Évaluation de la détermination du statut Rhésus-D fœtal sur plasma maternel par la technique d’hemi-nested PCR

AIMS

The aim of our study was to evaluate the possibility of identifying the fetal RhD status in maternal plasma using conventional hemi nested PCR analysis.

SUBJECTS AND METHODS

After informed written consent, 20 mL of peripheral blood were collected in 99 D-negative pregnant women either at an amniocentesis for prenatal diagnosis or at a prenatal checkup. Fetal DNA extracted from 400 microL of maternal plasma was analyzed by two different operators with a hemi-nested PCR extending an area of the RhD gene exon 10. The results were compared to the fetal RhD status obtained by PCR amniotic fluid analysis or blood analysis of newborns after delivery. The influence of mother's and baby's phenotype were also studied.

RESULTS

Among the 99 D-negative pregnant women, all Caucasian, 47 were in their second trimester and 52 in their third trimester (mean: 27.20 weeks of gestation +/-8.25). Sixty-nine fetuses were D-positive and thirty D-negative. The sensitivity and specificity of our technique were respectively 100% and 86.7% and 15% of discordant results were observed between the two operators. Four false positives were observed. According to maternal phenotype, a fetal unexpressed RHD gene was suspected in only one case because of a particular fetal phenotype (ddCcEe).

CONCLUSION

A conventional hemi nested PCR analysis of maternal plasma could be used for accurate fetal RhD status. However this procedure is difficult to apply for routine analysis because of the importance of anti-contamination measures required to obtain good results. Real time quantitative PCR analysis on fetal DNA is more suitable. Whatever the operating procedure used, polymorphism of RhD gene may follow in either false negative from presence of rearranged gene or false positive from occasional presence of a non functional RHD gene.

Anesthésie maternofœtale pour « ex utero intrapartum » traitement (EXIT) procédure : à propos de deux cas

The ex utero intrapartum treatment (EXIT) procedure is a surgical procedure maintaining utero-placental circulation during caesarean section. Anaesthetic implications are described: foetal transplacental anaesthesia to avoid first breathing and to permit surgical procedure on obstructed foetal airway, deep maternal haemodynamically stable anaesthesia to relax uterine smooth muscle during a long caesarean procedure but avoiding post-partum haemorrhage. Volatile anaesthesia with sevoflurane seems to be adequate for these aims. Two cases are described.

Risk factors for post-partum complications occurring after preeclampsia and HELLP syndrome. A study in 453 consecutive pregnancies

OBJECTIVE

To evaluate complications that occurred during the post-partum period for patients with preeclampsia or HELLP syndrome.

STUDY DESIGN

Retrospective analysis of 453 patients. The main outcome measures were maternal complications during post-partum period: fever >38.5 degrees C with proved infection, abdominal or perineal abscess, thrombo-embolic events, reoperation, need for blood transfusion, acute renal failure, eclampsia or disseminated intravascular coagulation. Statistic tests included univariate and multivariate analysis with stepwise descending logistic regression.

RESULTS

Patients were divided into 305 preeclampsia (67.3%) and 20 HELLP syndrome (4.4%), 128 (28.3%) had both. Eighty-five patients (18.8%) had at least one post-partum complication. The most frequent complication was infection: fever (41 patients, 9.1%) and abscess (30 patients, 6.6%). Twenty-six transfusions (5.7%), 10 disseminated intravascular coagulation (2.2%), seven thromboembolic events (1.5%), seven reoperations (1.5%) and one eclampsia (0.2%) were observed. There was no acute renal failure, no pulmonary oedema and no maternal death. Stepwise logistic regression showed five independent risk factors associated with post-partum complications: ascites or pulmonary oedema (OR: 1.84, 95% CI: 1.01-3.37), platelet count <100000/mm3 (OR: 1.96, 95% CI: 1.18-3.26), serum acid uric >360 micromol/l (OR: 2.36, 95% CI: 1.22-4.52), serum creatinine >120 micromol/l (OR: 2.99, 95% CI: 1.32-6.78), and proteinuria >5 g/l (OR: 1.80, 95% CI: 1.06-3.05).

