Platelet count at term pregnancy: a reappraisal of the threshold.

OBJECTIVE: To assess the safety of a new platelet count threshold for the definition of maternal thrombocytopenia late in pregnancy. METHODS: A platelet count was performed in 6770 pregnant women late in pregnancy and in 6103 of their newborns as well as in a control group of 287 age-matched nonpregnant healthy women. RESULTS: The prevalence of maternal thrombocytopenia (platelet count less than 150 x 10(9)/L) was 11.6%. The mean platelet counts (248 compared with 213 x 10(9)/L) and 2.5th percentile (164 compared with 116 x 10(9)/L) were significantly higher in healthy nonpregnant women than in pregnant women. Among thrombocytopenic pregnant women, 621 (79%) had platelet counts between 116 and 149 x 10(9)/L; none (0%; 95% confidence interval 0, 0.6) had complications related to thrombocytopenia, and none of their newborns had severe thrombocytopenia (platelet count less than 20 x 10(9)/L). CONCLUSION: In healthy pregnant women, a platelet count over 115 x 10(9)/L late in pregnancy does not require further investigation during pregnancy and may be considered a safe threshold.

Fetal echocardiography in pregnancies of women with congenital heart disease--clinical utility and limitations.

UNLABELLED: Women with important cyanotic or uncyanotic, operated or unoperated congenital heart disease (CHD) have been shown to carry an inherent risk during pregnancy for themselves and for their fetus. Obstetrical and fetal echocardiography has recently been upgraded by new technical developments in ultrasound machines. These improvements have increased the detection rate of congenital malformations and cardiac anomalies which ranged in the past between 4 and 60% for significant anomalies. Obesity or an unfavourable position of the fetus may, however, obscure the imaging quality and cause limitations to visualise the fetal heart from different angles and thus prevent the detection of anomalies. In addition, several cardiac anomalies develop throughout pregnancy and may not yet be present at an early date of screening. While the risk for a congenital cardiac malformation (CCM) in a normal population is 0.8-1%, the recurrence rate for CCM increases to 2 to 3% when a previous child has been affected but will become significantly higher when genetically determined anomalies have affected a family member or when the pregnant woman (5.8%) has CHD. The aim of fetal screening in women with CCM is to ascertain normal intrauterine growth, to exclude fetal CHD and/or to ascertain a malformation or arrhythmia which has been suspected during an obstetrical screening. The acquired detailed echocardiographic knowledge of the malformation or arrhythmia allows the explanation of a CCM to the future parents, to present therapeutic options during pregnancy or after birth and to plan delivery in a tertiary center that provides early cardiovascular and/or catheter interventions and disposes of intensive care facilities for affected newborns. Under certain conditions, termination can be discussed in early pregnancy. Very recent publications have shown how important a prenatal diagnosis can become in a new-born with transposition of the great arteries and a very restrictive foramen ovale (Circulation 1999). Therapeutic measures in the fetus have been attempted with very limited success so far; successful life saving treatment does, however, exist for fetal arrhythmias. IN CONCLUSION: Fetal echocardiography has become an important analytical tool in high-risk pregnancies, especially when parents are affected by a CCM. The examination is safe and can be performed with a high predictive and sensitivity rate.

Crohn's disease as a risk factor for the outcome of pregnancy.

BACKGROUND/AIMS: To study the effects of Crohn's disease on the course of pregnancy and the influence of pregnancy on the activity of Crohn's disease. METHODOLOGY: The course of 35 pregnancies in 23 women with Crohn's disease were reviewed over a 12 years period. RESULTS: Nine pregnancies (25%) started when Crohn's disease was active. We observed 2 exacerbations among the 9 pregnancies with active disease and 7 exacerbations among the 26 pregnancies with quiescent disease: this represents a total exacerbation rate of 26% similar to non-pregnant women with Crohn's disease. The course of pregnancy was normal with a full-term delivery in 22 cases (63%). We observed 5 premature deliveries (14%), 5 spontaneous abortions (14%), 1 induced abortion (3%) and 2 liveborns with severe malformations (6%). Preterm delivery was significantly associated with reactivation of Crohn's disease during pregnancy (P = 0.009), whereas fetal loss was significantly associated with activity of Crohn's disease at the time of conception (P = 0.015). CONCLUSIONS: Pregnancy does not appear to influence the course of Crohn's disease. The relapse rate of Crohn's disease during pregnancy is similar to that of the general Crohn's disease population. Active Crohn's disease at the time of conception or reactivation during pregnancy are risk factors for abnormal pregnancy outcome.

