Myeloperoxidase in the plasma and placenta of normal pregnant women and women with pregnancies complicated by preeclampsia and intrauterine growth restriction.

Myeloperoxidase (MPO) is a heme protein produced and released by activated neutrophils and monocytes, and increased MPO is considered important in the pathophysiology of cardiovascular diseases (CVD). Accumulating evidence suggests that preeclampsia (PE), idiopathic intrauterine growth restriction (IUGR), and CVD share many similar metabolic disturbances, including an enhanced systemic inflammatory response and endothelial dysfunction. We hypothesized that MPO plays an important role in the development of PE and IUGR. Plasma samples were collected mid-gestation and at delivery from women with normal pregnancies (n = 40) and those who subsequently developed PE (n = 20), IUGR (n = 11) or both (PE + IUGR, n = 8). Placental samples were obtained immediately after delivery from 22 women with normal pregnancies, 19 women with PE, 14 women with IUGR, and 14 women with PE + IUGR. The MPO concentrations were measured using ELISA. Women with PE + IUGR had significantly higher plasma MPO before delivery than normal pregnant women. There was no difference in plasma levels at mid-gestation or the placental concentrations between women with normal pregnancies and those who developed PE, IUGR, or PE + IUGR. Using explants prepared from the placentas of 8 women with normal pregnancies and 8 women with PE, we found no difference in the levels of MPO in the tissue homogenates and culture media between these two groups of women. Together, these results indicate that increased maternal circulating MPO in women with PE + IUGR is likely a result of enhanced systemic inflammation caused by the established disease rather than a primary pathophysiological factor.

Enhancement of anaerobic biohydrogen/methane production from cellulose using heat-treated activated sludge.

Anaerobic digestion is an effective technology to convert cellulosic wastes to methane and hydrogen. Heat-treatment is a well known method to inhibit hydrogen-consuming bacteria in using anaerobic mixed cultures for seeding. This study aims to investigate the effects of heat-treatment temperature and time on activated sludge for fermentative hydrogen production from alpha-cellulose by response surface methodology. Hydrogen and methane production was evaluated based on the production rate and yield (the ability of converting cellulose into hydrogen and methane) with heat-treated sludge as the seed at various temperatures (60-97 degrees C) and times (20-60 min). Batch experiments were conducted at 55 degrees C and initial pH of 8.0. The results indicate that hydrogen and methane production yields peaked at 4.3 mmol H2/g cellulose and 11.6 mmol CH4/g cellulose using the seed activated sludge that was thermally treated at 60 degrees C for 40 min. These parameter values are higher than those of no-treatment seed (HY 3.6 mmol H2/g cellulose and MY 10.4 mmol CH4/g cellulose). The maximum hydrogen production rate of 26.0 mmol H2/L/d and methane production rate of 23.2 mmol CH4/L/d were obtained for the seed activated sludge that was thermally treated at 70 degrees C for 50 min and 60 degrees C for 40 min, respectively.

Bax, Bak and mitochondrial oxidants are involved in hypoxia-reoxygenation-induced apoptosis in human placenta.

Although apoptosis is prominent in placental cells in pregnancy complications such as preeclampsia, the cause is unknown. We surmised that hypoxia-reoxygenation (HR) is the mechanism and hypothesized that mitochondrial oxidants and Bcl-2 proteins cause HR-induced placental apoptosis. Our goal was studying expression of five Bcl-2 proteins--Bcl-2, Bcl-xL, Bax, Bak, Bad--and testing effects of diazoxide and cyclosporine A on oxidative stress and apoptosis in villous tissues subjected to HR. Term human placentas were obtained from normal pregnancies following elective caesarean deliveries. Villous tissues were subjected to "repetitive HR" (one hour at 2% O(2) then one hour at 8% O(2), alternatively, for a total of 6h) or "prolonged HR" (3h at 2% O(2) then 3h of 8% O(2)). Samples maintained at 2% and 8% O(2) served as hypoxic and normoxic controls, respectively. Prolonged HR caused the most severe villous apoptotic changes, increased the expression of Bax and Bak mRNA and protein and reduced the expression of Bcl-2 mRNA. Pre-administration of diazoxide and cyclosporine A reduced TUNEL-positive nuclei and levels of nitrotyrosine and 4-hydroxy-2-nonenol after prolonged HR. Thus, duration of hypoxia and reoxygenation is important in determining severity of HR-induced apoptosis in placenta. These apoptotic changes are closely associated with Bax and Bak effects and oxidative stress in mitochondria.

