Pregnancy After Bariatric Surgery.

This JAMA Insights Clinical Update discusses general adaptations for pregnancy after bariatric surgery, including recommendations regarding nutrition, maternal health, and fetal and neonatal risks.

Development of a Machine Learning Model for Sonographic Assessment of Gestational Age.

Importance: Fetal ultrasonography is essential for confirmation of gestational age (GA), and accurate GA assessment is important for providing appropriate care throughout pregnancy and for identifying complications, including fetal growth disorders. Derivation of GA from manual fetal biometry measurements (ie, head, abdomen, and femur) is operator dependent and time-consuming. Objective: To develop artificial intelligence (AI) models to estimate GA with higher accuracy and reliability, leveraging standard biometry images and fly-to ultrasonography videos. Design, Setting, and Participants: To improve GA estimates, this diagnostic study used AI to interpret standard plane ultrasonography images and fly-to ultrasonography videos, which are 5- to 10-second videos that can be automatically recorded as part of the standard of care before the still image is captured. Three AI models were developed and validated: (1) an image model using standard plane images, (2) a video model using fly-to videos, and (3) an ensemble model (combining both image and video models). The models were trained and evaluated on data from the Fetal Age Machine Learning Initiative (FAMLI) cohort, which included participants from 2 study sites at Chapel Hill, North Carolina (US), and Lusaka, Zambia. Participants were eligible to be part of this study if they received routine antenatal care at 1 of these sites, were aged 18 years or older, had a viable intrauterine singleton pregnancy, and could provide written consent. They were not eligible if they had known uterine or fetal abnormality, or had any other conditions that would make participation unsafe or complicate interpretation. Data analysis was performed from January to July 2022. Main Outcomes and Measures: The primary analysis outcome for GA was the mean difference in absolute error between the GA model estimate and the clinical standard estimate, with the ground truth GA extrapolated from the initial GA estimated at an initial examination. Results: Of the total cohort of 3842 participants, data were calculated for a test set of 404 participants with a mean (SD) age of 28.8 (5.6) years at enrollment. All models were statistically superior to standard fetal biometry-based GA estimates derived from images captured by expert sonographers. The ensemble model had the lowest mean absolute error compared with the clinical standard fetal biometry (mean [SD] difference, -1.51 [3.96] days; 95% CI, -1.90 to -1.10 days). All 3 models outperformed standard biometry by a more substantial margin on fetuses that were predicted to be small for their GA. Conclusions and Relevance: These findings suggest that AI models have the potential to empower trained operators to estimate GA with higher accuracy.

Maximum Dose Rate of Intrapartum Oxytocin Infusion and Associated Obstetric and Perinatal Outcomes.

OBJECTIVE: Despite lack of evidence for a safety threshold for oxytocin dose rate, many hospital protocols specify a maximum rate. We investigated whether exceeding 20 milliunits/min of oxytocin was associated with adverse outcomes. METHODS: This is a secondary analysis of a double-blind, single-center, randomized controlled trial of nulliparous patients with singleton gestations at 36 weeks of gestation or later who presented in spontaneous labor randomized 1:1 to either a high-dose oxytocin titration regimen (initial-incremental rate of 6 milliunits/min) or standard-dose titration regimen (initial-incremental rate of 2 milliunits/min) for labor augmentation. A maximum oxytocin dose rate limit was not specified in the study protocol. For this secondary analysis, outcomes of participants who received oxytocin and exceeded a dose rate of 20 milliunits/min at any point in labor were compared with those whose rate remained at 20 milliunits/min or less. In addition, the cumulative proportions of labor and birth outcomes were calculated for each maximum dose rate of oxytocin reached among this study cohort. RESULTS: Of the 1,003 participants in the parent trial, 955 (95.2%) received oxytocin, as planned, and were included, with 190 (19.9%) exceeding a maximum dose rate of 20 milliunits/min. Those who exceeded 20 milliunits/min were older and were more likely to have rupture of membranes as their trial entry indication, have hypertensive disorders of pregnancy, receive intrapartum magnesium sulfate infusion, and receive oxytocin for longer. Those whose maximum rates exceeded 20 milliunits/min underwent cesarean delivery more frequently, but the majority (74%) still delivered vaginally. In multivariable analyses, there were no significant associations between maximum oxytocin dose rates greater than 20 milliunits/min and cesarean delivery (adjusted odds ratio [aOR] 1.57, 95% CI 1.00-2.46), peripartum infection (aOR 0.69, 95% CI 0.41-1.19), postpartum hemorrhage (aOR 1.37, 95% CI 0.70-2.71), or neonatal intensive care unit (NICU) admission (aOR 1.72, 95% CI 0.89-3.31). Although 85% of spontaneous vaginal deliveries occurred at maximum oxytocin dose rates of 20 milliunits/min or less, vaginal deliveries continued to occur at higher maximum dose rates. The cumulative proportions of NICU admissions and composite severe neonatal morbidity and mortality cases increased with increasing oxytocin dose rates even with maximum oxytocin dose rates at 20 milliunits/min or less. CONCLUSION: In multivariable analyses, there are no significant differences in maternal or perinatal adverse outcomes based on exceeding 20 milliunits/min of oxytocin. These data suggest that oxytocin dosing should be individualized to each patient and not be based on arbitrary thresholds. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov , NCT02487797.

