Maternal body mass index, delivery route, and induction of labor in a midwifery caseload

The purpose of this study was to identify the association between prepregnancy body mass index (BMI), weight gain in pregnancy, and newborn birth weight on route of delivery and induction of labor in patients receiving nurse-midwifery care. This retrospective cohort study examined the outcomes of 1500 consecutively delivered women who were cared for by two midwifery practices and delivered between January 1, 1998, and December 31, 2000. Cesarean delivery was significantly associated with the obese BMI (P < .001), nulliparity (P < .02), and newborn birth weight (P =.006). Prenatal weight gain did not have a significant correlation with cesarean birth (P = .24). In multivariable modeling, obese BMI, high newborn birth weight, nulliparity, and induction of labor increased the risk of cesarean birth. There was also a significant association between higher BMI and risk of induction of labor (P < .001). In a secondary analysis, obese BMI was associated with increased risk of induction in cases with ruptured membranes (OR 2.2; 95% CI 1.4-3.4) and postdates pregnancy (OR 2.0; 95% CI 1.1-3.4).     

Operative Deliveries in Low‐Risk Pregnancies in The Netherlands: Primary versus Secondary Care

ABSTRACT: Background: In The Netherlands, 35 percent of births take place in “primary care” to women considered at low risk and during labor, approximately 30 percent are referred to “secondary care.” High‐risk women and some low‐risk women deliver in secondary care. This study sought to compare planned place of birth and incidence of operative delivery among women at low risk of complications at the time of onset of labor. Methods: A retrospective analysis was conducted of data about births in The Netherlands during 2003 that were recorded routinely in the Netherlands Perinatal Registry. Mode of delivery was analyzed for women classified as low risk at labor onset according to their planned place of birth (intention‐to‐treat analysis). The primary outcome was the rate of operative deliveries (vacuum or forceps extraction or cesarean section). Results: Women at low risk who planned to give birth, and therefore labored and delivered in secondary care, had a significantly higher rate of operative deliveries than women who began labor in primary care where they intended to give birth (18% [3,558/19,850] vs 9% [7,803/87,187]) (OR 2.25, 95% CI 2.00–2.52). For cesarean section, the rates were 12 percent (2,419/19,850) versus 3 percent (2,990/87,817) (OR 3.97, 95% CI 3.15–5.01), irrespective of parity. Conclusions: The rate of operative deliveries was significantly lower for low‐risk pregnant women who gave birth in a primary care setting compared with similar women who planned birth in secondary care. As with any retrospective analysis, it was not possible to eliminate bias, such as possible differences between primary and secondary care in assignment of risk status. In addition, known risk factors for interventions, technologies such as induction of labor and fetal monitoring, are only available in secondary care. These findings clearly demonstrate the need for a prospective study to examine the relationship between planned place of birth and mode of delivery and neonatal and maternal outcomes. (BIRTH 35:4 December 2008)     

Outcomes of Planned Hospital Birth Attended by Midwives Compared with Physicians in British Columbia

ABSTRACT: Background: The impact of midwifery versus physician care on perinatal outcomes in a population of women planning birth in hospital has not yet been explored. We compared maternal and newborn outcomes between women planning hospital birth attended by a midwife versus a physician in British Columbia, Canada. Methods: All women planning a hospital birth attended by a midwife during the 2‐year study period who were of sufficiently low‐risk status to meet eligibility requirements for home birth as defined by the British Columbia College of Midwives were included in the study group (n =488). The comparison group included women meeting the same eligibility requirements but planning a physician‐attended birth in hospitals where midwives also practiced (n =572). Outcomes were ascertained from the British Columbia Reproductive Care Program Perinatal Registry to which all hospitals in the province submit data. Results: Adjusted odds ratios for women planning hospital birth attended by a midwife versus a physician were significantly reduced for exposure to cesarean section (OR 0.58, 95% CI 0.39–0.86), narcotic analgesia (OR 0.26, 95% CI 0.18–0.37), electronic fetal monitoring (OR 0.22, 95% CI 0.16–0.30), amniotomy (OR 0.74, 95% CI 0.56–0.98), and episiotomy (OR 0.62, 95% CI 0.42–0.93). The odds of adverse neonatal outcomes were not different between groups, with the exception of reduced use of drugs for resuscitation at birth (OR 0.19, 95% CI 0.04–0.83) in the midwifery group. Conclusions: A shift toward greater proportions of midwife‐attended births in hospitals could result in reduced rates of obstetric interventions, with similar rates of neonatal morbidity. (BIRTH 34:2 June 2007)     

Associated factors and outcomes of persistent occiput posterior position: A retrospective cohort study from 1976 to 2001

Objective. To identify maternal and fetal risk factors associated with persistent occiput posterior position at delivery, and to examine the association of occiput posterior position with subsequent obstetric outcomes.