CONCLUSION

We conclude that severity criteria for preeclampsia or HELLP syndrome combined with caesarean section increased the risk of complication during the post-partum period.

Effects of Antenatal Glucocorticoids on Circulatory Adaptation at Birth in the Ovine Fetus

OBJECTIVE

Adaptation to extra-uterine life requires dramatic increase in pulmonary blood flow. Mechanisms that induce pulmonary vasodilatation at birth are incompletely understood but include alveolar ventilation, increase in PaO2, and production of vasoactive mediators. We hypothesized that antenatal glucocorticoids (GC) increase pulmonary vasodilatation to birth-related stimuli.

STUDY DESIGN

To test this hypothesis, we studied the pulmonary hemodynamic response at birth to mechanical ventilation with low (<10%) and then with high (100%) FiO2 in chronically prepared late-gestation fetal lambs treated or not by antenatal maternal steroids.

RESULTS

Basal mean aortic and pulmonary artery pressure (PAP), left pulmonary blood flow, pulmonary vascular resistance (PVR), and blood gas were similar between control and dexamethasone-treated animals (GC group). During mechanical ventilation with low FiO2, mean PVR decreased by 40% in the control group (from 0.44 +/- 0.01 to 0.25 +/- 0.01 mm Hg/ml/min) and by 60% in the GC group (from 0.44 +/- 0.02 to 0.19 +/- 0.02 mm Hg/ml/min) (p < 0.01). When subsequently ventilated with 100% O2, there was no difference in PVR decrease between groups (0.15 +/- 0.02 mm Hg/ml/min in the GC group vs. 0.14 +/- 0.01 mm Hg/ml/min in the control group).

CONCLUSION

Antenatal GC enhance pulmonary vasodilatation induced by alveolar ventilation at birth but do not alter the pulmonary vascular response to O2. We speculate that antenatal steroids exposure improve adaptation at birth through acceleration of both parenchymal and vascular lung maturation.

Effects of nociceptive stimuli on the pulmonary circulation in the ovine fetus

The fetus is able to exhibit a stress response to painful events, and stress hormones have been shown to modulate pulmonary vascular tone. At birth, the increased level of stress hormones plays a significant role in the adaptation to postnatal life. We therefore hypothesized that pain may alter pulmonary circulation in the perinatal period. The hemodynamic response to subcutaneous injection of formalin, which is used in experimental studies as nociceptive stimulus, was evaluated in chronically prepared, fetal lambs. Fetal lambs were operated on at 128 days gestation. Catheters were placed into the ascending aorta, superior vena cava, and main pulmonary artery. An ultrasonic flow transducer was placed around the left pulmonary artery. Three subcutaneous catheters were placed in the lambs' limb. The hemodynamic responses to subcutaneous injection of formalin, to formalin after fetal analgesia by sufentanil, and to sufentanil alone were recorded. Cortisol and catecholamine concentrations were also measured. Pulmonary vascular resistances (PVR) increased by 42% ( P < 0.0001) after formalin injection. Cortisol increased by 54% ( P = 0.05). During sufentanil infusion, PVR did not change significantly after formalin. Cortisol increased by 56% ( P < 0.05). PVR did not change during sufentanil infusion. Norepinephrine levels did not change during any of the protocols. Our results indicate that nociceptive stimuli may increase the pulmonary vascular tone. This response is not mediated by an increase in circulating catecholamine levels. Analgesia prevents this effect. We speculate that this pulmonary vascular response to nociceptive stimulation may explain some hypoxemic events observed in newborn infants during painful intensive care procedures.

Role of fetal ultrasound and magnetic resonance imaging in the prenatal diagnosis of migration disorders

OBJECTIVES

To evaluate the contribution and limitations of fetal ultrasonography (US) and magnetic resonance imaging (MRI) for the diagnosis and management of migration disorders.

