Human fetal microglia acquire homeostatic immune-sensing properties early in development

Microglia, immune cells of the central nervous system (CNS), are important for tissue development and maintenance and are implicated in CNS disease, but we lack understanding of human fetal microglia development. Single-cell gene expression and bulk chromatin profiles of microglia at 9 to 18 gestational weeks (GWs) of human fetal development were generated. Microglia were heterogeneous at all studied GWs. Microglia start to mature during this developmental period and increasingly resemble adult microglia with CNS-surveilling properties. Chromatin accessibility increases during development with associated transcriptional networks reflective of adult microglia. Thus, during early fetal development, microglia progress toward a more mature, immune-sensing competent phenotype, and this might render the developing human CNS vulnerable to environmental perturbations during early pregnancy.

Reciprocal HLA-DR allogenicity between mother and child affects pregnancy outcome parameters

Successful pregnancy outcome depends on local immunoregulatory mechanisms preventing a detrimental immune response towards the semi-allogeneic fetus. We investigated the influence of HLA-DR (in)compatibility on pregnancy outcome parameters in 480 women. The parameters tested were birth weight, individualized birthweight ratio (IBR), gestational age, and maternal highest diastolic blood pressure. Irrespective of pregnancy complications, maternal-fetal HLA-DR incompatibility resulted in increased IBR. We conclude that reciprocal HLA-DR allogenicity between mother and child positively affect pregnancy outcome parameters.

Delivery or expectant management for prevention of adverse maternal and neonatal outcomes in hypertensive disorders of pregnancy: an individual participant data meta-analysis

OBJECTIVE

Hypertensive disorders affect 3-10% of pregnancies. Delayed delivery carries maternal risks, while early delivery increases fetal risk, so appropriate timing is important. The aim of this study was to compare immediate delivery with expectant management for prevention of adverse maternal and neonatal outcomes in women with hypertensive disease in pregnancy.

METHODS

CENTRAL, PubMed, MEDLINE and ClinicalTrials.gov were searched for randomized controlled trials comparing immediate delivery to expectant management in women presenting with gestational hypertension or pre-eclampsia without severe features from 34 weeks of gestation. The primary neonatal outcome was respiratory distress syndrome (RDS) and the primary maternal outcome was a composite of HELLP syndrome and eclampsia. The PRISMA-IPD guideline was followed and a two-stage meta-analysis approach was used. Relative risks (RR) and numbers needed to treat or harm (NNT/NNH) with 95% CI were calculated to evaluate the effect of the intervention.

RESULTS

Main outcomes were available for 1724 eligible women. Compared with expectant management, immediate delivery reduced the composite risk of HELLP syndrome and eclampsia in all women (0.8% vs 2.8%; RR, 0.33 (95% CI, 0.15-0.73); I2  = 0%; NNT, 51 (95% CI, 31.1-139.3)) as well as in the pre-eclampsia subgroup (1.1% vs 3.5%; RR, 0.39 (95% CI, 0.15-0.98); I2  = 0%). Immediate delivery increased RDS risk (3.4% vs 1.6%; RR, 1.94 (95% CI 1.05-3.6); I2  = 24%; NNH, 58 (95% CI, 31.1-363.1)), but depended upon gestational age. Immediate delivery in the 35th week of gestation increased RDS risk (5.1% vs 0.6%; RR, 5.5 (95% CI, 1.0-29.6); I2  = 0%), but immediate delivery in the 36th week did not (1.5% vs 0.4%; RR, 3.4 (95% CI, 0.4-30.3); I2 not applicable).

CONCLUSION

In women with hypertension in pregnancy, immediate delivery reduces the risk of maternal complications, whilst the effect on the neonate depends on gestational age. Specifically, women with a-priori higher risk of progression to HELLP, such as those already presenting with pre-eclampsia instead of gestational hypertension, were shown to benefit from earlier delivery. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Birth weight to placenta weight ratio and its relationship to ultrasonic measurements, maternal and neonatal morbidity: A prospective cohort study of nulliparous women

INTRODUCTION

Birth weight to placenta weight (BWPW)-ratio is an indicator of the ability of the placenta to maintain adequate nutrient supply to the fetus. We sought to investigate the relationship between BWPW-ratio with fetal growth, utero-placental Doppler and neonatal and maternal morbidity.

METHODS

We studied a group of 3311 women recruited to a prospective cohort study of nulliparous women (Rosie Hospital, Cambridge, UK) who delivered a live born infant at term and whose placental weight and birth weight were known. Ultrasonic indices and BWPW ratio were converted to gestational age adjusted z scores. Analysis of continuous variables was by multivariable linear regression. BWPW ratio was also categorized (lowest or highest quintile, both referent to quintiles 2 to 4) and associations with adverse outcomes analyzed using multivariable logistic regression.

