Second trimester maternal serum analytes in triploid pregnancies: correlation with phenotype and sex chromosome complement.

Second trimester maternal serum alpha-fetoprotein (MS-AFP), human chorionic gonadotrophin (hCG), unconjugated estiol (uE3), and inhibin-A (INH-A) levels were evaluated in pregnancies complicated by triploidy. In addition to seven new triploid pregnancies, the results for 67 published cases were reviewed. All cases appear to fall into two major groups. First, those identifiable as screen-positive for both Down syndrome and an open neural tube defect (ONTD) with elevated MS-AFP, grossly elevated hCG, low/normal uE3, and probably elevated INH-A. Pregnancies in the second group are identifiable as screen-positive for trisomy 18 with low/normal MS-AFP, and very low hCG, uE3 and INH-A. Triploid pregnancies with high maternal serum hCG nearly always show a placenta with partial mole (25/27 or 93%), a high frequency of ONTDs or ventral wall defects (VWDs) (8/28 or 29%) and have either an XXX or XXY karyotype (observed ratio 6:10, respectively). Low hCG is infrequently associated with a molar placenta (1/11 or 9%), does not appear to be associated with ONTDs or VWDs (0/29 or 0%), and shows an excess of XXX over XXY karyotypes (observed ratio 17:2). There were 16 cases with either a molar placenta, an ONTD or a VWD that received the MS-AFP and hCG tests. All 16 were screen-positive for an ONTD (MS-AFP> or =2 multiples of the median). In addition, all 31 cases that received MS-AFP, hCG, uE3 (and where available INH-A) were screen-positive for either Down syndrome or trisomy 18. The findings are discussed in the context of expected differences between digynic and diandric triploidy. It is suggested that the sex chromosome complement in triploidy is an important factor in determining risk for partial mole development and in utero survival.

Irreversible maternal brain injury during pregnancy: a case report and review of the literature.

Maternal brain death or massive injury leading to persistent vegetative state during pregnancy is a rare event. Since 1979, 11 cases, including the current one, of irreversible maternal brain damage in pregnancy have been reported. In all but one, the pregnancies were prolonged with a goal of achieving delivery of a viable infant. Current advances in medicine and critical care enable today's physician to offer prolonged life-support to maximize the chances for survival in the neonate whose mother is technically brain dead. We present a case at our institution and review all previously published cases in the English literature for comparison as well as make management recommendations.

Vanishing gastroschisis and short-bowel syndrome.

BACKGROUND: Gastroschisis occurs in 1 of every 4000 live births resulting in a neonate with an abdominal wall defect that requires repair. Surgical correction has high survival rates. CASE: An 18-year-old primigravida had a fetus with gastroschisis detected by ultrasound performed for elevated maternal serum alpha-fetoprotein. Subsequent ultrasound found resolution of the classic sonographic features of gastroschisis and evidence of intestinal obstruction. At birth, no obvious abdominal wall defect was seen. Laparotomy was done because of clinical and radiographic evidence of bowel obstruction, and we found significant bowel loss that resulted in short-bowel syndrome. CONCLUSION: Gastroschisis diagnosed antenatally can resolve in utero causing necrosis of portions of the small and large bowels, causing short-bowel syndrome and increased morbidity and mortality.

Efficacy of screening for fetal Down syndrome in the United States from 1974 to 1997.

OBJECTIVE: To estimate the 16-week prevalence of Down syndrome in the United States from 1974 to 1997 and to determine the efficacy of maternal age cutoffs and triple screens for detecting it antenatally. METHODS: Using natality statistics for the United States from 1974 to 1997 of maternal-age-specific live births to women 13-49 years old, we evaluated advanced maternal age (35-49 years at delivery) and the triple serum test (maternal serum alpha-fetoprotein, hCG, and unconjugated estriol) as screening tests for Down syndrome. Efficacy was evaluated using sensitivity, false-positive rate, positive predictive value, and likelihood ratio (likelihood ratio = sensitivity/false-positive rate). RESULTS: In 1974, the estimated second-trimester prevalence of Down syndrome was one in 740, but by 1997 that had increased to one in 504. The proportion of Down syndrome fetuses at 16 weeks' gestation in women 35-49 years old increased from 28.5% in 1974 to 47.3% in 1997. However, live births to women 35-49 years old increased more rapidly from 4.7% in 1974 to 12.6% in 1997. The likelihood ratio for maternal age to identify an affected pregnancy decreased during the study period and was substantially lower than that using the serum test. CONCLUSION: A maternal age cutoff of 35 years in the 1990s resulted in high false-positive rates and was less efficacious based on likelihood ratio and positive predictive value. Serum testing of all pregnant women would reduce the number of amniocenteses and decrease procedure-related losses.

