The prevalence of preterm and low birth weight infants among migrant women in the Pearl River Delta region, China: a population-based birth cohort study.

BACKGROUND: The existing literature evaluating the association between neonatal morbidity and migrant status presents contradictory results. The purpose of this study was to compare the risk of preterm birth (PTB) and low birth weight (LBW) among newborns from local and migrant women in China's Pearl River Delta (PRD) region. METHODS: In this observational population-based study, we included all live singleton deliveries from PRD region local women and migrant women. Data were sourced from the Guangdong Medical Birth Registry Information System between Jan 1, 2014, and Dec 31, 2020. Women were categorized into three groups by maternal migrant status: local women from PRD region, migrant women from Guangdong province or from other provinces. The outcome variables that were examined included two adverse birth outcomes: PTB and LBW. The association between the risk of PTB and LBW and maternal migrant status was assessed using logistic regression. RESULTS: During 2014-2020, 5,219,133 single live deliveries were recorded, corresponding 13.22% to local women and the rest to migrant women coming from Guangdong (53.51%) and other provinces (33.26%). PTB prevalence was highest among local women (5.79%), followed by migrant women from Guangdong (5.29%), and the lowest among migrants from other provinces (4.95%). This association did not change after including maternal age, infant sex, delivery mode, and birth season in the models. Compared to local women, migrant women from other provinces had a lower risk of LBW (4.00% vs. 4.98%, P < 0.001). The prevalence of PTB and LBW was higher among local women than migrants. The odds of delivery PTB and LBW were higher for women who were age ≥ 35. Among the three maternal migration groups, the age-LBW association displayed a typical U-shaped pattern, with those in the youngest (16-24 years) and oldest (≥ 35) age categories exhibiting the higher odds of delivering a LBW neonate. With respect to infant sex, the prevalence of PTB was significantly higher in males than females among the three maternal migration groups. An opposite trend was found for LBW, and the prevalence of LBW was higher in females among the three maternal migration groups. CONCLUSION: The findings of this study contribute to the understanding of the epidemiology of PTB and LBW among migrant women. Our study suggests that it is the health and robust nature of migrant mothers that predisposes them to better birth outcomes. It is important to recognize that the results of this study, while supportive of the healthy migrant effect, cannot be considered definitive without some exploration of motivation for moving and changes in lifestyle postmigration.

[Comparison of the effect of three ß-thalassemia prenatal screening strategies using in Guangdong province].