Methods. This is a retrospective cohort study of 30 839 term, cephalic, singleton births. Women with persistent occiput posterior (OP) position at delivery were compared to those with occiput anterior (OA) position. Demographics, obstetric history, and labor management were evaluated and subsequent obstetric outcomes examined. Potential confounding variables were controlled for using multivariate logistic regression analysis.

Results. The overall frequency of OP position was 8.3% in the study population. When compared to Caucasians, a higher rate of OP was observed among African-Americans (OR = 1.4, 95% CI 1.25–1.64) while no other racial/ethnic differences were noted. Other associated factors included nulliparity, maternal age ≥35, gestational age ≥41 weeks, and birth weight >4000 g, as well as artificial rupture of the membranes (AROM) and epidural anesthesia (p < 0.001 for all). Persistent OP was associated with increased rates of operative vaginal (OR = 4.14, 95% CI 3.57–4.81) and cesarean deliveries (OR = 13.45, 95% CI 11.94–15.15) and other peripartum complications including third or fourth degree perineal lacerations (OR = 2.38, 95% CI 2.03–2.79), and chorioamnionitis (OR = 2.10, 95% CI 1.81–2.44).

Conclusion. Epidural use, AROM, African-American ethnicity, nulliparity, and birth weight >4000 g are associated with persistent OP position at delivery, with higher rates of operative deliveries and obstetric complications. This information can be useful in counseling patients regarding risks and associated outcomes of persistent OP position.     

Evaluation of a Student‐Nurse Doula Program: An Analysis of Doula Interventions and Their Impact on Labor Analgesia and Cesarean Birth

Introduction: The aim of this study was to describe specific doula interventions, explore differences in doula interventions by attending provider (certified nurse‐midwife vs obstetrician), and examine associations between doula interventions, labor analgesia, and cesarean birth in women receiving doula care from student nurses. Methods: A secondary analysis of data from the Birth Companions Program at the Johns Hopkins University School of Nursing was conducted using t tests, chi‐square statistics, and logistic regression models. Results: In the 648 births in the sample, doulas used approximately 1 more intervention per labor with certified nurse‐midwife clients compared to obstetrician clients. In multivariate analysis, the increase in the total number of interventions provided by doulas was associated with decreased odds of epidural (adjusted odds ratio [AOR] 0.92; 95% confidence interval [CI], 0.86‐0.98) and cesarean birth (AOR 0.90; 95% CI, 0.85‐0.95). When examined separately, a greater number of physical interventions was associated with decreased odds of epidural (AOR 0.85; 95% CI, 0.78‐0.92) and cesarean birth (AOR 0.80; 95% CI, 0.73‐0.88), but number of emotional/informational interventions was not. Discussion: Student nurses trained as doulas have the opportunity to provide a variety of interventions for laboring clients. An increase in the number of interventions, especially physical interventions, provided by doulas may decrease the likelihood of epidural use and cesarean birth.     

Older Maternal Age and Intervention in Labor: A Population‐Based Study Comparing Older and Younger First‐Time Mothers in Victoria,Australia

