Prenatal vitamin C and E supplementation in smokers is associated with reduced placental abruption and preterm birth: a secondary analysis.

OBJECTIVE: Smoking and pre-eclampsia (PE) are associated with increases in preterm birth, placental abruption and low birthweight. We evaluated the relationship between prenatal vitamin C and E (C/E) supplementation and perinatal outcomes by maternal self-reported smoking status focusing on outcomes known to be impacted by maternal smoking. DESIGN/SETTING/POPULATION: A secondary analysis of a multi-centre trial of vitamin C/E supplementation starting at 9-16 weeks in low-risk nulliparous women with singleton gestations. METHODS: We examined the effect of vitamin C/E by smoking status at randomisation using the Breslow-Day test for interaction. MAIN OUTCOME MEASURES: The trial's primary outcomes were PE and a composite outcome of pregnancy-associated hypertension (PAH) with serious adverse outcomes. Perinatal outcomes included preterm birth and abruption. RESULTS: There were no differences in baseline characteristics within subgroups (smokers versus nonsmokers) by vitamin supplementation status. The effect of prenatal vitamin C/E on the risk of PE (P = 0.66) or PAH composite outcome (P = 0.86) did not differ by smoking status. Vitamin C/E was protective for placental abruption in smokers (relative risk [RR] 0.09; 95% CI 0.00-0.87], but not in nonsmokers (RR 0.92; 95% CI 0.52-1.62) (P = 0.01), and for preterm birth in smokers (RR 0.76; 95% CI 0.58-0.99) but not in nonsmokers (RR 1.03; 95% CI 0.90-1.17) (P = 0.046). CONCLUSION: In this cohort of women, smoking was not associated with a reduction in PE or the composite outcome of PAH. Vitamin C/E supplementation appears to be associated with a reduction in placental abruption and preterm birth among smokers.

Can changes in angiogenic biomarkers between the first and second trimesters of pregnancy predict development of pre-eclampsia in a low-risk nulliparous patient population?

OBJECTIVE: To determine if change in maternal angiogenic biomarkers between the first and second trimesters predicts pre-eclampsia in low-risk nulliparous women. DESIGN: A nested case-control study of change in maternal plasma soluble Flt-1 (sFlt-1), soluble endoglin (sEng) and placenta growth factor (PlGF). We studied 158 pregnancies complicated by pre-eclampsia and 468 normotensive nonproteinuric controls. SETTING: A multicentre study in 16 academic medical centres in the USA. POPULATION: Low-risk nulliparous women. METHODS: Luminex assays for PlGF, sFlt-1 and sEng performed on maternal EDTA plasma collected at 9-12, 15-18 and 23-26 weeks of gestation. Rate of change of analyte between first and either early or late second trimester was calculated with and without adjustment for baseline clinical characteristics. MAIN OUTCOME MEASURES: Change in PlGF, sFlt-1 and sEng. RESULTS: Rates of change of PlGF, sEng and sFlt-1 between first and either early or late second trimesters were significantly different in women who developed pre-eclampsia, severe pre-eclampsia or early-onset pre-eclampsia compared with women who remained normotensive. Inclusion of clinical characteristics (race, body mass index and blood pressure at entry) increased sensitivity for detecting severe and particularly early-onset pre-eclampsia but not pre-eclampsia overall. Receiver operating characteristics curves for change from first to early second trimester in sEng, PlGF and sFlt-1 with clinical characteristics had areas under the curve of 0.88, 0.84 and 0.86, respectively, and for early-onset pre-eclampsia with sensitivities of 88% (95% CI 64-99), 77% (95% CI 50-93) and 77% (95% CI 50-93) for 80% specificity, respectively. Similar results were seen in the change from first to late second trimester. CONCLUSION: Change in angiogenic biomarkers between first and early second trimester combined with clinical characteristics has strong utility for predicting early-onset pre-eclampsia.

Vitamin D status and recurrent preterm birth: a nested case-control study in high-risk women.

