Indicated preterm birth for fetal anomalies

Recurrent preterm birth risk assessment for two delivery subtypes: A multivariable analysis

OBJECTIVE

The study sought to develop and apply a framework that uses a clinical phenotyping tool to assess risk for recurrent preterm birth.

MATERIALS AND METHODS

We extended an existing clinical phenotyping tool and applied a 4-step framework for our retrospective cohort study. The study was based on data collected in the Genomic and Proteomic Network for Preterm Birth Research Longitudinal Cohort Study (GPN-PBR LS). A total of 52 sociodemographic, clinical and obstetric history-related risk factors were selected for the analysis. Spontaneous and indicated delivery subtypes were analyzed both individually and in combination. Chi-square analysis and Kaplan-Meier estimate were used for univariate analysis. A Cox proportional hazards model was used for multivariable analysis.

RESULTS

: A total of 428 women with a history of spontaneous preterm birth qualified for our analysis. The predictors of preterm delivery used in multivariable model were maternal age, maternal race, household income, marital status, previous caesarean section, number of previous deliveries, number of previous abortions, previous birth weight, cervical insufficiency, decidual hemorrhage, and placental dysfunction. The models stratified by delivery subtype performed better than the naïve model (concordance 0.76 for the spontaneous model, 0.87 for the indicated model, and 0.72 for the naïve model).

DISCUSSION

The proposed 4-step framework is effective to analyze risk factors for recurrent preterm birth in a retrospective cohort and possesses practical features for future analyses with other data sources (eg, electronic health record data).

CONCLUSIONS

We developed an analytical framework that utilizes a clinical phenotyping tool and performed a survival analysis to analyze risk for recurrent preterm birth.

Optimizing Term Delivery and Mode of Delivery

Full-term deliveries are defined as occurring between 39 weeks and 40 weeks and 6 days. Because contemporary research suggests improved outcomes with delivery in the term period compared with the early term period, nonindicated delivery should be pursued no earlier than 39 weeks. There are, however, multiple medical, obstetric, and fetal indications for delivery before 39 weeks, and the obstetric provider must weigh the risks and benefits of delivery versus expectant management on both the mother and fetus. This review serves to provide a basic framework of evidentiary support toward optimizing the term delivery.

The Impact of Fetal Anomalies on Contemporary Labor Patterns

OBJECTIVE

To compare labor patterns in pregnancies affected by fetal anomalies to low-risk singletons.

STUDY DESIGN

Labor data from the Consortium on Safe Labor, a multicenter retrospective study from 19 U.S. hospitals, including 98,674 low-risk singletons compared with 6,343 pregnancies with fetal anomalies were analyzed. Repeated-measures analysis constructed mean labor curves by parity, gestational age, and presence of fetal anomaly in women who reached full dilation. Interval-censored regression analysis adjusted for covariables was used to determine the median traverse times for labor progression.

RESULTS

Labor curves for all groups indicated slower labor progress for patients with fetal anomalies. The most significant trends in median traverse times were observed in the preterm nulliparous and term multiparous groups. The median traverse times from 4 cm to complete dilation in the preterm nulliparous control versus anomaly groups were 5.0 and 5.4 hours (p < 0.0001).

CONCLUSION

Labor proceeds at a slower rate in pregnancies affected by anomalies.

Intrauterine fetal demise after prenatal diagnosis of congenital heart disease: assessment of risk

OBJECTIVES

Elective deliveries in fetal congenital heart disease (CHD) attempt to balance fetal and neonatal risk with the goal of optimizing overall outcome. However, the magnitude of the risk for intrauterine fetal demise (IUFD) is unclear. This study aimed to (1) determine the rate of IUFD and (2) identify fetal risk factors associated with IUFD.

METHODS

Retrospective review of pregnancies complicated by CHD between 1998 and 2010. Data were collected regarding pregnancy outcome, extracardiac anomalies (ECA), genetic and cardiac diagnoses, severity of valve regurgitation, gestational age at birth and birth weight. Fisher's exact test and odds ratios were used to compare outcomes between groups.