Background: In Australia, birth rates for women aged 35 years or more are significant and increasing and a considerable percentage are first births. This study investigated the effect of maternal age on interventions in labor and birth for primiparous women aged 35 to 44 years compared with primiparous women aged 25 to 29 years. Methods: All primiparous women who gave birth in Victoria, Australia, in 2005 and 2006 (n = 57,426) were included in this population‐based cross‐sectional study. Women were stratified by admission status (private/public). Main outcome measures were induction of labor, augmentation of labor, use of epidural analgesia, and method of birth. Multivariate logistic regression was used to explore the relationship between maternal age and cesarean adjusted for confounders. Results: Older women were more likely to give birth by cesarean section whether admitted as public or private patients. For private patients, total cesarean rates were 31.8 percent (25–29 yr), 46.0 percent (35–39 yr), and 60.0 percent (40–44 yr; p < 0.001) compared with 27.5, 41.6, and 53.4 percent for public patients (p < 0.001). Older women who experienced labor were more likely to have an instrumental vaginal birth or an emergency cesarean section than younger women. Both were more common in women admitted as private patients. Age‐related trends were also seen for induction of labor and use of epidural analgesia. Rates were higher for private patients. Rates of induction were (37.8, 40.2, and 42.5%) for private patients compared with (32.1, 36.7, and 40.1%) for public patients and rates for epidural were (45.3, 49.9, and 48.1%) among private patients compared with (33.3, 38.8, and 39.3%) among public patients. Conclusions: Interventions in labor and birth increased with maternal age, and this effect was seen particularly for cesarean section among women admitted privately. These findings were not fully explained by the complications we considered. (BIRTH 38:1 March 2011)     

Maternal Temperature Elevation and Occiput Posterior Position at Birth Among Low‐Risk Women Receiving Epidural Analgesia

Introduction: To evaluate the relationship between maternal temperature elevation and occiput posterior position at birth as well as the association of fetal head position and temperature elevation on method of birth among women receiving epidural analgesia. Methods: We conducted a secondary analysis of data from the Fetal Orientation during Childbirth by Ultrasound Study (FOCUS), which used serial ultrasounds to evaluate the effect of epidural anesthesia on fetal position at birth in low‐risk women. The current analysis was limited to the 1428 study participants who received epidural analgesia. Results: In our population, 47% (n = 669) of women had a maximum intrapartum temperature greater than or equal to 99.6°F (37.6°C). The prevalence of fetal occiput posterior position at admission did not differ between women who later developed temperature elevations (24.4%) and those who did not (23.6%, P= .70). Women who developed an elevated temperature greater than or equal to 99.6°F (37.6°C) had an increased risk of occiput posterior fetal head position at birth regardless of the amount of temperature elevation (odds ratio [OR]= 2.0; 95% confidence interval [CI], 1.5‐2.8); the association persisted after control for potentially confounding factors (adjusted OR = 1.5; 95% CI, 1.1‐2.1). The cesarean birth rate among women with both temperature elevation and occiput posterior position at birth was more than 12 times the rate of women with neither risk factor (adjusted OR = 12.6; 95% CI, 7.5‐21.2). Discussion: Intrapartum temperature elevation among women receiving epidural analgesia, even if only to 99.6°F (37.6°C), is associated with approximately a 2‐fold increase in the occurrence of occiput posterior fetal head position at birth. Additionally, although this observational study cannot establish causal links, our findings suggest that the relationship between epidural‐related intrapartum temperature elevation and occiput posterior position at birth could contribute to an increased cesarean birth rate among women receiving epidural analgesia for pain relief in labor.     

In‐Hospital Birth Center with the Same Medical Guidelines as Standard Care: A Comparative Study of Obstetric Interventions and Outcomes

Background: A challenge of obstetric care is to optimize maternal and infant health outcomes and the mother’s experience of childbirth with the least possible intervention in the normal process. The aim of this study was to investigate the effects of modified birth center care on obstetric procedures during delivery and on maternal and neonatal outcomes. Methods: In a cohort study 2,555 women who signed in for birth center care during pregnancy were compared with all 9,382 low‐risk women who gave birth in the standard delivery ward in the same hospital from March 2004 to July 2008. Odds ratios (OR) were calculated with 95% confidence interval (CI) and adjusted for maternal background characteristics, elective cesarean section, and gestational age. Results: The modified birth center group included fewer emergency cesarean sections (primiparas: OR: 0.69, 95% CI: 0.58–0.83; multiparas: OR: 0.34, 95% CI: 0.23–0.51), and in multiparas the vacuum extraction rate was reduced (OR: 0.42, 95% CI: 0.26–0.67). In addition, epidural analgesia was used less frequently (primiparas: OR: 0.47, 95% CI: 0.41–0.53; multiparas: OR: 0.25, 95% CI: 0.20–0.32). Fetal distress was less frequently diagnosed in the modified birth center group (primiparas: OR: 0.72, 95% CI: 0.59–0.87; multiparas: OR: 0.45, 95% CI: 0.29–0.69), but no statistically significant differences were found in neonatal hypoxia, low Apgar score less than 7 at 5 minutes, or proportion of perinatal deaths (OR: 0.40, 95% CI: 0.14–1.13). Anal sphincter tears were reduced (primiparas: OR: 0.73, 95% CI: 0.55–0.98; multiparas: OR: 0.41, 95% CI: 0.20–0.83). Conclusion: Midwife‐led comprehensive care with the same medical guidelines as in standard care reduced medical interventions without jeopardizing maternal and infant health. (BIRTH 38:2 June 2011)     