Outcome of pregnancies complicated by ruptured membranes after genetic amniocentesis.

OBJECTIVE: We sought to compare perinatal outcomes of pregnancies complicated by preterm premature rupture of membranes after genetic amniocentesis with pregnancies complicated by spontaneous preterm premature rupture of membranes at a similar gestational age. STUDY DESIGN: A retrospective study was performed in which a computerized database was reviewed to identify all patients presenting to our institution with preterm premature rupture of membranes within 48 hours of a genetic amniocentesis from July 1988 to August 1999. Control subjects were matched for gestational age at preterm premature rupture of membranes. Patients were all managed expectantly. Outcomes were compiled from review of medical records. Descriptive statistics, the Student t test, and the chi(2) test were used, with P <.05 considered significant. RESULTS: During the study period, genetic amniocentesis was performed 1101 times. Eleven (1%) women presented within 48 hours with preterm premature rupture of membranes. The mean gestational age at the time of rupture was not different between the cases in which preterm premature rupture of membranes occurred after genetic amniocentesis compared with the control subjects in whom preterm premature rupture of membranes occurred spontaneously (16.5 weeks vs 17.6 weeks, respectively). Women with preterm premature rupture of membranes after amniocentesis experienced significantly longer latency periods (124 vs 28 days; P =.0001) and delivered at more advanced gestational ages (34.2 vs 21.6 weeks; P =.0002) than those with spontaneous preterm premature rupture of membranes. The perinatal survival rate was 91% in pregnancies complicated by preterm premature rupture of membranes after genetic amniocentesis compared with a rate of 9% in control subjects (P =.005). CONCLUSIONS: Pregnancies complicated by preterm premature rupture of membranes after genetic amniocentesis result in significantly better perinatal outcomes compared with pregnancies complicated by spontaneous preterm premature rupture of membranes at a similar gestational age. Expectant management should be considered in such cases.

Elevated maternal serum alpha-fetoprotein with low unconjugated estriol and the risk for lethal perinatal outcome.

OBJECTIVE: To determine whether a combination of elevated maternal serum alpha-fetoprotein (MSAFP) and low unconjugated estriol (E3) concentration identifies pregnancies at particularly high risk for fetal abnormality or poor outcome. METHODS: Pregnancy outcomes were reviewed for women with elevated MSAFP (> or =2.0 MoM) from our database of 50,315 women who had received triple marker testing from 1993-1998. Outcomes for those with low E3 (< or =0.7 MoM) were compared with those with normal E3 (>0.7 MoM). The incidences of fetal death, neural tube defects, chromosome abnormalities, congenital abnormalities, preterm birth, small-for-gestational age (SGA), twins, and inaccurate dates were compared in the two groups using Fisher's exact test with P < 0.05 considered significant. RESULTS: Of the 50,315 women screened, 1,435 (2.85%) had an elevated MSAFP. Pregnancy outcomes were obtained in 94% of those with elevated MSAFP and 70% of all patients screened. Neural tube defects were present in 57 fetuses/infants (21 anencephalic, 29 spina bifida, 7 encephalocele) of which 46 (81%) had an elevated MSAFP. Of the 1,435 women with an elevated MSAFP, 199 (14%) had a low E3. Compared to those women with elevated MSAFP but normal E3, women with elevated MSAFP and low E3 were at significantly increased risk for fetal death (20.6% vs. 2.8%, relative risk (RR) 8.9), anencephaly (9.0% vs. 0.1%, RR 122.8) and chromosome abnormality (2.5% vs. 0.6%, RR 4.0). CONCLUSIONS: Pregnancies complicated by elevated second trimester MSAFP and low E3 are at a particularly high risk (32%) for lethal perinatal outcomes. Twins, while a common cause of elevated MSAFP, are rarely found when an elevated MSAFP is associated with low E3.

