Chlamydia Trachomatis (C. Trachomatis) is an intracellular bacteria.  According to the CDC, this appears to be the most common of sexually transmitted diseases (STD).

Most authorities advocate screening all women for chlamydia during pregnancy.  If screening is not performed for all patients, those with the following high-risk criteria should be tested for chlamydia.

High Risk Groups(2, 3)

1.      Cervicitis

2.      History of multiple sexual partners

3.      History of sexual partner with venereal disease, especially urethritis

4.      Patient history of other sexually transmitted disease

5.      History of preterm delivery

6.      History of preterm rupture of membranes

The following are less specific risk factors:

1.      Age below twenty-five years

2.      Endocervical bleeding with swabbing


If patient falls within a risk group, preplan screening test.  Using area “4L Chla” just below the routine lab area of the Flow Sheet, circle this area of the Flow Sheet to show that you have done the test that day.  Many authorities consider retesting during the 3rd trimester for all or, at minimum, for high risk patients.  If you wish to do the screen on a future visit, circle the appropriate box along that line corresponding to the date that you plan to do the test.  After the test report is back, enter positive or negative in the appropriate circled box.  If it is positive, preplan a repeat test post-treatment by circling the appropriate box along the same line.

Risk to Fetus(3,8)

It is unclear if ascending infection is responsible for preterm rupture of membranes and preterm delivery.  However, an association appears to exist between primary chlamydial infection and preterm births.

Risk To Newborn

When coming in contact with maternal secretions during birth, the newborn is exposed to chlamydia.  This puts neonate at risk for  conjunctivitis and respiratory infections.

Inclusion conjunctivitis usually appears 5-14 days after birth manifested by mucopurulent conjunctival drainage.  Lower respiratory trace infections are usually  pneumonia or bronchiolitis.  These may appear 4 to 11 weeks after birth with cough and tachypnea.  Often these infants remain afebrile.  Some may require hospitalization.

For diagnostic tests and treatment for the above problems see below.

Maternal Symptoms

The mother is generally asymptomatic or has a purulent cervico-vaginal discharge.  However, she is at higher risk for postpartum  endometritis that usually presents between days 5-10 with low grade fever and uterine tenderness.

Risk to Mother

Postpartum pelvic infections are most common in the first few weeks but can occur up to 4 to 6 weeks after delivery.  The infection includes irregular bleeding, modest temperature elevation, and uterine tenderness.  See Section T Postpartum Endometritis, page 596.00 for further discussion.

Screening Tests

Fluorescein-labeled monoclonal antibody test (ELISA and DFA system) have an accuracy of 78% compared to 45% for endocervical cultures and 67% for male urethral swabs.  Use of newer nucleic acid-based tests ligase chain reaction (LCR) or polymerase chain reaction (PCR) have sensitivities for the above female, male specimens at 85% and 100% respectively.  Urine samples (initial 10-20 cc voided) are reliable and more convenient for screening both sexes.(8-11)

Be aware that some insurance carriers will not cover the more expensive LCR or PCR tests.

Specimens can be obtained from conjunctival drainage or from a nasopharyngeal culture in suspected neonatal respiratory infection.  Other tests, such as a pap smear or serology, are not accurate.


These are options with usual treatment of choice listed first, followed by alternatives.


1.      Azithromycin 1 gm PO once is rapidly becoming the treatment of choice.  Efficacy similar to erythromycin with less gastrointestinal side effects.  However, it is considerably more expensive.

2.      Erythromycin (not estolate)

a.      Erythromycin base 500 mg PO qid x 7 days

b.      Erythromycin base 250 mg orally four times a day for 14 days

c.      Erythromycin ethylsuccinate 800 mg orally four times a day for 7 days

d.      Erythromycin ethylsuccinate 400 mg orally four times a day for 14 days

3.      Amoxicillin 500 mg PO tid x 10 days.

4.      Clindamycin 450 mg PO qid x 7 days.

Sexual Partner

1.      Doxycycline 100 mg bid PO x 7 days

2.      Azithromycin 1 gm PO once is rapidly becoming the treatment of choice

3.      Erythromycin 500 mg PO qid x 7 days

5.      Floxacin 300 mg PO bid x 7 days


Topical drugs may not be effective in preventing ocular chlamydial infection.  For actual conjunctivitis or pneumonia, a suggested treatment is erythromycin 50 mg/kg/day divided qid x 14 days.  The newborn pharynx, rectum, and/or vagina may also be infected and cultures should be considered.

Risk Factor

If the patient has tested positive for chlamydia, enter this fact to risk factor section 31 of the Flow Sheet as:  Chlamydia Infection.


These women should have follow-up tests of cure.  Plan this by circling appropriate column on line 4L of the Flow Sheet and described in "Pre-Planning," on page 309.00

Patient Education

Distribute the pink patient education sheet C5(3) Chlamydia Infection in Pregnancy to the patient, plus handout on specific antibiotic.  Document this on back of Flow Sheet.


1.       Ryan GM, Abdella TN, et al:  Chlamydia trachomatis infection in pregnancy and effect of treatment on outcome.  Am J Obstet Gynecol 162:34, 1990.

2.       Cates W, Wasserheit JN:  Genital chlamydial infections:  Epidemiology and reproductive sequelae.  Am J Obstet Gynecol 164:1771, 1991.

3.       McGregor JA, French JI:  Chlamydia trachomatis infection during pregnancy.  Am J Obstet Gynecol 164:1782, 1991.

4.       Schachter J, Grossman M, et al:  Prospective Study of Perinatal transmission of Chlamydia Trachomatis.  JAMA 255:3374, 1986.

5.       Cohen L, Veille J-C, Calkins BM:  Improved Pregnancy Outcome Following Successful Treatment of Chlamydial Infection.  JAMA 263:3160, 1990.

6.       Chernesky MA, Jang D, Lee H, et al:  Diagnosis of Clamydia trachomatis infections in men and women by testing first-void urine by ligase chain reaction.  J Clin Microbiol 32:2682, 1994.

7.       Lee HH, Chernesky MA, Schacter J, et al:  Diagnosis of Chlamydia trachomatis genitourinary infection in women by ligase chain reaction assay of urine.  Lancet 345:213, 1995.

8.       Quinn TC, Welsh L, Lentz A, et al:  Diagnosis by AMLICOR PCR of Chlamydia trachomatis infection in urine samples from women and men attending sexually transmitted disease clinics.  J Clin Microbiol 34:1401, 1996.

9.       Buimer M, van Doornum GJ, Ching S, et al:  Detection of Chlamydia trachomatis and Neisseria gonorrhoeae by ligase chain reaction-based assays with clinical specimens from various sites:  implications for diagnostic testing and screening.  J Clin Microbiol 34:2395, 1996.

10.   Black CM, Marrazzo J, Johnson RE, et al:  Head-to-head multicenter comparison of DNA probe and nucleic acid amplification tests for Chlamydia trachomatis infection in women performed with an improved reference standard.  J Clin Microbiol. 40(10):3757-63, Oct 2002.

11.   MMWR:  Sexually transmitted diseases treatment guidelines 2002. vol 51, # RR-6, May 10, 2002.

12.   Miller JM, Martin DH:  Treatment of Chlamydia trachomatis infections in pregnant women.  Drugs;60(3):597-605. Sep, 2000.

13.   Brocklehurst P, Rooney G:  Interventions for treating genital chlamydia trachomatis infection in pregnancy.  Cochrane Database Syst Rev;(2):CD000054, 2000.

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