Maternal obesity and high-fat diet program offspring metabolic syndrome.

OBJECTIVE: We determined the potential programming effects of maternal obesity and high-fat (HF) diet during pregnancy and/or lactation on offspring metabolic syndrome. STUDY DESIGN: A rat model of maternal obesity was created using an HF diet prior to and throughout pregnancy and lactation. At birth, pups were cross-fostered, thereby generating 4 paradigms of maternal diets during pregnancy/lactation: (1) control (Con) diet during pregnancy and lactation (Con/Con), (2) HF during pregnancy and lactation (HF/HF), (3) HF during pregnancy alone (HF/Con), and (4) HF during lactation alone (Con/HF). RESULTS: Maternal phenotype during pregnancy and the end of lactation evidenced markedly elevated body fat and plasma corticosterone levels in HF dams. In the offspring, the maternal HF diet during pregnancy alone programmed increased offspring adiposity, although with normal body weight, whereas the maternal HF diet during lactation increased both body weight and adiposity. Metabolic disturbances, particularly that of hyperglycemia, were apparent in all groups exposed to the maternal HF diet (during pregnancy and/or lactation), although differences were apparent in the manifestation of insulin resistant vs insulin-deficient phenotypes. Elevated systolic blood pressure was manifest in all groups, implying that exposure to an obese/HF environment is disadvantageous for offspring health, regardless of pregnancy or lactation periods. Nonetheless, the underlying mechanism may differ because offspring that experienced in utero HF exposure had increased corticosterone levels. CONCLUSION: Maternal obesity/HF diet has a marked impact on offspring body composition and the risk of metabolic syndrome was dependent on the period of exposure during pregnancy and/or lactation.

Developmental origins of obesity: programmed adipogenesis.

The metabolic syndrome epidemic, including a marked increase in the prevalence of obesity and gestational diabetes mellitus (GDM) among pregnant women, represents a significant public health problem. There is increasing recognition that the risk of adult obesity is clearly influenced by prenatal and infant environmental exposures, particularly nutrition. This tenet is the fundamental basis of developmental programming. Low birth weight, together with infant catch-up growth, is associated with a significant risk of adult obesity. Exposure to maternal obesity, with or without GDM, or having a high birth weight also represents an increased risk for childhood and adult obesity. Animal models have replicated human epidemiologic findings and elucidated potential programming mechanisms that include altered organ development, cellular signaling responses, and epigenetic modifications. Prenatal care has made great strides in optimizing maternal, fetal, and neonatal health, and now has the opportunity to begin interventions which prevent or reduce childhood/adult obesity. Guidelines that integrate optimal pregnancy nutrition and weight gain, management of GDM, and newborn feeding strategies with long-term consequences on adult obesity, remain to be elucidated.

Adult sequelae of intrauterine growth restriction.

Fetal intrauterine growth restriction has been associated with adult disease in both human epidemiologic studies and in animal models. In some cases, intrauterine deprivation programs the fetus to develop increased appetite and obesity, hypertension, and diabetes as an adult. Although the mechanisms responsible for fetal programming remain poorly understood, both anatomic and functional (cell signaling) changes have been described in affected individuals. In some animal models, aspects of fetal programming can be reversed postnatally; however, at the present time, the best strategy for avoiding the adult consequences of fetal growth restriction is prevention.

AQP1 gene expression is upregulated by arginine vasopressin and cyclic AMP agonists in trophoblast cells.

Aquaporins (AQPs) are water channels that regulate water flow in many tissues. As AQP1 is a candidate to regulate placental fluid exchange, we sought to investigate the effect of arginine vasopressin (AVP) and cAMP agonists on AQP1 gene expression in first trimester-derived extravillous cytotrophoblasts (HTR-8/Svneo) and two highly proliferative carcinoma trophoblast-like cell lines but with a number of functional features of the syncytiotrophoblast namely; JAR and JEG-3 cells. Our data demonstrated that AVP (0.1 nM) significantly increased the expression of AQP1 mRNA at 10 h in HTR-8/SVneo and JEG-3 cells (P<0.05). Both SP-cAMP, a membrane-permeable and phosphodiesterase resistant cAMP, and forskolin, an adenylate cyclase stimulator significantly increased AQP1 mRNA expression in all cell lines after 2 h in a dose-dependent manner (P<0.05) with a parallel increase in protein expression. In the time course study, 5 microM of either SP-cAMP or forskolin significantly stimulated AQP1 mRNA expression after 2 h in HTR-8/SVneo cells and after 10 h in JAR and JEG-3 cells. AQP1 protein expression was highest after 20 h in both HTR-8/SVneo and JEG-3 cells (P<0.05). AVP-stimulated cAMP elevation was blocked in the presence of 9-(tetrahydro-2'-furyl) adenine (SQ22536) (100 microM), a cell-permeable adenylate cyclase inhibitor (P<0.05). These results indicate that in trophoblasts-like cells AQP1 gene expression is upregulated by both AVP and cAMP agonists. Furthermore, our data demonstrate that a cAMP-dependent pathway is responsible for the AVP effect on AQP1. Thus, modulation of AQP1 expression by maternal hormones may regulate invasion and fetal-placental-amnion water homeostasis during gestation.