RESULTS

A total of 501 pregnancies analyzed resulted in 445 live births, 22 IUFD, 16 terminations and 18 unknown outcomes. Amongst IUFD, 27% had a genetic diagnosis, 50% had an ECA and 27% had severe valve regurgitation. IUFD odds increased threefold with ECA and sevenfold with severe valve regurgitation. IUFD occurred in 1.2% without risk factors.

CONCLUSIONS

IUFD in fetuses with CHD is associated with ECA, genetic syndromes and severe valve regurgitation. In absence of these fetal characteristics, the occurrence of IUFD is low, although it remains higher than in fetuses without CHD.

Mode of delivery in pregnancies complicated by major fetal congenital heart disease: a retrospective cohort study

OBJECTIVE

To determine the mode of delivery in pregnancies complicated by complex fetal congenital heart disease (CHD).

STUDY DESIGN

Five-year retrospective cohort study at a tertiary fetal medicine center (2007 to 2011). Cases of complex fetal CHD (n=126) were compared with 45 069 non-anomalous singleton infants ⩾500 g to determine rates of emergency intrapartum cesarean section (CS), preterm delivery and induction of labor.

RESULT

Intrapartum CS is significantly higher in fetal CHD than non-anomalous controls (21% vs 13.5%, odds ratio (OR) 1.7, 95% confidence interval (CI): 1.0 to 2.7; P=0.035), predominantly related to CS for non-reassuring fetal status (OR 2.2, 95% CI: 1.1 to 4.1; P=0.022). Although fetal CHD did not increase emergency CS rates in nulliparous women, CS was significantly increased in multiparous pregnancies (OR 2.4, 95% CI: 1.8 to 4.6; P=0.014). Rates of preterm delivery (OR 3.4, 95% CI: 2.0 to 5.4; P<0.0001) and induction of labor (OR 1.9, 95% CI: 1.3 to 2.9; P=0.001) were higher in the CHD cases.

CONCLUSION

Emergency CS is increased in fetal CHD, attributed to a higher rate of CS for non-reassuring fetal status and seen mostly in multiparous women.

Stillbirth reduction efforts and impact on early births

A major justification for the intentional delivery of a pregnancy before 39 weeks' gestation is a reduction in stillbirth. However, there is a considerable downside to late preterm or early term deliveries. Infants born before 39 weeks' gestation are at increased risk for numerous complications and even death. Thus, it is critical to identify which medical problems and circumstances place the fetus at high enough risk for stillbirth so as to justify late preterm or early term birth. This article highlights information pertinent to the pros and cons of iatrogenic preterm birth in pregnancies at risk for stillbirth.

Metaanalysis of the prevalence of intrauterine fetal death in gastroschisis

OBJECTIVE

The objective of this study was to review the medical literature that has reported the risk for intrauterine fetal death (IUFD) in pregnancies with gastroschisis.

STUDY DESIGN

We systematically searched the literature to identify all published studies of IUFD and gastroschisis through June 2011 that were archived in MEDLINE, PubMed, or referenced in published manuscripts. The MESH terms gastroschisis or abdominal wall defect were used.

RESULTS

Fifty-four articles were included in the metaanalysis. There were 3276 pregnancies in the study and a pooled prevalence of IUFD of 4.48 per 100. Those articles that included gestational age of IUFD had a pooled prevalence of IUFD of 1.28 per 100 births at ≥36 weeks' gestation. The prevalence did not appear to increase at >35 weeks' gestation.

CONCLUSION

The overall incidence of IUFD in gastroschisis is much lower than previously reported. The largest risk of IUFD occurs before routine and elective early delivery would be acceptable. Risk for IUFD should not be the primary indication for routine elective preterm delivery in pregnancies that are affected by gastroschisis.

