Martin Chavez

Gestational diabetes in the United States: temporal trends 1989 through 2004

OBJECTIVE The objective of the study was to characterize trends in gestational diabetes (GDM) by maternal age, race, and geographic region in the United States. STUDY DESIGN The National Hospital Discharge Survey, comprised of births in the United States between 1989 and 2004 (weighted n = 58,922,266), was used to examine trends in GDM, based on an International Classification of Diseases, Ninth Revision, Clinical Modification code of 648.8. We examined temporal trends by comparing GDM rates in the earliest (1989-1990) vs most recent (2003-2004) biennial periods. Relative risks, quantifying racial disparity (black vs white) in GDM, were derived through logistic regression models after adjusting for confounders. These analyses were further stratified by maternal age and geographic region. RESULTS Prevalence rates of GDM increased from 1.9% in 1989-1990 to 4.2% in 2003-2004, a relative increase of 122% (95% confidence interval [CI] 120%, 124%). Among whites, GDM increased from 2.2% in 1989-1990 to 4.2% in 2003-2004 (relative increase of 94% [95% CI 91%, 96%]), and this was largely driven by an increase in the 25-34 year age group. In contrast, the largest relative increase in GDM (260% [95% CI 243%, 279%]) among blacks between 1989-1990 (0.6%) and 2003-2004 (2.1%) occurred to women aged younger than 25 years. The black-white disparity in GDM rates widened markedly among women aged younger than 35 years in the 1997-2004 periods. The largest relative increases were seen in the West (182% [95% CI 177%, 187%]) followed by the South and Northeast. The observed increase in GDM rates in the Northeast, Midwest, and South regions most likely is due to increase in GDM prevalence rates among blacks. CONCLUSION This study shows that the prevalence rate of GDM in the United States has increased dramatically between 1989 and 2004. The temporal increase and the widening black-white disparity in the rate of GDM deserves further investigation.

Three‐dimensional sonographic diagnosis of vasa previa

Vasa previa is said to occur when fetal vessels run in the membranes over the cervix, below the presenting part, without the support of placental tissue or umbilical cord1. Rupture of these vessels at the time of spontaneous or artificial rupture of the membranes not infrequently results in fetal exsanguination and death1. When the diagnosis is not made prenatally, over half of fetuses die, and median Apgar scores in survivors are low (median, 1 at 1 min and 4 at 5 min)2. In addition, over half of these survivors require neonatal blood transfusions2. Thus, a good outcome depends primarily on prenatal diagnosis by ultrasound and elective delivery before the membranes rupture1–8. Two variants of vasa previa have been described: Type 1 results from velamentous insertion of the cord, and Type 2 from vessels running between two lobes of a bilobed or succenturiate placenta3. Pregnancies with second-trimester low-lying placentae, placentae with accessory lobes, multiple pregnancies, and those resulting from in-vitro fertilization have previously been described as being at risk for vasa previa. Women with such conditions may benefit from routine prenatal determination of the placental cord insertion site1–3,5–7. We describe here the prenatal diagnosis and evaluation of vasa previa using three-dimensional (3D) sonography. In the first case, two-dimensional (2D) transvaginal sonography was performed on a woman at 30 weeks’ gestation because a bilobed placenta had been seen on 2D transabdominal sonography. Vasa previa was suspected. We then performed 3D transvaginal sonography with color and power Doppler using a Voluson Expert 730 (GE Medical Systems, Milwaukee, WI, USA) ultrasound machine. These confirmed the diagnosis of vasa previa. 3D multiplanar views revealed that a vessel overran the cervix in the anterior–posterior sagittal direction (Figures 1–3). The diagnosis of vasa previa and a bilobed placenta were confirmed at Cesarean delivery at 35 weeks’ gestation (Figure 4). Both mother and baby did well. In the second case, a 37-year-old woman was referred to our hospital at a gestational age of 24 weeks with a diagnosis of complete placenta previa and vaginal bleeding. Sonography at our center revealed an appropriately grown singleton live fetus, with normal amniotic fluid volume. On initial 2D transabdominal and transvaginal sonography, there appeared to be complete placenta previa. It was noted that the placental edge was just slightly to the right of the internal cervical os. When a mid-sagittal view of the cervix was obtained with 3D ultrasound, it became apparent that there were vessels overlying the cervix in an anterior–posterior direction, running through the membranes just along the lateral placental edge. Pulsed Doppler demonstrated a fetal umbilical arterial signal through these vessels. The patient was admitted to hospital. Steroids were administered for lung maturation and she was kept under close surveillance. At 33 weeks’ gestation, followup 3D transvaginal sonography was performed with color and power Doppler. Multiplanar imaging confirmed the diagnosis of vasa previa (Figures 5 and 6). An uncomplicated Cesarean delivery was performed at

Fetal Transcerebellar Diameter Measurement for Prediction of Gestational Age at the Extremes of Fetal Growth

The purpose of this study was to determine the accuracy of our previously published and prospectively validated transcerebellar diameter (TCD) nomogram in the prediction of gestational age (GA) in intrauterine growth‐restricted (IUGR) and large fetuses.

Three-dimensional sonography in the evaluation and management of fetal goiter

Fetal goiter is a rare complication of pregnancy, and may be the consequence of fetal hyperthyroidism or hypothyroidism. To our knowledge, this is the first report of three-dimensional (3D) sonography in the evaluation and treatment of fetal goiter. A 36-year-old woman in her fifth pregnancy presented for prenatal care at a gestational age of 13 weeks. Hyperthyroidism had been diagnosed 2 weeks previously during evaluation for palpitations and tachycardia. She was otherwise asymptomatic and her pregnancy had been otherwise uncomplicated. She had previously had a fullterm uncomplicated normal vaginal delivery, followed by three first-trimester spontaneous miscarriages. The physical examination was unremarkable. Her thyroidstimulating hormone (TSH) level was suppressed, and she had elevated free thyroxine levels. In addition, she had circulating thyroid-stimulating immunoglobin and thyroid-binding inhibitory immunoglobin. At 13 weeks she was started on 100 mg propylthiouracil (PTU) thrice daily. Targeted sonography at 23 weeks’ gestation revealed a fetal goiter with neck extension. At 27 weeks’ gestation 2D and 3D sonography and power Doppler angiography were performed (Figures 1–4) using a Voluson 730 (GE Medical Systems, Milwaukee, WI, USA) ultrasound machine. Because of the possibility that the goiter was the result of fetal hypothyroidism from transplacental transfer of PTU to the fetus, it was decided to reduce the PTU dose to 50 mg twice daily. Despite this reduction in the dose of PTU, the fetal goiter did not diminish in size. Consequently, cordocentesis was performed at 30 weeks’ gestation and it was determined that the fetus was profoundly hypothyroid, with a TSH level of 23.61 mIU/mL (normal range, 0.35–5.5 mIU/mL). Intra-amniotic injection of 500 μg thyroxine was therefore performed immediately. Because the goiter only demonstrated modest diminution in size (Figure 5) 2 weeks later, a further intra-amniotic injection of 250 μg thyroxine was administered. At 34 weeks’ gestation, the goiter was still present, although it had Figure 1 Three-dimensional multiplanar surface-rendered image of the fetal face and neck at 27 weeks demonstrating the fetal goiter.