Maternal BMI, 25-Hydroxyvitamin D serum level and Cervical Length Measurements: Markers for Preterm Delivery

Abstract

Background: Preterm delivery is the delivery between 20th -37th weeks of gestation. Aim of the work: to study the maternal BMI, 25-Hydroxyvitamin D (25(OH)D) serum level, and uterine cervical length (CL) as predicting factors for PTD. Patients and methods: A prospective study included 188 pregnant women recruited during 20th -24th weeks of gestation. The maternal BMI was calculated, the serum level of 25(OH)D was measured, and the uterine CL was measured via transabdominal and transvaginal ultrasound. All women followed until delivery time and then were divided into 2 groups; group1 (n=54) women who delivered preterm, and group2 (n=134) women who delivered at term. Results: BMI results showed statistical significance between women who delivered preterm and those who delivered at term (29.7±1.7 vs. 23.6±2.2 kg/m2, P<0.001). Serum 25(OH)D showed no significant difference between the studied groups. CL was significantly shorter in women who delivered preterm than other group (32.39±5.93 vs. 44.42±4.17 mm, P<0.001). At 25 mm as a cut-off value for CL, the sensitivity, specificity, PPV, and NPV were 90.7%, 78.4%, 62.8%, and 95.5%, respectively. Women with BMI >25kg/m2 had significantly longer cervix than those who had BMI <25kg/m2. Regarding the effect of CL on the mode of delivery, 65.4% of women with CL <25 mm delivered vaginally. Conclusion: Maternal BMI had a significant relation with PTD. Measuring the CL during 20th -24th weeks helps predict preterm delivery and the mood of delivery. There is an association between BMI and cervical length.

Could Maternal Vitamin D Concentration Affect Cervical Length in Mid-Pregnancy? A Report from an Iranian Tertiary Center

“…Interestingly, maternal BMI was not correlated with cervical length in mid gestation too. This finding is in contrast to some previous studies which reached a statistically significant positive correlation ( 27 – 31 ). Although this remains unexplained as similar or even greater sample size was studied here but some differences in study design, population study, and ethnical or geographical heterogeneity may justify this.…”

“…In Eltemamy et al study in 2021, 188 pregnant women at gestational age of 20 to 24 th weeks were assessed and followed till delivery. They found out that in patients who delivered preterm mid-trimester cervical length was significantly shorter but mean maternal serum vitamin D concentration did not differ between who delivered preterm and those delivered at term ( 27 ). But, the researchers did not investigate the association between cervical length and maternal vitamin D level.…”

Differences in cervical length during the second trimester among normal weight, overweight and obese women: A systematic review and meta-analysis

“…Therefore, 20 studies were included in this systematic review and 12 in the meta-analysis [3] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] . The characteristics of included studies are summarized in Table 1 .…”