No effect of embryo culture media on birthweight and length of newborns

STUDY QUESTION

Does the type of media used to culture embryos for IVF influence the birthweight and length of neonates?

SUMMARY ANSWER

No significant differences were observed in birthweight and length among the three embryo culture media used for in vitro embryo culture.

WHAT IS KNOWN ALREADY

Since the establishment of IVF as an assisted reproductive technology (ART), many different culture systems have been used for the development of human embryos. Some studies have shown that the types of culture media influence the newborn birthweight; however, other studies have shown no effect. To further explore this contradictory issue, we compared the birthweight and length of neonates born after the transfer of embryos cultured in one of three commercially available media.

STUDY DESIGN, SIZE AND DURATION

This retrospective analysis of birthweight and length of newborns included 1201 women who delivered singletons and 445 women who delivered twins. The following three commercially available culture media were used: G5™, Global and Quinn's advantage media. Women who underwent IVF-ET cycles between 2008 and 2010 were analyzed.

PARTICIPANTS/MATERIALS, SETTING AND METHODS

Patients younger than 40 years of age with a body mass index (BMI) <30 kg/m(2) were analyzed. Only data from singletons and twins born alive after the 20th week of gestation were included in the data analysis. Patients who received preimplantation genetic diagnosis (PGD) and donor oocytes were excluded.

MAIN RESULTS AND THE ROLE OF CHANCE

The analysis of 1201 singletons and 445 sets of twins showed no significant association between mean birthweight or mean birth length and the type of embryo culture medium. Inter-twin mean birthweight and length disparities were analyzed, but were not shown to be significantly different. Multiple linear regression analysis showed that maternal weight, maternal height, gestational age and infant gender were significantly related to birthweight, and paternal height, gestational age and newborn complications were significantly associated with birth length.

LIMITATIONS AND REASONS FOR CAUTION

The current study showed that birthweight and length of newborns were not associated with the embryo culture medium. More research needs to be performed to analyze the effects of other culture medium formulations and to evaluate the long-term effects of embryo culture medium on the health of children conceived through ART. WIDER IMPLICATIONS OF THESE FINDINGS: Our retrospective study suggests that embryo culture medium does not influence neonatal birthweight and length; however, the effects of culture medium on epigenetic variation of embryos need to be studied further.

Late preterm birth: a review of medical and neuropsychological childhood outcomes

Late preterm (LP) birth (34 0/7 - 36 6/7 weeks' gestation) accounts for nearly three-fourths of all preterm births, making this population a sizeable public health concern. The immature fetal development associated with LP delivery increases the risk of mortality and short-term medical complications. Which combination of maternal, fetal, or neonatal risk factors may be most critical has only recently begun to be addressed, and whether LP birth's disruptive impact on brain development will exert adverse effects on neuropsychological functioning in childhood and adolescence has been understudied. Early data have shown a graded response, with LP children often functioning better than very preterm children but worse than term children, and with subtle intellectual and neuropsychological deficits in LP children compared with healthy children born at term gestational age. Further characterization of the neuropsychological profile is required and would be best accomplished through prospective longitudinal studies. Moreover, since moderate and LP births result in disparate medical and psychological outcomes, the common methodology of combining these participants into a single research cohort to assess risk and outcome should be reconsidered. The rapidly growing LP outcomes literature reinforces a critical principle: fetal development occurs along a dynamic maturational continuum from conception to birth, with each successive gestational day likely to improve overall outcome.

Obstetric decision-making and the late and moderately preterm infant

The decision of when to deliver a patient for medical or obstetric complication directly affects the neonatal outcome. When the fetus is in danger due to suspected utero-placental insufficiency, the decision to deliver is thought to benefit the neonate. However, the opposite may be true when a normally developing fetus needs to be delivered for a maternal indication such as a persistently bleeding placenta praevia. These decisions are made daily by obstetric providers. The following is a review of obstetric decision-making for moderate and late preterm pregnancies.