Nonanomalous Singleton Pregnancies Research Articles

Association of maternal body mass index with success and outcomes of attempted operative vaginal delivery

Increasing maternal body mass index (BMI) is associated with increased morbidity at cesarean delivery in a dose-dependent manner. In some clinical scenarios, operative vaginal delivery is a strategy to prevent the morbidity associated with second stage cesarean delivery, but the relationship between maternal BMI and outcomes of attempted operative vaginal delivery is not well characterized. To assess whether success of and adverse outcomes after attempted operative vaginal delivery are associated with maternal BMI at delivery among nulliparous individuals. This is a secondary analysis from the prospective cohort Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-To-Be study. This analysis included cephalic liveborn non-anomalous singleton pregnancies ≥34 weeks at delivery with an attempted operative vaginal delivery (either forceps or vacuum). The primary exposure was maternal BMI at delivery (BMI ≥30 kg/m2 vs BMI <30 kg/m2 [referent]). The primary outcome was an unsuccessful operative vaginal delivery attempt, defined as a cesarean delivery following an attempted operative vaginal delivery. Secondary outcomes included maternal and neonatal adverse outcomes. Multivariable logistic regression was used, and statistical interaction between operative instrument type (vacuum vs forceps) and BMI was assessed. Of 10,038 assessed individuals, 791 (7.9%) had an attempted operative vaginal delivery and were included in this analysis. Forty-one percent (n=325) had a BMI ≥30 kg/m2 at delivery. Overall, 5% (42/791) of participants experienced an unsuccessful operative vaginal delivery. Individuals with a BMI ≥30 kg/m2 at delivery were more than twice as likely to have an unsuccessful operative vaginal delivery compared with those with a BMI <30 kg/m2 (8.0 vs 3.4%; p=0.005; adjusted odds ratio (aOR): 2.23, 95% confidence interval (CI) 1.16 to 4.28). Composite maternal morbidity and composite neonatal morbidity did not vary by BMI group. There was no evidence of interaction or effect modification by operative instrument type for rate of unsuccessful operative vaginal delivery attempt, composite maternal morbidity, or composite neonatal morbidity. Among nulliparous individuals who underwent an attempted operative vaginal delivery, those with a BMI ≥30 kg/m2 at delivery were more likely to have an unsuccessful operative vaginal delivery attempt compared with those with a BMI <30 kg/m2. There were no differences in composite maternal or neonatal morbidity after attempted operative vaginal delivery by BMI category.

Fetal growth restriction and small for gestational age as predictors of neonatal morbidity: which growth nomogram to use?

Fetal growth nomograms were developed to screen for fetal growth restriction and guide clinical care to improve perinatal outcomes; however, existing literature remains inconclusive regarding which nomogram is the gold standard. This study aimed to compare the ability of 4 commonly used nomograms (Hadlock, International Fetal and Newborn Growth Consortium for the 21st Century, Eunice Kennedy Shriver National Institute of Child Health and Human Development-unified standard, and World Health Organization fetal growth charts) and 1 institution-specific reference to predict small for gestational age and poor neonatal outcomes. This was a retrospective cohort study of all nonanomalous singleton pregnancies undergoing ultrasound at ≥20 weeks of gestation between 2013 and 2020 and delivering at a single academic center. Using random selection methods, the study sample was restricted to 1 pregnancy per patient and 1 ultrasound per pregnancy completed at ≥22 weeks of gestation. Fetal biometry data were used to calculate estimated fetal weight and percentiles according to the aforementioned 5 nomograms. Maternal and neonatal data were extracted from electronic medical records. Logistic regression was used to estimate the association between estimated fetal weight of <10th and <3rd percentiles compared with estimated fetal weight of 10th to 90th percentile as the reference group for small for gestational age and the neonatal composite outcomes (perinatal mortality, hypoxic-ischemic encephalopathy or seizures, respiratory morbidity, intraventricular hemorrhage, necrotizing enterocolitis, hyperbilirubinemia or hypoglycemia requiring neonatal intensive care unit admission, and retinopathy of prematurity). Receiver operating characteristic curve contrast estimation (primary analysis) and test characteristics were calculated for all nomograms and the prediction of small for gestational age and the neonatal composite outcomes. We restricted the sample to ultrasounds performed within 28 days of delivery; moreover, similar analyses were completed to assess the prediction of small for gestational age and neonatal composite outcomes. Among 10,045 participants, the proportion of fetuses classified as <10th percentile varied across nomograms from 4.9% to 9.7%. Fetuses with an estimated fetal weight of <10th percentile had an increased risk of small for gestational age (odds ratio, 9.9 [95% confidence interval, 8.5-11.5] to 12.8 [95% confidence interval, 10.9-15.0]). In addition, the estimated fetal weight of <10th and <3rd percentile was associated with increased risk of the neonatal composite outcome (odds ratio, 2.4 [95% confidence interval, 2.0-2.8] to 3.5 [95% confidence interval, 2.9-4.3] and 5.7 [95% confidence interval, 4.5-7.2] to 8.8 [95% confidence interval, 6.6-11.8], respectively). The prediction of small for gestational age with an estimated fetal weight of <10th percentile had a positive likelihood ratio of 6.3 to 8.5 and an area under the curve of 0.62 to 0.67. Similarly, the prediction of the neonatal composite outcome with an estimated fetal weight of <10th percentile had a positive likelihood ratio of 2.1 to 3.1 and an area under the curve of 0.55 to 0.57. When analyses were restricted to ultrasound within 4 weeks of delivery, among fetuses with an estimated fetal weight of <10th percentile, the risk of small for gestational age increased across all nomograms (odds ratio, 16.7 [95% confidence interval, 12.6-22.3] to 25.1 [95% confidence interval, 17.0-37.0]), and prediction improved (positive likelihood ratio, 8.3-15.0; area under the curve, 0.69-0.75). Similarly, the risk of neonatal composite outcome increased (odds ratio, 3.2 [95% confidence interval, 2.4-4.2] to 5.2 [95% confidence interval, 3.8-7.2]), and prediction marginally improved (positive likelihood ratio, 2.4-4.1; area under the curve, 0.60-0.62). Importantly, the risk of both being small for gestational age and having the neonatal composite outcome further increased (odds ratio, 21.4 [95% confidence interval, 13.6-33.6] to 28.7 (95% confidence interval, 18.6-44.3]), and the prediction of concurrent small for gestational age and neonatal composite outcome greatly improved (positive likelihood ratio, 6.0-10.0; area under the curve, 0.80-0.83). In this large cohort, Hadlock, recent fetal growth nomograms, and a local population-derived fetal growth reference performed comparably in the prediction of small for gestational age and neonatal composite outcomes.