Fetal ST segment heart rate analysis in labor: improvement of intervention criteria using interpolated base deficit.

OBJECTIVE: The addition of ST waveform analysis (STAN, Neoventa, Sweden) to fetal heart rate (FHR) tracings has been demonstrated to improve fetal outcome and reduce operative delivery rates, though the actual level of fetal acidosis at which STAN indicates intervention has not been assessed. We sought to determine if FHR ST segment analysis recommends intervention at appropriate levels of fetal acidosis. METHODS: FHR tracings of 10 acidotic and 10 non-acidotic infants with FHR tracings having a minimum of one STAN flag were retrospectively analyzed. Fetal base deficit (BD) was calculated by interpolation throughout the FHR tracing and STAN 'action' and 'ignore' flags assigned a fetal BD value. A secondary analysis was performed with a revised interpretation of FHR reassuring status. RESULTS: The mean (+/-SD) BD of the first STAN action was significantly greater than the first 'ignore' (4.0+/-2.1 vs. 3.0+/-0.8 mmol/L, p<0.05). Clarified STAN criteria for reassuring vs. non-reassuring FHR resulted in a first action BD of 6.0+/-2.0 mmol/L with 90% sensitivity and 100% specificity for prediction of fetal acidosis. CONCLUSION: The STAN monitor discriminates increasing levels of fetal BD. With clarification of the criteria for reassuring FHR, the calculated BDs of action flags are an appropriate threshold for emergent intervention, successfully predict acidotic fetuses, and avoid unnecessary intervention.

Cervical neck dislocation associated with the Zavanelli maneuver.

BACKGROUND: In the management of shoulder dystocia, fetal head replacement into the uterus has been advocated should delivery attempts remain unsuccessful. Reports of the Zavanelli maneuver have been remarkably optimistic despite the challenges of the procedure. CASE: A gravida 3 para 2 (two previous vaginal deliveries of more than 4,500-g infants) with gestational diabetes presented at term. Following a low forceps delivery, shoulder dystocia was encountered and was unable to be relieved with standard maneuvers. A cesarean delivery was performed, shoulders disimpacted, and the infant delivered abdominally. A 4,680-g stillborn infant was delivered with radiologic and autopsy evidence of cervical C5-C6 dislocation. CONCLUSION: Despite published reports of high success rates and limited fetal consequences, physicians should be aware of adverse consequences including cervical neck trauma associated with use of the Zavanelli maneuver.

Do placental sections accurately reflect umbilical cord nucleated red blood cell and white blood cell differential counts?

OBJECTIVE: Elevated levels of umbilical cord nucleated red blood cells (nRBCs) have been used to assess in utero hypoxia. Although the umbilical nRBC value has been the 'gold standard', umbilical blood may not be obtained at delivery. We determined if the levels of nRBCs and white blood cell (WBC) counts in fixed placental sections might serve as a proxy for cord blood values. STUDY DESIGN: Umbilical blood and placenta were collected from 25 deliveries at Harbor-UCLA Medical Center. Umbilical blood and placental sections were analyzed for nRBCs (per 100 WBC) and WBC differential, and compared with the t-test or the Mann-Whitney rank sum test. RESULTS: nRBC counts were equivalent in umbilical cord and placental sections (5 vs. 4/100 WBC). Umbilical lymphocyte and polymorphonuclear leukocyte (PMN) counts were normally distributed, averaging 35 +/- 9 and 56 +/- 2/100 WBC, respectively. Placental lymphocyte (33 +/- 2/100 WBC) and PMN (60 +/- 2/100 WBC) counts were equivalent to cord blood values. CONCLUSION: WBC differentials and nRBC counts are equivalent in umbilical cord blood and processed placental pathology sections. For infants in whom cord blood cell counts are desired though umbilical cord samples are unavailable, fixed placental sections may serve as a proxy.

A randomized controlled trial of prophylactic maneuvers to reduce head-to-body delivery time in patients at risk for shoulder dystocia.

