Risk Of Stillbirth In Pregnancies Research Articles

Risk of Stillbirth in Pregnancies Complicated by Diabetes, Stratified by Fetal Growth.

To compare stillbirth rates per week of expectant management stratified by birth weight in pregnancies complicated by gestational diabetes mellitus (GDM) or pregestational diabetes mellitus. A national population-based retrospective cohort study of singleton, nonanomalous pregnancies complicated by pregestational diabetes or GDM was performed using national birth and death certificate data from 2014 to 2017. Stillbirth rates per 10,000 patients (stillbirth incidence at gestational age week/ongoing pregnancies-[0.5×live births at gestational age week]) were determined for each week of pregnancy from 34 to 39 completed weeks of gestation. Pregnancies were stratified by birth weight, categorized as having small-for-gestational-age (SGA), appropriate-for-gestational-age (AGA), or large-for-gestational-age (LGA) fetuses, assigned by sex-based Fenton criteria. Relative risk (RR) and 95% CI for stillbirth were calculated for each gestational age week compared with the GDM-related AGA group. We included 834,631 pregnancies complicated by either GDM (86.9%) or pregestational diabetes (13.1%) in the analysis, with a total of 3,033 stillbirths. Stillbirth rates increased with advancing gestational age for pregnancies complicated by both GDM and pregestational diabetes regardless of birth weight. Compared with pregnancies with AGA fetuses, those with both SGA and LGA fetuses were significantly associated with an increased risk of stillbirth at all gestational ages. Ongoing pregnancies at 37 weeks of gestation complicated by pregestational diabetes with LGA or SGA fetuses had respective stillbirth rates of 64.9 and 40.1 per 10,000 patients. Pregnancies complicated by pregestational diabetes had an RR of stillbirth of 21.8 (95% CI 17.4-27.2) for LGA fetuses and 13.5 (95% CI 8.5-21.2) for SGA fetuses compared with GDM-related AGA at 37 weeks of gestation. The greatest absolute risk of stillbirth was in pregnancies complicated by pregestational diabetes at 39 weeks of gestation with LGA fetuses (97/10,000). Pregnancies complicated by both GDM and pregestational diabetes affected by pathologic fetal growth have an increased risk of stillbirth with advancing gestational age. This risk is significantly higher with pregestational diabetes, especially pregestational diabetes with LGA fetuses.

Perinatal mortality and neonatal and maternal outcome per gestational week in term pregnancies: A registry-based study.

Human pregnancy is considered term from 37+0/7 to 41+6/7 weeks. Within this range, both maternal, fetal and neonatal risks may vary considerably. This study investigates how gestational age per week is related to the components of perinatal mortality and parameters of adverse neonatal and maternal outcome at term. A registry-based study was made of all singleton term pregnancies in the Netherlands from January 2014 to December 2017. Stillbirth and early neonatal mortality, as components of perinatal mortality, were defined as primary outcomes; adverse neonatal and maternal events as secondary outcomes. Neonatal adverse outcomes included birth trauma, 5-minute Apgar score ≤3, asphyxia, respiratory insufficiency, neonatal intensive care unit admission and composite neonatal outcome. Maternal adverse outcomes included instrumental vaginal birth, emergency cesarean section, obstetric anal sphincter injury, postpartum hemorrhage, hypertensive disorders of pregnancy and composite maternal outcome. The primary outcomes were evaluated by comparing weekly prospective risks of stillbirth and neonatal death using a fetuses-at-risk approach. Secondly, odds ratios (OR) for perinatal mortality, adverse neonatal and maternal outcome using a births-based approach were compared for each gestational week with all births occurring after that week. Data of 581 443 births were analyzed. At 37, 38, 39, 40, 41 and 42 weeks, the respective weekly prospective risks of stillbirth were 0.015%, 0.022%, 0.031%, 0.036%, 0.069% and 0.081%; the respective weekly prospective risks of early neonatal death were 0.051%, 0.047%, 0.032%, 0.031%, 0.039% and 0.035%. The OR for adverse neonatal outcomes were the lowest at 39 and 40 weeks. The OR for adverse maternal outcomes, including operative birth, continuously increased with each gestational week. The prospective risk of early neonatal death for babies born at 39 weeks is lower than the risk of stillbirth in pregnancies continuing beyond 39+6/7 weeks. Birth at 39 weeks was associated with the best combined neonatal and maternal outcome, fewer operative births and fewer maternal and neonatal adverse outcomes compared with pregnancies continuing beyond 39 weeks. This information with appropriate perspectives should be included when counseling term pregnant women.

