Isolated Single Umbilical Artery and Fetal Echocardiography: A 25-Year Experience at a Tertiary Care City Hospital.

OBJECTIVES: To review our 25-year experience with a single umbilical artery and fetal echocardiography to estimate the need for this test in cases of an isolated single umbilical artery. METHODS: We conducted a retrospective review of 436 patients with a diagnosis of a single umbilical artery at our institution between 1990 and 2015. Two hundred eighty-eight women had both an anatomic survey and a fetal echocardiogram. Pregnancies with concurrent extracardiac anomalies or aneuploidy were excluded. The study population was divided into 3 groups based on cardiac views on the anatomic survey: normal, incomplete, and suspicious. Echocardiographic results were compared among the 3 groups. The primary outcome measure was the incidence of cardiac anomalies in the normal group at fetal echocardiography. The data were analyzed by the χ2 test or Fisher exact test. RESULTS: The mean maternal age ± SD of the group was 29.2 ± 6.2 years; 44.1% were primiparas. The mean gestational age at diagnosis was 22.6 ± 5.2 weeks, and the mean gestational age at fetal echocardiography was 25.1 ± 3.6 weeks. In the normal group, 99.1% (230 of 232) of women had a normal fetal echocardiogram; the 2 abnormal cases were ventricular septal defects. Normal echocardiograms were obtained in 81.8% (36 of 44) and 25.0% (3 of 12) of the "incomplete" and "suspicious" groups, respectively. CONCLUSIONS: Fetuses with a single umbilical artery, in the absence of structural abnormalities, and with normal cardiac views at the time of the anatomic survey do not warrant an echocardiogram.

First Trimester Aneuploidy Screening Markers in Women with Pre-Gestational Diabetes Mellitus.

OBJECTIVE: To investigate whether maternal serum pregnancy associated plasma protein-A (PAPP-A), total ß human chorionic gonadotropin (hCG) levels and nuchal translucency (NT) measurements differ in women with pre-gestational diabetes mellitus (PGDM) compared to non-diabetic controls and to assess whether correction factors are needed for diabetic women in calculation of aneuploidy risks. STUDY DESIGN: We performed a retrospective study of all women who underwent first trimester aneuploidy screening (11 + 0 to 13 + 6 weeks) from 2005 to 2011. The primary study outcome was the difference in PAPP-A, ß-hCG and NT multiples of median between women with PGDM and non-diabetic women. RESULTS: Of 6741 eligible patients, 103 patients with PGDM were using insulin and 4 patients were using oral hypoglycemic agents; the latter were excluded due to small number. There was 12% reduction of median PAPP-A (p = 0.001) and 18% reduction of median hCG (p = 0.006) in women with PGDM receiving insulin. There was no difference in NT. CONCLUSIONS: In women with PGDM receiving insulin, PAPP-A and ß-hCG levels are significantly lower compared to non-diabetic women. This suggests that when calculating risks for aneuploidy, correction factors should be considered to adjust PAPP-A and ß-hCG concentrations to those seen in non-diabetic women.

Efficacy of the genetic sonogram in a stepwise sequential protocol for down syndrome screening.

OBJECTIVES: The purpose of this study was to evaluate the efficacy of the genetic sonogram in Down syndrome screening for women who have received the stepwise sequential test. METHODS: This retrospective cohort study included women with singleton pregnancies who underwent stepwise sequential (first-trimester combined and second-trimester serum) screening and then had a genetic sonogram between March 2005 and January 2010. Stepwise sequential Down syndrome risks were multiplied by either a positive or negative likelihood ratio based on the second-trimester sonographic findings to determine the final Down syndrome risk. A final Down syndrome risk of 1:270 or higher was considered screen positive. RESULTS: A total of 6286 women fulfilled our criteria, including 17 with Down syndrome-affected fetuses. After stepwise sequential testing, the Down syndrome detection rate was 88.2% (15 of 17), and after the genetic sonogram, there was a non-significant reduction in detection to 82.4% (14 of 17; P > .05). For the 6269 unaffected pregnancies, the genetic sonogram converted 58 screen-negative results (1%) to positive and 183 screen-positive results (3.1%) to negative. The net effect was a change in the false-positive rate from 6.2% (390 of 6269) after stepwise sequential screening to 4.2% (266 of 6269) after the genetic sonogram. CONCLUSIONS: The genetic sonogram should be applied cautiously for women who have received prior prenatal screening tests. Women with screen-positive results need to be counseled that a negative sonographic result can be falsely reassuring. Conversely, for women with screen-negative results who have a risk close to the cutoff, a sonographic examination could assist in the decision of whether to accept or reject amniocentesis.