OBJECTIVE: To assess whether prophylactic use of the McRoberts maneuver and suprapubic pressure decreased the head-to-body time, as a proxy for shoulder dystocia, in at-risk patients. METHODS: Patients with estimated fetal weights over 3800 g were randomized to undergo the McRoberts maneuver and suprapubic pressure before delivery of the fetal head (prophylactic maneuvers) or to undergo maneuvers only after delivery of the head, if necessary (controls). A total of 185 patients were enrolled in the study. After exclusions (eg, abdominal delivery), there were 128 evaluable vaginal deliveries. The study had the power to detect a 30% difference in head-to-body time between groups. RESULTS: Head-to-body delivery times did not differ between the prophylactic and control patients (24 +/- 18 seconds versus 27 +/- 20 seconds, P =.38). In addition, the two groups did not differ in rates of admission of the infant to the special care nursery or in birth injuries. There was a significant increase in the risk of delivering by cesarean for patients randomized to the use of prophylactic maneuvers. CONCLUSION: This study does not support the hypothesis that prophylactic use of the McRoberts maneuver and suprapubic pressure speeds delivery in a population of patients at increased risk for shoulder dystocia.

Unopposed orexic pathways in the developing fetus.

Fetal swallowing has important roles in fetal gastrointestinal development, and perhaps fetal somatic growth and maturation. Ingestive behavioral responses must develop in utero to provide for acquisition of water and food intake during the neonatal period. At birth, the rat, ovine and human fetus have developed mechanisms to acquire food via intact mechanisms of taste, suckling and swallowing. Our preliminary studies suggest that in sheep and likely in human fetuses, putative orexic-mediated ingestive responses are present near term gestation. We hypothesize that both orexic (appetite) and satiety mechanisms develop during the last third of gestation and the related neurotransmitters involved in this process are functional. The potential in utero imprinting of orexic mechanisms may influence infant, childhood and ultimately adult appetite "set-points". Thus, dysfunctional appetite, and perhaps obesity, may result from maternal environmental influences during critical stages of development.

Role of aquaporin 1 in fetal fluid homeostasis.

INTRODUCTION: The homeostasis of maternal-fetal fluid exchange is critically important in pregnancy. We sought to investigate the function of aquaporin 1 (AQP1) during pregnancy by examining fluid compartments of AQP1 knockout (AQP1-KO) mice. METHODS: Homozygous pregnant AQP1 knockout (KO) mice and control pregnant wild type CD1 mice were sacrificed. Placenta and fetal membranes were examined by immunohistochemical staining for expression of AQP1. The total number of embryos, atrophic embryos, and fetal and placental weight was recorded in each subgroup. Amniotic fluid amount in each sac was measured and amniotic fluid composition was determined. Analysis of variance of factorial design and one-factor analysis of variance were used for statistics. RESULTS: Immunohistochemistry performed on CD1, though not AQP1-KO, placenta revealed that AQP1 was expressed at the vascular endothelial cell, trophocyte, and amnion epithelial cell. In AQP1-KOs, the number of embryos decreased with advancing gestational age. Although the fetal weight of AQP1-KO mice was significantly lower than wild type, amniotic fluid amount was increased in AQP1-KO mice. The AQP1-KO placenta demonstrated increased degeneration with evidence of altered blood vessel structure and increased syncytiotrophoblast nodules. CONCLUSIONS: These findings demonstrate a critical role of AQP1 in placental and fetal growth and maternal-fetal fluid homeostasis.

Does preeclampsia predict the risk of late postpartum eclampsia?

Objective To investigate potential predictive symptoms of late postpartum eclampsia (LPE). Study Design Retrospective review of patients delivered at a single academic medical center and diagnosed with eclampsia greater than 48 hours postdelivery. Results Among 19 patients with eclampsia, 5 (26%) patients with confirmed eclampsia seized greater than 48 hours after delivery. None of these patients showed evidence of preeclampsia intrapartum or immediately postpartum and none received intrapartum magnesium sulfate. Prior to seizure activity, 4 of 5 (80%) patients had increased blood pressure and 2 of 5 (40%) had central nervous system symptoms (headache and visual changes). Conclusion Gestational hypertension (GHTN) may be a risk factor for LPE. Consideration of seizure prophylaxis for patients with GHTN may facilitate the prevention of LPE.

Vacuum-assisted vaginal delivery simulation--quantitation of subjective measures of traction and detachment forces.