Comprehensive fetal ultrasonographic growth measurements in triplet gestations.

OBJECTIVE: Our purpose was to create tables and graphs of ultrasonographically derived fetal growth parameters in longitudinally studied triplet gestations from a single center. STUDY DESIGN: All triplet pregnancies managed by our division from 1987 through 1998 were identified. All had first-trimester dating sonograms and complete obstetric sonograms obtained by means of 3.5- or 5.0-MHz curvilinear transducers with freeze-freeze capability and on-screen calipers. Sonograms to assess fetal growth were obtained every 2 to 4 weeks, from 16 to 18 weeks' gestation until delivery. Fetal parameters obtained with each sonogram included biparietal diameter; head circumference; bicerebellar diameter; abdominal circumference; femur, humerus, tibia, and fibula lengths; estimated fetal weight; and head circumference/abdominal circumference ratio. Regression analysis was performed with JMP and Cricket Graph software packages, and lines of best fit with 95% confidence intervals were generated. RESULTS: A total of 443 ultrasonographic examinations were performed for 33 triplet pregnancies (99 fetuses). Each had between 3 and 6 sonograms obtained, all between 16 and 35 weeks' gestation. Scatterplots of each of the fetal growth parameters against gestational age were created with regression lines of best fit and 95% confidence intervals. All growth parameters were dependent on gestational age. CONCLUSION: A comprehensive set of fetal growth measurements in triplets from the United States is now available and can be used to assess longitudinal fetal growth.

Rotational versus nonrotational forceps: maternal and neonatal outcomes.

OBJECTIVE: Our purpose was to evaluate maternal and neonatal morbidity associated with rotations performed with Leff forceps in comparison with nonrotational forceps deliveries. STUDY DESIGN: A review of 267 rotational and nonrotational forceps deliveries from August 1996 through February 1998 was performed. Multiple maternal and neonatal outcome measures were compared and results were analyzed by chi(2) with the Fisher exact test and the Student t test. RESULTS: One hundred sixty-three traditional low-forceps or outlet forceps deliveries were compared with 104 rotational forceps deliveries performed with Leff forceps. There were no significant differences between the 2 groups in maternal age, gestational age, gravidity, parity, total labor duration, birth weight, and Apgar scores. There were significantly lower rates of episiotomy, third- and fourth-degree lacerations, and sulcus lacerations in the rotation group, and the second stage of labor was also shorter. The neonatal intensive care unit admission rate was higher in the rotation group; however, none of the admissions were directly related to the mode of delivery. CONCLUSION: Rotational deliveries performed with Leff forceps are associated with less maternal morbidity and shorter second stage of labor than are deliveries performed with traditional forceps. Leff forceps are a safe option for rotation of the persistent occipitoposterior fetal position.

Cost-effectiveness of estimating gestational age by ultrasonography in Down syndrome screening.

OBJECTIVE: To quantify the financial benefits of using ultrasound estimation of gestational age in maternal serum screening for Down syndrome. METHODS: Maternal age-specific sensitivity and false-positive rates for Down syndrome were derived for the triple test (alpha-fetoprotein, hCG, and unconjugated estriol) using gestational age based on ultrasound dating and also time from the last menstrual period (LMP). These rates were entered into a formula to determine the societal financial net benefit of Down syndrome screening. The average per-case net benefits of ultrasound- and LMP-dated pregnancies were then compared. Average net benefits were also calculated separately with ultrasound versus LMP dating for triple tests referred to our laboratory, and the additional costs associated with any post-test ultrasound scans, repeat testing, or recalculations were estimated. RESULTS: The use of ultrasound dating resulted in higher detection rates for Down syndrome and lower false-positive rates, which translated into an average per-case savings to society of $33.54. For women referred to our program with LMP dating, there was an average reduction of $31.60 in net benefits, plus added costs of $14.39 attributable to extra ultrasound, repeat testing, and recalculation. CONCLUSION: When ultrasound dating is available before serum screening, it should be used preferentially to establish Down syndrome risk. Routine first-trimester ultrasound examination can be justified for women with a known LMP if the cost of the ultrasound examination is less than $46.