Prevalence of and Risk Factors for Iron Deficiency in Twin and Singleton Newborns.

Iron deficiency (ID) in utero and in infancy can cause irreversible neurocognitive damage. Iron status is not routinely tested at birth, so the burden of neonatal ID in the United States is unknown. Infants born from twin or higher-order pregnancies may be at elevated risk of inadequate nutrient endowment at birth. The present study sought to compare the burden of neonatal ID in cord blood serum samples from twin (n = 54) and singleton pregnancies (n = 24). Iron status (serum ferritin (SF), soluble transferrin receptor (sTfR), hepcidin) and inflammation (C-reactive protein (CRP) and interleukin-6 (IL-6)) biomarker concentrations were measured by immunoassay. The prevalence of ID (SF < 76 ng/mL) among twins was 21% (23/108) and among singletons 20% (5/24). Gestational age at birth, maternal race and infant sex predicted SF levels. Maternal anemia (hemoglobin < 11 g/dL) was observed in 40% of mothers but was not associated with neonatal iron biomarkers. More research is needed to identify risk factors and regulatory mechanisms for inadequate fetal iron accrual to identify higher risk pregnancies and neonates for screening and intervention.

Neonatal Birthweight, Infant Feeding, and Childhood Metabolic Markers.

OBJECTIVE: Antenatal and early neonatal nutritional environment may influence later metabolic health. Infants of mothers with gestational diabetes mellitus (GDM) have higher risk for childhood obesity and metabolic syndrome (MetS). Leptin and adiponectin are known biomarkers for MetS and may guide interventions to reduce later obesity. We sought to examine the relationship between birthweight, early infancy feeding practices, and biomarkers for MetS in offspring of women with mild GDM. STUDY DESIGN: Secondary analysis of a prospective observational follow-up study on the offspring of women who participated in a multicenter randomized treatment trial on mild GDM. Children were evaluated by research coordinators and biospecimens collected at the age of 5 to 10. Plasma concentrations of leptin and adiponectin were compared between large for gestational age (LGA) and average birthweight (AGA) infants, and according to whether solid foods were introduced early (<6 months of age) or at the recommended age (≥6 months of age). Multivariable analysis adjusted for fetal sex, race/ethnicity, and maternal body mass index. RESULTS: Leptin and adiponectin were measured in 336 plasma samples. In bivariate analysis, compared with AGA children, LGA children had lower leptin (5.0 ng/mL [3.6-6.0] vs. 5.8 ng/mL [4.5 = 6.6], p = 0.01) and similar adiponectin (6.3 µg/mL [5.1-7.9] vs. 6.4 µg/mL [5.3-8.6], p = 0.49) concentrations. Maternal/child characteristics were similar between the early/delayed solid feeding groups. Leptin and adiponectin concentrations were similar in the early fed and delayed feeding groups (5.8 ng/mL [4.6-6.7] vs. 5.6 ng/mL [4.2-6.6], p = 0.50 and 6.4 µg/mL [5.4-8.1] vs. 6.4 µg/mL [5.1-8.8], p = 0.85, respectively). After controlling for covariates, children who were LGA and AGA at birth had similar leptin concentrations. CONCLUSION: Birthweight and early infancy feeding practice are not associated with alterations in leptin and adiponectin in children of women with mild GDM. KEY POINTS: · Adipocytokines are markers of metabolic status.. · Children of women with mild GDM may be at risk for MetS.. · Biomarkers similar in LGA and AGA groups.. · Biomarkers similar in early and delayed solid-fed groups.. · Nonhuman milk does not modify effect of feeding practice..

