Dataset Information

Women's prepregnancy underweight as a risk factor for preterm birth: a retrospective study.

ABSTRACT:

Objective

To investigate the distribution of known factors for preterm birth (PTB) by severity of maternal underweight; to investigate the risk-adjusted relation between severity of underweight and PTB, and to assess whether the relation differed by gestational age.

Design

Retrospective cohort study.

Setting

State of California, USA.

Methods

Maternally linked hospital and birth certificate records of 950 356 California deliveries in 2007-2010 were analysed. Singleton live births of women whose prepregnancy body mass index (BMI) was underweight (<18.5 kg/m² ) or normal (18.50-24.99 kg/m² ) were analysed. Underweight BMI was further categorised as: severe (<16.00), moderate (16.00-16.99) or mild (17.00-18.49). PTB was grouped as 22-27, 28-31, 32-36 or <37 weeks (compared with 37-41 weeks). Adjusted multivariable Poisson regression modeling was used to estimate relative risk for PTB.

Main outcome measures

Risk of PTB.

Results

About 72 686 (7.6%) women were underweight. Increasing severity of underweight was associated with increasing percent PTB: 7.8% (n = 4421) in mild, 9.0% (n = 1001) in moderate and 10.2% (475) in severe underweight. The adjusted relative risk of PTB also significantly increased: adjusted relative risk (aRR) = 1.22 (95% CI 1.19-1.26) in mild, aRR = 1.41 (95% CI 1.32-1.50) in moderate and aRR = 1.61 (95% CI 1.47-1.76) in severe underweight. These findings were similar in spontaneous PTB, medically indicated PTB, and the gestational age groupings.

Conclusion

Increasing severity of maternal prepregnancy underweight BMI was associated with increasing risk-adjusted PTB at <37 weeks. This increasing risk was of similar magnitude in spontaneous and medically indicated births and in preterm delivery at 28-31 and at 32-36 weeks of gestation.

Tweetable abstract

Increasing severity of maternal underweight BMI was associated with increasing risk of preterm birth.

SUBMITTER: Girsen AI

PROVIDER: S-EPMC5069076 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Women's prepregnancy underweight as a risk factor for preterm birth: a retrospective study.

Girsen A I AI Mayo J A JA Carmichael S L SL Phibbs C S CS Shachar B Z BZ Stevenson D K DK Lyell D J DJ Shaw G M GM Gould J B JB

BJOG : an international journal of obstetrics and gynaecology 20160513 12

<h4>Objective</h4>To investigate the distribution of known factors for preterm birth (PTB) by severity of maternal underweight; to investigate the risk-adjusted relation between severity of underweight and PTB, and to assess whether the relation differed by gestational age.<h4>Design</h4>Retrospective cohort study.<h4>Setting</h4>State of California, USA.<h4>Methods</h4>Maternally linked hospital and birth certificate records of 950 356 California deliveries in 2007-2010 were analysed. Singleton ...[more]

PMID: 27172996

Similar Datasets

Project description:OBJECTIVE: To determine whether a short interval between pregnancies is an independent risk factor for adverse obstetric outcome. DESIGN: Retrospective cohort study. SETTING: Scotland. SUBJECTS: 89 143 women having second births in 1992-8 who conceived within five years of their first birth. MAIN OUTCOME MEASURES: Intrauterine growth restriction (birth weight less than the 5th centile for gestational age), extremely preterm birth (24-32 weeks), moderately preterm birth (33-36 weeks), and perinatal death. RESULTS: Women whose subsequent interpregnancy interval was less than six months were more likely than other women to have had a first birth complicated by intrauterine growth restriction (odds ratio 1.3, 95% confidence interval 1.1 to 1.5), extremely preterm birth (4.1, 3.2 to 5.3), moderately preterm birth (1.5, 1.3 to 1.7), or perinatal death (24.4, 18.9 to 31.5). They were also shorter, less likely to be married, and more likely to be aged less than 20 years at the time of the second birth, to smoke, and to live in an area of high socioeconomic deprivation. When the outcome of the second birth was analysed in relation to the preceding interpregnancy interval and the analysis confined to women whose first birth was a term live birth (n = 69 055), no significant association occurred (adjusted for age, marital status, height, socioeconomic deprivation, smoking, previous birth weight vigesimal, and previous caesarean delivery) between interpregnancy interval and intrauterine growth restriction or stillbirth. However, a short interpregnancy interval (< 6 months) was an independent risk factor for extremely preterm birth (adjusted odds ratio 2.2, 1.3 to 3.6), moderately preterm birth (1.6, 1.3 to 2.0), and neonatal death unrelated to congenital abnormality (3.6, 1.2 to 10.7). The adjusted attributable fractions for these associations were 6.1%, 3.9%, and 13.8%. The associations were very similar when the analysis was confined to married non-smokers aged 25 and above. CONCLUSIONS: A short interpregnancy interval is an independent risk factor for preterm delivery and neonatal death in the second birth.