Crack abuse during pregnancy: maternal,fetal and neonatal complication

Objective: The aim of this study was to assess the effects of crack on pregnancy outcomes.

Methods: We studied 88 crack user pregnant women in this study. These women were matched to a drug-free group (n?=?90) chosen from the population of the same hospital. Maternal outcomes including preeclampsia, placenta abruption, gestational diabetes and preterm labor, and neonatal complication including low birth weight and low Apgar score in 5?min were compared in crack using and drug-free groups. Data were analyzed by SPSS software. Chi-square test and Student’s t-test and Relative Risks (RRs) were used in this study.

Results: The results of our study showed that crack abuse during pregnancy was associated with higher rate of preeclampsia p?=?0.003 (RR, 1.731; 95% CI, 1.777–2.545), placental abruption p?=?0.001 (RR, 2.439; 95% CI, 1.369–4.343), preterm labor p?<?0.000 (RR, 3.249; 95% CI, 2.053–5.141) and low birth weight p?<?0.000 (RR, 2.179; 95% CI, 1.462–3.247).

Conclusions: Crack abuse had significant influence on pregnancy outcomes. Crack appears to influence the prevalence of low birth weight, preterm labor, preeclampsia and placental abruption.     

Risk factors for arrest of descent during the second stage of labor.

OBJECTIVE: To define obstetrical risk factors for arrest of descent during the second stage of labor and to determine perinatal outcome. STUDY DESIGN: All singleton, vertex, term deliveries with an unscarred uterus, between the years 1988 and 1999 were included. Univariable and multivariable analysis were performed to investigate independent risk factors associated with arrest of descent during the second stage of labor and the perinatal outcome. RESULTS: The study included 93266 deliveries, of these 1545 (1.7%) were complicated with arrest of descent during the second stage of labor. Using a multivariable analysis, the following obstetric risk factors were found to be significantly associated with arrest of descent: nulliparity (OR=7.8, 95% CI=6.9-8.7; P<0.001), birth weight >4 kg (OR=2.3, 95% CI=1.9-2.8; P<0.001), epidural analgesia (OR=1.8, 95% CI=1.6-2.0; P<0.001), hydramnios (OR=1.6, 95% CI=1.3-2.0; P<0.001), hypertensive disorders (OR=1.5, 95% CI=1.3-1.8; P<0.001), gestational diabetes A1 and A2 (OR=1.5, 95% CI=1.2-1.8; P<0.001), male gender (OR=1.4, 95% CI=1.2-1.5; P<0.001), premature rupture of membranes (PROM, OR=1.3, 95% CI=1.04-1.6; P=0.021), and induction of labor (OR=1.2, 95% CI=1.02-1.4; P=0.030). Deliveries complicated by arrest of descent resulted in cesarean section in 20.6%, vacuum extraction in 74.0%, and forceps delivery in 5.4%. Newborns delivered after arrest of descent during the second stage of labor had significantly higher rates of low Apgar scores (<7) at 1 and 5 min, as compared to the controls (12.7 vs. 2.1%, P<0.001; and 0.9 vs. 0.2%, P<0.001, respectively). Nevertheless, no significant differences were noted between the groups regarding perinatal mortality (0.38 vs. 0.44%; P=0.759). CONCLUSIONS: Major risk factors for arrest of descent during the second stage of labor were nulliparity, fetal macrosomia, epidural analgesia, hydramnios, hypertensive disorders and gestational diabetes mellitus. These risk factors should be carefully evaluated during pregnancy in order to actively manage high-risk pregnancies.     