[Pregnancy and scuba diving: what precautions?]. / Grossesse et plongée sous-marine: quelles précautions?

Scuba diving is a leisure activity increasingly popular amongst women. Many women are concerned about the risks associated with diving and a known or planned pregnancy. In order to advise these young women, we have reviewed the literature concerning women and diving as well as animal studies on the subject. The different international federations and the Undersea and Hyperbaric Medical Society advise against scuba diving for pregnant women or those planning a pregnancy, but no randomized trials or trials provide a solid scientific basis. The fetal circulation is characterized by the exclusion of the pulmonary circulation by 2 right to left shunts. As the lung appears to act as a filter against the progression of micro-bubbles to the main circulation, the fetus may be therefore particularly exposed to gas emboli. However, the placenta could play this role in certain animal species. Nitrox diving appears to be particularly promising, but studies on the subject are still insufficient to recommend it for pregnant women.

Maternal antiplatelet antibodies in predicting risk of neonatal thrombocytopenia.

OBJECTIVE: To determine the incidence of maternal antiplatelet antibodies in cases of thrombocytopenia during pregnancy, using the monoclonal antibody-specific immobilization of platelet antigens assay; and to assess the usefulness of this assay for predicting risk of neonatal thrombocytopenia. METHODS: A total of 6770 pregnant women were included in the study, and the monoclonal antibody-specific immobilization of platelet antigens assay was done when platelet counts were less than 150 x 10(9)/L. Platelet counts were determined in 6103 newborns. RESULTS: The incidence of maternal thrombocytopenia was 11.6% (95% confidence interval [CI] 10.8, 12.4). Among newborns, 1.3% (95% CI 0.5, 2.7) born to thrombocytopenic mothers were thrombocytopenic, compared with 0.4% (95% CI 0.2, 0.6) born to nonthrombocytopenic women. Antiplatelet antibodies were detected in 37 (8.6%) of 430 thrombocytopenic women; autoantibodies were detected in 28 cases (circulating or bound to platelets), alloantibodies in eight cases, and an association of alloantibodies and autoantibodies in one case. The positive and negative likelihood ratios for predicting neonatal thrombocytopenia were 4.6 and 0.7, respectively. CONCLUSION: The monoclonal antibody-specific immobilization of platelet antigens assay did not predict the risk of neonatal thrombocytopenia in an unselected population of thrombocytopenic pregnant women.

Neonatal thrombocytopenia: incidence and characterization of maternal antiplatelet antibodies by MAIPA assay.

Neonatal thrombocytopenia (NNT) which is frequent in distressed newborns was uncommon in a non-selected population of neonates. The aim of this prospective study was to determine the frequency of NNT and, in confirmed NNT, to search for maternal antiplatelet antibodies with a monoclonal antibody-specific immobilization of platelet antigens (MAIPA) assay. Among the 8388 newborns studied, 40 (0.5%, 95% CI 0.3-0.6) had confirmed NNT, which was severe (platelet count < 50 x 10[9]/l) in 10 cases (0.12%, 95% CI 0.05-0.20). Antiplatelet antibodies were detected in 10/31 studied mothers of thrombocytopenic newborns (32.3%): they were alloantibodies in five cases and autoantibodies in five other cases. Among these 10 newborns, seven had severe thrombocytopenia and four had bleeding complications. As controls, antiplatelet antibodies were also searched for in mothers of non-thrombocytopenic newborns: antiplatelet antibodies were present in 8.5% (95% CI 5.9-11.7) of thrombocytopenic mothers (n = 400) and 3.2% (95% CI 0.7-9.0) of non-thrombocytopenic mothers (n = 95). The difference was significant between the control groups and the group of mothers of thrombocytopenic newborns. In conclusion, our data indicate that an immune origin is frequent in NNT and should be looked for, particularly when the platelet count is < 50 x 10(9)/l.