OBJECTIVE: To compare the effect of three ß-thalassemia prenatal screening strategies in Guangdong province. METHODS: A total of 13 284 hospital-delivered couples and 13 369 newborns were recruited from 91 hospitals in 21 counties or districts of Guangdong province from June to December 2012. Mean cell volume (MCV), mean corpuscular hemoglobin (MCH) and hemoglobin A2 (Hb A2) were tested for all the couples, and all the couples and newborns were detected by 17 types of ß-globin gene mutations. The effect of three ß-thalassemia prenatal screening strategies were compared as following: (1) MCV/MCH with Hb A2 serial screening (SS): Hb A2 was tested if the woman's MCV < 82 fl and (or) MCH < 27 pg. If the woman's Hb A2 > 3.5, it meant positive. And if the woman was ß-thalassemia carrier and her husband's Hb A2 > 3.5, it meant couple positive. (2) MCV/MCH with Hb A2 parallel screening (PS): if the woman's MCV < 82 fl and (or) MCH < 27 pg and (or) Hb A2 > 3.5 pg, it meant couple positive. And the husband would be tested for ß-globin gene mutations if the woman was ß-thalassemia carrier. (3) MCV/MCH with Hb A2 serial screening for couples (SSC): if one of the couple or both of them had MCV < 82 fl and (or) MCH < 27 pg, the couple would be tested for Hb A2, and if one of the couple got Hb A2 > 3.5, it meant couple positive. RESULTS: (1) For the SS strategy, the sensitivity was 92.69% (583/629); the specificity was 99.87% (12 638/12 655); the positive predictive value was 97.17% (583/600); and the negative predictive value was 99.64% (12 638/12 684). The results of ß-globin gene mutations tested showed that the rate of ß-thalassemia carriers was 4.74% (629/13 284) in the 13 284 pregnant women, and it was 4.29% (570/13 284) in their husbands. (2) The SS strategy detected 27 (0.20%, 27/13 284) ß-thalassemia carrier couples. For the SS strategy detecting ß-thalassemia carrier couples, the missed diagnosis rate was 11.11% (3/27); the sensitivity was 88.89% (24/27); the specificity was 100.00% (27/27); the positive predictive value was 100.00% (24/24); and the negative predictive value was 99.98% (13 257/13 260). (3) When using the SS strategy for 13 369 offsprings, there were 582 ß-thalassemia carriers (4.35%, 582/13369), including 578 (99.31%, 578/582) minor ß-thalassemia, 3 (0.52%, 3/582) intermedia ß-thalassemia and 1 (0.17%, 1/582) major ß-thalassemia. The SS strategy detected 25 fetuses who needed ß-thalassemia prenatal diagnosis. (4) For the PS strategy, the sensitivity was 98.09% (617/629); the specificity was 88.73% (11 229/12 655); the positive predictive value was 30.20% (617/2 043); and the negative predictive value was 99.89% (11 229/11 241). (5) When using the PS strategy for the ß-thalassemia carrier couples, the sensitivity was 100.00% (27/27); the specificity was 95.55% (12 667/13 257); the positive predictive value was 4.38% (27/617); and the negative predictive value was 100.0% (12 667/12 667). (6) The PS strategy detected 28 fetuses who needed ß-thalassemia prenatal diagnosis in 13 369 offsprings. (7) For the SSC strategy, the sensitivity was 93.80% (590/629); the specificity was 95.75% (12 117/12 655); the positive predictive value was 52.30% (590/1 128); and the negative predictive value was 99.68% (12 117/12 156). When the SSC strategy was used for the husbands, the sensitivity was 92.28% (526/570); the specificity was 95.27% (12 112/12 714);the positive predictive value was 46.63% (526/1 128); and the negative predictive value was 99.64% (12 112/12 156). (8) When the SSC strategy was used in ß-thalassemia carrier couples, the sensitivity was 100.00% (27/27); the specificity was 91.69% (12 156/13 257); the positive predictive value was 2.39% (27/1 128); and the negative predictive value was 100.00% (12 156/12 156). (9) The SSC strategy detected 28 fetuses who needed ß-thalassemia prenatal diagnosis. CONCLUSIONS: All the three ß-thalassemia prenatal screening strategies had good effect in clinical practice and public health. While in the high-prone area of ß-thalassemia, MCV/MCH with Hb A2 parallel screening and MCV/MCH with Hb A2 serial screening for couples stratigies were better.

[Association between APOBEC3G polymorphisms and susceptibility to chronic hepatitis B].

OBJECTIVE: To investigate the association between rs185983011 single-nucleotide polymorphisms (SNP) of apolipoprotein B mRNA editing enzyme catalytic polypeptide-like 3G (APOBEC3G) and the susceptibility to chronic hepatitis B. METHODS: The blood samples were collected from 186 healthy subjects and 159 patients with chronic hepatitis B. The rs185983011 SNP was detected and genotyped by sequencing with Sanger's method to analyze the relationship between rs185983011 SNP and chronic hepatitis B. RESULTS: Only C/C and C/T genotypes of the alleles of rs185983011 SNP were found in the tested subjects, and the C/C genotype was predominant (97.7%). The distribution frequencies of rs185983011 SNP genotypes and alleles showed no significant difference between healthy subjects and patients with chronic hepatitis B (P>0.05). CONCLUSION: The predominant genotype of rs185983011 SNP of APOBEC3G is C/C in the tested subjects, and rs185983011 SNP does not appear to associate with the susceptibility to chronic hepatitis B.