Tumour necrosis factor-alpha converting enzyme in human gestational tissues from pregnancies complicated by chorioamnionitis.

Chorioamnionitis increases the risk of preterm labour and is associated with adverse neonatal outcomes including cerebral palsy. Tumour necrosis factor-alpha (TNF-alpha) derived from the gestational tissues (placenta, fetal membranes and maternal decidua) is thought to play a pivotal role in the induction of cytokine response in chorioamnionitis. Tumour necrosis factor-alpha converting enzyme (TACE) is essential for the release of TNF-alpha. Our aim was to determine whether the expression of TACE is increased in human gestational tissues from pregnancies complicated by chorioamnionitis, and whether lipopolysaccharide (LPS) causes increased expression of TACE in the human gestational tissues in vitro. The immunostaining of TACE was generally more intense, in particular in the syncytiotrophoblast and stromal cells, in villous samples from pregnancies complicated by chorioamnionitis than those from normal pregnancies. Increased immunoreactivity of TACE was also noted in the amnion and choriodecidua. In parallel, there was an increased infiltration of monocytes/macrophages within the villous stroma and choriodecidua. As a complement to our in vivo findings, LPS significantly increased the levels of mRNA and protein of TACE in a dose-dependent response in villous and fetal membrane explant cultures. Together, our results imply a potential role of TACE in the pathogenesis of chorioamnionitis.

Outcome of congenital cystic adenomatoid malformation of the lung after antenatal diagnosis.

OBJECTIVE: We evaluated the outcome of fetuses diagnosed with having congenital cystic adenomatoid malformation (CCAM) on ultrasonographic examination and managed conservatively. METHODS: A retrospective study of 19 cases of CCAM diagnosed antenatally in our hospital was conducted between 1990 and 2001. Complete clinical information was available for all patients, with a mean follow-up of 62 months. RESULTS: The median gestational age at which CCAM was diagnosed was 23 weeks and there were eight live births. With conservative postnatal management, seven neonates had no major complications and one developed bronchopneumonia. CONCLUSION: Taken together, the findings of the present study and a review of the literature strongly support the conservative management of selected neonates with CCAM.

The influence of image magnification in first-trimester screening for Down syndrome by fetal nuchal translucency in Asians.

OBJECTIVE: The aim of this prospective study was to evaluate the impact of image magnification in the measurements of crown-rump length (CRL) and nuchal translucency (NT) thickness for first-trimester Down syndrome screening in Asians. METHODS: Ultrasound measurements of NT and CRL were performed in 561 consecutive Taiwanese unaffected fetuses and 11 cases of Down syndrome fetuses between 12 and 14 weeks of gestation. All sonographic images were measured by one qualified examiner to prospectively undergo first-trimester NT screening for Down syndrome. Fetal CRL and NT thickness were measured on three separated images including the original image, regular image, and the magnified image. RESULTS: A significant mean difference (0.59 +/- 4.24 mm) of CRL was found between measurements on the original and regular image (p < 0.001). There was a significant mean difference of NT thickness measurements between the regular and magnified image (0.12 +/- 0.25 mm, p < 0.001). Seven out of the 11 cases (63.6%) of Down syndrome with NT thickness > or =2.5 mm was measured on three separated images. A significantly reduced incidence of NT thickness > or =2.5 mm on the magnified image was noted than those of the original and regular image measurements in unaffected cases (p < 0.001). Either using the assessing method by the 95th centile cutoff value of NT thickness or combined risk, our results could achieve observed detection rate of 63.6% measured on three separated images. CONCLUSIONS: Our data indicate that the image magnification could reduce the false-positive rate by using a fixed cutoff value of NT thickness, but would have no influence on the results when using the assessing method either by the 95th centile cutoff value of NT thickness or the combined risk. In order to place the caliper more accurately, a magnified image should be recommended as a standard image in the measurements of the NT thickness.

Prediction of pregnancy rate of in vitro fertilization and embryo transfer in women aged 40 and over with basal uterine artery pulsatility index.