METHODS

Over a 5-year period, 14 fetuses with pathological migration disorders, without an infectious context, were taken care of in our centre. All underwent US; nine underwent MRI as well. Sonographic and MRI data were compared with neuropathological data.

RESULTS

The diagnosis of gyral disorders was obtained by US in 1/14 cases; other cerebral abnormalities were found suggesting neuronal disorder in the remainder. Cerebral MRI suggested gyral abnormality in eight of the nine cases.

CONCLUSIONS

US performance is increasing. MRI appears to be a promising method for the diagnosis of fetal migration disorders, giving better results than US. It may be recommended in cases of abnormal cerebral US findings or familial clinical history. However, interpretation of MRI can be tricky and the resulting diagnosis occurs late within the pregnancy.

Pulmonary vasodilator effects of norepinephrine during the development of chronic pulmonary hypertension in neonatal lambs

BACKGROUND

This experimental study was performed to determine the effects of norepinephrine on: (i) the pulmonary vascular tone during the development of pulmonary hypertension (PH) in the fetus and (ii) the circulatory adaptation at birth after chronic intrauterine PH.

METHODS

Chronically instrumented fetal lambs were randomized into two groups: (i) a group with PH obtained by antenatal partial ligation of the ductus arteriosus (DA) (n=9) and (ii) a control group without DA ligation (n=6). Pulmonary vascular responses to norepinephrine (1.5 microg min(-1)) were measured in utero 7 days after surgery. At day 8 post-surgery, after delivery, animals were ventilated for 3 h with oxygen 100%. The group with PH was randomly assigned to receive norepinephrine or saline.

RESULTS

Mean pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) were higher in the PH group (P<0.01). Norepinephrine-induced decrease in PVR was more pronounced in the PH group than in the control group (63 vs 35%, respectively; P<0.01). In the PH group, the decrease in PVR during mechanical ventilation was greater in the animals receiving norepinephrine than in the animal receiving saline (from 1.05 (0.12) to 0.1 (0.02) vs from 1.04 (0.1) to 0.2 (0.04) mm Hg ml(-1) min(-1), respectively; P<0.01). After 3 h of ventilation, mean PVR in the PH lambs treated by norepinephrine was similar to those measured in the control lambs. Aortic pressure was higher in the group treated with norepinephrine.

CONCLUSION

The data suggest that norepinephrine may improve post-natal pulmonary adaptation in the newborn with persistent PH both by increasing systemic vascular pressure and by increasing pulmonary blood flow.

Could the consequences of premature delivery be further attenuated by means of new prenatal strategies?

The last 10 years have already seen improvements in the short- and long-term prognosis for premature neonates. Nevertheless, progress in the prenatal evaluation of predictive factors for neonatal diseases and more detailed and reliable knowledge of fetal physiology could allow the development of new treatments with consequent expectations of further improvements in the prognosis for such premature newborns. Global strategies for the management of preterm labour, ranging from a policy for prenatal transfer to centres offering the appropriate level of perinatal care, should continue to be expanded, and long-term evaluations must also be continued.

[Important elevation of uric acid associated with vomiting at the third trimester of pregnancy: report of five cases with favorable outcome]

We report five cases of vomiting associated with a very important increase of maternal plasma uric acid (> 595 mmol/l, 100 mg/l) at the third trimester of pregnancy. In all cases, elevation was transitory and regressive with rehydratation. Pregnancies proceeded normally to term and delivered healthy babies. An important rise of plasmatic uric acid during pregnancy can be found in severe hypertensive disorders (preeclampsia, HELLP syndrome, acute fatty liver). Nevertheless, it can be related to transient renal insufficiency without any severe pathology. In our five observations, digestive disorders seem to be the reason for this phenomenon and spontaneous prognosis was excellent in all cases.

Acute pulmonary oedema during nicardipine therapy for premature labour; Report of five cases

We report five maternal cases of acute pulmonary oedema which occurred during treatment with nicardipine for tocolysis.