OBJECTIVE: To determine whether vitamin D status is associated with recurrent preterm birth, and any interactions between vitamin D levels and fish consumption. DESIGN: A nested case-control study, using data from a randomised trial of omega-3 fatty acid supplementation to prevent recurrent preterm birth. SETTING: Fourteen academic health centres in the USA. POPULATION: Women with prior spontaneous preterm birth. METHODS: In 131 cases (preterm delivery at <35 weeks of gestation) and 134 term controls, we measured serum 25-hydroxyvitamin D [25(OH)D] concentrations by liquid chromatography-tandem mass spectrometry (LC-MS) from samples collected at baseline (16-22 weeks of gestation). Logistic regression models controlled for study centre, maternal age, race/ethnicity, number of prior preterm deliveries, smoking status, body mass index, and treatment. MAIN OUTCOME MEASURES: Recurrent preterm birth at <37 and <32 weeks of gestation. RESULTS: The median mid-gestation serum 25(OH)D concentration was 67 nmol/l, and 27% had concentrations of <50 nmol/l. Serum 25(OH)D concentration was not significantly associated with preterm birth (OR 1.33; 95% CI 0.48-3.70 for lowest versus highest quartiles). Likewise, comparing women with 25(OH)D concentrations of 50 nmol/l, or higher, with those with <50 nmol/l generated an odds ratio of 0.80 (95% CI 0.38-1.69). Contrary to our expectation, a negative correlation was observed between fish consumption and serum 25(OH)D concentration (-0.18, P < 0.01). CONCLUSIONS: In a cohort of women with a prior preterm birth, vitamin D status at mid-pregnancy was not associated with recurrent preterm birth.

Late first-trimester invasive prenatal diagnosis: results of an international randomized trial.

OBJECTIVE: To assess, in a randomized trial, the safety and accuracy of amniocentesis and transabdominal chorionic villus sampling (CVS) performed at 11-14 weeks of gestation, given that this time frame is increasingly relevant to early trisomy screening. METHODS: We compared amniocentesis with CVS from 77 to 104 days of gestation in a randomized trial in a predominantly advanced maternal age population. Before randomization, the feasibility of both procedures was confirmed by ultrasonography, and experienced operators performed sampling under ultrasound guidance; conventional cytogenetic analysis was employed. The primary outcome measure was a composite of fetal loss plus preterm delivery before 28 weeks of gestation in cytogenetically normal pregnancies. RESULTS: We randomized 3,775 women into 2 groups (1,914 to CVS; 1,861 to amniocentesis), which were comparable at baseline. More than 99.6% had the assigned procedure, and 99.9% were followed through delivery. In contrast to previous thinking, in the cytogenetically normal cohort (n = 3,698), no difference in primary study outcome was observed: 2.1% (95% confidence interval 1.5, 2.8) for CVS and 2.3% (95% confidence interval, 1.7, 3.1) for amniocentesis. However, spontaneous losses before 20 weeks and procedure-related, indicated terminations combined were increased in the amniocentesis group (P =.07, relative risk 1.74). We found a 4-fold increase in the rate of talipes equinovarus after amniocentesis (P =.02) overall and in week 13 (P =.03, relative risk = 4.65), but data were insufficient to determine this risk in week 14. CONCLUSION: Amniocentesis at 13 weeks carries a significantly increased risk of talipes equinovarus compared with CVS and also suggests an increase in early, unintended pregnancy loss. LEVEL OF EVIDENCE: I

Fetal gender and aneuploidy detection using fetal cells in maternal blood: analysis of NIFTY I data. National Institute of Child Health and Development Fetal Cell Isolation Study.

OBJECTIVES: The National Institute of Child Health and Human Development Fetal Cell Isolation Study (NIFTY) is a prospective, multicenter clinical project to develop non-invasive methods of prenatal diagnosis. The initial objective was to assess the utility of fetal cells in the peripheral blood of pregnant women to diagnose or screen for fetal chromosome abnormalities. METHODS: Results of fluorescence in situ hybridization (FISH) analysis on interphase nuclei of fetal cells recovered from maternal blood were compared to metaphase karyotypes of fetal cells obtained by amniocentesis or chorionic villus sampling (CVS). After the first 5 years of the study we performed a planned analysis of the data. We report here the data from 2744 fully processed pre-procedural blood samples; 1292 samples were from women carrying singleton male fetuses. RESULTS: Target cell recovery and fetal cell detection were better using magnetic-based separation systems (MACS) than with flow-sorting (FACS). Blinded FISH assessment of samples from women carrying singleton male fetuses found at least one cell with an X and Y signal in 41.4% of cases (95% CI: 37.4%, 45.5%). The false-positive rate of gender detection was 11.1% (95% CI: 6.1,16.1%). This was higher than expected due to the use of indirectly labeled FISH probes in one center. The detection rate of finding at least one aneuploid cell in cases of fetal aneuploidy was 74.4% (95% CI: 76.0%, 99.0%), with a false-positive rate estimated to be between 0.6% and 4.1%. CONCLUSIONS: The sensitivity of aneuploidy detection using fetal cell analysis from maternal blood is comparable to single marker prenatal serum screening, but technological advances are needed before fetal cell analysis has clinical application as part of a multiple marker method for non-invasive prenatal screening. The limitations of the present study, i.e. multiple processing protocols, are being addressed in the ongoing study.