Subsequent obstetrics outcomes after intrauterine death during the first pregnancy

Abstract

Objective: We aimed to determine whether the risks of adverse outcomes were greater in women who had pregnancies ending in stillbirth than in those with no previous history of stillbirth.

Methods: This retrospective cohort study included all women who had undergone their first and second deliveries at Bakirkoy Women’s and Children’s Education and Research Hospital between 2002 and 2011. Women who delivered following a previous stillbirth after 20 complete weeks of gestation were compared with those who had delivered but had no history of stillbirth after 20 weeks of gestation.

Results: We compared 201 subsequent births to women with previous histories of stillbirth with 402 live births to women with no such history. The rates of pre-eclampsia [odds ratio (OR), 3.4; 95% confidence interval (CI), 1.5–7.4], HELLP syndrome (OR, 3.1; 95% CI, 1.2–9.6), low birth weight (OR, 1.6; 95% CI, 0.7–3.5) and malpresentation (OR, 2.9; 95% CI, 1.6–4.8) were significantly higher in the case group. Howewer, the rates of stillbirth were similar between the groups.

Conclusion: We found increased rates of obstetric and perinatal complications in subsequent pregnancies in women with histories of stillbirth. Thus, the results of this study suggest that pregnant women with histories of stillbirth should be followed closely, beginning in the early gestational period.     

Mode of Delivery after Epidural Analgesia in a Cohort of Low‐Risk Nulliparas

Abstract: Background: Although epidural analgesia is widespread and very effective for alleviating labor pain, its use is still controversial, as the literature is inconsistent about the risk of adverse birth outcome after administration of epidural analgesia. The aim of this study was to explore associations between epidural analgesia and mode of delivery. Methods: Data were obtained from a prospective cohort from nine Danish labor wards and comprised 2,721 term nulliparous women with spontaneous onset of labor and a singleton fetus in cephalic presentation. Information about epidural analgesia, mode of delivery, and birth complications was obtained by the staff attending labor. Additional information was provided from self‐administered questionnaires in gestational week 37. Multiple logistic regression analyses were used to estimate the association between epidural analgesia and birth outcomes. Results are presented as crude and adjusted odds ratios (OR [95% CI]). Results: Of the total cohort, 21.6 percent required epidural analgesia, 8.7 percent had emergency cesarean section, and 14.9 percent had vacuum extraction. Women with epidural analgesia had a higher risk of emergency cesarean section (adjusted OR: 5.8; 95% CI: 4.1–8.1), and vacuum extraction (adjusted OR: 1.7; 95% CI: 1.3–2.2). In a subgroup of the cohort with a very low overall risk of cesarean section, 3.4 percent had emergency cesarean section and an increased risk of emergency cesarean section was also found in this group (adjusted OR: 3.5; 95% CI: 1.5–8.2). Conclusions: In nulliparous women of a very low‐risk population, use of epidural analgesia for labor pain was associated with higher risks of emergency cesarean section and vacuum extraction. (BIRTH 38:4 December 2011)     

Epidural analgesia and severe perineal tears: a literature review and large cohort study

Abstract

Objective: Our objectives were to study the association between epidural analgesia and risk of severe perineal tears (SPT), and identify additional risk factors for SPT.

Methods: We conducted a historical cohort study of women with term delivery between 2006 and 2011. Inclusion criteria were an uncomplicated singleton pregnancy, cephalic presentation and vaginal delivery. Multivariate logistic regression models were constructed to study the association between epidural analgesia and SPT, controlling for potential confounders. Additional models studied the association between prolonged second stage and instrumental labor and SPT.

Results: During the study period, 61?308 eligible women gave birth, 31?631 (51.6%) of whom received epidural analgesia. SPT occurred in 0.3% of births. Deliveries with epidural had significantly higher rates of primiparity, induction and augmentation of labor, prolonged second stage of labor, instrumental births and midline episiotomies. The univariate analysis showed a significant association between the use of epidural and SPT (OR: 1.78, 95% CI: 1.34–2.36); however, this association disappeared when parity was introduced (OR: 0.95, 95% CI: 0.69–1.29). Instrumental deliveries and prolonged second stage of labor were both strongly associated with SPT (ORs of 1.82 and 1.77)

Conclusions: Epidural analgesia was not associated with SPT once confounding factors were controlled for.     