Routine CMV screening during pregnancy

Cytomegalovirus (CMV) screening during pregnancy has been widely discussed for several years, but still no consensus has been agreed. With a number of live births of 750,000 per year in France, we would expect 7500 infected infants at birth per year (rate of congenital infection of 1%). Among infected infants at birth, the number of severely infected foetuses would be approximately 75, the number of infants with severe sequelae would be 480, 675 approximately would present with hearing loss and the number of asymptomatic infants would be 6270. Five different preventive methods for congenital CMV infection are possible: (1) Routine CMV screening at the beginning of pregnancy for primary prevention. (2) Secondary prevention by antenatal diagnosis of congenital CMV infection complications. (3) Tertiary prevention by serological testing during pregnancy. (4) Tertiary prevention by serological screening at birth. (5) Tertiary prevention: Hearing loss screening at birth. The aims of this review are to define the advantages and disadvantages of these different methods of CMV screening during pregnancy and to determine if the current available information would make systematic testing acceptable.

Effets maternels et fœtaux d'une prise de poids maternelle excessive au cours de la grossesse dans une population de patientes de poids normal avant la grossesse

OBJECTIVE

To study the effects of increased gestational weight gain in women of normal prepregnant weight.

PATIENTS AND METHODS

We compared 174 patients gaining more than 18 kg to 174 patients gaining between 9 and 15 kg. Body mass index was normal for every woman included in the study.

RESULTS

Weight gain > or =18 kg was associated with increased risk of vascular complications (5.2% vs. 1.1%, P < 0.05) but not with increased risk of mellitus diabetes (5.2% vs. 4.0%, NS). Weight gain > or =18 kg prolonged labor length (414.4 +/- 147 min vs. 376.5 +/- 166.4 min, P < 0.05) and increased the rate of cesarean section (19.5% vs. 10.3%, P < 0.05). Neonatal outcome was similar in both groups, mean birth weight was greater (3413.6 +/- 427.0 g vs. 3163.4 +/- 495.1 g, P < 0.05) and the frequency of infants weighing more than 4000 g at birth was increased (8.0% vs. 4.0%, P < 0.05) among women gaining more than 18 kg.

CONCLUSION

Excess weight gain in pregnancy affects gestational and delivery outcomes and results in higher frequency of fetal macrosomia. These results confirm recommendations on weight gain in pregnancy as guidelines for pregnant women.

Higher risk of persistent pulmonary hypertension of the newborn after cesarean

Authors suggest that high incidence of persistence pulmonary hypertension among neonates delivered by elective cesarean is related to lower levels of circulating norepinephrine in neonates after cesarean section than after vaginal delivery.

Pericardial teratoma complicated by hydrops: successful fetal therapy by thoracoamniotic shunting

Pericardial teratoma is a potentially curable lesion that may become life threatening when it induces mediastinal compression and fetal hydrops. So far, cases with fetal hydrops have been managed by elective delivery or pericardial needle decompression. We report a case in which pericardial teratoma resulted in fetal hydrops. Following transpleural needling of the fetal pericardium at 29 weeks and 6 days, pericardial effusion decreased but hydrops persisted, while major unilateral pleural effusion appeared. A thoracoamniotic shunt was placed at 30 weeks and 5 days. Hydrops resolved, although incompletely. The baby was delivered at 32 weeks and was operated upon on day 3. This observation suggests that fetal hydrops associated with pericardial teratoma may improve following thoracoamniotic shunting. Fetal therapy may limit the risks of respiratory distress arising from the combined effect of airways compression and lung immaturity.

[Comparative analysis of rate scales of urinary incontinence in women]

OBJECTIVE

Rate scales are used to analyse urinary incontinence. There are many scales making it difficult to compare the different studies of urinary incontinence. The purpose of this study was to evaluate and compare the rate scales pertaining specifically to urinary incontinence.

PATIENTS AND METHOD

A review of the literature was performed for publications specifically addressing rate scales of urinary incontinence. Each scale was evaluated using the following four criteria: principal characteristics (reference source, number of items addressed, scoring method, language), objectives (type of incontinence, severity and quality of life measures), psychometric properties (scientific validity, reliability and responsiveness) and linguistic validation.

RESULTS

Thirteen scales were identified. These were divided into two groups: (1) those based on "classifications" and (2) those based on specific questionnaires. Scales based on classifications were not precise and are never scientifically validated. Scales based on questionnaires were more elaborate and more detailed; nevertheless, the study of their psychometric properties was often incomplete.

DISCUSSION AND CONCLUSION

Classification-based rate scales are inadequate to analyse urinary incontinence. Questionnaire-based rate scales are superior, but at minimum, they should address the previously stated objective and psychometric criteria. The choice of questionnaire should depend on whether it is to be used in clinical practice or for research protocol.

Randomised comparison of uterine artery Doppler and aspirin (100 mg) with placebo in nulliparous women: the Essai Régional Aspirine Mère-Enfant study (Part 2)

OBJECTIVE

To assess the effectiveness of a pre-eclampsia prevention strategy based on routine uterine artery Doppler flow velocity waveform examination during the second trimester of pregnancy, followed by a prescription for 100 mg aspirin in the case of abnormal Doppler findings.

DESIGN

Multicentre randomised controlled trial.

SETTING

Eleven centres in the north of France and one in Belgium.

POPULATION

One thousand and eight hundred and fifty-three nulliparous women recruited between 14 and 20 weeks of gestation.

METHODS

Randomisation either to undergo a uterine Doppler examination between 22 and 24 week of gestation or to take a placebo. Women with abnormal Doppler waveforms received 100 mg of aspirin daily from Doppler examination through 36 weeks.

MAIN OUTCOME MEASURES

Pre-eclampsia was defined as hypertension (> or = 140 and/or 90 mmHg) associated with proteinuria (> or = 0.5 g/L).

RESULTS

One thousand two hundred and fifty-three women (67%) were randomised into the systematic Doppler group and 617 (33%) into the placebo group. Of the 1175 patients in the Doppler group who underwent this examination, 239 (20.3%) had abnormal uterine artery Doppler and received a prescription for aspirin. Despite the aspirin prescription, the frequency of pre-eclampsia did not differ between the systematic Doppler group and the placebo group (28 of 1237 [2.3%] vs 9 of 616 [1.5%]; RR = 1.55, 95% CI 0.7-3.3). Furthermore, the groups did not differ in the frequency of children who were very small for their gestational age (< or =3rd centile) or for perinatal deaths. Compared with patients with normal Doppler findings, those with abnormal Doppler were at high risk of pre-eclampsia (RR = 5.5, 95% CI 2.5-12.2) and of giving birth to a small-for-gestational-age child (RR = 3.6, 95% CI 1.6-8.1).

CONCLUSION

Despite its sensitivity in screening for pre-eclampsia, routine uterine Doppler in the second trimester cannot be recommended for nulliparous patients.

[Hyperemesis in the first trimester of pregnancy: role of biological hyperthyroidism and fetal sex]

OBJECTIVES

Our objectives were to link hyperemesis gravidarum with biochemical hyperthyroidism and hormonal modification (HCG and estradiol) and to test the hypothesis that biological abnormalities (ionogram and liver enzyme) are more often reported in hyperemesis gravidarum with biochemical hyperthyroidism.

STUDY DESIGN

Thirty three patients admitted in "Hôpital Jeanne de Flandre" with hyperemesis gravidarum were studied prospectively.

RESULTS

Twenty-two patients (66.7%) had biochemical hyperthyroïdsm (suppressed thyroid stimulating hormone or increased triiodothyronine index or tetraiodothyronine index). Hyperthyroid patients were more likely than euthyroid patients to have abnormal electrolyte levels (16/22 [72.7%] vs 3/1 [27.3%], P < 0.02) or increased liver enzyme levels (8/22 [36.4%] vs 3/11 [27.3%]). The severity of hyperemesis was found to vary directly with the degree of hyperthyroidism. We report a female predominance among the offspring of mothers with hyperemesis gravidarum.