High-Dose Compared With Standard-Dose Oxytocin Regimens to Augment Labor in Nulliparous Women: A Randomized Controlled Trial.

OBJECTIVE: To evaluate whether a high-dose oxytocin regimen reduces the risk for primary cesarean birth and other obstetric morbidities when compared with standard dosing. METHODS: In a double-blind randomized clinical trial of nulliparous women at or beyond 36 weeks of gestation who were undergoing augmentation of labor, participants were assigned to high-dose (initial and incremental rates of 6 milliunits/min) or standard-dose (initial and incremental rates of 2 milliunits/min) oxytocin regimens. The primary outcome was cesarean birth. Prespecified secondary outcomes included labor duration, clinical chorioamnionitis, endometritis, postpartum hemorrhage, Apgar score 3 or less at 5 minutes, umbilical artery acidemia, neonatal intensive care unit admission, perinatal death, and a severe perinatal morbidity composite. A sample size of 501 per group (n=1,002) was planned to detect a 6.6% absolute reduction in rate of the primary outcome, from 20% in the standard-dose group to 13.4% in the high-dose group with 80% power. RESULTS: From September 2015 to September 2020, 1,003 participants were randomized-502 assigned to high-dose and 501 assigned to standard dosing. The majority of participants were of White race, were married or living as married, and had commercial insurance. Baseline characteristics between groups were similar. The primary outcome occurred in 14.5% of those receiving high-dose compared with 14.4% of those receiving standard-dose oxytocin (relative risk, 1.01; 95% CI 0.75-1.37). The high-dose group had a significantly shorter mean labor duration (9.1 vs 10.5 hours; P<.001), and a significantly lower chorioamnionitis incidence (10.4% vs 15.6%; relative risk, 0.67; 95% CI 0.48-0.92) compared with standard dosing. Umbilical artery acidemia was significantly less frequent in the high-dose group in complete case analysis, but this finding did not persist after multiple imputation (relative risk, 0.55; 95% CI 0.29-1.04). There were no significant differences in other secondary outcomes. CONCLUSION: Among nulliparous participants who were undergoing augmentation of labor, a high-dose oxytocin regimen, compared with standard dosing, did not affect the cesarean birth risk but significantly reduced labor duration and clinical chorioamnionitis frequency without adverse effects on perinatal outcomes. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02487797.

Growth restriction: identifying fetuses at risk.

PURPOSE: Examine risks of intrauterine growth restriction (IUGR) and composite perinatal outcomes with estimated fetal weights (EFW) 10-20th%, and compare outcomes using umbilical artery Doppler (UAD). MATERIALS AND METHODS: Retrospective, cohort evaluating ultrasound (US) EFW 10-20th%, between 2002 and 2012. Cases were identified with EFW % 10-20. Controls, EFW >20th% were obtained for each case, matched by gestational age, and US date. Unadjusted and adjusted logistic regression was used for outcomes. RESULTS: Seven hundred and sixty-seven cases met criteria with matched controls. Fetuses having EFW 10-20th% (GA 33.6 ± 3.7 weeks) had increased IUGR on follow up ultrasound (OR 26.5[10.2-68.7], p < .01), small for gestational age (SGA) (OR 9.2 [6.9-12.3], p < .01), neonatal intensive care unit (NICU) admissions (OR 2.4 [1.6-3.6], p < .01), and composite perinatal morbidity (OR 7.8 [6.0-10.1], p < .01) on adjusted analyses. Abnormal UAD in cases had greater rates of 5 min Apgar <7, NICU admission and composite morbidity (p < .05). CONCLUSIONS: Pregnancies with EFW 10-20th% at the time of initial US are at increased risk for developing IUGR and being SGA at birth, with more NICU admissions and composite perinatal outcomes; abnormal UAD evaluation in cases conveyed further increase in outcomes.