Predictors of adverse perinatal outcomes in fetal growth restriction using a combination of maternal clinical factors and simple ultrasound parameters.

To identify predictors of adverse perinatal outcomes in pregnancies with fetal growth restriction (FGR) using a combination of maternal clinical factors and simple ultrasound parameters and develop a risk-scoring model for predicting adverse perinatal outcomes. A retrospective study of 370 non-anomalous singleton pregnancies with FGR was conducted. Multivariate logistic regression analysis was used to identify factors associated with adverse perinatal outcomes; P< 0.05 was considered statistically significant. The discriminative ability was measured with the area under the receiver operating characteristic curve (AUC). A weighted score for each predictor was calculated. Adverse perinatal outcomes occurred in 165/370 (44.6%) cases. There were eight predictive factors, including a history of pregnancy-induced hypertension (PIH) (score=1), chronic hypertension (score=3), PIH (score=2), maternal weight gain less than 8kg (score=1), early-onset FGR (score=1), estimated fetal weight less than 5th percentile (score=2), amniotic fluid index less than 5cm (score=3), and abnormal umbilical artery Doppler (score=2), with total scores ranging from 0 to 15. AUC for the eight-item predictive model was 0.799 (95% confidence interval 0.753-0.845). A combination of maternal clinical factors and simple ultrasound parameters showed acceptable predictive performance for adverse perinatal outcomes in FGR.

Perinatal survival among very preterm singletons born after detection of early-onset fetal growth restriction with or without maternal hypertensive disorders: A population-based study in France

ObjectiveTo investigate the management and survival of very preterm singletons born because of fetal growth restriction (FGR) with or without maternal hypertensive disorders in France. Study designFrom a population-based cohort of very preterm births between 22 and 31 weeks in France in 2011, the study population included all non-anomalous singleton pregnancies delivered because of detected FGR with or without maternal hypertensive disorders. Antenatal detection of FGR was defined as an estimated fetal weight <10th percentile with or without fetal Doppler abnormalities or growth arrest. All fetuses were alive at the time of detection of FGR. Indicators of active perinatal management (antenatal steroids, pre-labor cesarean and birth in level 3 maternity unit) and fetal/neonatal outcomes (terminations of pregnancy (TOP), stillbirths, neonatal deaths and survival to discharge) were compared by gestational age between FGR associated with maternal hypertensive disorders and isolated FGR. ResultsOverall, 398 pregnancies delivered before 32 weeks for FGR associated with hypertensive disorders and 234 for isolated FGR. Active perinatal care was rare before 26 weeks in both groups and about one in five cases associated with maternal hypertensive disorders received steroids and was born by prelabor cesarean compared to none for isolated FGR. Before 25 weeks of gestation age, more pregnancies resulted in TOP when FGR was associated with hypertensive disorders compared to isolated FGR (respectively, 76.2 % vs 28.0 % at 22–23 weeks, P = 0.002 and 57.9 % vs 21.1 % at 24 weeks, P = 0.028) whereas stillbirths were more common among isolated FGR (respectively, 23.8 % vs 72.0 % at 22–23 weeks, P = 0.002 and 36.8 % vs 73.7 % at 24 weeks, P = 0.030). Survival to discharge was higher at any gestational age when the cause of birth was FGR associated with hypertensive disorders compared to isolated FGR. ConclusionThe management and pregnancy outcomes differed when FGR was associated with maternal hypertensive disorders or isolated. The proportion of TOP was higher when FGR was associated with hypertensive disorders and the proportion of stillbirths was higher in isolated FGR.

The association of obesity with stillbirth

Because antepartum testing is recommended at 34 weeks if pre-pregnancy BMI is ≥40 kg/m2 (class III obesity) or at 37 weeks if it is 35≤BMI< 40 kg/m2 (class II obesity), our aim was to determine the rate of stillbirth with maternal obesity at varying strata. This was a retrospective cohort study of patients with optimally dated, non-anomalous singleton pregnancies delivering at a single academic center between 1 Jan 2013 and 30 Apr 2022. BMI at first prenatal visit was used a proxy for pre-pregnancy BMI. Pregnancies complicated by chronic hypertension, gestational or overt diabetes treated with insulin were excluded as were aneuploidy or growth restriction. Antepartum testing was not available to patients without medical or fetal complications, regardless of BMI. In patients with class III obesity who reached 34 weeks gestation, the rate of stillbirth was calculated at 34 0/7-36 6/7, 37 0/7-38 6/7, and >39 weeks. In those with class II obesity who reached 37 weeks, the rate of stillbirth was calculated at 37 0/7-38 6/7 and >39 weeks. Rates of stillbirth were then compared between normal weight cohort (18.5≤BMI< 25) at these gestational age epochs. Cox proportional regression hazard models were used to estimate the risk of stillbirth in relation to BMI. There were 3060 patients with class III obesity, 5049 patients with class II obesity, and 17555 patients with normal BMI examined. Compared with patients with normal BMI, stillbirth rate was significantly increased beyond 39 weeks in class III obesity (P=0.021, hazard ratio 3.67 with 95% CI 1.07 to 12.56), but not prior to this gestational age. No significant increased risk of stillbirth was identified in class II obesity at term. In our population, we found an increased risk of stillbirth in class III obesity beyond 39 weeks. We did not observe an increased risk prior to this gestational age in class III obesity nor significant risk at term in those with class II obesity. Our findings warrant further investigation into the necessity of antepartum testing in patients with class II and III obesity.

Patient Decisions Regarding Fetal Monitoring in the Periviable Period and Perinatal and Maternal Outcomes.

Management of delivery at periviable gestation requires complex counseling and decision making, including difficult choices about monitoring and potential cesarean delivery (CD) for fetal benefit. Our objective was to characterize decisions that patients make regarding fetal monitoring and potential CD for fetal benefit when delivering in the periviable period, and associations with perinatal and obstetric outcomes. We hypothesize that a significant number of patients forgo monitoring and potential CD for fetal benefit in the periviable period when offered the opportunity to do so. Retrospective cohort study of nonanomalous singleton pregnancies delivering between 230/7 and 256/7 weeks at a tertiary care center from 2015 to 2020 as based on our institutional clinical practice. Since 2015, these patients are offered the ability to accept or decline fetal monitoring, potential CD for fetal benefit, and active resuscitation of a liveborn neonate. The frequency of patients desiring potential CD for fetal benefit was identified, and associations with CD and intrapartum demise were analyzed. Fifty subjects were included. Seventy-eight percent (n = 39) desired monitoring and potential CD for fetal benefit, and 84% (n = 42) desired resuscitation if the neonate was born alive. This varied by gestational age: 55% (6/11) of patients delivering between 230/7 and 236/7 weeks desired fetal monitoring and potential CD for fetal benefit, while 90% (19/21) of patients delivering between 250/7 and 256/7 weeks desired fetal monitoring and potential CD for fetal benefit (p = 0.02). Sixty-nine percent of pregnancies in which potential CD for fetal benefit was desired resulted in CD (27/39), of which 85% were classical (23/27). Intrapartum fetal demise occurred in 45% (5/11) of pregnancies in which monitoring was not performed. While a majority of patients delivering between 230/7 and 256/7 weeks desired monitoring and potential CD for fetal benefit, this varied significantly by gestational age. The decision to perform monitoring and potential CD for fetal benefit was associated with a high frequency of CD, while the decision to forgo monitoring was associated with high frequency of intrapartum demise. · Patients desires vary in the setting of periviable delivery.. · Periviable monitoring is associated with cesarean delivery.. · Forgoing monitoring is associated with intrapartum demise..

Perinatal and 2-year neurodevelopmental outcome in late preterm fetal compromise: the TRUFFLE 2 randomised trial protocol

IntroductionFollowing the detection of fetal growth restriction, there is no consensus about the criteria that should trigger delivery in the late preterm period. The consequences of inappropriate early or late...

Association of the Cerebro-Placental Ratio With Adverse Outcomes in Pregnancies Affected by Gestational Diabetes Mellitus.

Cerebro-placental ratio (CPR) is a doppler tool contributes to clinical decision-making in pregnancies affected by small for gestational age weight (SGA). Pregnancies affected by gestational diabetes mellitus (GDM) tend to have higher newborn weight, but greater risk of adverse perinatal outcomes. We hypothesized that in GDM-complicated-pregnancies CPR will be associated with adverse perinatal outcomes even in the absence of SGA. This prospective single-center cohort study included non-anomalous singleton pregnancies in women with GDM. Those with pre-pregnancy diabetes mellitus, hypertensive disorder or suspected SGA were excluded. Routine fetal sonographic assessment included CPR-defined as middle cerebral artery pulsatilty index/umbilical artery pulsatilty index. Masked CPR measurement closest to birth was used, classified as >10th (normal) or ≤10th centile (low). Primary outcome was a composite, consisting of stillbirth, Caesarean birth due to abnormal fetal heart rate pattern, 5-minute Apgar <7, cord arterial pH < 7.0, hypoxic ischemic encephalopathy, or NICU admission >24hours. Of 281 participants, 24 (8.5%) had low CPR, at a mean gestational age of 36.3 weeks (IQR 34.0-37.4). Birthweight percentile was significantly lower among the low CPR group (35th [IQR 16-31] versus 60th [IQR 31-82]; P=.002). There was no statistically difference in the primary composite outcome between the groups (8.3% versus 7.0%, P=.68). Low CPR was significantly associated with a higher risk of neonatal hypoglycemia (adjusted odds ratio 3.2, 95% CI 1.2-8.3). In pregnancies affected by GDM, CPR ≤10th percentile was not associated with adverse perinatal outcome but was associated with neonatal hypoglycemia.

Pregnancy Outcomes among Women with Class III Obesity with Pre-diabetic Early Hemoglobin A1C.

We aimed to assess the risk of developing gestational diabetes mellitus (GDM) in women with a normal A1C (<5.7) compared with those with an A1C in the pre-diabetic range (5.7-6.4). This study comprises of a retrospective cohort of non-anomalous singleton pregnancies with maternal body mass index (BMI) ≥40 at a single institution from 2013 to 2017. Pregnancies with multiple gestation, late entry to care, type 1 or 2 diabetes, and missing diabetes-screening information were excluded. The primary outcome was development of GDM. Secondary outcomes included fetal growth restriction, macrosomia, gestational age at delivery, large for gestational age, delivery BMI at delivery, total weight gain in pregnancy, induction of labor, shoulder dystocia, and cesarean delivery. Bivariate statistics were used to compare demographics, pregnancy complications, and delivery characteristics of women who had an early A1C < 5.7 and A1C 5.7 to 6.4. Multivariable analyses were used to estimate the odds of the primary outcome. Eighty women (68%) had an early A1C <5.7 and 38 (32%) had a A1C 5.7 to 6.4. Women in the lower A1C group were less likely to be Black (45 vs. 74%, p = 0.01). No differences in other baseline demographics were observed. The median A1C was 5.3 for women with A1C < 5.7 and 5.8 for women with A1C 5.7 to 6.4 (p < 0.001). GDM was significantly more common in women with A1C 5.7 to 6.4 (3.8 vs. 24%, p = 0.002). Women with pre-diabetic range A1C had an odd ratio of 11.1 (95% CI 2.49-48.8) for GDM compared with women with a normal A1C. Women with class III obesity and a pre-diabetic range A1C are at an increased risk for gestational diabetes when compared with those with a normal A1C in early pregnancy. · One in 3 women with class III obesity had a pre-diabetic range early A1C.. · Class III obese women who have a pre-diabetic A1C have a higher risk of gestational diabetes.. · In this high-risk population, early A1C results in the pre-diabetic range are associated with higher rates of gestational diabetes..

Perinatal Outcomes Among Patients With Sepsis During Pregnancy

Rates of maternal sepsis are increasing, and prior studies of maternal sepsis have focused on immediate maternal morbidity and mortality associated with sepsis during delivery admission. There are no data on pregnancy outcomes among individuals who recover from their infections prior to delivery. To describe perinatal outcomes among patients with antepartum sepsis who did not deliver during their infection hospitalization. This retrospective cohort study was conducted using data from August 1, 2012, to August 1, 2018, at an academic referral center in San Francisco, California. Included patients were all individuals with nonanomalous, singleton pregnancies who delivered after 20 weeks' gestation during the study period. Data were analyzed from March 2020 through March 2021. Antepartum admission for infection with clinical concern for sepsis and hospital discharge prior to delivery. The primary outcome was a composite of perinatal outcomes associated with placental dysfunction and consisted of 1 or more of the following: fetal growth restriction, oligohydramnios, hypertensive disease of pregnancy, cesarean delivery for fetal indication, child who is small for gestational age, or stillbirth. Among 14 565 patients with nonanomalous singleton pregnancies (mean [SD] age at delivery, 33.1 [5.2] years), 59 individuals (0.4%) were in the sepsis group and 14 506 individuals (99.6%) were in the nonsepsis group; 8533 individuals (59.0%) were nulliparous. Patients with sepsis, compared with patients in the reference group, were younger (mean [SD] age at delivery, 30.6 [5.7] years vs 33.1 [5.2] years; P < .001), were more likely to have pregestational diabetes (5 individuals [8.5%] vs 233 individuals [1.6%]; P = .003), and had higher mean (SD) pregestational body mass index scores (26.1 [6.1] vs 24.4 [5.9]; P = .03). In the sepsis group, the most common infections were urinary tract infections (24 patients [40.7%]) and pulmonary infections (22 patients [37.3%]). Among patients with sepsis, 5 individuals (8.5%) were admitted to the intensive care unit, the mean (SD) gestational age at infection was 24.6 (9.0) weeks, and the median (interquartile range) time from infection to delivery was 82 (42-147) days. Antepartum sepsis was associated with higher odds of placental dysfunction (21 patients [35.6%] vs 3450 patients [23.8%]; odds ratio, 1.77; 95% CI, 1.04-3.02; P = .04). On multivariable logistic regression analysis, antepartum sepsis was an independent factor associated with placental dysfunction (adjusted odds ratio, 1.88; 95% CI, 1.10-3.23; P = .02) after adjusting for possible confounders. This study found that pregnancies complicated by antepartum sepsis were associated with higher odds of placental dysfunction. These findings suggest that increased antenatal surveillance should be considered for these patients.

Second trimester cerebroplacental ratio versus umbilicocerebral ratio for the prediction of adverse perinatal outcomes

Introduction An abnormal third trimester cerebroplacental ratio has been previously associated with adverse perinatal outcome. The less studied inverse of the cerebroplacental ratio, the umbilicocerebral ratio, has been proposed as a better predictor of adverse perinatal outcome. However, little is known about the implication of either an abnormal cerebroplacental ratio or umbilicocerebral ratio in the second trimester. The objective of this study was to evaluate the relationship between an abnormal second trimester cerebroplacental ratio and adverse perinatal outcome and provide comparison to an abnormal second trimester umbilicocerebral ratio. Materials and methods This retrospective cohort study in a single tertiary referral center utilized data from all non-anomalous singleton pregnancies that underwent Doppler assessment of the cerebroplacental ratio between 20 and 28 weeks gestation. The study period was 1 January 2015 to 31 July 2018. Abnormal cerebroplacental ratio was defined as less than the 5th percentile for gestational age. If patients had more than one ultrasound during the study period (i.e. for serial assessment of fetal growth), the lowest value of the cerebroplacental ratio was recorded. The primary outcome was a composite of clinically relevant adverse perinatal outcomes including preterm delivery, small for gestational age, and neonatal intensive care unit admission. Secondary outcomes included urgent delivery for fetal distress (operative vaginal delivery or cesarean section) and hypertensive disorders of pregnancy. An abnormal umbilicocerebral ratio was defined as greater than 95th percentile for gestational age. Areas under the curve were calculated and compared for cerebroplacental ratio and umbilicocerebral ratio. Results 2326 pregnancies met inclusion criteria. Of these, 91 (3.9%) had an abnormal second trimester cerebroplacental ratio. Fetuses with an abnormal second trimester cerebroplacental ratio had a 2.3-fold (95% CI 1.5–3.6, p < .05) increased risk of adverse perinatal outcome after adjusting for potential confounders such as chronic hypertension, pregestational diabetes, and smoking during pregnancy. Significantly increased risks of preterm delivery (OR 2.0, 95% CI 1.1–38, p < .05) and neonatal intensive care unit admission (OR 2.1, 95% CI 1.2–3.6, p < .05) were also seen in a subgroup analysis of abnormal cerebroplacental ratio in appropriate for gestational age infants. 132 (5.7%) fetuses had an abnormal second trimester umbilicocerebral ratio, and these fetuses had a 2.0-fold (95% CI 1.4–3.0, p < .05) increased risk of adverse perinatal outcome. The area under the curve for CPR and UCR for prediction of the primary outcome was 0.6 for both (95% CI 0.57–0.61 and 0.57–0.62, respectively, both p < .05). Conclusion An abnormal second trimester cerebroplacental ratio or umbilicocerebral ratio is associated with adverse perinatal outcome. However, the predictive ability of either ratio remains suboptimal.

Pregnancy outcomes among women with class III obesity with normal early glucola

Background Because obese women are at increased risk for insulin resistance and development gestational diabetes (GDM), the American College of Obstetricians and Gynecologists (ACOG) recommends early GDM screening in this population. For obese women with a normal early 1-hour 50 g oral glucose challenge test (eGCT), the risk of developing GDM later in the pregnancy is unknown. Thus, we aimed to assess the risk of developing gestational diabetes based on the value of a normal eGCT. Study Design Retrospective cohort of non-anomalous singleton pregnancies with maternal body mass index (BMI) ≥40 at the time of entry to prenatal care at a single institution from 2013 to 2017. Pregnancies with abnormal early 1-hour 50 g glucose challenge test (eGCT), multiple gestation, late entry to care, type 1 or 2 diabetes, and missing diabetes-screening information are excluded. Primary outcome was development of GDM. Secondary outcomes include fetal growth restriction, macrosomia, gestational age at delivery, large for gestational age, delivery BMI, total weight gain in pregnancy, induction of labor, shoulder dystocia, and cesarean delivery. Bivariate statistics compare demographics, pregnancy complications and delivery characteristics of women who had an eGCT≤ 100 mg/dL (low-normal eGCT) and women who had an eGCT of 101–134 mg/dL (high-normal eGCT). Regression models used to estimate odds of primary outcome. Results Of 169 women, 66(39%) had a low-normal eGCT, and 103(61%) had a high-normal eGCT. Women in the low-normal eGCT group were more likely to use recreational drugs (p = 0.03), other baseline demographics did not differ. The rate of GDM was low in this population (5.3%), with no difference in the rate of GDM between with a low-normal eGCT (1.5%) and high-normal eGCT (7.7%) (p = 0.09). The median neonatal birthweight was higher in the high-normal GCT group (3405 g) as compared to the low-no GCT (3285 g) (p = 0.03). Conclusions Among women with class 3 obesity, the specific value of an early normal GCT was not associated with developing gestational diabetes mellitus later in the pregnancy. Larger studies are needed confirm these findings.

226 Second trimester cerebroplacental ratio as a predictor of adverse perinatal outcomes

An abnormal cerebroplacental ratio in the third trimester is associated with adverse perinatal outcome. However, little is known about the implication of an abnormal cerebroplacental ratio in the second trimester. The objective of this study is to evaluate the relationship between second trimester cerebroplacental ratio and adverse perinatal outcome. This retrospective cohort study in a single tertiary referral center utilized data from all non-anomalous singleton pregnancies that underwent Doppler assessment of the cerebroplacental ratio between 20 and 28 weeks gestation. The study period was January 1, 2015 to July 31, 2018. Abnormal cerebroplacental ratio was defined as less than 5th percentile for gestational age. The primary outcome was a composite of adverse perinatal outcomes that included preterm delivery, a small for gestational age neonate, and neonatal intensive care unit (NICU) admission. Urgent delivery for fetal distress (operative vaginal or cesarean section) was a secondary outcome. 2326 pregnancies met inclusion criteria. Of these, 91 (3.9%) had an abnormal second trimester cerebroplacental ratio. Fetuses with an abnormal second trimester cerebroplacental ratio had a 2.3-fold (95% CI 1.5-3.6, p<.0005) increased risk of adverse perinatal outcome after adjusting for potential confounders such as chronic hypertension, pregestational diabetes, and smoking during pregnancy. Fetuses with an abnormal second trimester cerebroplacental ratio had a 2.8-fold (95% CI, 1.7-4.6; p<0.0001) increased risk of prematurity, after adjusting for confounders. An abnormal second trimester cerebroplacental ratio was also associated with a 1.9-fold (95% CI 1.1-3.5, p<0.05) increased risk of urgent delivery for fetal distress. In a subgroup analysis of appropriate for gestational age fetuses, an abnormal cerebroplacental ratio was associated with a significantly increased risk of preterm delivery and NICU admission after controlling for maternal comorbidities. An abnormal second trimester cerebroplacental ratio may predict adverse perinatal outcome.

61 Maternal mid-upper arm circumference is associated with small for gestational age in a Zambian cohort

Low pre-pregnancy body mass index (BMI) increases the risk of small for gestational age (SGA) infants. Alternative anthropometric measures such as mid-upper arm circumference (MUAC) that are easier to obtain than height and weight are needed where resources are scarce. We aimed to quantify the relationship between MUAC and SGA in a pregnant cohort with high HIV prevalence in Zambia. The Zambian Preterm Birth Prevention Study cohort enrolls pregnant women at early antenatal visits in Lusaka, Zambia. Participants are provided standard antenatal care including assessments of demographics, medical history, physical exam including BMI and MUAC, and routine ultrasound. Newborn weight is documented within 24 hours of birth. For this analysis, eligible participants were women with non-anomalous singleton pregnancies. We constructed linear and Poisson regression models adjusting for key confounders to assess the relationship between maternal MUAC and infant birthweight centile (BWC) or SGA, respectively. BWC was calculated using INTERGROWTH-21st references and the primary outcome was defined as severe (<3%ile; SGA3) and moderate SGA (<10%ile; SGA10). We examined the effect of maternal HIV (HIV+ vs HIV-) in all models. The performance of MUAC compared to BMI in predicting SGA was evaluated using ROC analysis. A total of 775 (75%) HIV- and 259 (25%) HIV+ women were included in the analysis. HIV+ women had a lower median baseline MUAC compared to HIV- women (27cm vs 28cm, p=0.01). Increasing maternal MUAC was associated with higher BWC (coeff: 0.95%; p<0.001). The predictive value of MUAC versus BMI for SGA was similar (SGA3: AUC 0.67 vs 0.65; p=0.22 and SGA10: AUC 0.60 vs 0.61; p=0.52). While HIV+ participants did not have an increased risk of SGA3 (RR 0.96, p=0.9) or SGA10 (RR 1.09, p=0.6), maternal HIV increased the effect of MUAC on BWC (coeff: HIV+ 1.48% vs HIV- 0.81%, p=0.004). Early pregnancy mid-upper arm circumference appears to be an alternative to BMI in SGA prediction in Zambia. HIV infection may exacerbate the effect of maternal malnutrition on fetal growth.

870 Normalization of an abnormal second trimester cerebroplacental ratio in the third trimester equalizes perinatal risks

An abnormal cerebroplacental ratio (CPR) is associated with increased risk of adverse perinatal outcomes. It is unknown if these risks persist with normalization of the cerebroplacental ratio later in gestation. This is a sub-analysis of a retrospective cohort study that utilized data from all non-anomalous singleton pregnancies that underwent Doppler assessment of the CPR between 20-28 weeks gestation at a single tertiary referral center. The perinatal outcomes of patients who had reassessment of the CPR after 32 weeks gestation were analyzed. The final CPR obtained before delivery was used. An abnormal ratio was defined as less than 5th percentile for gestational age. Adverse perinatal outcomes included preterm delivery, a small for gestational age neonate, and neonatal intensive care unit admission. 2326 patients were included in the original study, of which 3.9% had an abnormal CPR in the second trimester. 32 (35.1%) of these patients did not have reassessment of the CPR after 32 weeks, either due to delivery before 32 weeks (37.5%) or because the ratio was not obtained (62.5%). Patients with an abnormal CPR in the second trimester that had no ultrasound reassessment in the third trimester had a significantly earlier gestational age at delivery (34.8 weeks) compared to patients with a normal CPR that had no ultrasound reassessment (38.5 weeks). Of patients with an abnormal CPR in the second trimester, 50 (54.9%) experienced normalization of the cerebroplacental ratio after 32 weeks gestation. These patients were not significantly more likely to experience preterm delivery, a small for gestational age neonate, or neonatal intensive care unit admission when compared to patients who maintained a normal ratio throughout gestation. The association of adverse perinatal outcome with an abnormal second trimester cerebroplacental ratio is driven mostly by very preterm birth (<32 weeks). In approximately half of patients, the ratio normalized in the third trimester and was then associated with an average risk for an adverse outcome.

973 The risk of perinatal mortality by week of expectant management in pregnancies complicated by diabetes

The optimal timing of delivery of pregnancies complicated by diabetes is unknown. The risk of neonatal morbidity and mortality decreases with advancing gestation, which is countered by an increased risk of stillbirth. The objective of this study was to compare the risk of stillbirth and infant death per week of expectant management versus delivery in pregnancies complicated by pregestational (PGD) and gestational diabetes (GDM). A population based retrospective cohort study of non-anomalous singleton pregnancies complicated by either PGD or GDM was performed using national linked birth and death certificate data from 2014-2016. The incidences of stillbirth and neonatal death were determined for each week of pregnancy from 34 to 40 completed weeks’ gestation. A composite perinatal mortality risk with each week of expectant management was calculated by adding the risk of still birth in a given week to the neonatal death risk of delivery in the following week. The relative risk (RR) and 95% confidence interval (CI) of perinatal mortality with expectant management versus delivery was calculated comparing the composite perinatal mortality with the neonatal death risk of delivery in the same week. A total of 989,477 pregnancies were included (PGD: 12.6%, GDM: 87.4%). For both PGD and GDM pregnancies, the risk of stillbirth increased while the risk of infant death decreased with advancing gestation; Table 1. In PGD pregnancies, the risk of neonatal mortality was significantly lower at 37 weeks’ gestation compared to the composite perinatal mortality, favoring delivery over expectant management (RR: 0.52; CI: 0.38-0.71). For GDM pregnancies, this risk was significantly reduced with immediate delivery at 38 weeks’ gestation (RR: 0.48; CI: 0.40-0.59); Figure 1. There does not appear to be a benefit for iatrogenic preterm delivery in either PGD or GDM pregnancies, with results favoring delivery at 37 and 38 weeks’ gestation respectively. This data does not consider glycemic control and delivery timing should be individualized.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

651 Clinical efficacy of a machine learning model for prediction of shoulder dystocia

A newly introduced shoulder dystocia (SD) machine learning (ML) model (Tsur et al, 2019) uses maternal demographics, obstetric history, and sonographic evaluation within 5 weeks from delivery. Our primary aim was to externally validate the calculator for prediction of SD or birth injury in patients who attempted a vaginal delivery. Secondary objective was to assess the clinical utility in optimizing the number of cesarean delivery (CD) for suspected large for gestational age. We conducted a multicenter retrospective study of all non-anomalous singleton pregnancies with a sonographic estimated fetal weight (EFW) ≥ 35 weeks between January 2013 and June 2019. All people who attempted labor or underwent a cesarean delivery due to suspected fetal macrosomia with EFW ≥4000g within 4 weeks from delivery were included. A matched number of people with EFW between 3500g and 3999g were also included in the analysis. The ROC area under the curve (AUC) was used as the primary metric of the model performance and was compared to EFW (ACOG recommendations). A total of 490 people met inclusion criteria, of whom 381 (77.8%) attempted labor and 109 (22.2%) had a CD for suspected fetal macrosomia. We had 19 cases of SD or birth injury in our cohort. The ML model achieved an AUC of 0.77, significantly better than EFW alone (0.61, p-value = 0.028). Furthermore, we evaluated the clinical performance of various risk scores above 0.5 (Table). A risk score of 0.92 could identify and prevent 53% of SD or neonatal injury cases while reducing the rate of CD for suspected macrosomia by 6%. In this validation cohort, using a ML model was found to be more accurate than EFW alone in prediction of SD or neonatal birth injury. Based on these findings, we are planning a prospective study investigating efficacy of the ML model compared to the current recommendations in reducing the rate of SD, associated neonatal morbidity and cesarean delivery for the indication of macrosomia.

961 Patient decisions regarding fetal monitoring in the periviable period and association with outcomes

Management of delivery at periviable gestation requires complex counseling and decision making, including difficult choices about fetal monitoring and intervention for fetal benefit. It is not clear how patients view these decisions, or how these decisions impact outcomes. We hypothesize that, when offered, a significant number of patients forgo monitoring and intervention in the periviable period. Retrospective cohort study of non-anomalous singleton pregnancies delivering between 23w0d and 25w6d at a tertiary care center from 2015 to 2020. Since 2015, we offer patients at these gestational ages options for fetal monitoring, intervention for fetal benefit, and active resuscitation of a liveborn neonate. We aim to characterize the frequency of patients desiring intervention for fetal benefit and identify associated patient characteristics, as well as describe the association with cesarean delivery (CD) and intrapartum demise. 50 subjects were included. 78% desired intervention for fetal benefit, and 84% desired resuscitation if the neonate was born alive, varying significantly by gestational age (Figure). Those desiring intervention were less likely to have a college degree (27% vs 80%, p=0.02) and be nulliparous (46.2% vs 81.8%, p=0.03) (Table). 69% of pregnancies in which intervention was desired resulted in CD (27/39), of which 85% were classical (23/27). Most were in the context of malpresentation (66.7%, 18/27), though 43% (9/21) of patients with cephalic presentation desiring intervention underwent CD for nonreassuring fetal status. Intrapartum demise occurred in 45% (5/11) of pregnancies in which monitoring was not performed. While a majority of patients between delivering between 23w0d and 25w6d desired monitoring and intervention for fetal benefit, this varied significantly by gestational age and patient characteristics. The decision to perform monitoring and intervention for fetal benefit was associated with high frequency of CD, while the decision to forgo monitoring was associated with high frequency of intrapartum demise.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Neonatal Seizures Among Low-Risk Pregnancies at Term: Risk Factors and Adverse Outcomes.

To examine risk factors and adverse outcomes for neonatal-maternal dyads among low-risk pregnancies at term with subsequent neonatal seizures. United States vital statistics data sets were used for this retrospective study. Inclusion criteria were low-risk women (without hypertensive disease or diabetes) with nonanomalous singleton pregnancies, who delivered after labor at 37-41 weeks of gestation. The primary composite neonatal adverse outcome included 5-minute Apgar score less than 5, assisted ventilation longer than 6 hours, and neonatal death. A secondary outcome was composite maternal adverse outcome. Multivariable Poisson regression models with robust error variance were used, with adjusted relative risk (aRR) and 95% CI reported. Of 19.76 million live births during the study interval, 11.7 million (59.4%) met inclusion criteria. The rate of neonatal seizures after low-risk pregnancies delivered at term was 0.2 per 1,000 live births. The maternal risks factors associated with neonatal seizures included no prenatal care, smoking during pregnancy, being overweight or obese, and gestational age of 41 weeks. The strongest risk factors for neonatal seizures were chorioamnionitis (relative risk [RR] 5.04, 95% CI 4.40-5.77; aRR 3.27, 95% CI 2.84-3.76) and route of delivery, with operative vaginal (RR 3.62, 95% CI 3.20-4.09; aRR 3.02, 95% CI 2.66-3.43) and cesarean (RR 4.13, 95% CI 3.81-4.48; aRR 3.14, 95% CI 2.86-3.45) higher than spontaneous vaginal. Compared with neonates without seizures, those with seizures had higher risk of composite neonatal adverse outcome (RR 64.55, 95% CI 61.83-67.39; aRR 37.09, 95% CI 35.20-39.08). Compared with women who delivered neonates without seizures, those who delivered neonates with seizures had higher risk of composite maternal adverse outcome (RR 16.27, 95% CI 13.66-19.37; aRR 9.70, 95% CI 8.15-11.53). We identified modifiable maternal risk factors associated with neonatal seizures among low-risk pregnancies at term. Though infrequent, neonatal seizures are associated with higher risk of adverse outcomes in neonatal-maternal dyads.

Pregnancy Outcomes Among Class 3 Obese Women With Normal Early Glucola [31D

INTRODUCTION: ACOG recommends early screening for glucose intolerance in obese women, who are at increased risk of insulin resistance. We aimed to assess the risk of developing GDM based on the value of a normal early 50g oral glucose challenge test (GCT). METHODS: Retrospective cohort of non-anomalous singleton pregnancies with maternal BMI ≥40 at one institution, 2013–2017. Pregnancies with multiple gestation, late entry to care, type 1 or 2 diabetes, and missing diabetes-screening information are excluded. Primary outcome was development of GDM. Secondary outcomes include fetal growth restriction, fetal macrosomia, gestational age at delivery, large for gestational age, delivery BMI, total pregnancy weight gain, labor induction, shoulder dystocia, and cesarean delivery. Bivariate statistics compare demographics, pregnancy complications and delivery characteristics of women with early GCT &gt;100 and women who with early GCT 101–134. Regression models used to estimate odds of primary outcome. RESULTS: Of 169 women, 66 (39%) had an early GCT &lt;100, and 103 (61%) had an early GCT of 101–134. Women with low normal eGCT were more likely to use recreational drugs (P=.03). Other baseline demographics did not differ. The rate of GDM was low in this population (5.3%), with no difference in the rate of GDM between women with a low normal eGCT and high normal eGCT (P=.9). The median neonatal birthweight was higher in the normal GCT group as compared to the low GCT (P=.03). CONCLUSION: Among women with class 3 obesity, the specific value of an early normal GCT was not predictive of developing GDM by the third trimester.