Future directions.

With the continued explosion of genetic technology, the number of disorders amenable to screening is expanding geometrically. Historically, most genetic screening has been in the newborn period. Much more can be done for the fetus if genetic screening and diagnosis are accomplished early in the pregnancy rather than after birth. The principal requirements to make neonatal screening disorders possible in the first trimester center around those tests that can be one on a molecular basis, and the development of fetal cell isolation from the maternal circulation. Over the course of the next decade, it is likely that many of the tests currently performed in the newborn period will be accomplished in the early or mid-gestational period.

The new genetic era in reproductive medicine: possibilities, probabilities and problems.

The "New Genetic Era" will be a period of enormous exponential growth in our knowledge of the structure and function of the basic information blocks of life. The Human Genome Project will soon provide a complete and accurate sequence of the human genome. This will give us an abundance of basic genetic knowledge and provide a molecular understanding of disease, allowing for improved diagnosis and more sensitive and specific screening for disease. This will, we hope, lead to better treatments, prevention and cures through gene therapy, patient-specific drug design, and earlier and more specific behavioral interventions to prevent disease. With this information comes a complexity of legal, ethical and social concerns about potential use and abuse. The public has expressed its concerns about the potential for genetic discrimination. However, genetic information is enhancing our knowledge as to the causes of infertility, allowing diagnosis of more diseases in the prenatal period, and may aid our identification of patients at increased risk for breast and ovarian cancer. Doctors involved in reproductive medicine must become knowledgeable about the new genetic era so as to offer our patients the most appropriate and informed care.

Prenatal diagnosis of congenital nephrosis by in utero kidney biopsy.

The diagnosis of congenital nephrosis is difficult during the antepartum period. The combination of an elevated amniotic fluid alpha-fetoprotein, a negative acetylcholinesterase, and a negative ultrasound examination is highly indicative of congenital nephrosis; however, these findings can also be associated with a normal gestation. This is the first report of pathologic confirmation of congenital nephrosis from an in utero fetal kidney biopsy.

Patients with a prior failed transvaginal cerclage: a comparison of obstetric outcomes with either transabdominal or transvaginal cerclage.

OBJECTIVE: Our purpose was to compare the incidence of preterm birth after a prior failed vaginal cerclage in patients who had a subsequent transabdominal or a transvaginal cerclage. STUDY DESIGN: We conducted a retrospective cohort study of singleton pregnancies in women who had undergone (9-14 weeks) either a transabdominal or a transvaginal prophylactic cerclage after >/=1 prior failed transvaginal cerclage. Prior failed transvaginal cerclage was defined as a preterm birth at <33 weeks' gestation in the immediate prior pregnancy despite a transvaginal cerclage. All transabdominal cerclage procedures were performed by a single attending physician (George Davis, DO). Patients with a cervix too short for transvaginal cerclage placement, placenta previa, or major fetal anomalies were excluded. Primary outcome was preterm birth at <35 weeks' gestation. RESULTS: Forty transabdominal and 24 transvaginal cerclage pregnancies were analyzed. These 2 groups were similar in race and payer status but differed in age (34.0 +/- 4.2 vs 31.3 +/- 4.6 years, respectively; P =.01). The transabdominal cerclage group had more prior failed cerclage procedures per patient (1.8 +/- 1.0 vs 1.1 +/- 0.3; P =.02) and more prior 14- to 24-week spontaneous abortions per patient (2.4 +/- 1.3 vs 1.5 +/- 1.0; P =.02) than the transvaginal cerclage group. Preterm delivery at both <35 and <33 weeks' gestation was less common in the transabdominal cerclage group (18% vs 42%, P =.04; 10% vs 38%, P =.01; respectively) than in the transvaginal cerclage group. Gestational age at delivery was 36. 3 +/- 4.1 weeks in the transabdominal cerclage group and 32.8 +/- 8. 6 weeks in the transvaginal cerclage group (P =.03). Preterm premature rupture of membranes also occurred less often in the transabdominal cerclage group than in the transvaginal cerclage group (8% vs 29%, P =.03). CONCLUSION: In patients with a prior failed transvaginal cerclage, transabdominal cerclage is associated with a lower incidence of preterm delivery and preterm premature rupture of membranes in comparison with transvaginal cerclage.