PURPOSE: The purpose was to determine the effect of basal uterine perfusion on the pregnancy rates of in vitro fertilization and embryo transfer (IVF-ET) in women aged 40 and above. METHODS: A total of 47 patient aged 40 and over underwent IVF-ET. The conception cycles and the nonconception cycles were compared. RESULTS: Of the 47 patients, 4 patients were pregnant (8.5%). The mean age, basal follicle stimulating hormone (FSH), basal estradiol (E2) level, antral follicle count (AFC), number of ampoules of gonadotropin used, E2 levels and endometrial thickness on the day of human chorionic gonadotropin (hCG) administration, number of retrieved and fertilized oocytes, and number of transferred embryos were not statistically significant between the conception and nonconception cycles. However, the basal uterine artery pulsatility index (UA PI) was significantly lower in the conception cycles (P < 0.001). The receiver operating characteristics (ROC) curve analysis for basal FSH, AFC, and basal UA PI in predicting the pregnancy rate of IVF in patients aged > or = 40 were demonstrated. The best prediction rate was achieved by a pulsatility index cutoff of < 2.0 for a receptive uterus. CONCLUSIONS: Increased uterine perfusion in the early follicular phase enhanced the pregnancy rate of IVF in women aged 40 and above. It is therefore essential that patients aged > or = 40 with poor basal uterine perfusion should be identified early in the early follicular phase of the menstrual cycle to apply appropriate intervention to improve the uterine circulation for the subsequent chance of pregnancy.

Risk factors for pre-eclampsia in an Asian population.

OBJECTIVE: To identify the risk factors for pre-eclampsia in an Asian population. METHOD: We conducted a retrospective cohort study involving 29375 Taiwanese women who delivered between July 1990 and September 1998, excluding pregnancies complicated by chronic hypertension or fetal malformations. RESULT: Four hundred and fifteen women had pre-eclampsia (1.4%). Women who had a history of pre-eclampsia (OR 6.3, 95% CI 4.4, 9.2), multiple gestation (OR 3.6, 95% CI 2.4, 5.5), a prepregnancy BMI > 24.2 kg/m(2) (OR 2.4, 95% CI 1. 8, 3.1), were > 34 years of age (OR 1.8, 95% CI 1.4, 2.4), nulliparous (OR 1.3, 95% CI 1.2, 1.5), had urinary tract infection (OR 4.8, 95% CI 1.5, 15.8), or worked during pregnancy (OR 1.9, 95% CI 1.4, 2.4) were at increased risk of pre-eclampsia. CONCLUSION: Some of the risk factors for pre-eclampsia among Asian women are the same as those of other ethnic groups, whereas some of the risk factors are different.

Spleen laceration, a rare complication of laparoscopy.

A 31-year-old woman had secondary infertility of 4 years' duration. Hysterosalpingography revealed bilateral distal tubal occlusion with bilateral hydrosalpinx-like appearance. At laparoscopy, both oviducts were occluded with marked hydropic change. Salpingoplasty was performed to correct bilateral hydrosalpinges and reform the fimbriated tubal ends. The procedure was performed uneventfully by an experienced surgeon in 45 minutes. Nine hours after the operation an emergency exploratory laparotomy was performed due to massive intraabdominal bleeding. The cause was a small tear, 3 cm long and 1 cm deep, with active bleeding in the inferior splenic tail. The laceration was repaired successfully with 1-0 chromic suture. The etiology of splenic laceration during laparoscopic surgery is uncertain. Many complications of laparoscopy are physiologic, and this one might have occurred while establishing pneumoperitoneum. Distortion and stretching of small vascular adhesions of the spleen with the abdominal wall also may have played a role. Gynecologists must be aware of the physiologic insult to patients during laparoscopy.

Agkistin, a snake venom-derived glycoprotein Ib antagonist, disrupts von Willebrand factor-endothelial cell interaction and inhibits angiogenesis.

Glycoprotein (GP) Ib, an adhesion receptor expressed on both platelets and endothelial cells, mediates the binding of von Willebrand factor (vWF). Platelet GPIb plays an important role in platelet adhesion and activation, whereas the interaction of vWF and endothelial GPIb is not fully understood. We report here that agkistin, a snake venom protein, selectively blocks the interaction of vWF with human endothelial GPIb and inhibits angiogenesis in vivo. Agkistin specifically blocked human umbilical vein endothelial cell (HUVEC) adhesion to immobilized vWF in a concentration-dependent manner. Fluorescein isothiocyanate (FITC)-conjugated agkistin bound to HUVECs in a saturable manner. AP1, a monoclonal antibody (mAb) raised against GPIb, specifically inhibited the binding of FITC-conjugated agkistin to HUVECs in a dose-dependent manner, but other anti-integrin mAbs raised against alpha(v)beta(3), alpha(2)beta(1), and alpha(5)beta(1) did not affect this binding reaction. However, neither agkistin (2 microgram/ml) nor AP1 (40 microgram/ml) apparently reduced HUVEC viability. Both agkistin and AP1 exhibited a profound anti-angiogenic effect in vivo when assayed by using the 10-day-old embryo chick chorioallantoic membrane model. These results suggest endothelial GPIb plays a role in spontaneous angiogenesis in vivo, and the anti-angiogenic effect of agkistin may be because of disruption of the interaction of endogenous vWF with endothelial GPIb.

