Birth outcome and risk of neonatal hypoglycaemia following in utero exposure to pivmecillinam: a population-based cohort study with 414 exposed pregnancies

[Use of antibiotics during pregnancy]

BACKGROUND

Antibiotics are the most widely used medication on prescription in pregnancy. It is therefore important to investigate whether antibiotic use in pregnancy can harm the foetus. During the last decade the availability of data from national registries has made it possible to conduct large-scale epidemiological studies. In this article we aimed to review recent studies on the risk of congenital anomalies and miscarriage resulting from the use of antibiotics in pregnancy.

METHOD

A literature search was conducted in MedLine, Embase and PubMed for the period 1 December 2005-1 December 2015. We identified 1,316 articles, of which 23 met the inclusion criteria.

RESULTS

Recent epidemiological studies have focused on investigating the risks of malformations and pyloric stenosis after exposure to macrolides, nitrofurantoin, penicillins and trimethoprim-sulphamethoxazole. In nine of ten studies that included in total more than 38,000 patients exposed to macrolides, and two studies with more than 7,000 exposed to nitrofurantoin, no significantly increased risk of malformations was discovered. There are some contradictory findings for certain groups of antibiotics with regard to the risk of miscarriage, heart defects and pyloric stenosis.

INTERPRETATION

Recent studies indicate that erythromycin and nitrofurantoin can be used as second-line drugs in the first trimester. The results from recent studies concur with the recommendations for pregnant women in national guidelines regarding antibiotic use in the primary health service.

Empirical treatment of acute cystitis in women

Empirical antimicrobial treatment for acute cystitis in women requires continuing reassessment as the antimicrobial susceptibility of community isolates of Escherichia coli evolves. Current recommendations for 3 days trimethoprim or trimethoprim/sulphamethoxazole are compromised by increasing resistance of community E. coli to these agents. Fluoroquinolones are an alternate 3-day therapy, but increasing resistance is being reported from some countries, and widespread community use may promote resistance, limiting effectiveness of these agents for more serious infections. Alternate regimens supported by recent clinical trials suggest pivmecillinam given twice daily for 7 days is as effective as 3 days of quinolone therapy, while microbiological cure is 80% with 3 days therapy twice daily, and 90% with 3 days therapy thrice daily. Nitrofurantoin given for 7 days has a cure rate of 80-85%. Fosfomycin trometamol as a single dose has cure rates of 75-85%. All these agents are effective, but a compromise in efficacy or duration of therapy compared with current 3-day regimens may have to be considered.

A population-based study of maternal use of amoxicillin and pregnancy outcome in Denmark

AIMS

Amoxicillin is a widely used penicillin, but data on its safety in pregnancy are limited. We examined the association between amoxicillin exposure during pregnancy and birth weight, preterm delivery, congenital malformations, perinatal death, and spontaneous abortion.

METHODS

We identified all primiparous women with a live birth, or a stillbirth after the 28th gestational week, from 1 January 1991-31 December 2000 in the County of North Jutland, Denmark. Data on prescriptions for amoxicillin and outcome were obtained from population-based registries. Using a follow-up and a case-control design, we compared pregnancy outcomes between women who had been prescribed amoxicillin during pregnancy and those who had not, adjusting for available potentially confounding factors.

RESULTS

We identified 401 primiparous women who redeemed a prescription for amoxicillin during their pregnancy. The control group consisted of 10 237 primiparous women who did not redeem any prescriptions from 3 months before pregnancy until the end of pregnancy. The adjusted mean birth weight of children born to amoxicillin-exposed mothers was 57 g [95% confidence interval (CI) 9, 105] higher than that of children born to controls. Odds ratios among amoxicillin-exposed relative to controls were: low birth weight 0.63 (95% CI 0.26, 1.53), preterm delivery 0.77 (95% CI 0.49, 1.21), congenital malformation 1.16 (95% CI 0.54, 2.50), and spontaneous abortion 0.89 (95% CI 0.66, 1.18). We did not observe any cases of perinatal death in the amoxicillin-exposed women.

CONCLUSIONS

We did not find any increased risk of adverse pregnancy outcome associated with amoxicillin exposure during pregnancy, but additional studies are warranted.