Timing of cerclage removal after preterm premature rupture of membranes: maternal and neonatal outcomes.

OBJECTIVE: Our aim was to evaluate immediate versus delayed removal of cerclage for women with preterm premature rupture of membranes with respect to maternal and neonatal outcomes. STUDY DESIGN: We retrospectively analyzed women with preterm premature rupture of membranes at <34 weeks' gestation with prior cerclage placement. Exclusion criteria included presentation with chorioamnionitis, active labor, or nonreassuring fetal status. Timing of cerclage removal, immediate (<24 hours) or delayed (>24 hours), was compared. RESULTS: There were 25 women in the delayed-removal group and 37 in the immediate-removal group. Average times to removal were 206.8 +/- 7.4 and 5.4 +/- 0.2 hours, respectively. Use of betamethasone was similar for both groups; however, antenatal antibiotic use (100% vs 80%; P =.03) and short-term tocolytic use (20% vs 3%; P =.04) were higher in the delayed-removal group. Duration of latency was significantly longer with delayed removal (10.1 vs 5.0 days; P <. 001). Delivery occurred >48 hours from preterm premature rupture of membranes in 96% (24/25) versus 54% (20/37; P <.001) and >7 days from rupture in 56% (14/25) versus 24% (9/37; P =.02), respectively. Rates of neonatal sepsis (at <10 days) and maternal infection were not statistically different. Neonatal outcomes did not significantly differ regarding mortality, respiratory distress syndrome, birth weight, or duration of stay in the intensive care nursery. CONCLUSION: With the current management scheme for preterm premature rupture of membranes, cerclage retention significantly increases duration of latency without significantly altering maternal or neonatal outcomes.

The challenge of prenatal diagnosis in twin pregnancies.

Prenatal diagnosis in multiple gestations poses unique problems. The use of screening modalities is limited, diagnostic procedures are more complicated, and the management of discordant results may be required. This article reviews work, both past and present, regarding these issues.

First trimester prenatal diagnosis: chorionic villus sampling.

Chorionic villus sampling has been used successfully for first trimester diagnosis of genetic disorders for over 14 years. When performed between 10 and 14 weeks' gestation, it is both safe and effective in the diagnosis of fetal chromosomal, biochemical, and molecular disorders, with risks comparable to those of second trimester amniocentesis. Cytogenetic results have been confirmed to be reliable and accurate. Although confined placental mosaicism occurs in approximately 1% of cases requiring interpretation, and occasionally additional invasive testing, its finding adds additional information about perinatal outcome and can alert the practitioner to fetal genetic disorders. Earlier concerns about procedure-induced limb defects have been reduced with the accumulation of additional data, showing minimal to no risk when chorionic villus sampling is performed after 70 days of gestation. In experienced hands, it may be the procedure of choice for sampling multiple gestations. Secondary to the advantage of safe, early diagnosis, chorionic villus sampling appears to be the optimal choice for first trimester testing.

Prenatal confirmation of true fetal trisomy 22 mosaicism by fetal skin biopsy following normal fetal blood sampling.

Trisomy 22 mosaicism diagnosed at 20 weeks' gestation by amniocentesis in a 35-year-old woman was not confirmed by fetal blood sampling. Subsequent fetal skin biopsy revealed trisomy 22 in 7 of the 15 fibroblasts analysed. We conclude that, depending on the chromosome involved, fetal skin biopsy should be considered in the diagnostic work-up when mosaicism is found in amniotic fluid.

Mosaicism: implications for postnatal outcome.

Mosaicism detected in the cytogenetic analysis of chorionic villi or cultured amniocytes can present a difficult and at times impossible interpretative dilemma. The finding may be indicative of a generalized fetal mosaicism. However, in the majority of cases, the abnormal cell line is representative of either an in-vitro event or a chromosomal error that is restricted to the extra-embryonic tissues. Advances in laboratory medicine have provided insight into the determination of which cases of true mosaicism have the greatest risk of being clinically significant with regard to the fetal genotype and phenotype. Despite the presence of a normal fetal karyotype, certain chromosomes involved in confined placental mosaiciam may increase the risk of poor perinatal outcome or predispose the fetus or neonate to the adverse effects of genetic imprinting owing to the development of uniparental disomy.

