Obstetrics & Gynaecology/Pregnancy & intrapartum antibiotics

Antibiotics in pregnancy & labour

also: GBS prophylaxis · pregnancy UTI · benzylpenicillin labour · chorioamnionitis

Overview

Antibiotic use specific to pregnancy and labour — GBS intrapartum prophylaxis, the safe agents for UTI in pregnancy, and the agents to AVOID.

Mechanism

Pathogen-directed antibiotics; the pregnancy distinctives are which agents are safe by trimester. IV benzylpenicillin during labour prevents early-onset neonatal GBS sepsis.

Indications

Group B Strep intrapartum prophylaxis
UTI / asymptomatic bacteriuria in pregnancy (always treat)
Chorioamnionitis

The agents

Benzylpenicillin (intrapartum)GBS prophylaxis

IV in labour

For GBS carriers / previous GBS baby / GBS bacteriuria / pyrexia in labour. Clindamycin if penicillin-allergic.

NitrofurantoinUTI

Safe 1st/2nd trimester; AVOID at term (neonatal haemolysis).

Cefalexin / amoxicillinUTI

Pregnancy-safe alternatives.

Co-amoxiclavchorioamnionitis/severe

Broad-spectrum.

Adverse effects

Trimethoprim (1st trimester) → neural tube defectsserious

Folate antagonist — AVOID in the 1st trimester.

Nitrofurantoin at term → neonatal haemolysisserious

As per each agentcommon

Cautions & contraindications

Trimethoprim in the 1st trimesterpregnancy

Folate antagonist → NTDs.

Nitrofurantoin at term / labourpregnancy

Neonatal haemolysis.

Tetracyclines & fluoroquinolones in pregnancypregnancy

Teeth/bone, cartilage.

Interactions

As per agents

Monitoring & kinetics

Treat ALL bacteriuria in pregnancy (asymptomatic too) — pyelonephritis/preterm risk,GBS status

Oral for UTI; IV benzylpenicillin intrapartum for GBS.

Source: RCOG — GBS (Green-top 36) · NICE CKS — UTI in pregnancy