Hormonal contraceptive use before and after conception in relation to preterm birth and small for gestational age: an observational cohort study.

ABSTRACT:

Objective

To evaluate whether hormonal contraceptives, used before or in early pregnancy, confer increased risk of preterm birth or reduced fetal growth.

Design

Population-based cohort study conducted by the Norwegian Institute of Public Health (Mother and Child Cohort Study, 1998-2008) with linkage to the Norwegian Prescription Registry and to the Medical Birth Registry of Norway.

Setting

Norway.

Population

Of the 48,615 pregnancies meeting study inclusion criteria, 44,734 pregnancies were included in the complete case analysis.

Methods

We characterised hormonal contraception by type (combination oral, progestin-only oral, vaginal ring, transdermal, and injectable) and specific progestin component. We used generalised estimating equations to estimate th

SUBMITTER: Jensen ET 

PROVIDER: S-EPMC4400183 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature