Obstetrics Department, São Paulo Federal University, São Paulo, Brazil.
Arch Gynecol Obstet. 2012 Apr;285(4):959-66. doi: 10.1007/s00404-011-2102-8. Epub 2011 Oct 18.
To investigate differences in pre-pregnancy BMI status in patients with spontaneous preterm birth (PTB) compared with term birth and assess the role of ethnicity as a risk modifier in BMI-associated PTB.
A case-control study involving self-reported African American and Caucasian women delivering singletons in Nashville, TN, USA, 2003-2009. Maternal pre-pregnancy BMI was recorded in 447 PTB-cases (African American = 145, Caucasian = 302) and 1315 term-birth controls (African American = 522; Caucasian = 793). Crude and adjusted odds ratio (OR and AOR) for PTB were calculated using normal BMI (18.5-24.9 kg/m(2)) as reference. Age, education, marital status, income, smoking, parity, previous PTB and pregnancy weight gain were included as covariates in logistic regression.
No significant differences were noted in the OR for PTB among different BMI categories when women of different ethnicity were combined. Odds of PTB were greater in obese than in normal weight Caucasian women, even after adjusting for confounders (AOR = 1.84, 95%CI [1.15, 2.95]). Obese African American women had a decreased crude OR for PTB, although this was not significant after adjusting for confounders (AOR = 0.72, 95%CI [0.38, 1.40]). The odds for early PTB (<32 weeks) were decreased in obese compared with normal weight African American women (OR = 0.23, 95%CI [0.08, 0.70]), whereas they were increased in obese compared with normal weight Caucasian women (OR = 2.30, 95%CI [1.32, 4.00]).
The risk for PTB in women with different pre-pregnancy BMI categories differs according to ethnicity.
研究自发性早产（PTB）患者与足月产患者的孕前 BMI 状况差异，并评估种族作为 BMI 相关 PTB 的风险修饰因子的作用。
这是一项病例对照研究，纳入了 2003 年至 2009 年在美国田纳西州纳什维尔分娩单胎的自报非裔美国人和白种人女性。447 例 PTB 病例（非裔美国人 145 例，白种人 302 例）和 1315 例足月产对照（非裔美国人 522 例，白种人 793 例）记录了产妇的孕前 BMI。采用正常 BMI（18.5-24.9kg/m²）作为参考，计算 PTB 的粗比值比（OR）和调整比值比（AOR）。将年龄、教育程度、婚姻状况、收入、吸烟、产次、既往 PTB 和妊娠体重增加作为逻辑回归的协变量。
当不同种族的女性合并时，不同 BMI 类别与 PTB 的 OR 之间没有显著差异。调整混杂因素后，肥胖白人女性 PTB 的可能性大于正常体重白人女性（AOR=1.84，95%CI[1.15，2.95]）。肥胖非裔美国女性 PTB 的粗 OR 降低，但调整混杂因素后无统计学意义（AOR=0.72，95%CI[0.38，1.40]）。与正常体重非裔美国女性相比，肥胖非裔美国女性发生早期 PTB（<32 周）的可能性降低（OR=0.23，95%CI[0.08，0.70]），而与正常体重白人女性相比，肥胖白人女性发生 PTB 的可能性增加（OR=2.30，95%CI[1.32，4.00]）。
不同孕前 BMI 类别的女性 PTB 的风险因种族而异。