Maternal urine alpha-fetoprotein concentrations between 14 and 21 weeks of gestation.

BACKGROUND: The aim of this study was to ascertain the normal range of the midtrimester maternal urine alpha-fetoprotein (AFP) concentrations in Taiwanese pregnancies. METHODS: AFP was measured in the urine samples, obtained before genetic amniocentesis, from 268 women with normal singleton pregnancies between 14 and 21 weeks of gestation. Week-specific median values for urine AFP/creatinine (Cr) were calculated by weighted linear regression after log transformation and the data were converted to units in the multiple of the median (MoM). The gestational age in all cases was determined by ultrasound parameters. RESULTS: The levels of urine AFP and AFP/Cr increased gradually with advancing gestational age. The AFP/Cr MoM values of singleton pregnancies after log transformation showed a normal distribution with a mean (standard deviation) of 0.0071 (0.3228). The median, 10th and 90th centiles of AFP/Cr were 0.98, 0.43 and 3.61 MoM, respectively. Of the pregnant Taiwanese women studied, 4.9% (13/268) and 16% (43/268) had urine AFP/Cr MoM levels less than 0.31 MoM and 0.5 MoM respectively. CONCLUSION: The establishment of a reference range which allows for gestational differences in AFP/Cr levels is essential for further antenatal testing.

Second-trimester maternal urine human chorionic gonadotrophin beta-core fragment concentrations in Asian pregnancies with fetal chromosomal abnormalities.

The aim of this study was to investigate the second trimester concentrations of maternal urine human chorionic gonadotrophin beta-core fragment (HCGbetacf) in Asian pregnanci2es with fetal chromosomal abnormalities. HCGbetacf concentrations were analysed from 34 urine samples in chromosomally abnormal pregnancies, including 28 cases of Down's syndrome, one case of trisomy 18, and five cases of other chromosomal abnormalities (one mosaic deletion and four translocations), and in a cohort of 268 normal pregnancies receiving second trimester amniocentesis. Results were normalized to urine creatinine (Cr) concentration and converted to the multiple of the median (MOM) concentration for the appropriate gestation. The median HCGbetacf MOM concentrations of Down's syndrome pregnancies (12.89) was significantly higher than that of normal pregnancies (1. 06) (P < 0.00001). Wide variations of HCGbetacf concentrations were observed in other chromosomally abnormal pregnancies. There were 18 of 28 (64%) Down's syndrome cases but one of five (20%) other chromosomally abnormal cases with HCGbetacf concentrations above the 95th centile of the control values (8.22 MOM cut-off). These findings suggest that HCGbetacf could be a potential marker in urine screening for fetal Down's syndrome in Asians.

Effect of a sonographically diffusely enlarged uterus without distinct uterine masses on the outcome of in vitro fertilization-embryo transfer.

PURPOSE: Our objective was to study the effect of a sonographically diffusely enlarged uterus without distinct uterine masses on the outcome of in vitro fertilization-embryo transfer (IVF-ET). METHODS: Nineteen primary infertility patients undergoing IVF-ET who had a sonographically diffusely enlarged uterus without distinct uterine masses were enrolled. An age-controlled group of 144 primary infertility patients undergoing IVF-ET with a normal uterus and no history of uterine surgery was included. RESULTS: The age, day 3 follicle stimulating hormone, antral follicle count, ovarian response, endometrial thickness, number of retrieved and fertilized oocytes, number of transferred embryos, clinical pregnancy rate, and total delivery rate were not statistically different between the two groups (P < 0.05). Patients with a sonographically diffused enlarged uterus without distinct uterine masses had a higher spontaneous abortion rate (66.7%) than controls (P < 0.04; odds ratio = 7.5; 95% confidence interval, 1.16-48.56). CONCLUSIONS: A high spontaneous abortion rate was found in patients with a sonographically diffusely enlarged uterus without distinct uterine masses undergoing IVF-ET. Enhanced luteal support was required.