Uterine rupture and risk factors for caesarean delivery following induced labour in women with one previous lower segment caesarean section

Objective: To determine the outcome of induction of labor, specifically incidence of uterine rupture and reliable predictors of repeat caesarean delivery, in women undergoing induction of labor after previous caesarean section. Methods: A review of obstetric and perinatal records of 167 women who had their labor induced after one transverse lower uterine incision performed at previous caesarean delivery in a referral tertiary hospital in Nigeria between January 2006 and December 2009. Results: The incidence of uterine rupture was 2.4%. Independent risk factors for repeat caesarean delivery were absence of prior vaginal delivery (OR 3.7; 95% CI 1.9–7.1), duration of latent phase >2?h (OR 4.3; 95% CI 1.7–11.2), postdated pregnancy (OR 2.2; 95% CI 1.1–4.0) and previous caesarean for non-recurrent indication (OR 2.1; 95% CI 1.1–4.0). Conclusion: Choice of appropriate delivery option for this cohort of women based on the identified risk factors is essential to minimize the incidence of failed vaginal birth and its associated adverse maternal and neonatal outcome.     

Mode of delivery and other pregnancy outcomes of patients with documented scoliosis

The aim of this study was to explore whether scoliosis is a risk factor for adverse obstetric outcomes and specifically for cesarean delivery (CD) and labor dystocia. Association between scoliosis and pregnancy outcome was studied before. Confounding conclusions prevent proper counseling of patients. Appropriate statistical analysis of a suitable cohort is helpful in resolving this issue. A retrospective population-based study comparing all singleton pregnancies of women with and without documented scoliosis was conducted. Deliveries occurred between the years 1988 and 2009. Multiple logistic regression models were used to control for confounders. Out of 229,116 patients which were included in our cohort, 0.043% (n?=?98) had a documented scoliosis. These patients had higher rates of fertility treatments (7.1% vs. 1.6%; p?<?0.001). Scoliosis was found to be significantly associated with labor induction (36.7% vs. 26.3 %; p?=?0.02) and cesarean deliveries (21.4% vs. 13.1%; p?=?0.014). Using multiple logistic regression models, with CD as the outcome variable, controlling for confounders such as nulliparity, labor induction and maternal age, scoliosis was not found to be an independent risk factor for CD (OR?=?1.56, 95% CI 1.9–2.7; p?=?0.121). Scoliosis is not a risk factor for adverse pregnancy outcome, and specifically for labor dystocia.     

Adenomyosis and adverse perinatal outcomes: increased risk of second trimester miscarriage,preeclampsia, and placental malposition

Objective: To evaluate the potential impact of adenomyosis on the pregnancy outcomes by retrospectively investigating adenomyosis-complicated pregnancy cases.

Methods: We performed a retrospective case–control study. Forty-nine singleton pregnancy cases complicated with adenomyosis were included in this study. The controls (n?=?245) were singleton pregnant women without adenomyosis and were frequency matched to adenomyosis cases by age, parity, and the need for assisted reproductive technology for this conception. The incidence of obstetrical complications and delivery and neonatal outcomes were examined.

Results: Patients in the adenomyosis group were significantly more likely to have a second trimester miscarriage (12.2% versus 1.2%, odds ratio (OR): 11.2, 95% confidence interval (95% CI): 2.2–71.2), preeclampsia (18.3% versus 1.2%, OR: 21.0, 95% CI: 4.8–124.5), placental malposition (14.2% versus 3.2%, OR: 4.9, 95% CI: 1.4–16.3), and preterm delivery (24.4% versus 9.3%, OR: 3.1, 95% CI: 1.2–7.2), compared with the control group.

Conclusion: Adenomyosis was associated not only with an increased incidence of preterm delivery, as previously reported, but also with an increased risk of second trimester miscarriage, preeclampsia, and placental malposition, which could lead to poor perinatal outcomes.     

