Professional Abstract
Objective
To determine the effectiveness of herpes treatment on reducing the risk of preterm delivery and low birthweight in pregnant women
Study Design
| Design Element |
Description |
| Design |
Observational: cohort study |
| Population |
89,132 pregnant women in northern California who were at least 18 years old |
Interventions/
Comparators |
Treatment effectiveness:
- Pregnant women with genital herpes who received treatment
- Pregnant women with genital herpes who did not receive treatment
- Pregnant women without genital herpes
Effectiveness of treatment timing:
- Pregnant women with genital herpes who received treatment before the third trimester
- Pregnant women with genital herpes who received treatment during the third trimester
- Pregnant women with genital herpes who did not receive treatment
Effectiveness of treatment duration:
- Pregnant women with genital herpes who received treatment for up to 20 days
- Pregnant women with genital herpes who received treatment for 20 days or more
- Pregnant women with genital herpes who did not receive treatment
|
| Outcomes |
Preterm delivery (birth before 37 weeks gestation); low birthweight (babies born weighing under 5 pounds 8 ounces) |
| Timeframe |
Not applicable |
This prospective observational cohort study examined whether treating genital herpes in pregnant women reduced the risk of preterm delivery and low birthweight compared with no treatment. Researchers also compared the effectiveness of treatment timing and duration on improving birth outcomes.
Researchers collected information on clinical diagnosis and treatment using electronic health records and pharmacy databases from a large clinical registry in northern California.
The study included 89,132 women who were at least 20 weeks pregnant. Of these, 35% were White, 26% were Asian, 6% were African American, and 6% were other races. In addition, 26% were Hispanic. The average age was 31. In this study, 14% of women had indications of genital herpes infection, used herpes medicine, or both.
Women who had genital herpes during pregnancy, doctors, and patient health organizations provided input on the study.
Results
Preterm delivery. Among women who had genital herpes,
- Treatment during pregnancy resulted in a 27% lower risk of preterm delivery compared with no treatment (adjusted hazard ratio [aHR]=0.73; 95% confidence interval [CI]: 0.60, 0.88).
- Compared with women who did not receive treatment, women who received treatment before the third trimester had a 31% lower risk of preterm delivery (aHR=0.69; 95% CI: 0.54, 0.87) while women who received treatment during the third trimester had a 22% lower risk (aHR=0.78; 95% CI: 0.60, 1.01).
- Compared with women who did not receive treatment, women who received treatment for 20 days or more had a 49% lower risk of preterm delivery (aHR=0.51; 95% CI: 0.40, 0.66). Women who received treatment for less than 20 days did not differ significantly from those who did not receive treatment.
The risk of preterm delivery did not differ significantly between women who received treatment for genital herpes during pregnancy and women who did not have genital herpes.
Low birthweight. Compared with no treatment, receiving treatment, treatment timing, and treatment duration did not reduce the risk of low birthweight.
Limitations
Because researchers did not randomly assign women to receive treatment, differences seen across outcomes may be because of differences in the patient populations.
Conclusions and Relevance
In this study, compared with no treatment, treatment for genital herpes during pregnancy reduced the risk of preterm delivery but not low birthweight. Among women with genital herpes, treatment before the third trimester and treatment that lasted 20 days or more reduced the risk of preterm delivery.
Future Research Needs
Future research could use a clinical trial to further examine how genital herpes treatment during pregnancy affects birth outcomes.