Anti-M Alloimmunization: Management and Outcome at a Single Institution.

Objective The objective of this study was to review the management strategies and outcomes in gravidas with anti-M alloimmunization over 15 years. Study Design Data collected from 195 pregnant patients with anti-M antibodies from July 2000 through June 2016 were reviewed retrospectively. We analyzed indirect antiglobulin test titer results, paternal or fetal/neonatal M antigen status, antepartum course, and perinatal outcomes. Results Anti-M antibodies were found in 146 women and 195pregnancies. Among those with positive indirect antiglobulin tests, 193 pregnancies had titers at or below 1:4. Only one patient with an initial low titer experienced a more than twofold increase to a titer 1:64. Two women underwent an amniocentesis and cordocentesis. Ninety-five (73.6%) of the 129 infants tested were positive for the M antigen. Nine infants required phototherapy. There were no cases of hemolytic disease of the fetus or newborn, mild or severe. Conclusion The incidence of severe hemolytic disease of the newborn due to anti-M is extremely low. We found no cases in our review of 195 pregnancies, despite several cases of severe hemolytic disease of the newborn reported in the literature. We have created an algorithm for the management of anti-M antibodies in pregnancy based on our data and extensive literature review.

Outcomes With Cerclage Alone Compared With Cerclage Plus 17α-Hydroxyprogesterone Caproate.

OBJECTIVE: To examine the differences in perinatal outcomes among women with a prior preterm birth who received cerclage compared with cerclage plus 17α-hydroxyprogesterone caproate. METHODS: Women with transvaginal cerclage placement and a prior delivery between 16 and 36 weeks of gestation were identified over a 10-year period (July 2002 to May 2012) in this retrospective cohort study. Exclusion criteria were delivery at another institution, abdominal cerclage, multiple gestations, and major fetal anomalies. Maternal demographics, gestational age at cerclage, gestational age at delivery, preterm prelabor rupture of membranes (PROM), and birth weight were compared between women with a cerclage and cerclage plus 17α-hydroxyprogesterone caproate. The primary outcome was delivery at less than 24 weeks of gestation. RESULTS: Of the 411 women who had a cerclage, 260 met inclusion criteria. Of these, 171 received a cerclage alone and 89 received cerclage plus 17α-hydroxyprogesterone caproate. The two groups were not different with respect to maternal demographics and gestational age at cerclage. There was a significant difference among those who received indomethacin at the time of cerclage, betamethasone administration, and history of a loop electrosurgical excision procedure-cold knife cone and cerclage. Delivery at less than 24 weeks of gestation occurred in 6% of women receiving both 17α-hydroxyprogesterone caproate and cerclage compared with 16% in the cerclage only group (odds ratio [OR] 0.31, 95% confidence interval 0.10-0.78, P=.01). In the multivariate analysis controlling for indomethacin use, prior cerclage, and loop electrosurgical excision procedure-cold knife cone there was a 73% reduction in delivery in the combined treatment group compared with cerclage alone (adjusted OR 0.26, P=.02). A multivariant analysis was conducted with correction for indomethacin at the time of cerclage, prior cerclage, and loop electrosurgical excision procedure-cold knife cone and cerclage surgery. Even after controlling for significant variables, there remained a 73% reduction in delivery at less than 24 weeks of gestation in the cerclage plus 17α-hydroxyprogesterone caproate cohort (adjusted OR 0.26, P=.02). CONCLUSION: Women receiving transvaginal cerclage plus 17α-hydroxyprogesterone caproate had a 69% relative reduction in delivery at less than 24 weeks of gestation when compared with women receiving cerclage alone. We found no difference in overall preterm delivery or preterm PROM. In this cohort, compared with cerclage alone, the likelihood of a viable neonate improves with both treatments.