OBJECTIVE: Excessive traction has been alleged as the cause of newborn complications associated with vacuum delivery. We sought to quantify subjective levels of physician vacuum traction in a simulated obstetric delivery model, dependent upon level of training. METHODS: Three groups of physicians, based on training level applied traction (minimal, average, maximal) on a pre-applied vacuum model and forces were continually recorded. Detachment force was recorded with traction in both the pelvic axis and at an oblique angle. RESULTS: Quantified traction force increased from subjective minimal to average to maximal pulls. Within each level, there were no differences between the groups in the average traction force. Detachment force was significantly less when traction was applied at an oblique angle as opposed to the pelvic axis (11.1 ± 0.3 vs 12.2 ± 0.3 kg). CONCLUSION: Providers appear to be good judges of the force being applied, as a clear escalation in force is noted with minimal, average and maximal force pulls. There appears to be a relatively short learning curve for use of the vacuum, as junior residents' applied force was not different from those of more experienced practitioners. Using the KIWI device, detachment force is lower when traction is applied at an oblique angle.

Early compensatory adaptations in maternal undernourished pregnancies in rats: role of the aquaporins.

OBJECTIVE: To investigate the effect of maternal undernutrition (MUN) during pregnancy on fetal and placental weight, amniotic fluid (AF) volume, AF osmolality and ion concentrations at gestational ages E16 and E20. We also quantified protein expression of water channels (aquaporins; AQPs). METHODS: Pregnant rat dams were fed an ad libitum diet (AdLib; n = 6) or were 50% MUN (n = 6) beginning at E10 of gestation. At E16 and E20, we assessed the effect of MUN on fetal and placental weights, AF volume and osmolality, and placental expression of AQP1, 8 and 9. We focused on two uterine positions (proximal and mid-horns) with the extremes of nutrient/oxygen supply. We also separately studied the basal zone (hormone production) and the labyrinth zone (feto-maternal exchange). RESULTS: We showed that at E16, MUN fetal, and placental weights were unchanged and that, similarly, MUN AF volume, osmolality were comparable to AdLib. At E20, however, MUN fetal and placental zonal weights were significantly decreased. Inversely, due to MUN, maternal and fetal plasma osmolality and Na+ concentrations were significantly increased. Further, MUN AF volume was significantly reduced, while AF osmolality and Na+ concentration were increased at E20. CONCLUSION: Placental basal zone showed variable changes in AQP expression unrelated to position in the uterus or the gestational age (and thus severity of the fetal/placental growth restriction). In the labyrinth zone, MUN placental AQP1 was significantly decreased, whereas AQP8 and 9 expressions were significantly increased at E16 and E20. Dysregulation of AQPs' expression prior to the occurrence of oligohydramnios may represent a compensatory mechanism under conditions of early MUN.

Prediction of preterm birth: nonsonographic cervical methods.

A short cervix in the second trimester is a powerful predictor of preterm birth risk. Multiple cervical length screens for patients in midpregnancy will likely become the standard of obstetrical care as a result of the development of effective methods (eg, cerclage, progesterone) to prevent early delivery in patients with a short cervix. Because of the high cost and infrastructure requirements, providing multiple cervical length evaluations through transvaginal ultrasound will likely be a significant barrier to universal screening. A cost-effective, low-technology method of cervical length screening is necessary to implement such programs. Available data suggest that digital examination is not sufficiently sensitive and reproducible to reliably screen for short cervix in presymptomatic patients in the mid trimester. New modalities for nonsonographic cervical length assessment (ie, Cervilenz) provide for a cost-effective, sensitive, and reproducible method of screening patients for short cervical length, which deserves further research in comparing its efficacy to sonographic cervical length.

Cyclic adenosine monophosphate regulation of aquaporin gene expression in human amnion epithelia.

Cell membrane aquaporins (AQPs) may con t r i b u t e importantly to the regulation of intramembranous absorption of amniotic fluid. Recently, the authors demonstrated that human amnion AQP3 expression is upregulated by second-messenger cyclic adenosine monophosphate (cAMP). The present study was undertaken to determine the cAMP regulation of other AQP types, specifically AQP1, 8, and 9, in human amnion epithelia in vitro. Human amnion epithelial cell cultures were prepared from amnion of normal-term pregnancy. To investigate the effect of cAMP on AQP expression, primary human amnion cell cultures were incubated for 2, 10, and 20 hours with culture medium containing either 50 microM forskolin, an adenylate cyclase activator that stimulates cellular production of cAMP, or 100 microM SP-cAMP, a cAMP agonist that stimulates protein kinase A. Total RNA was isolated from the cultured cells, and semiquantitative real-time reverse transcription polymerase chain reaction was carried out to determine the relative level of AQPs mRNA expression. In primary amnion epithelial cell culture, AQP1 mRNA expression increased significantly at 10 hours (0.219 +/- 0.006 to 0.314 +/- 0.008, P < .05) and remained elevated for 20 hours (0.223 +/- 0.004 to 0.323 +/- 0.012, P < .05) following forskolin treatment. AQP8 mRNA expression increased significantly at 2 hours (0.069 +/- 0.003 to 0.086 +/- 0.012, P < .05) and remained upregulated for 20 hours following forskolin treatment. Forskolin stimulation of AQP9 mRNA expression was evidenced by 10 hours (0.098 +/- 0.005 to 0.115 +/- 0.006, P < .05) and maintained for 20 hours. In contrast to forskolin, SP-cAMP incubation resulted in no change in AQP1, 8, or 9 mRNA expression. Human amnion epithelial cell AQP1, 8, and 9 mRNA expression is upregulated by cAMP as their expression is simulated by forskolin. Lack of effect of SP-cAMP, the protein kinase A activator, on AQP1, 8, and 9 mRNA expression suggests that cAMP upregulates human amnion AQP1, 8, and 9 mRNA expression via the protein kinase A independent pathway.