Project description:INTRODUCTION:Bacterial vaginosis (BV) and vaginal microbiota disruption during pregnancy are associated with increased risk of spontaneous preterm birth (SPTB), but clinical trials of BV treatment during pregnancy have shown little or no benefit. An alternative hypothesis is that vaginal bacteria present around conception may lead to SPTB by compromising the protective effects of cervical mucus, colonising the endometrial surface before fetal membrane development, and causing low-level inflammation in the decidua, placenta and fetal membranes. This protocol describes a prospective case-cohort study addressing this hypothesis. METHODS AND ANALYSIS:HIV-seronegative Kenyan women with fertility intent are followed from preconception through pregnancy, delivery and early postpartum. Participants provide monthly vaginal specimens during the preconception period for vaginal microbiota assessment. Estimated date of delivery is determined by last menstrual period and first trimester obstetrical ultrasound. After delivery, a swab is collected from between the fetal membranes. Placenta and umbilical cord samples are collected for histopathology. Broad-range 16S rRNA gene PCR and deep sequencing of preconception vaginal specimens will assess species richness and diversity in women with SPTB versus term delivery. Concentrations of key bacterial species will be compared using quantitative PCR (qPCR). Taxon-directed qPCR will also be used to quantify bacteria from fetal membrane samples and evaluate the association between bacterial concentrations and histopathological evidence of inflammation in the fetal membranes, placenta and umbilical cord. ETHICS AND DISSEMINATION:This study was approved by ethics committees at Kenyatta National Hospital and the University of Washington. Results will be disseminated to clinicians at study sites and partner institutions, presented at conferences and published in peer-reviewed journals. The findings of this study could shift the paradigm for thinking about the mechanisms linking vaginal microbiota and prematurity by focusing attention on the preconception vaginal microbiota as a mediator of SPTB.

Project description:BackgroundIn vitro fertilization (IVF) births contribute to a considerable proportion of preterm birth (PTB) each year. However, there is no formal surveillance of adverse perinatal outcomes for less invasive fertility treatments. The study objective was to describe associations between fertility treatment (in vitro fertilization, intrauterine insemination, usually with ovulation drugs (IUI), or ovulation drugs alone) and preterm birth, compared to no treatment in subfertile women.MethodsThe Fertility Experiences Study (FES) is a retrospective cohort study conducted at the University of Utah between April 2010 and September 2012. Women with a history of primary subfertility self-reported treatment data via survey and interviews. Participant data were linked to birth certificates and fetal death records to asses for perinatal outcomes, particularly preterm birth.ResultsA total 487 birth certificates and 3 fetal death records were linked as first births for study participants who completed questionnaires. Among linked births, 19% had a PTB. After adjustment for maternal age, paternal age, maternal education, annual income, religious affiliation, female or male fertility diagnosis, and duration of subfertility, the odds ratios and 95% confidence intervals (CI) for PTB were 2.17 (CI 0.99, 4.75) for births conceived using ovulation drugs, 3.17 (CI 1.4, 7.19) for neonates conceived using IUI and 4.24 (CI 2.05, 8.77) for neonates conceived by IVF, compared to women with subfertility who used no treatment during the month of conception. A reported diagnosis of female factor infertility increased the adjusted odds of having a PTB 2.99 (CI 1.5, 5.97). Duration of pregnancy attempt was not independently associated with PTB. In restricting analyses to singleton gestation, odds ratios were not significant for any type of treatment.ConclusionIVF, IUI, and ovulation drugs were all associated with a higher incidence of preterm birth and low birth weight, predominantly related to multiple gestation births.

Project description:PurposeWhile it is well documented that maternal adverse exposures contribute to a series defects on offspring health according to the Developmental Origins of Health and Disease (DOHaD) theory, paternal evidence is still insufficient. Advanced paternal age is associated with multiple metabolism and psychiatric disorders. Birth weight is the most direct marker to evaluate fetal growth. Therefore, we designed this study to explore the association between paternal age and birth weight among infants born at term and preterm (<37 weeks gestation).MethodsA large retrospective study was conducted using population-based hospital data from January 2015 to December 2019 that included 69,964 cases of singleton infant births with complete paternal age data. The primary outcome was infant birth weight stratified by sex and gestational age including small for gestational age (SGA, 10th percentile) and large for gestational age (LGA, 90th percentile). Birth weight percentiles by gestational age were based on those published in the INTERGROWTH-21st neonatal weight-for gestational-age standard. Logistic regression analysis and linear regression model were used to estimate the association between paternal age and infant birth weight.ResultsAdvanced paternal age was associated with a higher risk for a preterm birth [35-44 years: adjusted odds ratio (OR) = 1.13, 95%CI (1.03 to 1.24); >44 years: OR = 1.36, 95%CI (1.09 to 1.70)]. Paternal age exerted an opposite effect on birth weight with an increased risk of SGA among preterm infants (35-44years: OR = 1.85, 95%CI (1.18 to 2.89) and a decreased risk among term infant (35-44years: OR = 0.81, 95%CI (0.68 to 0.98); >44 years: OR = 0.50, 95%CI (0.26 to 0.94). U-shaped associations were found in that LGA risk among term infants was higher in both younger (<25 years) (OR = 1.32; 95%CI, 1.07 to 1.62) and older (35-44 years) (OR = 1.07; 95% CI, 1.01 to 1.14) fathers in comparison to those who were 25 to 34 years old at the time of delivery.ConclusionsOur study found advanced paternal age increased the risk of SGA among preterm infants and for LGA among term infants. These findings likely reflect a pathophysiology etiology and have important preconception care implications and suggest the need for antenatal monitoring.

Dataset Information

Women's prepregnancy underweight as a risk factor for preterm birth: a retrospective study.

Objective

Design

Setting

Methods

Main outcome measures

Results

Conclusion

Tweetable abstract

Publications

Women's prepregnancy underweight as a risk factor for preterm birth: a retrospective study.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets