Association of Recorded Estimated Fetal Weight and Cesarean Delivery in Attempted Vaginal Delivery at Term:

To evaluate the association between documentation of estimated fetal weight, and its value, with cesarean delivery

Disease Severity and Perinatal Outcomes of Pregnant Patients With Coronavirus Disease 2019 (COVID-19)

OBJECTIVE: To describe coronavirus disease 2019 (COVID-19) severity in pregnant patients and evaluate the association between disease severity and perinatal outcomes. METHODS: We conducted an observational cohort study of all pregnant patients with a singleton gestation and a positive test result for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) who delivered at 1 of 33 U.S. hospitals in 14 states from March 1 to July 31, 2020. Disease severity was classified by National Institutes of Health criteria. Maternal, fetal, and neonatal outcomes were abstracted by centrally trained and certified perinatal research staff. We evaluated trends in maternal characteristics and outcomes across COVID-19 severity classes and associations between severity and outcomes by multivariable modeling. RESULTS: A total of 1,219 patients were included: 47% asymptomatic, 27% mild, 14% moderate, 8% severe, 4% critical. Overall, 53% were Hispanic; there was no trend in race–ethnicity distribution by disease severity. Those with more severe illness had older mean age, higher median body mass index, and pre-existing medical comorbidities. Four maternal deaths (0.3%) were attributed to COVID-19. Frequency of perinatal death or a positive neonatal SARS-CoV-2 test result did not differ by severity. Adverse perinatal outcomes were more frequent among patients with more severe illness, including 6% (95% CI 2–11%) incidence of venous thromboembolism among those with severe–critical illness compared with 0.2% in mild–moderate and 0% in asymptomatic (P<.001 for trend across severity). In adjusted analyses, severe–critical COVID-19 was associated with increased risk of cesarean birth (59.6% vs 34.0%, adjusted relative risk [aRR] 1.57, 95% CI 1.30–1.90), hypertensive disorders of pregnancy (40.4% vs 18.8%, aRR 1.61, 95% CI 1.18–2.20), and preterm birth (41.8% vs 11.9%, aRR 3.53, 95% CI 2.42–5.14) compared with asymptomatic patients. Mild–moderate COVID-19 was not associated with adverse perinatal outcomes compared with asymptomatic patients. CONCLUSION: Compared with pregnant patients with SARS-CoV-2 infection without symptoms, those with severe–critical COVID-19, but not those with mild–moderate COVID-19, were at increased risk of perinatal complications

Cost-Efficient Multiply Matched Case-Control Study Designs

In multiply matched case-control studies, a number of cases and controls may be included in each matched set. However, when per participant costs between cases and controls differ, investigators should be aware of how the number of cases and controls per matched set affect the overall total study cost. Traditional statistical approaches to designing case-control studies do not account for study costs. Given an effect size, the power to detect differences is typically a function of the numbers of cases andcontrols within each matched set. Therefore, the same level of power will be achieved based on various combinations of the numbers of cases and controls. Typical matched case-control studies match a case to a number of controls by levels of one or more known factors. Several authors have shown that for study designs with one case per matched set, the optimal number of controls within each matched set that minimizes the total study cost is the square root of the ratio of the cost of a case to the cost of a control. Herein, we extend this result to the setting of a multiply matched case-control study design, when one or more cases are matched to controls within each matched set. A Shiny web application implementation of the proposed methods is presented

Labor Induction at 39 Weeks Compared with Expectant Management in Low-Risk Parous Women

OBJECTIVE: Our objective was to compare outcomes among low-risk parous women who underwent elective labor induction at 39 weeks versus expectant management. STUDY DESIGN: This is a secondary analysis of an observational cohort of 115,502 mother-infant dyads who delivered at 25 hospitals between 2008 and 2011. The inclusion criteria for this analysis were low-risk parous women with nonanomalous singletons with at least one prior vaginal delivery after 20 weeks, who delivered at ≥39 weeks. Women who electively induced between 39 and 39 weeks were compared with women who expectantly managed ≥39 weeks. The primary outcome for this analysis was cesarean delivery. Secondary outcomes were composites of maternal adverse outcome and neonatal adverse outcome. Multivariable logistic regression was used to estimate adjusted odds ratios (aOR). RESULTS: Of 20,822 women who met inclusion criteria, 2,648 (12.7%) were electively induced at 39 weeks. Cesarean delivery was lower among women who underwent elective induction at 39 weeks than those who did not (2.4 vs. 4.6%, adjusted odds ratio [aOR]: 0.70, 95% confidence interval [CI]: 0.53-0.92). The frequency of the composite maternal adverse outcome was significantly lower for the elective induction cohort as well (1.6 vs. 3.1%, aOR: 0.66, 95% CI: 0.47-0.93). The composite neonatal adverse outcome was not significantly different between the two groups (0.3 vs. 0.6%; aOR: 0.60, 95% CI: 0.29-1.23). CONCLUSION: In low-risk parous women, elective induction of labor at 39 weeks was associated with decreased odds of cesarean delivery and maternal morbidity, without an increase in neonatal adverse outcomes. KEY POINTS: · 39-week elective induction is associated with decreased cesarean delivery in low-risk parous women.. · Compared with expectant management, maternal adverse outcomes were lower with elective induction.. · Neonatal adverse outcomes are unchanged between elective and expectant management groups.

Association of Recorded Estimated Fetal Weight and Cesarean Delivery in Attempted Vaginal Delivery at Term

OBJECTIVE: To evaluate the association between documentation of estimated fetal weight, and its value, with cesarean delivery. METHODS: This was a secondary analysis of a multi-center observational cohort of 115,502 deliveries from 2008 to 2011. Data were abstracted by trained and certified study personnel. We included women ≥37 weeks attempting vaginal delivery with live, non-anomalous, singleton, vertex fetuses, and no history of cesarean delivery. Rates and odds ratios were calculated for women with ultrasound or clinical estimated fetal weight, compared to women without documentation of estimated fetal weight. Further subgroup analyses were performed for estimated fetal weight categories (<3,500, 3,500 to 3,999, and ≥4,000 grams) stratified by diabetic status. Multivariable analyses were performed to adjust for important potential confounding variables. RESULTS: We included 64,030 women. Cesarean delivery rates were 18.5% in the ultrasound estimated fetal weight (EFW) group, 13.4% in the clinical EFW group, and 11.7% in the no documented EFW group (p < 0.001). After adjustment (including for birth weight), the adjusted OR (aOR) of cesarean delivery was 1.44 (95% CI 1.31–1.58, p<0.001) for women with ultrasound EFW and 1.08 for clinical EFW (95% CI 1.01–1.15, p=0.017), compared to women with no documented EFW (referent). The highest estimates of fetal weight conveyed the greatest odds of cesarean delivery. When ultrasound EFW was ≥4,000 grams, the aOR was 2.15 (95% CI 1.55–2.98, p<0.001) in women without diabetes, and 9.00 (95% CI 3.65–22.17, p<0.001) in women with diabetes, compared to those with EFW <3,500 grams. CONCLUSION: In this contemporary cohort of women attempting vaginal delivery at term, documentation of estimated fetal weight (obtained clinically or, particularly, by ultrasound) was associated with increased odds of cesarean delivery. This relationship was strongest at higher fetal weight estimates, even after controlling for the effects of birth weight and other factors associated with increased cesarean delivery risk

Antenatal Corticosteroids and Preterm Neonatal Morbidity and Mortality among Women with and without Diabetes in Pregnancy

OBJECTIVE: The objective of this study was to determine whether antenatal corticosteroid exposure has a differential association with preterm neonatal morbidity among women with and without diabetes. STUDY DESIGN: Secondary analysis of an observational cohort of 115,502 women and their neonates born in 25 U.S. hospitals (2008-2011). Women who delivered at 23 to 33 weeks\u27 gestation and received antenatal corticosteroids were compared with those who did not receive antenatal corticosteroids. Women with a stillbirth and women who delivered a neonate that was not resuscitated were excluded. The primary outcome was neonatal respiratory distress syndrome or death within 48 hours. Secondary outcomes included composite neonatal morbidity (respiratory distress syndrome, necrotizing enterocolitis, grades 3-4 intraventricular hemorrhage, sepsis, or death) and mechanical ventilation. Multivariable modified Poisson regression was used to estimate the association between antenatal corticosteroid exposure and neonatal outcomes. Maternal diabetes (pregestational and gestational) was evaluated as a potential effect modifier, and sensitivity analyses were conducted to evaluate whether receipt of a partial, single, or multiple course(s) of antenatal corticosteroids influenced results. RESULTS: A total of 4,429 women with 5,259 neonates met inclusion criteria: 3,716 (83.9%) women received antenatal corticosteroids and 713 (16.1%) did not. Of the 510 diabetic women (181 pregestational and 329 gestational), 439 (86.1%) received antenatal corticosteroids. Of the 3,919 nondiabetic women, 3,277 (83.6%) received antenatal corticosteroids. Antenatal corticosteroid exposure was not associated with respiratory distress syndrome or early death (adjusted relative risk [aRR] = 0.94, 95% confidence interval [CI]: 0.85-1.04), composite neonatal morbidity (aRR = 0.98, 95% CI: 0.89-1.07), or mechanical ventilation (aRR = 0.95, 95% CI: 0.86-1.05). There was no significant effect modification of maternal diabetes on the relationship between antenatal corticosteroids and neonatal outcomes ( \u3e 0.05), and outcomes were similar in sensitivity analyses of partial, single, or multiple courses of corticosteroids. DISCUSSION: Antenatal corticosteroid administered to reduce preterm neonatal morbidity does not appear to have a differential association among women with diabetes compared with those without. KEY POINTS: · Antenatal corticosteroids are used ubiquitously in women with and without diabetes.. · Maternal diabetes does not appear to modify the neonatal effect of antenatal corticosteroids.. · Larger studies of antenatal corticosteroids are needed to confirm our findings in diabetic women.

Association of Body Mass Index With the Use of Health Care Resources in Low-Risk Nulliparous Pregnancies After 39 Weeks of Gestation

OBJECTIVE: To compare health care medical resource utilization in low-risk nulliparous pregnancies according to body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) categories. METHODS: This is a secondary analysis of a multicenter randomized controlled trial of induction of labor between 39 0/7 39 and 4/7 weeks of gestation compared with expectant management in low-risk nulliparous pregnant people, defined as those without standard obstetric indications for delivery at 39 weeks. Body mass index at randomization was categorized into four groups (lower than 25, 25-29, 30-39, and 40 or higher). The primary outcome of this analysis was time spent in the labor and delivery department from admission to delivery. Secondary outcomes included length of stay (LOS) postdelivery, total hospital LOS, and antepartum, intrapartum, and postpartum resource utilization, which were defined a priori. Multivariable generalized linear modeling and logistic regressions were performed, and 99% CIs were calculated. RESULTS: A total of 6,058 pregnant people were included in the analysis; 640 (10.6%) had BMIs of lower than 25, 2,222 (36.7%) had BMIs between 25 and 29, 2,577 (42.5%) had BMIs of 30-39, and 619 (10.2%) had BMIs of 40 or higher. Time spent in the labor and delivery department increased from 15.1±9.2 hours for people with BMIs of lower than 25 to 23.5±13.6 hours for people with BMIs of 40 or higher, and every 5-unit increase in BMI was associated with an average 9.8% increase in time spent in the labor and delivery department (adjusted estimate per 5-unit increase in BMI 1.10, 99% CI 1.08-1.11). Increasing BMI was not associated with an increase in antepartum resource utilization, except for blood tests and urinalysis. However, increasing BMI was associated with higher odds of intrapartum resource utilization, longer total hospital LOS, and postpartum resource utilization. For example, every 5-unit increase in BMI was associated with an increase of 26.1% in the odds of antibiotic administration, 57.6% in placement of intrauterine pressure catheter, 5.1% in total inpatient LOS, 31.0 in postpartum emergency department visit, and 23.9% in postpartum hospital admission. CONCLUSION: Among low-risk nulliparous people, higher BMI was associated with longer time from admission to delivery, total hospital LOS, and more frequent utilization of intrapartum and postpartum resources. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT01990612

First or second trimester SARS-CoV-2 infection and subsequent pregnancy outcomes

BACKGROUND: SARS-CoV2 infection during pregnancy is associated with adverse pregnancy outcomes including fetal death and preterm birth. It is not known whether that risk occurs only during the time of acute infection or whether risk persists later in pregnancy. OBJECTIVE: The goal of this analysis was to evaluate whether the risk of SARS-CoV-2 infection during pregnancy persists after acute maternal illness. STUDY DESIGN: A retrospective cohort study of pregnant patients with and without SARS-CoV2 infection delivering at 17 hospitals in the United States between March and December 2020. Patients experiencing a SARS-CoV-2 positive test at or prior to 28 weeks\u27 gestation with a subsequent delivery hospitalization were compared with those without a positive SAR-CoV-2 test at the same hospitals with randomly selected delivery days during the same period. Deliveries occurring \u3c20 weeks\u27 gestation in both groups were excluded. Study outcomes included fetal or neonatal death, preterm birth less than 37 weeks\u27 gestation and less than 34 weeks\u27 gestation, hypertensive disorders of pregnancy, any major congenital malformation, and size for gestational age less than 5 or 10 percentiles at birth based on published standards. Hypertensive disorders of pregnancy that were collected included hypertensive disorders of pregnancy and preeclampsia with severe features, both overall and with delivery \u3c37 weeks\u27 gestation. RESULTS: Of 2,326 patients who tested positive for SARS-CoV-2 during pregnancy and were at least 20 weeks\u27 gestation at delivery from March through December 2020, 402 patients (delivering 414 fetuses/neonates) were SARS-CoV-2 positive before 28 weeks\u27 gestation and prior to their admission for delivery; they were compared to 11,705 patients without a positive SARS-CoV-2 test. In adjusted analyses, those with SARS-CoV-2 prior to 28 weeks\u27 had a subsequent increased risk of fetal/neonatal death [2·9% vs 1·5%, adjusted relative risk (aRR) 1·97, 95% confidence interval (CI),1·01 - 3·85], preterm birth \u3c37 weeks\u27 (19·6% vs 13·8%, aRR, 1·29; 95%CI, 1·02 - 1·63) and hypertensive disorders of pregnancy with delivery less than 37 weeks\u27 gestation (7·2% vs 4·1%, aRR 1·74, 95% CI 1·19-2·55). There were no significant differences in the rates of preterm birth \u3c34 weeks\u27, any major congenital malformation, size for gestational age less than the 5 or 10 percentiles. There were also no significant differences in the rate of gestational hypertension overall or in preeclampsia with severe features. CONCLUSION: There is a modest increase in risk of adverse pregnancy outcomes subsequent to SARS-CoV-2 infection