Association of pelvic inflammatory disease (PID) with ectopic pregnancy and preterm labor in Taiwan: A nationwide population-based retrospective cohort study

Chun-Chung Huang; Chien-Chu Huang; Shao-Yi Lin; Cherry Yin-Yi Chang; Wu-Chou Lin; Chi-Hsiang Chung; Fu-Huang Lin; Chang-Huei Tsao; Chun-Min Lo; Wu-Chien Chien

doi:10.1371/journal.pone.0219351

Association of pelvic inflammatory disease (PID) with ectopic pregnancy and preterm labor in Taiwan: A nationwide population-based retrospective cohort study

PLoS One. 2019 Aug 13;14(8):e0219351. doi: 10.1371/journal.pone.0219351. eCollection 2019.

Authors

Chun-Chung Huang¹, Chien-Chu Huang^{2

3}, Shao-Yi Lin⁴, Cherry Yin-Yi Chang^{2

5}, Wu-Chou Lin^{2

5}, Chi-Hsiang Chung⁶, Fu-Huang Lin⁶, Chang-Huei Tsao^{7

8}, Chun-Min Lo¹, Wu-Chien Chien^{7

9

6}

Affiliations

¹ Department of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan.
² Department of Obstetrics and Gynecology, China Medical University Hospital, Taichung, Taiwan.
³ Graduate Institution of Biomedical Sciences, China Medical University, Taichung, Taiwan.
⁴ Department of Mechanical and Computer-Aided Engineering, National Formosa University, Yunlin, Taiwan.
⁵ China Medical University, Department of Medicine, Taichung, Taiwan.
⁶ School of Public Health, National Defense Medical Center, Taipei, Taiwan.
⁷ Department of Medical Research, Tri-Service General Hospital, Taipei, Taiwan.
⁸ Department of Microbiology & Immunology, National Defense Medical Center, Taipei, Taiwan.
⁹ Graduate Institution of Life Science, National Defense Medical Center, Taipei, Taiwan.

Abstract

Background: Pelvic inflammatory disease (PID) is an infectious disease that causes tubal occlusion and other pelvic and abdominal adhesions. The incidence of pelvic inflammatory disease (PID) has increased due to the sexually active status of the young population. This leads to a more serious problem and a larger effect than previously observed. However, there have been few studies on this topic in Asian populations.

Aim: We aimed to evaluate the risk of preterm labor and/or ectopic pregnancy in Taiwanese women following PID.

Design: Using the Taiwan National Health Insurance Database, we designed a retrospective cohort study that included 12- to 55-year-old pregnant women between 2000 and 2010. We selected a 1:3 age-matched control group of non-PID women. The endpoint was any episode of preterm labor or ectopic pregnancy; otherwise, the patients were tracked until 31 December 2010.

Methods: The risk factors for preterm labor or ectopic pregnancy were explored. For cases included from the index date until the end of 2010, we analyzed the risk of incident preterm labor or ectopic pregnancy. With the use of a multivariate Cox proportional hazard regression analysis, we calculated the hazard ratio (HR) with a 95% CI and compared it with that of the control group.

Results: This study examined 30,450 patients with PID and 91,350 controls. During the follow-up period, patients in the PID group were more likely to develop preterm labor or ectopic pregnancy than patients in the control group. The cumulative incidence rates for developing preterm labor were 1.84% (561/30,450 individuals) in patients with PID and 1.63% (1492/91,350 individuals) in patients without PID. On the other hand, the cumulative incidence rate for developing ectopic pregnancy in patients with PID was 0.05% (14/30,450 individuals) but was only 0.04% (33/91,350 individuals) in patients without PID. Compared with those without PID, the patients with PID had a 1.864 times (P<0.001) higher risk of developing preterm labor and a 2.121 times (P = 0.003) higher risk of developing ectopic pregnancy.

Conclusion: Our study provided evidence of an increased risk of preterm labor or ectopic pregnancy in PID patients.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Case-Control Studies
Child
Female
Humans
Incidence
Middle Aged
Obstetric Labor, Premature / epidemiology
Obstetric Labor, Premature / etiology*
Pelvic Inflammatory Disease / complications*
Pregnancy
Pregnancy, Ectopic / epidemiology
Pregnancy, Ectopic / etiology*
Retrospective Studies
Risk Factors
Taiwan / epidemiology
Young Adult

Grants and funding

This study was funded by Tri-Service General Hospital Research Foundation (TSGH- C107-004 and TSGH- C108-003). The funder has no role in the design, concept, data collection and interpretation, analysis, drafting or other process in this paper.