Associations of High Body Mass Index and Excessive Gestational Weight Gain with Pregnancy Outcomes in Women with Type 1 Diabetes: A Systematic Review and Meta-analysis
The increased risk of pregnancy complications in type 1 diabetes is mainly attributed to maternal hyperglycemia. However, it is unclear if other potentially-modifiable factors, also contribute to risk in this population.
PURPOSE
To assess if high body-mass-index (BMI) and excessive gestational-weight-gain (GWG) are associated with perinatal complications in type 1 diabetes.
DATA SOURCES
We searched MEDLINE, Embase, PubMed, Scopus, Web of Science and Cochrane databases to January 2024.
STUDY SELECTION
Studies examining associations between periconception BMI or GWG and perinatal complications in type 1 diabetes were included.
DATA EXTRACTION
We used a predesigned data extraction template to extract study data including year, country, sample size, participants’ characteristics, exposure and outcomes.
DATA SYNTHESIS
We included 29 studies (18,965 pregnancies; 1978-2019) in the meta-analysis. A 1kg/m2 /1kg increase in preconception BMI or GWG was associated with a 3% and 11% increase in perinatal complications respectively (BMI OR 1.03 (95%CI 1.01-1.06); GWG OR 1.11 (95%CI 1.04-1.18)). Preconception BMI ≥ 25kg/m2 or excessive GWG was associated with a 22% and 50% increase in perinatal complications respectively (BMI OR 1.22 (95%CI 1.11-1.34); GWG OR 1.50 (95%CI 1.31-1.73)).
BMI was associated with congenital malformation, preeclampsia, and neonatal-intensive-care-unit admission. Excessive GWG was associated with preeclampsia, Caesarean delivery, large-for-gestational-age and macrosomia.
LIMITATIONS
Retrospective study design, variable measurement for exposures /outcomes, small number of studies for some outcomes, no data from Asia and Africa.
CONCLUSIONS
Addressing maternal BMI pre-pregnancy and preventing excessive GWG should be key clinical priorities to improve outcomes in pregnant women with type 1 diabetes.