Second-trimester maternal serum screening for Down's syndrome: free beta-human chorionic gonadotrophin (HCG) and alpha-fetoprotein, with or without unconjugated oestriol, compared with total HCG, alpha-fetoprotein and unconjugated oestriol.

The aim of our study was to compare three protocols for second-trimester maternal serum screening for Down's syndrome in the same serum samples, using two triple tests [total human chorionic gonadotrophin (HCG), alpha-fetoprotein, unconjugated oestriol; and free beta-HCG, alpha-fetoprotein, unconjugated oestriol] and a double test (free beta-HCG and alpha-fetoprotein). The three protocols were compared in a series of 23 serum samples from Down's syndrome pregnancies and in a cohort of 2516 pregnant women receiving routine antenatal care between June 1992 and June 1993. Among the 23 affected cases, at a cut-off risk of 1:380, the detection rate of Down's syndrome was comparable with the double test (74%; 17/23) and the triple tests (65%; 15/23) (not significantly different). At the same cut-off risk, in the cohort of 2516 pregnant women screened between 15 and 18 weeks gestation, both protocols using free beta-HCG achieved a significant reduction of the number of false positive cases (P = 0.013 and 0.004 for double and triple tests respectively). We conclude that, compared to total HCG, alpha-fetoprotein and unconjugated oestriol, use of free beta-HCG and alpha-fetoprotein represents a better second-trimester screening test for Down's syndrome, because it significantly decreases the false positive rate at a lower running cost. The addition of unconjugated oestriol to the double test adds no further advantage.

Is intrapartum vibratory acoustic stimulation a valid alternative to fetal scalp pH determination?

OBJECTIVES: To determine the association between fetal heart rate accelerations, whether spontaneous or induced by vibratory acoustic stimulation, and subsequent scalp pH values in presence of a suspicious intrapartum fetal heart rate tracing, and thereby assess the ability of accelerations to predict a concurrent normal fetal scalp blood pH. DESIGN: Prospective observational study of 253 labours involving 421 pH samples. SETTING: Tertiary care university hospital of Genoeva. INTERVENTION: Vibratory acoustic stimulation through the maternal abdominal wall for five seconds prior to fetal blood sampling. MAIN OUTCOME MEASURES: Spontaneous fetal heart rate reactivity (accelerations) in the 10 min preceding vibratory acoustic stimulation, vibratory acoustic-induced reactivity prior to fetal blood sampling, and scalp pH value. RESULTS: The positive predictive value of a reactive fetal heart rate response after vibratory acoustic stimulation was 78% (95% CI 73-84%) and 97% (95% CI 94-99%) for scalp pH values of > 7.25 and > or = 7.20, respectively. Similar observations occurred with spontaneous reactivity. Of concern, 7 out of 31 (23%) occasions where the scalp blood pH was less than 7.20 appeared to be associated with a normal fetal heart rate response to vibratory acoustic stimulation. CONCLUSION: Fetal heart rate acceleration induced by vibratory acoustic stimulation was significantly associated with a normal scalp blood pH higher than 7.25. However, vibratory acoustic stimulation offers no advantage over observation of spontaneous fetal heart rate tracings and cannot safely replace fetal blood sampling during labour.

[Toxoplasmosis in pregnancy: prevention, prenatal diagnosis and treatment]. / Toxoplasmose en cours de grossesse: prévention, diagnostic prénatal et traitement.

Maternal infection with Toxoplasma gondii acquired during pregnancy occurs in more than 500 women per year in Switzerland. Systematic screening at the beginning of pregnancy allows the introduction of health education programs. The screening during pregnancy is performed to diagnose primary maternal infections and to propose prenatal diagnosis and treatment. The administration of specific antibiotherapy during pregnancy (spiramycine or the association of pyrimethamine and sulfonamides) significantly reduces the risk of fetal infection. Prenatal diagnosis of congenital toxoplasmosis is possible and reliable. It avoids unnecessary termination of pregnancy when the fetus is not infected and specific therapy in case of infection (association of pyrimethamine and sulfonamides). Prenatal treatment may be proposed without prenatal diagnosis as of the 16th week of gestation. In any case, prenatal treatment seems to reduce the incidence of severe congenital toxoplasmosis.

