[Study on height-weight indices in newborns of different gestational ages].

OBJECTIVE: To establish height-weight indices in newborns of different gestational ages and to provide reference data for evaluation of intrauterine fetal growth. METHODS: The weight, height, crown-rump length, head circumference, and chest circumference of 8 357 newborns were measured in Maternal and Child Health Care Hospital of Bao'an District of shenzhen between 2005 and 2006, with the method of fact-finding investigation with cross-sectional cluster sampling, to establish the height-weight indices in newborns of different gestational ages. RESULTS: Five gender-specific height-weight indices (Quetelet Index, QI; Kaup Index, KI; Rohrer Index, RI; Livi Index, LI; Polock Index, PI) in newborns of different gestational ages (28-44 weeks of gestation) in three different groups (boys+girls, boys, and girls) were established in Shenzhen, China, and were expressed as mean gestational weeks±SD. The five indices above all increased with increasing gestational age, and the highest values appeared at 41-43 gestational weeks, suggesting that body density and enrichment degree increased constantly with increasing gestational age. Three indices (QI, KI and PI) were higher in boys than in girls (P<0.05). CONCLUSIONS: With the increasing gestational age, the body density and enrichment degree of newborns increase, and the enrichment degree in boys is better than that in girls.

The accuracy and influencing factors for preference of self-sampling in group B streptococcus screening: a cross-sectional study.

OBJECTIVE: Self-sampling with proper instruction in 35-37 weeks' gestation is an option to clinician sampling to prevent early-onset invasive group B streptococcal disease of infants. We aimed to assess the accuracy of self-sampling and influencing factors of preference for collection method in Chinese women. METHODS: We compared the screening results of self-sampling with clinician collection in a sample of 520 women in late pregnancy. We collected their demographics, clinical information and preference for collection method. A multi-nominal logistic regression model was used to measure the association between the influencing factors and these participants' preference. RESULTS: A good agreement between the two collection methods was found with a Cohen's Kappa coefficient 0.83 (95%CI = 0.71-0.95). The prevalence of GBS infection in the two methods is statistically different in this low-risk group when self-sampling presented a better outcome in terms of detecting positive cases. Self-sampling is preferable by 20.9% of the participants. No less pain during self-sampling and age older than 35 years old was statistically related to preference for clinician collection. CONCLUSION: The accuracy of self-sampling is no worse than clinician collection. It could be an option for those younger than 35 years old, especially for those who report low pain threshold. Pregnant women are able to collect rectovaginal samples prior to their antenatal visit. Self-sampling followed by appropriate transportation of the sample to an advanced laboratory could eliminate the effects of local laboratory capacity. There are implications in increasing GBS screening participation in resource-limited settings.

A randomised controlled trial in comparing maternal and neonatal outcomes between hands-and-knees delivery position and supine position in China.

BACKGROUND: the supine position is the most frequently offered for birth delivery in China and many other countries, but the hands-and-knees position is now gaining prominence with doctors in China. This study aims to examine the differences in maternal and neonatal outcomes among low-risk women who gave birth either in the hands-and-knees position or the supine position. METHODS: a randomised controlled trial was conducted in 11 hospitals in China from May to December in 2012. In total, 1400 women were recruited and randomly allocated to either the experimental group (n=700, 446 completed the protocol) who delivered in hands-and-knees position and the control group (n=700, 440 completed the protocol) who delivered in supine position. Women who could not maintain the randomised position during the second stage of labour were allowed to withdraw from the study. The primary maternal outcome measured was rate of episiotomy. Secondary outcomes included degree of perineum laceration, rate of emergency caesarean section, rate of shoulder dystocia, and duration of labour, postpartum bleeding, neonatal Apgar score, and the rate of neonatal asphyxia. Because outcome data were only collected for women who gave birth in the randomised position, per-protocol analyses were used to compare groups. The primary outcome, episiotomy, was also compared between groups using logistic regression adjusting for maternal age，gestational age at birth, whether the woman was primiparous, the process of second stage of labour and birthweight. FINDINGS: as compared with the control group, the experimental group had lower rates of episiotomy and second-degree perineum laceration (including episiotomy), and higher rates of intact perineum and first-degree perineum laceration, with a longer duration of second stage of labour. No significant differences were found in the amount of postpartum bleeding, shoulder dystocia, neonatal asphyxia and neonatal Apgar scores at 1minute and 5minutes. Adjusted for maternal age, gestational age, parity, duration of second stage of labour and birth weight, the hands-and-knees position reduced the need for episiotomy (OR=0.024, p<0.001). CONCLUSIONS: this study provided evidence that women who could maintain the hands-and-knees position during the second stage of labour had lower rates of episiotomy and second-degree perineum laceration (including episiotomy). Both midwives and obstetricians are suggested to learn the skills to assist women with delivery in this position.