CONCLUSION

Our results are suggestive of the involvement of hyperthyroidism and fetal sex in the pathogenesis of hyperemesis gravidarum. Also these hypothesis are not clearly understood, human chorionic gonadotrophin occurred in the two mechanisms.

[Fertility after ectopic pregnancy: the population-based register of the urban area around Lille, Northern France]

The aims of this work were the evaluation of the reproductive outcome after ectopic pregnancy, and the assessment of the role of infertility risk factors and treatment's strategy. All patients in the population-based register of the urban area around Lille, Northern France, were followed-up. 345 women treated between April 1994 and March 1997, who were trying to become pregnant were interviewed by telephone every 6 months and then every year. The cumulative pregnancy rates were calculated by the Kaplan-Meier estimation. Associations between infertility risk factors and intrauterine pregnancy were tested by the logrank test, and by a Cox model for multivariate analysis. The mean duration of follow-up was 22 months, and 228 (66%) women had obtained a new pregnancy at the time of the analysis. 23 (10%) of the first pregnancies were recurrences. For women for whom EP occurred with an IUCD (17 patients), the 1 year intrauterine pregnancy (IUP) reached 67%. For the others, the 1 year IUP rate was 56%, and reached 67% after 2 years. After adjusting factors associated with fertility with a Cox regression, 3 factors seemed to lower reproductive performances: age > 35 years, previous history of infertility, and anterior tubal damage. More than half the women treated for EP obtained spontaneously a normally progressive pregnancy after 1 year. Reproductive performances are associated with characteristics of the patients, but do not depend on radical or conservative treatment.

[What's new in fetal medicine?]

One of the major progress in fetal medicine in recent years is the increased sensitivity of sonographic screening for foetal malformations, due to technical improvement but also to a better training of professionals. Screening for chromosomal abnormalities is no longer based on maternal age alone. Second trimester maternal serum screening (MSS) is increasingly used: thus in 1997, 376,798 MSS tests were performed in France, yielding to the prenatal diagnosis of 391 cases of Down's syndrome. First trimester sonographic nuchal translucency measurement (NTM) is an effective screening method when performed under stringent conditions. Quality control however, is more difficult to implement on a large scale for NTM than for MSS. Performing screening tests sequentially carries a danger of generating an unnecessarily high number of amniocentesis, which may be obviated by a rational calculation of an individual's risk to carry an aneuploid baby. First trimester MSS is expected to become standard practice in the next years, probably in combination with NTM. Cytogenetics underwent substantial innovations recently, due to the ever-increasing use of molecular cytogenetics. FISH techniques allow: 1) precise analysis of unexpected structural chromosomal abnormalities diagnosed by routine amniocentesis, 2) rapid screening of the most common aneuploidies by amniocentesis when a fetal structural anomaly is detected by 3rd trimester ultrasound, 3) diagnosis of micro-deletions suspected by fetal ultrasound or post-mortem. Prenatal diagnosis by maternal blood sampling and fetal cells or DNA analysis is now part of routine clinical practice in selected cases, such as fetal sexing in families affected by an X linked disease. Thus one can select those pregnancies eligible to invasive prenatal diagnosis. Pre implantation diagnosis, which has not been legal in France until 1999 is now increasingly used as an alternative to first trimester diagnosis. As for fetal therapy, a major recent breakthrough is the prenatal management of twin to twin transfusion syndrome by either amnioreduction or laser coagulation of inter-twin vascular shunts. In addition, new pathophysiologic concepts involving the renin angiotestin system could lead to further therapeutic innovations. A European randomised trial is now being completed to establish the respective indications of drainage and Laser. All this underscores that fetal medicine is no longer solely a succession of dramatic technical breakthroughs, but is entered an era of large-scale diffusion that requires evidence based evaluation.