Appetite during the second and third trimesters mediates the impact of prenatal environmental tobacco smoke exposure on symmetric full-term low birth weight.

Objective: To examine the relationship of prenatal environmental tobacco smoke (ETS) exposure and full-term low birth weight (FT-LBW) when taking anthropometric proportionality into consideration, and explore whether appetite mediates their association.Study design: We conducted a case-control study among pregnant women at two Women and Children's Hospitals in Guangdong, China. Information was collected through interview and medical records review. A series of logistic and linear regressions were used to examine the relationships of prenatal ETS exposure, appetite, and FT-LBW.Results: After adjusting for the potential confounders, prenatal ETS exposure was significantly negatively associated with FT-LBW (OR: 1.83, 95%CI: 1.35-2.48) and negatively correlated with maternal appetite in second and third trimester during pregnancy (ß: -0.11, standard error: 0.03). Moreover, mediation analysis illustrated that maternal appetite partially mediated 12.00% of their relationship. However, subgroup analysis showed that prenatal ETS exposure was linked to higher risk of symmetric FT-LBW (OR: 2.26, 95%CI: 1.56-3.26) but not asymmetric FT-LBW. And maternal appetite explained only 6.45% of their relationship.Conclusions: Maternal prenatal ETS exposure increased risk of having symmetric FT-LBW infant, and appetite might mediate their relationship partially. This study emphasizes the importance of sample homogeneity and stresses the needs to improve the public awareness of the harmful effects of ETS.

Maternal exercise during pregnancy reduces the risk of preterm birth through the mediating role of placenta.

OBJECTIVE: The extent of research on maternal exercise during pregnancy and the risk of preterm birth (PTB) have grown substantially, but conclusions still remained controversial. Thus, this study aims to examine the relationship of maternal exercise during pregnancy and PTB and explore whether placenta mediates their relationship. STUDY DESIGN: We investigated 849 pregnant women delivering PTB newborns (cases) and 1306 delivering full-term appropriate for gestational age newborns (controls) in this case-control study. Information concerning maternal exercise during pregnancy, sociodemographics and obstetric characteristics were collected at Women and Children's Hospitals of Shenzhen and Foshan in Guangdong, China. A series of logistic and linear regressions were used to examine the relationships of maternal exercise during pregnancy, placenta, and PTB. RESULTS: After adjusting for the potential confounders, maternal exercise frequency and duration during pregnancy were negatively associated with PTB. Moreover, compared with mother taking no exercise during pregnancy, those taking exercise lowered the risk of PTB except those taking low/medium frequency and short duration exercise, and their adjusted ORs ranged from 0.43 to 0.65. Furthermore, mediation analysis illustrated that placental weight partially mediated 65.20% of the effects of maternal exercise frequency on PTB, as well as 41.98% of the association between maternal exercise duration and PTB. CONCLUSIONS: Maternal exercise during pregnancy is beneficial for lowering the risk of PTB, especially when taking appropriate and enough exercise. Placenta weight may partially mediate the association between maternal exercise during pregnancy and PTB.

Gene-gene-environment interactions of prenatal exposed to environmental tobacco smoke, CYP1A1 and GSTs polymorphisms on full-term low birth weight: relationship of maternal passive smoking, gene polymorphisms, and FT-LBW.

OBJECTIVE: To examine the interaction effects of prenatal exposed to environmental tobacco smoke (ETS) and genotypes of cytochrome P4501A1 (CYP1A1), glutathione S-transferases (GSTs) on the risk of full-term low birth weight (FT-LBW). STUDY DESIGN: We conducted a case-control study among pregnant women at two Women and Children's Hospitals in Guangdong, China (n = 910). Information was collected through interview, medical records review, and blood lab tests. Maternal selfreport and serum cotinine concentration were combined to define prenatal exposed to ETS. Logistic regression approach was applied for statistical analysis. RESULTS: Our results showed that regardless of genotypes, prenatal exposed to ETS significantly increased the risk of FT-LBW. Then, two-way interactions showed increased prevalence of FT-LBW in prenatal exposed to ETS mothers with the CYP1A1 variant genotype (MspI "CC"), or with GSTT1-null genotype. Furthermore, three-way interactions showed that women with CYP1A1 variant (MspI "TC" or BsrDI "AG") genotypes and GSTT1 "null" genotype had higher risk to give birth of FT-LBW. Additionally, among nonexposed ETS mothers, genotype did not independently confer adverse effects on FT-LBW. CONCLUSIONS: Our results revealed that prenatal exposed to ETS is independently associated with FT-LBW while gene polymorphisms of CYP1A1 and GSTs merely play modified roles in this process. This study extends understanding of three-way interaction, and stresses the need to tobacco control toward pregnant women for better pregnant outcomes.

