Affiliation:
1. NHC Key Lab of Reproduction Regulation, Shanghai Engineering Research Center of Reproductive Health Drug and Devices, Shanghai Institute for Biomedical and Pharmaceutical Technologies, School of Publi
2. Department of Medical Genetics, NHC Key Laboratory of Healthy Birth and Birth Defect Prevention in Western China, First People's Hospital of Yunnan Province
Abstract
Abstract
Background
The effect of pre-pregnancy intrauterine device (IUD) use on subsequent preterm birth (PTB) remains unclear. To investigate the association between IUD use before pregnancy and subsequent PTB.
Methods
A total of 242,009 women who participated in the National Free Preconception Health Examination Project (NFPHEP) in Yunnan from 2013 to 2019 were included in the study. All study participants were classified into three groups according to their use of pre-pregnancy contraceptive methods: non-method users, IUD users, and other method users. We used multivariable Poisson regression model to investigate the association between the use of an IUD before pregnancy and subsequent PTB. Further models analyzed the multiplicative and additive interactions between pre-pregnancy IUD use and county deprivation.
Results
Of all the participants, 45,772 (18.9%) used IUDs before pregnancy, 39,627 (16.4%) used other contraceptive methods, and 156,506 (64.7%) were non-method users. The overall PTB rate was 4.8% (95% confidence interval [95% CI], 4.7–4.9%), and women in the IUD group had a significantly lower PTB rate (4.3%, 95% CI 4.1–4.5%) than women in the non-method users (4.9%, 95% CI 4.8–5.1%) and other method groups (4.7%, 95% CI 4.5–4.9%). IUD use before pregnancy was associated with a reduced risk of subsequent PTB (model 1: adjusted relative risk [aRR] 0.84, 95% CI 0.79 to 0.88; model 2: aRR 0.84, 95% CI 0.79 to 0.90). In counties with a normal level of development, IUD users had a 30% lower risk of subsequent PTB than non-users (aRR 0.70, 95% CI 0.63 to 0.77). Compared with non-IUD users from the least developed counties, those from counties with a normal level of socioeconomic development had the lowest risk of subsequent PTB (aRR 0.72, 0.62 to 0.83). The additive interaction between pre-pregnancy IUD use and low level of county development was statistically significant (relative excess risk due to interaction [RERI] -0.27, -0.40 to -0.13).
Conclusion
Pre-pregnancy IUD use is associated with a reduced risk of subsequent PTB. Pre-pregnancy IUD users in counties with a normal level of development were associated with a lower risk of subsequent PTB than their counterparts in the least developed countries.
Publisher
Research Square Platform LLC
Reference44 articles.
1. The epidemiology, etiology, and costs of preterm birth;Frey HA;Semin Fetal Neonatal Med,2016
2. Global, regional, and national causes of under-5 mortality in 2000-15: an updated systematic analysis with implications for the Sustainable Development Goals;Liu L;Lancet,2016
3. Neonatal mortality and leading causes of deaths: a descriptive study in China, 2014–2018;Liu Y;BMJ open,2021
4. Behavioral problems and cognitive performance at 5 years of age after very preterm birth: the EPIPAGE Study;Delobel-Ayoub M;Pediatrics,2009
5. Mental health of extremely low birth weight survivors in their 30s;Lieshout RJ;Pediatrics,2015