866 Risk of stillbirth in pregnancies complicated by diabetes stratified by fetal growth: a national cohort

866 Risk of stillbirth in pregnancies complicated by diabetes stratified by fetal growth: a national cohort

The joint effects of obesity and pregestational diabetes on the risk of stillbirth

Objective: Obesity and pregestational diabetes (PGDM) may interact to further increase the risk of stillbirth than either risk factors independently. The objective of this study was to determine the risk of stillbirth in pregnancies complicated by both conditions.Method: This was a retrospective cohort analysis of singleton nonanomalous births using the updated Texas vital records database between 2006 and 2014. Gestational diabetes and hypertensive diseases were additionally excluded from analysis. Analysis was stratified into 10 strata based on BMI class: underweight, normal weight, overweight, obese and morbidly obese, and PGDM. Furthermore, gestational age was stratified into the four periods for analysis: 24–33, 34–36, 37–39, and 40–42 weeks. The rate of stillbirth per 10,000 pregnancies were calculated for each stratum. The risks of stillbirth associated with each BMI class and PGDM were compared to normal weight nondiabetic pregnancies for each gestational period using proportional hazard regression models.Result: After all exclusions, 3,097,123 births remained for analysis, including 5997 stillbirths. The overall rate of stillbirth increased from 15.0 per 10,000 pregnancies in normal weight pregnancies to 26.7 per 10,000 pregnancies in the morbidly obese group. The rate of stillbirth further increased with coexistence of PGDM to 119.9 per 10,000 pregnancies in the normal weight group and 209.8 per 10,000 pregnancies in the morbidly obese group. Compared to normal weight nondiabetic pregnancies the overall adjusted hazard ratio (aHR) of stillbirth associated with morbid obesity without PGDM was 1.57 [1.38, 1.79]. However, when further complicated by PGDM, the aHR was 6.67 [5.05, 8.81] in normal weight pregnancies and 12.86 [9.36, 17.67] in morbidly obese pregnancies. The highest risk of stillbirth was seen between 37 and 39 weeks, when the aHR in the diabetic normal weight group was 9.63 [5.65, 16.40] and the aHR in the diabetic morbidly obese group was 25.34 [15.58, 41.22].Conclusion: PGDM and obesity both independently increased the risk of stillbirth. The joint effect of obesity and PGDM is stronger than the summation or multiplication of the individual effects of each risk factor.

Risk of stillbirth in low-risk singleton term pregnancies following fertility treatment: a national cohort study.

To assess the risk of stillbirth in low-risk in vitro fertilisation (IVF) pregnancies. Register-based national cohort study. Denmark 2003-2013. Cohort of 425 732 singleton pregnancies including 10 235 conceived following IVF/intracytoplasmic sperm injection (ICSI), 4521 conceived following intrauterine insemination (IUI), and 410 976 spontaneously conceived. Information on pregnancy, obstetrical risk factors, stillbirth, and fertility treatment was obtained from the Danish national health registers for all pregnancies after gestational week 21+6 . We estimated the overall and gestational age-specific risk of stillbirth in low-risk term pregnancies following IVF, ICSI, and IUI. Further, we estimated the association between stillbirth and IVF and ICSI respectively as well as fresh or frozen-thawed embryo transfer. Risk of stillbirth. The number of stillbirths in spontaneously conceived and IVF/ICSI low-risk term pregnancies was 525 (0.1%) and 35 (0.3%), respectively. In multivariate analysis, the risk of stillbirth in pregnancies following IVF/ICSI was increased (odds ratio 2.1, 95% CI 1.4-3.1). The risk of stillbirth was correspondingly increased in time-to-event analyses taking risk time for each fetus into account from gestational week 37 and onwards (hazard ratio 2.4, 95% CI 1.6-3.6). In sub-analyses, the risk of stillbirth was increased for pregnancies following ICSI (odds ratio 2.2, 95% CI 1.2-3.1), but not IVF (odds ratio 1.7, 95% CI 0.9-3.1). We found a systematically increased risk of stillbirth in low-risk term pregnancies following IVF/ICSI. Whether the risk was related to the treatment or to underlying subfertility is uncertain. The results may indicate a need for obstetrical surveillance for these pregnancies when reaching term. Increased risk of stillbirth in low-risk term pregnancies following fresh cycle IVF/ICSI.