Prenatal diagnosis of collagen disorders by direct biochemical analysis of chorionic villus biopsies.

We have developed a method for early prenatal diagnosis of molecular disorders of collagens I and III. The method takes advantage of the fact that isolated chorionic villi contain significant amounts of collagens in their extracellular matrix (stroma) and that they synthesize collagens in vitro. After metabolic labeling of chorion villus biopsies in toto with radioactive amino acids, collagens are extracted and analyzed by SDS-PAGE. Direct staining of the gel shows collagens synthesized in vivo, whereas autoradiofluorography identifies collagens synthesized during incubation in vitro. Unlike collagens synthesized by cultured amniotic fluid cells, collagens extracted from chorionic villi are not overmodified and thus allow better identification of molecular defects. Results are available within 3 to 5 d after biopsy. Using this method, we have correctly excluded Ehlers-Danlos syndrome type IV in two pregnancies, Ehlers-Danlos syndrome type VII in one pregnancy, and lethal osteogenesis imperfecta in four pregnancies. In addition, we correctly predicted a healthy fetus and an embryo affected with lethal osteogenesis imperfecta in consecutive pregnancies from a couple in which the asymptomatic mother was a somatic mosaic for a COL1A1 G-to-A transition (Gly355Asp). Direct collagen analysis of chorion villus biopsies labeled in toto is rapid and reliable and may become the method of choice for the prenatal diagnosis of selected collagen disorders.

Acid-base and hematologic values at blood sampling in the evaluation of trisomic fetuses: a case-control study.

OBJECTIVE: To investigate whether nonhydropic trisomic fetuses display specific alterations of acid-base and/or hematologic values. METHODS: Acid-base and hematologic variables were analyzed in 28 trisomic fetuses (12 with trisomy 21 and 16 with trisomy 18) and 28 chromosomally normal controls matched for gestational age and fetal size undergoing fetal blood sampling at 18-36 weeks' gestation. RESULTS: There were no differences between the groups in pH, oxygen pressure, carbon dioxide pressure, and base excess. Compared with matched controls, hematocrit, hemoglobin, and red blood cell counts were significantly higher in fetuses with trisomy 21 and significantly lower in those with trisomy 18. All other hematologic variables were similar in trisomic fetuses and their controls. CONCLUSIONS: Growth retardation in trisomic fetuses is associated with decreased oxygen supply, as it is in chromosomally normal growth-retarded fetuses. The higher perinatal mortality that occurs with trisomies 21 and 18 is not explained by more pronounced hypoxemia for a given degree of growth retardation. There is no specific association of acid-base and hematologic values that is diagnostic of chromosomal abnormality at fetal blood sampling.

[Prenatal diagnosis of arrhythmias and associated congenital cardiac abnormalities using ultrasonography]. / Le diagnostic prénatal des arythmies et des malformations cardiaques congénitales associées par ultrasonographie.

Cardiac arrhythmias are one of the most frequent indications for a 2D and Doppler fetal echocardiographic assessment (DE). If accompanied by a non-immune fetal hydrops, arrhythmias (A) involve an increased risk of intrauterine death. Some A and mainly the bradyarrhythmias (BA) can be the first sign of major cardiac malformation (CM). In a series of 404 pregnancies between week 17 and 40 of gestation (mean 27.6 weeks), a Doppler echocardiography was carried out; in 137 (35%) fetuses (F) this examination was based on the indication of arrhythmia. 33 (24.2%) of these fetuses showed a cardiac malformation. Bradyarrhythmias were found in 20 F; 5 had a complete AV-block including, 4 with an important cardiac abnormality (TU, complete AV-canal, corr. TGV). SVT's and auricular flutters (AF) made transplacental treatment necessary in 4 fetuses (1 AF, 3 SVT); they had no major cardiac malformation. PAC's were present in 59 pregnancies of which several had minor or major anomalies. Doppler echocardiography served to define the arrhythmia and the structural cardiac malformation, but also to follow transplacental treatment. These investigations have allowed us to schedule delivery under neonatal surveillance. After birth, 5 neonates had to be treated for persistent dysrhythmia (5 SVT, 2 complete AB-blocks), and 10 for a major cardiac malformation.