TOG release: Managing sexually transmitted infections in pregnancy

Exploring the interactions between STIs and pregnancy, this new review looks at chlamydia, gonorrhoea, trichomonas vaginalis, bacterial vaginosis, anogenital warts, genital herpes and syphilis.

In the last decade new diagnoses of STIs from genitourinary medicine clinics in the UK have risen by 153%.

More than 111,000 new diagnoses of chlamydia were made in women in England in 2010. Chlamydia has been linked to preterm birth, low birth weight and an increased risk of complications the earlier in the pregnancy the infection occurs.

There is some evidence that treatment of chlamydia in pregnancy reduces complications. However, up to 34% of women with chlamydia delivering vaginally will develop a bacterial infection following childbirth, states the review.  Approximately 50% of neonates born to women with untreated chlamydia will develop neonatal conjunctivitis and about 15% will develop chlamydia pneumonitis (chest infection).

The review recommends that women who have chlamydia treated in pregnancy should be retested 5-6 weeks after completion of treatment and have repeat screening in the third trimester.

Gonorrhoea is less common, however, almost 40% of women with gonorrhoea are co-infected with chlamydia. The effects of gonorrhoea on early pregnancy are unclear, however, prospective studies of effects later in pregnancy show gonorrhoea to be associated with increased risk of preterm rupture of membranes, preterm birth and low birth weight.

Gonorrhoea increases the risk of postpartum infection, which can be severe. Neonatal conjunctivitis occurs in up to 50% of exposed babies.

Anogenital warts are the most common viral STI in the UK. They are caused by infection with low-risk subtypes of human papillomavirus (HPV). Vertical transmission of HPV occurs in up to 1 in 80 cases and can cause genital and laryngeal warts in infants.

Treatment of anogenital warts in pregnancy does not reduce the risk of vertical transmission, so no treatment is an option, states the review. However, treatment may improve symptoms and limit the extent of it.

The review also looks at bacterial vaginosis, which affects about 15% of pregnant women, many of whom will not have symptoms. It is associated with preterm rupture of membranes, preterm birth, low birthweight and postpartum infection, with an increased risk of complications the earlier in pregnancy the condition occurs.

Overall, there is no evidence to support screening and treating asymptomatic pregnant women for bacterial vaginosis, finds the review.

STIs in pregnancy should be managed in conjunction with genitourinary medicine physicians and management should include antimicrobial therapy, counselling, partner notification and safer sex advice, concludes the review.

Janet Wilson, Consultant in Genitourinary Medicine, Leeds General Infirmary and co-author of the review said:

“We are seeing more and more women in pregnancy with STIs. They may require test of cure or repeat screening later in pregnancy and re-testing for blood-borne STIs, including HIV. They should also receive advice on partner notification, sexual abstinence during treatment and safer sex. However, women can be reassured that, with appropriate intervention, neonatal complications are still rare.”

TOG’s Editor–in-Chief, Jason Waugh, added:

“The prevalence of STIs has increased in all age groups in the UK which is a worrying trend. It is important that pregnant women with STIs are treated in a multidisciplinary team and given information about their condition and any support they may need.”


For more information please contact Naomi Weston on 020 7772 6357 or [email protected]


The Obstetrician & Gynaecologist (TOG) is published quarterly and is the Royal College of Obstetricians and Gynaecologists’ (RCOG) medical journal for continuing professional development. TOG is an editorially independent, peer reviewed journal aimed at providing health professions with updated information about scientific, medical and clinical developments in the specialty of obstetrics and gynaecology.


Allstaff S,Wilson J. The management of sexually transmitted infections in pregnancy. The Obstetrician & Gynaecologist 2012;14:25–32.