which we know is important in early fetal development.”
The study’s authors wrote: “In this cohort study of pregnant individuals and their infants, first-trimester TMP-SMX exposure to treat UTI was associated with increased risk of any malformation, severe cardiac malformation, other cardiac malformation, and cleft lip and palate compared with β-lactam (another type of antibiotic) exposure.”
They added: “Our results support the current ACOG (American College of Obstetricians and Gynecologists) recommendation for caution in using TMP-SMX during the first trimester.”
Symptoms of a UTI
- Pain or a burning sensation when urinating
- Needing to urinate more often, including at night
- Needing to urinate suddenly or more urgently than normal
- Cloudy urine
- Blood in urine
- Pain in the lower stomach, back, or under the ribs
- A high temperature
- A temperature below 36 degrees
- Feeling tired or weak
Children with a UTI may display general signs of being unwell, wet themselves, or vomit. A UTI may also cause confusion or agitation in older or frail people, or people with a urinary catheter.
The NHS advises anyone who is pregnant and believes they may have a UTI to ask their GP for an urgent appointment, or call NHS 111.