Urine free beta-human chorionic gonadotropin levels between 14 and 21 weeks of gestation in Taiwanese pregnancies.

BACKGROUND: The purpose of this study was to determine the reference range of maternal urine free beta-human chorionic gonadotropin (beta -hCG) concentrations between 14 and 21 weeks of gestation. METHODS: We measured the concentrations of urine free beta -hCG from 268 healthy singleton Taiwanese pregnancies between 14 and 21 weeks of gestation. Results were corrected for creatinine (Cr) concentration and converted to the multiple of the median (MOM) level for the appropriate gestation. Gestational ages of all cases were determined using ultrasound dating. RESULTS: The median levels of urine free beta -hCG and free beta-hCG/Cr had a downward trend in association with the increasing gestation age. The median, 5th, 10th, 90th and 95th centiles of free beta- hCG/Cr MOM values were 1.02, 0.20, 0.25, 2.32 and 3.38 MOM, respectively. Urine free beta- hCG/Cr MOM values showed a log Gaussian distribution with the mean and standard deviation (SD) distribution of -0.0657 and 0.3792, respectively. CONCLUSION: To allow for differences in free beta -hCG/Cr median values at various ages of gestation, establishment of the reference range is essential for further development of maternal urine screening for Down syndrome.

Urine free beta-hCG and total estriol for Down syndrome screening during the second trimester in an Asian population.

OBJECTIVE: To evaluate second-trimester free beta-hCG and total estriol (E3) in the maternal urine as markers for Down syndrome screening in an Asian population. METHODS: Free beta-hCG and total E3 were measured in the urine samples of 28 Taiwanese Down syndrome pregnancies and 268 unaffected singleton pregnancies at 14-25 weeks. Results were normalized to urine creatinine concentrations and converted to multiples of the median (MoM) levels. Gestational ages were estimated by ultrasound measurements. RESULTS: Median values of free beta-hCG, total E3, free beta-hCG to total E3 ratio, and the free beta-hCG to total E3 MoM ratio in Down syndrome pregnancies were 4.75 MoM, 0.66 MoM, 8.99 MoM, and 9.51, respectively. At a 5% false-positive rate, the observed detection rates were 36% (ten of 28) with total E3, 71% (20 of 28) with free beta-hCG, 68% (19 of 28) with free beta-hCG/total E3, and 71% (20 of 28) with free beta-hCG/total E3 MoM. When combined with maternal age, the expected detection rates were 65% with total E3, 71% with free beta-hCG, 76% with free beta-hCG/total E3, 80% with free beta-hCG/total E3 MoM, and 89% when combining free beta-hCG, total E3, and maternal age. CONCLUSION: Urine free beta-hCG and total E3 are useful markers for Down syndrome screening during the second trimester in Taiwanese women.

Tumor vascular pattern and blood flow impedance in the differential diagnosis of leiomyoma and adenomyosis by color Doppler sonography.

PURPOSE: Our objective was to evaluate the differences between leiomyoma and adenomyosis by color Doppler sonography with new criteria. METHODS: A total of 78 patients with symptomatic uterine nodularities who were sonographically suspected to have leiomyoma or adenomyosis without other coexisting pathologic conditions was enrolled in the study. All patients underwent transvaginal color Doppler sonography (7.0-MHz vaginal probe) or transabdominal color Doppler sonography (5.0 MHz) during the early follicular phase. The morphology, tumor vascular pattern, and blood flow impedance of the uterine tumors were measured. All of the patients underwent surgery and the pathologic reports were used as references. RESULTS: The mean age was not statistically significant in patients with adenomyosis versus leiomyoma (P > 0.05). The morphologic criteria for adenomyosis and leiomyoma by sonography detected 79% of adenomyosis and 84% of leiomyoma. Adenomyosis had 87% randomly scattered vessels or intratumoral signals and 88% of leiomyomas showed peripheral scattered vessels or outer feeding vessels. Eighty-two percent of adenomyosis had a pulsitility index (PI) of arteries within or around uterine tumors > 1.17 and 84% of leiomyomas had a PI < or = 1.17. The reliability test of tumor vascular pattern and blood flow impedance were better than that of using morphological criteria alone. CONCLUSIONS: With the aid of color Doppler sonography, tumor vascular pattern and blood flow impedance of the arteries within or around uterine tumors could more accurately diagnose adenomyosis and leiomyoma in addition to the morphologic criteria on transvaginal sonography.