Obstetric outcomes subsequent to intrauterine death in the first pregnancy

Objective  To compare obstetric outcomes in the pregnancy subsequent to intrauterine death with that following live birth in first pregnancy.
Design  Retrospective cohort study.
Setting  Grampian region of Scotland, UK.
Population  All women who had their first and second deliveries in Grampian between 1976 and 2006.
Methods  All women delivering for the first time between 1976 and 2002 had follow up until 2006 to study their next pregnancy. Those women who had an intrauterine death in their first pregnancy formed the exposed cohort, while those who had a live birth formed the unexposed cohort.
Main outcome measures  Maternal and neonatal outcomes in the second pregnancy, including pre-eclampsia, placental abruption, induction of labour, instrumental delivery, caesarean delivery, malpresentation, prematurity, low birthweight and stillbirth.
Results  The exposed cohort ( n = 364) was at increased risk of pre-eclampsia (OR 3.1, 95% CI 1.7–5.7); placental abruption (OR 9.4, 95% CI 4.5–19.7); induction of labour (OR 3.2, 95% CI 2.4–4.2); instrumental delivery (OR 2.0, 95% CI 1.4–3.0); elective (OR 3.1, 95% CI 2–4.8) and emergency caesarean deliveries (OR 2.1, 95% CI 1.5–3.0); and prematurity (OR 2.8, 95% CI 1.9–4.2), low birthweight (OR 2.8, 95% CI 1.7–4.5) and malpresentation (OR 2.8, 95% CI 2.0–3.9) of the infant as compared with the unexposed cohort ( n = 33 715). The adjusted odds ratio for stillbirth was 1.2 and 95% CI 0.4–3.4.
Conclusion  While the majority of women with a previous stillbirth have a live birth in the subsequent pregnancy, they are a high-risk group with an increased incidence of adverse maternal and neonatal outcomes.     

The impact of fetal gender on preterm birth in a southern Chinese population

Objective: This study was conducted to determine whether carrying a singleton male fetus increases the risk of preterm birth (PTB) in Chinese women. Methods: A retrospective cohort study was conducted on women with singleton pregnancies and delivered in our hospital. Maternal characteristics, pregnancy outcome, and incidence of PTB, were compared between women carrying a male versus a female fetus. The independent effect of a male fetus on PTB was examined with multiple logistic regression analysis adjusting for the other confounding factors identified. Results: There were significant differences in maternal and infant characteristics between women with a male versus a female fetus. Despite similar or lower incidences of complications and labor induction, women with a male fetus had increased birth <37 weeks (7.0% versus 6.2%, p?<?0.001) and birth at 34–36 weeks (5.15% versus 4.4%, p?<?0.001), but not for birth <34 weeks (2.0% versus 1.8%, p?=?0.163). Regression analysis confirmed the association between male fetus with birth at 34–36 weeks (aOR 1.11, 95% CI 1.10–1.33) and spontaneous preterm labor (aOR 1.09, 95% CI 1.00–1.19). Conclusions: The results confirmed that carrying a male fetus is an independent risk factor for spontaneous preterm labor and PTB at 34–36 weeks gestation in southern Chinese women.     

The effect of prepregnancy body mass index on birth weight,preterm birth,cesarean section,and preeclampsia in pregnant women

Objective: The objective of this study is to determine the impact of maternal prepregnancy BMI on birth weight, preterm birth, cesarean section, and preeclampsia among pregnant women delivering singleton life birth.

Methods: A cross-sectional study of 4397 women who gave singleton birth in Tehran, Iran from 6 to 21 July 2015, was conducted. Women were categorized into four groups: underweight (BMI?2), normal (BMI 18.5–25?kg/m²), overweight (BMI 25–30?kg/m²) and obese (BMI >30?kg/m²), and their obstetric and infant outcomes were analyzed using both univariate and multivariate logistic regression.

Results: Prepregnancy BMI of women classified 198 women as underweight (4.5%), 2293 normal (52.1%), 1434 overweight (32.6%), and 472 as obese (10.7%). In comparison with women of normal weight, women who were overweight or obese were at increased risk of preeclampsia (odds ratio (OR)?=?1.47, 95% CI?=?1.06–2.02; OR?=?3.67, 95% CI?=?2.57–5.24, respectively) and cesarean section (OR?=?1.21, 95% CI?=?1.04–1.41; OR?=?1.35, 95% CI?=?1.06–1.72, respectively). Infants of obese women were more likely to be macrosomic (OR?=?2.43, 95% CI?=?1.55–3.82).

Conclusion: Prepregnancy obesity is a risk factor for macrosomia, preeclampsia, and cesarean section and need for resuscitation.