[Sportschosun, Jang Jong-ho] A study has found that women who continue smoking in early pregnancy face up to a 10-fold higher risk of gestational diabetes mellitus.
A research team led by Professor Ryu Hyun-mi of the Department of Obstetrics and Gynecology at Bundang CHA Women's Hospital, CHA University, and the Smart MEC Care R&D Center announced that smoking before pregnancy or in early pregnancy is associated with an increased risk of severe gestational diabetes mellitus requiring insulin treatment. The findings were published in the British medical journal BMJ Open.
Gestational diabetes mellitus (GDM) is a glucose metabolism disorder first detected or developed during pregnancy, and it can affect both the mother and the fetus. In particular, A2GDM, which requires insulin treatment, places a greater burden on prenatal care than A1GDM, which can be managed with diet alone, and calls for more intensive blood sugar control.
Using data from the Korean Pregnancy Outcome Study, collected through a research project on the prevalence of pregnancy-related complications and identification of risk factors conducted by the Korea Disease Control and Prevention Agency (KDCA) and the National Institute of Health, the team analyzed the relationship between smoking in early pregnancy and the incidence and severity of gestational diabetes mellitus in 3,457 Korean women with singleton pregnancies. Gestational diabetes mellitus was evaluated by dividing cases into A1GDM, which is controlled with diet alone, and A2GDM, which requires medication such as insulin.
The analysis found that 231 of the 3,457 participants, or 6.7%, were diagnosed with gestational diabetes mellitus. Of those, 198 had A1GDM and 33 had A2GDM.
In particular, smoking before pregnancy and smoking in early pregnancy were significantly associated with an increased risk of A2GDM. Women who smoked before pregnancy had about a fourfold higher risk of A2GDM than non-smokers, while those who continued smoking in early pregnancy had about a 10-fold higher risk. By contrast, no significant association was found with A1GDM, which can be controlled with diet alone.
A clear trend was also observed in the analysis by smoking amount. When cumulative smoking exposure exceeded four pack-years, the risk of A2GDM increased sharply, and the risk rose further as exposure increased from 4 to 6 pack-years and beyond 6 pack-years. This suggests that not only smoking status before and during pregnancy, but also cumulative smoking exposure, may be linked to gestational diabetes mellitus requiring insulin treatment.
In a secondhand smoke analysis among non-smokers, exposure appeared to increase the overall risk of gestational diabetes mellitus, but the result did not reach statistical significance. The research team said that the importance of managing not only direct smoking but also secondhand smoke exposure should be confirmed through further studies.
Professor Ryu Hyun-mi said, "This study is meaningful because it analyzed the relationship between smoking and gestational diabetes mellitus not simply by whether it occurs, but by severity."
She added, "Direct smoking before pregnancy and in early pregnancy was associated with an increased risk of gestational diabetes mellitus requiring insulin treatment, and the risk also tended to rise as smoking exposure increased. Smoking cessation counseling and exposure management are important for women planning a pregnancy or in early pregnancy."
The study is expected to provide evidence for smoking cessation education before and during early pregnancy, as well as for the development of prenatal care strategies.
Jang Jong-ho, bellho@sportschosun.com