Living with parents or with parents-in-law and postpartum depression: A preliminary investigation in China.

BACKGROUND: Few studies have investigated the association between puerperal women's living situation and postpartum depression. The aim of this study was to examine the association between living with parents or with parents-in-law and postpartum depression among Chinese puerperal women. METHODS: A total of 1126 participants who completed questionnaire were included in our analysis. Postpartum depression status was assessed using the Edinburgh Postnatal Depression Scale. Logistic regression models were used to estimate the association between living with puerperal women's parents or with parents-in-law and risk of postpartum depression after adjustment for potential confounders. RESULTS: The prevalence of postpartum depression among participants was 11.8%. Of the 1126 participants, 524 (46.5%) lived only with their husbands, 387 (34.4%) lived with their parents-in-law, and 215 (19.1%) lived with their parents. Compared with those living only with their husbands, puerperal women living with their parents-in-law had higher risk of postpartum depression after adjustment for potential confounders (OR=2.48; 95% CI: 1.20, 5.15). No association between living with puerperal women's parents and postpartum depression was found after adjustment for confounders (OR=1.05; 95%CI: 0.42, 2.65). LIMITATIONS: Although we adjusted for a wide range of potential confounders, we cannot rule out the possibility of residual confounding by other unmeasured factors, such as breastfeeding, intimate partner violence, and marital relationship. CONCLUSIONS: Our findings suggest that living with parents-in-law may be a risk factor for postpartum depression among Chinese puerperal women. Future preventive interventions should include strategies that target the puerperal women who lived with parents-in-law.

Human Papillomavirus (HPV) infection in women participating in cervical cancer screening from 2006 to 2010 in Shenzhen City, South China.

PURPOSE: Human papillomavirus (HPV) infection plays an important role in the development of cervical cancer, but the prevalence of HPV infection in women of Shenzhen city remains unclear. The present study was performed to describe the change of cervical HPV infection in females who participated in voluntary cervical cancer screening from 2006 to 2010 in Shenzhen city, China. METHODS: A total of 4, 413 women were recruited. HPV infections were genotyped by polymerase chain reaction (PCR) and reversed dot blot hybridization in Shenzhen Maternity and Child Health Hospital. RESULTS: The prevalence of HPV infection was 13.8%. The five most commonly found HPV types were HPV16 (3.47%), HPV58 (1.68%), HPV33 (1.38%), HPV43 (1.36%) and HPV18 (1.27%). The secular trends of major HPV type-specific were diverse. Among of them, the prevalence of HPV18 increased sharply while others increased slowly or even decreased in the period. The change of total HPV, single HPV and multiple HPV infection were similar during the five years. CONCLUSIONS: Our findings suggested that HPV infection is common with HPV16 and HPV 58 as the primary subtypes in women in Shenzhen city. The prevalence of HPV 18 infection is increasing faster than any others, which will lead it to be one of the main subtypes in this city in the future.

Interaction between maternal passive smoking during pregnancy and CYP1A1 and GSTs polymorphisms on spontaneous preterm delivery.

OBJECTIVE: The present study aimed to examine the association between maternal passive smoking during pregnancy and the risk of spontaneous PTD and to explore the potential interaction of the single or joint gene polymorphism of CYP1A1 and GSTs with maternal passive smoking on the risk of spontaneous PTD. METHOD: We investigated whether the association between maternal passive smoking and PTD can be modified by 2 metabolic genes, i.e. cytochrome P4501A1 (CYP1A1) and glutathione S-transferases (GSTs), in a case-control study with 198 spontaneous preterm and 524 term deliveries in Shenzhen and Foshan, China. We used logistic regression to test gene-passive smoking interaction, adjusting for maternal socio-demographics and prepregnancy body mass index. RESULTS: Overall, maternal passive smoking during pregnancy was associated with higher risk of PTD (adjusted odds ratio = 2.20 [95% confidence interval: 1.56-3.12]). This association was modified by CYP1A1 and GSTs together, but not by any single genotype. For cross-categories of CYP1A1 Msp I and GSTs, maternal passive smoking was associated with higher risk of PTD among those women with CYP1A1 "TC/CC"+ GSTs "null", but not among women with other genotypes; and this interaction was significant (OR = 2.66 [95% CI: 1.19-5.97]; P-value: 0.017). For cross-categories of CYP1A1 BsrD I and GSTs, maternal passive smoking was associated with higher risk of PTD only among those women with CYP1A1"AG/GG"+ GSTs "null", but not among women with other genotypes; and this interaction was significant (OR = 3.00 [95% CI: 1.17-7.74]; P-value: 0.023). CONCLUSIONS: Our findings suggest that the combined genotypes of CYP1A1 and GSTs can help to identify vulnerable pregnant women who are subject to high risk of spontaneous PTD due to passive smoking.