Aquaporin 3 expression in human fetal membranes and its up-regulation by cyclic adenosine monophosphate in amnion epithelial cell culture.

OBJECTIVE: The cell membrane water channel protein aquaporins (AQPs) may be important in regulating the intramembranous (IM) pathway of amniotic fluid (AF) resorption. The objective of the present study was to determine whether aquaporin 3 (AQP3) is expressed in human fetal membranes and to further determine if AQP3 expression in primary human amnion cell culture is regulated by second-messenger cyclic adenosine monophosphate (cAMP). METHODS: AQP3 expression in human fetal membranes of normal term pregnancy was studied by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC). To determine the effect of cAMP on AQP3 expression, primary human amnion cell cultures were treated in either heat-inactivated medium alone (control), or heat-inactivated medium containing: (1) SP-cAMP, a membrane-permeable and phosphodiesterase resistant cAMP agonist, or (2) forskolin, an adenylate cyclase stimulator. Total RNA was isolated and multiplex real-time RT-PCR employed for relative quantitation of AQP3 expression. RESULTS: We detected AQP3 expression in placenta, chorion, and amnion using RT-PCR. Using IHC, we identified AQP3 protein expression in placenta syncytiotrophoblasts and cytotrophoblasts, chorion cytotrophoblasts, and amnion epithelia. In primary amnion epithelial cell culture, AQP3 mRNA significantly increased at 2 hours following forskolin or SP-cAMP, remained elevated at 10 hours following forskolin, and returned to baseline levels by 20 hours following treatment. CONCLUSION: This study provides evidence of AQP3 expression in human fetal membranes and demonstrates that AQP3 expression in primary human amnion cell culture is up-regulated by second-messenger cAMP. As AQP3 is permeable to water, urea, and glycerol, modulation of its expression in fetal membranes may contribute to AF homeostasis.

Placental and fetal membrane Nephrin and Neph1 gene expression: response to inflammation.

OBJECTIVE: Fetal and amniotic fluid (AF) proteins (eg, alpha fetoprotein [AFP]) are measurable in the maternal circulation. Elevated maternal serum AFP levels indicate a risk for fetal anomalies or for obstetrical complications that are often associated with inflammation (eg, preterm labor). However, little is known of the mechanism of protein exchange between the fetus, AF, and maternal circulation. Nephrin and Neph1 are cell membrane proteins that restrict glomerular protein filtration and which are differentially expressed with renal inflammation. We sought to investigate whether nephrin and Neph1 were expressed in placenta and fetal membranes, and whether inflammation modified the expression. METHODS: Pregnant rats at 18 days' gestation were injected with lipopolysacchride (LPS) or control saline intraperitoneally (IP) and killed at 1, 6, and 12 hours after injection. Placenta and fetal membranes were obtained and real-time polymerase chain reaction (PCR) performed for determination of nephrin and Neph1 levels. RESULTS: Nephrin and Neph1 were expressed in both placenta and fetal membranes. Following maternal LPS administration, nephrin mRNA significantly increased in the membranes (0.22 +/- 0.02 to 0.51 +/- 0.050, P <.05), while Neph1 expression significantly declined in the placenta (0.19 +/- 0.05 to 0.10 +/- 0.01, P <.05). CONCLUSION: Fetal membranes and placenta of the rat express mRNA for the protein barriers nephrin and Neph 1, suggesting a role in the regulation of protein transfer from the fetus to mother. Under basal conditions, AF AFP transfer across fetal membranes may account for maternal serum AFP levels, whereas gestational inflammatory conditions (eg, preterm labor, threatened abortion) may augment AFP transfer across the placenta.