Association between maternal prepregnancy body mass index and risk of preterm birth in more than 1 million Asian American mothers

Combined effects of pre-pregnancy BMI and gestational weight gain on preterm birth: comparison between spontaneous and ART conception

BACKGROUND

Inappropriate pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) are both linked to preterm birth (PTB); however, which one plays a dominant role in PTB risk is not yet sure. We aimed to evaluate the combined effect of pre-pregnancy BMI and GWG on the risk of PTB in singleton pregnancies conceived both spontaneously and through assisted reproductive technology (ART).

METHODS

The data included all mothers (n = 17,540,977) who had a live singleton birth from the US National Vital Statistics System (NVSS) 2015-2019. Logistic regression models, quantile-g-computation, and generalized additive model were used to analyze the combined association of pre-pregnancy BMI and GWG with PTB.

RESULTS

The singleton PTB rate was significantly higher in ART pregnancies (11.5%) than in non-ART pregnancies (7.9%). When compared to those women with pre-pregnancy normal weight and GWG within Institute of Medicine (IOM) guidelines, the highest PTB risk was observed in non-ART women with pre-pregnancy underweight and GWG below IOM guidelines (aOR 2.56; 95% CI 2.53-2.60) and in ART women with pre-pregnancy obese and GWG below IOM guidelines (aOR 2.56; 95%CI 2.36-2.78). GWG dominated the combined effect with its joint effect coefficient of - 0.281 (P < 0.05) in non-ART women and - 0.108 (P < 0.05) in ART women.

CONCLUSIONS

Inappropriate GWG played a dominant role in increasing the risk of PTB in both non-ART and ART populations. Counseling regarding pre-pregnancy BMI and especially GWG appears to be even more crucial for pregnancies conceived via ART, given their impact on PTB.

Vaginal and oral probiotics effect in the prevention of preterm delivery in patients visiting Kamali Hospital, Karaj, Iran in 2020

INTRODUCTION

The prevalence of preterm labor (PTL) is growing, and annually one in ten babies is born prematurely. Various studies have examined the effect of oral or vaginal probiotics on the prevention of preterm labor, which has yielded contrasting results. This study aimed to compare the impact of vaginal and oral probiotics on the prevention of preterm delivery.

METHODS

This clinical trial was performed among 185 pregnant women with a gestational age greater than or equal to 25 weeks visiting Kamali Hospital, Karaj, Iran in 2020. The participants were divided into three groups; intervention group 1 receiving Oral probiotic pill once a day until 37 weeks of pregnancy, intervention group 2 receiving probiotic vaginal suppository once a day until 37 weeks of pregnancy, and control group not receiving any intervention. Patients were then followed up until the end of pregnancy.

RESULTS

Demographic characteristics and gestational age at the time of intervention were not significantly different among the three groups. Overall, 26.7 % in the control group, 30 % in intervention group 1 %, and 22.5 % in intervention group 2 had deliveries less than 37 weeks. There was no significant difference in the frequency of preterm labor and the duration of pregnancy among the groups (all p > 0.05).

CONCLUSION

Probiotics use does not increase the rate of preterm delivery or reduce the duration of pregnancy, but the rate of preterm delivery was lower in the oral probiotic group. Further clinical studies on the impact of probiotics on PTL can yield valuable results.