Stillbirth and large for gestational age at birth

Aim: A previous large case-control study had documented association between large for gestational age birth weight and stillbirth. We sought to replicate this novel finding.Methods: Retrospective cohort with nested case-control analyses. The data source was a large Canadian perinatal database. Stillbirth was defined as no signs of life at delivery ≥23-weeks gestation. Small and large for gestational age at birth weights were defined using standard Canadian, American, and ultrasound norms.Results: The study population was comprised of 693,186 live births and 3275 stillbirths. Using population norms, large for gestational age (LGA) at birth was not associated with stillbirth in adjusted analysis (OR 0.57, 95% CI [0.45, 0.71]). A statistically significant interaction between pre-existing diabetes and LGA was observed (OR 2.48, 95% CI [1.20, 5.15]). Further case-control analysis found if ultrasound norms were used and controls were selected by date of delivery then LGA was associated with stillbirth (OR 1.91, 95% CI [1.64–2.22]). However, if controls were matched by gestational age at birth then the association was no longer apparent (OR 0.98, 95% CI [0.85–1.13]).Conclusions: Large for gestational age at birth is not associated with stillbirth in the general population. Previously reported association between LGA and stillbirth was likely an artifact of the sampling strategy. LGA may increase the risk of stillbirth in pregnancies complicated by pre-existing and gestational diabetes.

Gastroschisis: mortality risks with each additional week of expectant management

Prior studies have evaluated the overall risk of stillbirth in pregnancies with fetal gastroschisis. However, the gestational age at which mortality is minimized, balancing the risk of stillbirth against neonatal mortality, remains unclear. We sought to evaluate the gestational age at which prenatal and postnatal mortality risk is minimized for fetuses with gastroschisis. This was a retrospective cohort study of singleton pregnancies delivered between 24 0/7 and 39 6/7 weeks, using 2005 through 2006 US national linked birth and death certificate data. Among pregnancies with fetal gastroschisis, prospective risk of stillbirth and risk of infant death were determined for each gestational age week. Risk of infant death with delivery was further compared to composite fetal/infant mortality risk with expectant management for 1 additional week. Among 2,119,049 pregnancies, 860 cases (0.04%) of gastroschisis were identified. The overall stillbirth rate among gastroschisis cases was 4.8%, and infant death occurred in 8.3%. Prospective risk of stillbirth became more consistently elevated beginning at 35 weeks, rising to 13.9 per 1000 pregnancies (95% confidence interval, 10.8-17.1) at 39 weeks. Risk of infant death concurrently nadired in the third trimester, ranging between 62.4-66.8 per 1000 live births between 32-39 weeks. Comparing mortality with expectant management vs delivery, relative risk was significantly greater with expectant management between 37-39 weeks, reaching 1.90 (95% confidence interval, 1.73-2.08) at 39 weeks with a number needed to deliver of 17.49 (95% confidence interval, 15.34-20.32) to avoid 1 excess death. Risk of prenatal and postnatal mortality for fetuses with gastroschisis may be minimized with delivery as early as 37 weeks.

Differences in post‐mortem findings after stillbirth in women with and without diabetes

The reason for the fivefold increased risk of stillbirth in women with diabetes is not known. Further understanding of the underlying mechanisms may facilitate identification of pregnancies at increased risk. We have compared post-mortem reports in matched pairs of stillbirths in women with and without diabetes. Post-mortem reports were provided by the Centre for Maternal and Child Enquiries. Stillbirths as a result of lethal congenital and genetic abnormalities were excluded. Whole body, placenta and organ weights and histo-pathological findings in cases and controls were compared and also related to published reference values. We analysed post-mortem reports on 23 matched pairs of stillbirths from 2009 to 2010. Mean placental weight in women with diabetes was 75 g less than in control subjects (95% CI -143 to -7 g; P = 0.032). In maternal diabetes, the thymus was often small and showed a 'starry sky' pattern on histology in 11 of 20 cases compared with four of 22 controls (P = 0.03). This histological finding was associated with a particularly low mean placental weight z-score -2.1 (1.1) standard deviations below a reference population corrected for gestational age. In over half of the stillbirths occurring in women with diabetes, there was a 'starry sky' appearance in the fetal thymus on histology, this being associated with a small placenta. These findings are consistent with a critical subacute metabolic disturbance being a prominent cause of the increased risk of stillbirth in pregnancies complicated by maternal diabetes.

Risk of stillbirth after 37 weeks in pregnancies complicated by small-for-gestational-age fetuses