Impact of diabetes on aneuploidy screening.

Maternal pregestational diabetes mellitus is a known risk factor for multiple nonchromosomal congenital anomalies, but there is no clear evidence that diabetes increases the risk for aneuploidy. However, diabetes affects maternal serum analyte concentrations that are used for aneuploidy screening and can alter the false-positive rates of the screening tests. Correction factors are used for women with pregestational diabetes for second-trimester serum analytes used in aneuploidy screening. There is considerable variation in the reported literature regarding the effect of diabetes on first-trimester serum analytes and how it might have an impact on aneuploidy screening.

Fetal hydronephrosis as a predictor of neonatal urologic outcomes.

OBJECTIVES: The ability to predict surgically relevant fetal renal hydronephrosis is limited. We sought to determine the most efficacious second- and third-trimester fetal renal pelvis anteroposterior diameter cutoffs to predict the need for postnatal surgery. METHODS: We retrospectively reviewed the medical records of mothers and neonates who had a prenatal sonographic examination in our Perinatal-Pediatric Urology Clinic and received follow-up care. Hydronephrosis was defined as a renal pelvis anteroposterior diameter of 5 mm or greater in the second trimester and 7 mm or greater in the third trimester. Hydronephrosis was subdivided into mild, moderate, and severe. RESULTS: Of 8453 fetuses, 96 met the criteria and were referred to our clinic. Isolated hydronephrosis was diagnosed in 74 fetuses, of which 53 received postnatal follow-up evaluations. The areas under the receiver operating characteristic curves for predicting postnatal surgery in the second and third trimesters were 0.770 and 0.899, respectively. The second-trimester renal anteroposterior diameter threshold that best predicted post-natal surgery was 9.5 mm (sensitivity, 71.4%; specificity, 81.1%). The third-trimester threshold that best predicted postnatal surgery was 15.0 mm (sensitivity, 85.7%; specificity, 94.6%). CONCLUSIONS: The fetal renal anteroposterior diameter on second- and third-trimester sonography is predictive of an increased risk for neonatal urologic surgery. Surgical risk is best predicted by a third-trimester renal anteroposterior diameter threshold of 15 mm.

Distortions of sex ratios at birth in the United States; evidence for prenatal gender selection.

OBJECTIVE: The normal male to female livebirth sex ratio ranges from 1.03 to 1.07. Higher ratios in China, India and Korea reflect prenatal sex selection. We reviewed sex ratios for US births to investigate potential prenatal sex selection. METHODS: We reviewed all US livebirths from 1975 to 2002 using National Center for Health Statistics birth certificates in 4-year intervals. We compared the sex ratios of Blacks, Chinese, Filipinos, Asian Indians and Koreans relative to Whites. We also compared the sex ratios by birth order for first, second and third and more births (third+) from 1991 to 2002. RESULTS: The male to female sex ratio from 1975 to 2002 was 1.053 for Whites, 1.030 (p < 0.01) for Blacks, 1.074 (p < 0.01) for Chinese and 1.073 (p < 0.01) for Filipinos. From 1991 to 2002, the sex ratio increased from 1.071 to 1.086 for Chinese, 1.060 to 1.074 for Filipinos, 1.043 to 1.087 for Asian Indians and 1.069 to 1.088 for Koreans. The highest sex ratios were seen for third+ births to Asian Indians (1.126), Chinese (1.111) and Koreans (1.109). CONCLUSION: The male to female livebirth sex ratio in the United States exceeded expected biological variation for third+ births to Chinese, Asian Indians and Koreans strongly suggesting prenatal sex selection.