Insulin may stimulate its own insulin secretion and is a potent growth factor for the pancreatic β-cell. Complications of pregnancy, such as diabetes and intrauterine growth restriction, are associated with changes in fetal insulin concentrations, secretion, and β-cell mass. However, glucose concentrations are also abnormal in these conditions. The direct effect of chronic fetal hyperinsulinemia with euglycemia on fetal insulin secretion and β-cell mass has not been tested. We hypothesized that chronic fetal hyperinsulinemia with euglycemia would increase glucose-stimulated insulin secretion (GSIS) and β-cell mass in the ovine fetus. Singleton ovine fetuses were infused with iv insulin to produce high physiological insulin concentrations, or saline for 7-10 days. The hyperinsulinemic animals also received a direct glucose infusion to maintain euglycemia. GSIS, measured at 133 ± 1 days of gestation, was significantly attenuated in the hyperinsulinemic fetuses (P < .05). There was no change in β-cell mass. The hyperinsulinemic fetuses also had decreased oxygen (P < .05) and higher norepinephrine (1160 ± 438 vs 522 ± 106 pg/mL; P < .005). Acute pharmacologic adrenergic blockade restored GSIS in the hyperinsulinemic-euglycemic fetuses, demonstrating that increased adrenergic signaling mediates decreased GSIS in these fetuses.

The medical management of infants with the trisomy 13 and trisomy 18 syndromes is challenging and controversial. Both conditions have high neonatal and infant mortality, and surviving children display significant cognitive and motor disabilities. Currently, there exists a tension in the neonatal and perinatal communities regarding care. One view holds that management should consist solely of comfort care, while another opinion recommends offering medical and surgical intervention in appropriate situations. The purpose of this manuscript is to present a model for the care of fetuses and infants with trisomy 13 and 18 during the prenatal, perinatal, and postnatal periods. Adopting the pathways approach as a framework, we have identified several pertinent decision points, characterizing the goals of care and the resources needed for the decision points at various times. Additionally, we identified themes surrounding parental and professional experiences. The authors propose a care model for trisomy 13 and 18 that uses shared decision making as its foundational principle and the pathways approach as the method. Our model requires further investigation as a strategy for care in order to render it useful in other complex medical situations. © 2016 Wiley Periodicals, Inc.

Insulin is an important fetal growth factor. However, chronic experimental hyperinsulinemia in the fetus fails to accelerate linear and lean mass growth beyond normal rates. Mechanisms preventing accelerated lean mass accretion during hyperinsulinemia are unknown. To address potential mechanisms, late-gestation fetal sheep were infused with iv insulin and glucose to produce euglycemic hyperinsulinemia (INS) or saline for 7-9 days. Fetal substrate uptake and protein metabolic rates were measured. INS fetuses had 1.5-fold higher insulin concentrations (P < .0001) and equivalent glucose concentrations. INS fetuses had 20% more Pax7(+) nuclei in the biceps femoris, which indicates the potential for hyperinsulinemia to increase the number of myoblasts within late-gestation fetal skeletal muscle. Additionally, the percentage of Pax7(+) myoblasts that expressed Ki-67 was 1.3-fold higher and expression of myogenic regulatory factors was 50% lower in INS fetuses (MYF5 and MYOG [myogenin], P < .005), which indicates a shift toward myoblast proliferation over differentiation. There were no differences for fetal body, organ, or muscle weights, although INS placentas weighed 28% less (P < .05). Protein synthesis and accretion rates did not change in INS fetuses, nor did fiber muscle size. Essential amino acid concentrations were lower in the INS group (P < .05) except for tryptophan. Umbilical blood flow, net total amino acids, and O2 uptakes rates did not differ between groups. Arterial O2 content was 33% lower (P < .005) and norepinephrine was 100% higher in the INS fetuses (P < .01), all of which are factors that may counteract fetal protein accretion during hyperinsulinemia despite an increase in myoblast proliferation.

OBJECTIVE We aimed to determine if a threshold number of forceps deliveries in residency predicts use of forceps in independent practice. STUDY DESIGN We surveyed Obstetrics and Gynecology residency graduates of two academic programs from 2008-12 regarding the use of operative vaginal delivery in practice. At these programs, residents are trained in both forceps and vacuums. Individual case log data were obtained with the number of forceps deliveries performed by each respondent during residency. Respondents were grouped as currently using any forceps or vacuums alone. A logistic regression model estimated the probability of forceps use, predicted by the number of residency forceps deliveries. From the resulting receiver operating characteristic curve we assessed sensitivity, specificity, positive predictive value and area under the curve. RESULTS The response rate was 85% (n=58); 90% (n=52) practice obstetrics. Seventy-nine percent (n=41) use forceps in practice. The mean number of forceps performed during residency was 22.3 ± 1.3 (mean ± standard error) in the any forceps group and 18.5 ± 2.1 in the vacuums only group (p=0.14). While the model performed only moderately (area under the curve 0.61, 0.42–0.81), more than 13 residency forceps deliveries corresponded to a 95% sensitivity (95% CI, 84–99) and a positive predictive value of 83% (95% CI, 69–92) for using forceps in practice. The specificity of this threshold is 27% (95% CI, 6–61). CONCLUSION While exceeding 13 forceps deliveries made it highly likely that obstetricians would use them in practice, further study is necessary to set goals for a number of resident forceps deliveries that translate into use in practice.

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