The evidence for delivering small-for-gestational-age (SGA) fetuses at 37 weeks remains conflicting. We examined the risk of stillbirth per week of gestation beyond 37 weeks for pregnancies complicated by SGA. Singleton pregnancies undergoing routine second trimester ultrasound from 1990-2009 were examined retrospectively. The risk of stillbirth per 10,000 ongoing SGA pregnancies with 95% confidence intervals (CIs) was calculated for each week of gestation ≥37 weeks. Using a life-table analysis with correction for censoring, conditional risks of stillbirth, cumulative risks of stillbirth per 10,000 ongoing SGA pregnancies and relative risks (RRs) were calculated with 95% CIs for each week of gestation. Among 57,195 pregnancies meeting inclusion criteria the background risk of stillbirth was 56/10,000 (95% CI, 42.3-72.7) with stillbirth risk for SGA pregnancies of 251/10,000 (95% CI, 221.2-284.5). The risk of stillbirth after the 37th week was greater compared with pregnancies delivered in the 37th week (47/10,000, 95% CI, 34.6-62.5 vs 21/10,000, 95% CI, 13.0-32.1; RR, 2.2; 95% CI, 1.3-3.7). The cumulative risk of stillbirth rose from 28/10,000 ongoing SGA pregnancies at 37 weeks to 77/10,000 at 39 weeks (RR, 2.75; 95% CI, 1.79-4.2). Among pregnancies complicated by SGA <5% the cumulative risk of stillbirth at 38 weeks was significantly greater than the risk at 37 weeks (RR, 2.3; 95% CI, 1.4-3.8). There is a significantly increased risk of stillbirth in pregnancies complicated by SGA delivered after the 37th week. Given these findings, we advocate a policy of delivery of SGA pregnancies 37-38 weeks.

Antenatal detection of fetal growth restriction and stillbirth risk in mothers with high and low body mass index

ObjectiveMaternal obesity is associated with an increased risk of stillbirth. The authors wanted to study the relationship between stillbirth risk and the antenatal detection of intrauterine growth restriction (IUGR) in...

Cesarean Delivery and Risk of Stillbirth in Subsequent Pregnancy: A Retrospective Cohort Study in an English Population

Rates of cesarean section have increased in the past 2 to 3 decades in the United Kingdom and elsewhere. Apart from immediate maternal and infant complications, there appears to be an increased risk of placenta previa, placental abruption, and uterine rupture during labor in subsequent pregnancies. Recent studies suggest an increased risk of stillbirth in pregnancies following cesarean delivery. The investigators attempted to clarify this risk in a retrospective cohort study of 81,784 singleton deliveries taking place in the UK in the years 1968–1989. Excluding those caused by congenital anomalies there were 290 stillbirths, 113 of which were classified as explained, and 177 as unexplained. Mothers having a previous cesarean delivery tended to be older than the others, to have lower parity, to be of higher social class, and to have had previous adverse pregnancy outcomes. Unadjusted hazard ratios for all stillbirths, those that were explained, and those unexplained were, respectively, 1.54 (95% confidence interval [CI], 1.04–2.29), 2.13 (95% CI, 1.22–3.72), and 1.19 (95% CI, 0.68–2.09). After adjusting for maternal age, parity, social class, previous adverse pregnancy outcomes, body mass index, and smoking status, the respective hazard ratios were 1.58 (95% CI, 0.95–2.63), 2.08 (95% CI, 1.00–4.31), and 1.24 (95% CI, 0.60–2.56). Stillbirths following a previous cesarean section were more likely than in the “unexposed” group to be explained, and they were likelier to be associated with abruption/hemorrhage or mechanical causes. It was estimated, using a hazard ratio of 1.58 to approximate the adjusted relative risk in a population with a section rate of 7.1% and an average stillbirth rate of 0.35%, that approximately 4% of all stillbirths in the population may be ascribed to previous cesarean delivery. These findings affirm an increased risk of stillbirth in women previously having a cesarean section. The risk is most evident in cases of explained stillbirth. Further research is needed to determine whether this association is causal and, if so, what mechanisms might be involved.

The risk of stillbirth in pregnancies before and after the onset of diabetes.

There is significant controversy as to whether or not stillbirth is increased in pregnancies prior to the onset of diabetes. An observed increase may be indicative of risks associated with untreated gestational diabetes. It is generally accepted that the risk of stillbirth in pregnancies that occur after the onset of diabetes has been diminished by modern obstetric care. However, the degree of residual risk is not well quantified. This study sought to examine the rates of stillbirth before and after the onset of diabetes compared with the general population. Retrospective cohort and nested case-control study. The study population was drawn from the UK-based General Practice Research Database, comprising some 300 practices, with data collection from the late 1980s until September 1999. From the base population, 913 diabetic women who had had a pregnancy were identified and 10,000 subjects without diabetes were randomly chosen as controls. Stillbirth was defined as death in utero after 20 weeks or with birth weight >500 g. The stillbirth rates were higher in prediabetic pregnancies (19.7/1000), and in those occurring after the diagnosis of diabetes (33.7/1000), compared with the non-diabetic population (5.5/1000). Stillbirths were matched to four live births by maternal age and year of birth. Prediabetic pregnancy and pregnancy after the onset of diabetes were strongly associated with stillbirth: odds ratio (OR)=4.68 (1.67, 13.08) and OR=4.39 (2.22, 8.64), respectively. The risk of stillbirth was increased in both prediabetic and post-diabetic pregnancy.