Maternal serum screening for fetal trisomy 18: a comparison of fixed cutoff and patient-specific risk protocols.

OBJECTIVE: To compare the effectiveness of two widely used protocols for second-trimester screening for fetal trisomy 18. METHODS: Second-trimester screening results for 41,565 women were reviewed to determine whether pregnancies could be considered to be at high risk for trisomy 18. The screening test was considered positive if either maternal serum concentrations of alpha-fetoprotein (MSAFP), hCG, and unconjugated estriol (E3) fell below defined levels, or the second-trimester patient-specific risk (based on maternal age and serum analytes) was greater than 1:100. Detection rates, false-positive rates, and pregnancy outcomes for the two protocols were compared. RESULTS: The fixed-cutoff method showed a 23% detection rate and a 0.19% false-positive rate for trisomy 18. These low rates were in close agreement with a theoretical expectation for fixed-cutoff trisomy 18 screening. The risk-based approach resulted in a 69% detection rate and a 0.45% false-positive rate. Both methods identified pregnancies with other fetal anomalies. CONCLUSION: Overall, the risk-based method is more effective than the fixed-cutoff approach to trisomy 18 screening.

Relationship of amniotic fluid markers of intra-amniotic infection with histopathology in cases of preterm labor with intact membranes.

OBJECTIVE: To evaluate the correlation of amniotic fluid (AF) markers (AFMs) of intra-amniotic infection with histopathologic findings in cases of preterm labor with intact membranes, between 22 and 36 weeks' gestation. STUDY DESIGN: We reviewed the charts of patients admitted in preterm labor with intact membranes between January 1993 and December 1996. Those having amniocentesis were identified, and AFMs were compared with histopathology in patients who delivered within 48 hours of the amniocentesis. The AFMs evaluated were glucose, polymorphonuclear leukocytes, Gram stain, and culture. All placentae were reviewed by a single pathologist blinded to the AF findings. Histologic evidence of acute inflammation was defined by findings of both subchorial intervillositis and marginating choriodeciduitis. The sensitivities, specificities, and positive and negative predictive values of the various AFMs were calculated. RESULTS: Of 556 women with intact membranes presenting in preterm labor, 181 (32.6%) had amniocentesis and 88 delivered within 48 hours of the amniocentesis. Histopathologic chorioamnionitis was seen in 53 patients (60.2%). The findings (with their sensitivity, specificity, and positive and negative predictive values) were: polymorphonuclear leukocytes at > 10/high-power field (22.6%, 97.2%, 92.3%, and 46.1%), positive Gram stain (26.4%, 94.6%, 87.5%, and 47.3%), culture (28.3%, 92.1%, 83.3%, and 47.9%), and glucose of < 15 mg/dl (28.3%, 94.6%, 88.2%, and 47.9%), respectively. Using a receiver-operator characteristic curve for different level of AF glucose, a glucose level of < 20 mg/dl was the most sensitive AF predictor of histologic chorioamnionitis. CONCLUSION: Histopathologic evidence of chorioamnionitis was present in 60.2% of cases of preterm births due to preterm labor in women who at our institution were offered and accepted amniocentesis and subsequently delivered within 48 hours. AFMs may be useful predictors of histologic chorioamnionitis. The most efficient AFM for chorioamnionitis in this group of patients was glucose at < 20 mg/dl.

Management of parvovirus infection in pregnancy and outcomes of hydrops: a survey of members of the Society of Perinatal Obstetricians.