Chorionic villus sampling.

Chorionic villus sampling (CVS) has been used a successful and safe first-trimester prenatal diagnostic technique for over 12 years. Developed to avoid the medical and psychological complications of later prenatal diagnosis by amniocentesis, CVS rapidly has become a primary tool for the diagnosis of fetal cytogenetic, molecular, and biochemical disorders. In addition, its development has led to an improved understanding of several biological processes, including confined placental mosaicism and uniparental disomy.

Genetic diagnosis in multiple pregnancies.

A twin gestation presents unique problems in both genetic counseling and prenatal diagnosis. This article describes the specific genetic counseling concerns for a twin gestation and outlines the available techniques for genetic prenatal diagnosis. The technical aspects, risks and benefits to the pregnancy of amniocentesis and of chorionic villi sampling are compared. Although the risk of miscarriage after amniocentesis in a twin gestation is at least double that for a singleton, much of this additional risk is secondary to the inherent hazards of twins and not procedure-related. In experienced centers, chorionic villi sampling is equally safe and efficacious, and allows an earlier diagnosis that may be beneficial when discordant results are found. The aspects of serum screening unique to twin gestations are also outlined. Prenatal diagnosis by both chorionic villus sampling and amniocentesis can be safely performed in twin gestations and higher-order multiple gestations. Serum screening is also useful, but appears to have a lower sensitivity and specificity than in singletons.

Ultrasonographically guided intrauterine contraceptive device removal before chorionic villus sampling.

OBJECTIVE: Management of a retained intrauterine contraceptive device with no visible string during early pregnancy presents a dilemma. Because these devices are frequently used by multiparous women, it is not unusual that many women with retained devices are also of advanced maternal age. We describe our experience with ultrasonographically guided first-trimester retrieval of an intrauterine contraceptive device in conjunction with chorionic villus sampling. STUDY DESIGN: Patients with a first-trimester pregnancy and a retained intrauterine contraceptive device where no string was visible were offered ultrasonographically guided retrieval of the device. If the patient had genetic risks and desired prenatal diagnosis, chorionic villus sampling was offered at the same office visit. RESULTS: Six patients underwent intrauterine contraceptive device retrieval, under continuous ultrasonographic guidance, by use of an intrauterine contraceptive device hook. All patients had a posterior or fundal device. One patient had two in situ: a Lippes Loop (Ortho Pharmaceutical Corp., Raritan, N.J.) removed by its string and a Cu-7 (G.D. Searle & Co., Chicago) removed under ultrasonographic guidance. The remaining five patients had a Cu-7. Four of six patients had chorionic villus sampling performed immediately after the intrauterine contraceptive device removal and one patient had chorionic villus sampling 3 weeks later. There were two losses in our series: one after a lengthy procedure and one before documented viability. All infants were structurally normal and born at term. CONCLUSION: First-trimester ultrasonographically guided retrieval of a retained intrauterine contraceptive device may be safely performed in conjunction with chorionic villus sampling.

Incidence of bacteremia associated with chorionic villus sampling.

OBJECTIVE: To assess the frequency of transient bacteremia among women undergoing transabdominal and transcervical chorionic villus sampling (CVS). METHODS: One hundred fourteen women undergoing CVS consented to participate in a university review board-approved study protocol. Exclusion criteria included known cardiac valve anomaly or replacement (or other prosthetic) and antibiotic use within the preceding 21 days. Blood cultures (aerobic and anaerobic) were drawn by a single operator on all patients, before CVS and within 15 minutes after completing CVS. Either the catheter tip or needle tip aspirate from each procedure was also sent for culture. RESULTS: Post-procedure bacteremia was detected in two (1.8%) of the patients undergoing CVS. These two patients both had their procedures performed transcervically, resulting in a 4.1% (two of 49) bacteremia rate after transcervical CVS, compared to none (zero of 65) in the transabdominal group (P = .36). The incidence of positive cultures from sampling instruments was also higher in the transcervical group (16.3 versus 0%; P = .003), but did not result in comparable rates of bacteremia among patients with positive instrument cultures. CONCLUSIONS: In this study, CVS was associated with a low rate of bacteremia, regardless of the procedure route. Recommendations for antibiotic prophylaxis in women with abnormal cardiac valves should parallel those for spontaneous vaginal delivery and other comparable genitourinary procedures.