Delivery of a severely anaemic fetus after partial molar pregnancy: clinical and ultrasonographic findings.

The incidence of a normal live fetus and a partial molar placenta is extremely rare. Although triploidy is the most frequent association, a fetus with normal karyotype can survive in cases of partial molar pregnancy. We report a case of partial molar placenta in which a live female baby was delivered at 32 weeks gestation by a 30-year-old woman. At the 18th week, ultrasonographic examination revealed a normal fetus with a huge, multicystic placenta. Chromosomal evaluation by amniocentesis revealed a normal female karyotype (46,XX), and serial biometric measurement of the fetus showed normal growth during pregnancy. There were no obstetric complications until the 32nd gestational week when preterm rupture of the membranes occurred. The electronic fetal heart beat tracing showed a repeated sinusoid pattern and late deceleration after admission. The patient underwent emergency Caesarean section and delivered a 1551-g, anaemic female baby with an Apgar score of 1, 4 and 6 at 1, 5 and 10 min, respectively. The baby recovered within 2 weeks after respiratory support and transfusion of packed red blood cells. Although anaemia is one of the risk factors that jeopardize the fetus in the case of partial molar pregnancy, termination is not indicated when the fetus is normal and no complications have occurred.

Risk factors for placenta accreta.

OBJECTIVE: To identify risk factors associated with placenta accreta in a large cohort study. METHODS: Data for this study came from the Taiwan Down Syndrome Screening Group, an ongoing project on feasibility of serum screening in an Asian population. Women who had serum screening for Down syndrome at 14-22 weeks' gestation using alpha-fetoprotein (AFP) and free beta-hCG between January 1994 and June 1997, and delivered in the same institution, were included (n = 10,672). Those who had multiple gestations (n = 200), overt diabetes (n = 11), or fetal malformations (n = 101) were excluded. If a woman was involved more than once, one randomly selected pregnancy was included in the analysis (n = 9349). Twenty-eight pregnancies were complicated by placenta accreta, diagnosed by clinical presentation (n = 26) or histologic confirmation (n = 2). Multiple logistic regression with adjustment for potentially confounding variables was used to identify independent risk factors for placenta accreta. RESULTS: Women who had placenta previa (odds ratio [OR] 54.2; 95% confidence interval [CI] 17.8, 165.5) and second-trimester serum levels of AFP and free beta-hCG greater than 2.5 multiples of the median (OR 8.3; 95% CI 1.8, 39.3 and OR 3.9; 95% CI 1.5, 9.9, respectively), and were 35 years and older (OR 3.2; 95% CI 1.1, 9.4) were at increased risk of having placenta accreta. CONCLUSION: Risk factors for placenta accreta include placenta previa, abnormally elevated second-trimester AFP and free beta-hCG levels, and advanced maternal age.

Midtrimester maternal serum free beta-human chorionic gonadotropin levels: normal reference values for Taiwanese women.

BACKGROUND: The purpose of this study was to establish normative median values for maternal serum free beta-human chorionic gonadotropin (beta-hCG) during the second trimester of pregnant Taiwanese women. MATERIALS AND METHODS: We collected the data of midtrimester serum free beta-hCG concentration levels from 15,132 normal Taiwanese singleton pregnancies between 14 and 22 weeks' gestation. The maternal age on the day of delivery and maternal weight at the time of sampling were recorded in all cases. The relationship between gestational days and multiple of the median (MoM) levels of serum markers was analyzed using nonlinear regression methods. RESULTS: The median values of free beta-hCG in pregnant Taiwanese women were higher than those of pregnant white women. The log10 standard deviation distribution of free beta-hCG MoM values in the study population was 0.275 with a log10 mean of 0.0097. There were 1.81% of pregnancies with free beta-hCG levels less than 0.3 MoM and 11.33% with levels less than 0.5 MoM; 12.91% had serum levels greater than 2.0 MoM and 5.29% had serum levels greater than 3.0 MoM. CONCLUSION: Because of differences in race and methodology, any laboratory intended to provide determination of free beta-hCG for Down syndrome screening should establish its own normal reference values.