OBJECTIVE: Our purpose was to investigate the evaluation and management of parvovirus infection during pregnancy. STUDY DESIGN: Surveys were mailed to members of the Society of Perinatal Obstetricians residing in the United States and Canada in July 1997. They were asked about their evaluation and management of parvovirus infection, including whether they repeated and confirmed serologic studies, what their initial and follow-up evaluations included, whether they had had any cases of parvovirus-associated hydrops in the past 2 years, and if so, what were the management and outcomes of the hydropic fetuses. RESULTS: Surveys were mailed to 1623 members of the Society of Perinatal Obstetricians and 541 completed surveys were returned. Sixty-eight percent of the respondents repeated and confirmed serologic studies. Eighty-nine percent used ultrasonography in their initial management of pregnant patients with recent parvovirus infection, 7.5% used amniocentesis for polymerase chain reaction, and 2% used fetal blood sampling. The outcomes of the 539 cases of parvovirus-induced hydrops included spontaneous resolution in 34%, death without intrauterine transfusion in 30%, resolution after intrauterine transfusion in 29%, death after intrauterine transfusion in 6%, and pregnancy termination in 1%. Almost all cases of nonimmune hydrops reported occurred between 16 and 32 weeks. CONCLUSIONS: Approximately one third of the cases of parvovirus-induced nonimmune hydrops resolved spontaneously, whereas 83.5% of hydropic fetuses transfused survived.

Resolution of human parvovirus B19-induced nonimmune hydrops after intrauterine transfusion.

Our objective is to report our experience with cases of prolonged recovery from nonimmune hydrops secondary to human parvovirus B19 infection occurring after intrauterine transfusion. We reviewed cases referred to our unit over a 10 year period for exposure to parvovirus B19 infection. Those cases with serologic evidence of recent infection were identified. The cases requiring intrauterine transfusion were reviewed for demographic details, time of exposure, parvovirus B19 serology, gestational age at detection of nonimmune hydrops, number and results of fetal blood samples, duration from intrauterine transfusion to resolution of hydrops, and neonatal outcome. Of 38 cases identified through serologic evidence of recent parvovirus B19 infection, 35 (92.1%) did not develop hydrops, and these were followed by serial ultrasonography for 8 weeks from the time of exposure. Three cases (7.9%) developed hydrops and required intrauterine transfusion; in two the transfusion was intravascular and in one it was intraperitoneal. The mean duration from intrauterine transfusion to resolution of hydrops was 8 weeks 2 days. Pregnancy outcome in all cases was normal. In cases of nonimmune hydrops secondary to parvovirus B19 infection, resolution of the hydrops after intrauterine transfusion may take up to 12 weeks with a normal pregnancy outcome.

Fetal hydrops in the first trimester associated with maternal parvovirus infection.

We present a case of fetal hydrops associated with maternal parvovirus infection during the first trimester of pregnancy that sonographically mimicked findings associated with fetal aneuploidy. The transabdominal sonograms of this fetus at 12.9 weeks' gestational age were consistent with increased nuchal translucency thickness. Transvaginal sonographic evaluation of the fetus showed generalized subcutaneous sonolucency suggestive of early fetal hydrops. An etiologic evaluation identified serologic evidence of recent maternal parvovirus infection and a normal karyotype. The pregnancy ended in fetal demise. Our findings suggest that visualization of nuchal translucency thickening in the first trimester should prompt a complete sonographic evaluation for fetal hydrops, which, if identified, should lead to serologic evaluation for parvovirus infection.

Iatrogenic monoamniotic twins as a complication of therapeutic amniocentesis.

BACKGROUND: Therapeutic amniocentesis has been accepted widely as a safe and efficacious way to treat the polyhydramnios-oligohydramnios sequence associated with twin-twin transfusion syndrome. CASE: A 28-year-old woman, gravida 2, para 1, diagnosed with twin-twin transfusion syndrome at 28 weeks' gestation was treated with serial amniocenteses. The dividing membrane was ruptured inadvertently during therapeutic amniocentesis, with subsequent complete disruption of the amniotic membrane. Iatrogenic monoamniotic twins with cord entanglement and knotting resulted. CONCLUSION: Creation of monoamniotic twins by disruption of the dividing membrane can be a complication of therapeutic amniocentesis for twin-twin transfusion syndrome. Such disruption may result in the same morbidity and mortality that are seen in naturally occurring monoamniotic twins.

Long-term outcome of children following maternal human parvovirus B19 infection.

OBJECTIVE: To determine the long-term outcomes of children exposed in utero to maternal parvovirus B19 infection. METHODS: All pregnant women with serologic evidence of recent parvovirus B19 infection and a comparison group with serologic evidence of past infection from January 1988 to December 1994 were sent questionnaires or contacted by phone about the health and development of their children. Information requested included: pregnancy complications, date of delivery, birth weight, sex, birth defects, need for special care, significant health problems, and developmental delays. All women had serology done at either the Centers for Disease Control and Prevention or the virology laboratory of the Connecticut Department of Health. The data were analyzed using descriptive statistics, chi2 analysis with Fisher exact test, or Student t test in appropriate cases. P < .05 was considered significant. RESULTS: Outcome information was obtained from 113 of 117 immunoglobulin-M positive women. The 113 respondents had 103 term singletons, two sets of twins (of which one neonate died of complications of prematurity), one hydropic stillborn, four spontaneous abortions, and one ectopic pregnancy. The mean gestational age at time of exposure was 15.6 weeks. The median age of the liveborn infants in study and comparison groups was 4 years. Eight of the 108 (7.3%) surviving children, one set of twins (exposed at 27 weeks), and six singletons (exposed at 7, 8, 9, 20, 27, and 35 weeks) had developmental delays in speech, language, information processing, and attention. Outcomes were obtained for 99 of 110 patients with past infection; they had 83 liveborn singletons, five sets of twins, two stillborns, and five spontaneous abortions. Seven of the 93 (7.5%) children had developmental delays, similar to the study group. Post-hoc power analysis revealed that 712 infected patients would be needed to find a twofold difference in the risk of abnormal neurologic development; our study had 30% power to find such a difference. CONCLUSION: There is no apparent increase in the frequency of developmental delays in children with exposure in utero to parvovirus, but larger studies are needed.

Monoamniotic twins: improved perinatal survival with accurate prenatal diagnosis and antenatal fetal surveillance.

OBJECTIVE: Our goal was to report our 10-year experience with monoamniotic twins and to compare that experience with cases reported in the literature. STUDY DESIGN: Records of all monoamniotic twin pregnancies managed at the University of Connecticut Health Center from March 1986 to August 1996 were reviewed. A MEDLINE search from January 1966 to August 1996 was performed, and each report was screened for accuracy of diagnosis. Only cases with umbilical cord entanglement of nonconjoined like-sex twins, the obstetrician's confirmation at delivery, or pathologic confirmation of monoamniotic placentation were included. Data collected were as follows: birth outcome, gestational age at delivery, birth weight, gender, Apgar scores, hematocrit, cord knotting, and neonatal complications. Cases from the literature were divided into those with prenatal diagnosis and those without. RESULTS: Thirteen monoamniotic pregnancies resulting in 26 infants who were born alive were managed at our center. The average gestational age at diagnosis was 16.3 weeks. All had antenatal fetal surveillance including serial sonograms and nonstress tests. The average gestational age and birth weight at delivery were 32.9 weeks and 1669 gm, respectively. Cord entanglement was noted in all cases, with knotting in 8 of 13. Two pairs of 26 newborns had evidence of twin-twin transfusion syndrome. Eight of 13 monoamniotic pregnancies were delivered because of nonreassuring results of nonstress test, two because of preterm labor, two electively because of lung maturity, and one because of intrauterine growth restriction. Two of the 26 infants died in the neonatal period, one of congenital heart disease and one of sepsis and asphyxia. The MEDLINE search revealed 96 articles with a total of 202 sets of monoamniotic twins. Comparison of cases (13 sets) with the historic control group without prenatal diagnosis (77 sets) showed a 71% reduction in relative risk of perinatal mortality. CONCLUSIONS: With accurate prenatal diagnosis, intensive fetal surveillance, and appropriately timed delivery, perinatal survival of monoamniotic twins is improved; it was 92% in this series.