RESULTS

Lowest quintile of BWPW-ratio was associated (adjusted odds ratio [95% CI], P) with both neonatal morbidity (1.55 [1.12-2.14], 0.007) and maternal diabetes (1.75 [1.18-2.59], 0.005). Highest quintile of BWPW ratio was associated with a reduced risk of maternal obesity (0.71 [0.53 to 0.95], 0.02) and preeclampsia (0.51 [0.31 to 0.84], 0.008), but higher (adjusted z score [95% CI], P) uterine artery Doppler mean pulsatility index (PI) at 20 weeks of gestation (0.09 [0.01-0.18], 0.04) and umbilical artery Doppler PI at 36 weeks of gestation (0.16 [0.07-0.25], <0.001).

CONCLUSION

BWPW-ratio is related to ultrasonic measurements and both neonatal and maternal morbidity. Therefore, this ratio may be an indicative marker of immediate and longer term health risks for an individual.

Caesarean section rates and adverse neonatal outcomes after induction of labour versus expectant management in women with an unripe cervix: a secondary analysis of the HYPITAT and DIGITAT trials

OBJECTIVE

To evaluate caesarean section and adverse neonatal outcome rates after induction of labour or expectant management in women with an unripe cervix at or near term.

DESIGN

Secondary analysis of data from two randomised clinical trials.

SETTING

Data were collected in two nationwide Dutch trials.

POPULATION

Women with hypertensive disease (HYPITAT trial) or suspected fetal growth restriction (DIGITAT trial) and a Bishop score ≤6.

METHODS

Comparison of outcomes after induction of labour and expectant management.

MAIN OUTCOME MEASURES

Rates of caesarean section and adverse neonatal outcome, defined as 5-minute Apgar score ≤6 and/or arterial umbilical cord pH <7.05 and/or neonatal intensive care unit admission and/or seizures and/or perinatal death.

RESULTS

Of 1172 included women with an unripe cervix, 572 had induction of labour and 600 had expectant management. We found no significant difference in the overall caesarean rate (difference -1.1%, 95% CI -5.4 to 3.2). Induction of labour did not increase caesarean rates in women with Bishop scores from 3 to 6 (difference -2.7%, 95% CI -7.6 to 2.2) or adverse neonatal outcome rates (difference -1.5%, 95% CI -4.3 to 1.3). However, there was a significant difference in the rates of arterial umbilical cord pH <7.05 favouring induction (difference -3.2%, 95% CI -5.6 to -0.9). The number needed to treat to prevent one case of umbilical arterial pH <7.05 was 32.

CONCLUSIONS

We found no evidence that induction of labour increases the caesarean rate or compromises neonatal outcome as compared with expectant management. Concerns over increased risk of failed induction in women with a Bishop score from 3 to 6 seem unwarranted.

TWEETABLE ABSTRACT

Induction of labour at low Bishop scores does not increase caesarean section rate or poor neonatal outcome.

The possible role of virus-specific CD8(+) memory T cells in decidual tissue

The most abundant lymphocyte present in decidual tissue is the CD8(+) T cell. It has been shown that most decidual CD8(+) T cells have an effector-memory phenotype, but expressed reduced levels of perforin and granzyme B compared with the peripheral CD8(+) effector-memory T cells. The specificity of these CD8(+) memory T cells has yet to be determined. One hypothesis is that the decidual memory T cells are virus-specific T cells that should protect the fetus against incoming pathogens. As virus-specific CD8(+) memory T cells can cross-react with human leukocyte alloantigens, an alternative, but not mutually exclusive, hypothesis is that these CD8(+) T cells are fetus-specific. Using virus-specific tetramers, we found increased percentages of virus-specific CD8(+) T cells in decidual tissue compared with peripheral blood after uncomplicated pregnancy. So far, no evidence has been obtained for a cross-reactive response of these virus-specific T cells to fetal human leukocyte antigens. These results suggest that the virus-specific memory T cells accumulate in the placenta to protect the fetus from a harmful infection.

Comparison of conventional versus three-dimensional ultrasound in fetal renal pelvis measurement and their potential prediction of neonatal uropathies

OBJECTIVE

To establish a threshold value for fetal renal pelvis dilatation measured by automatic volume calculation (SonoAVC) in the third trimester of pregnancy to predict neonatal uropathies, and to compare these results with conventional antero-posterior (AP) measurement, fetal kidney 3D volume and renal parenchymal thickness.

METHODS

In a prospective cohort study, 125 fetuses with renal pelvis AP diameter of ≥5 mm both at 20 weeks of gestation and in the third trimester, underwent an additional 3D volume measurement of the fetal kidney in the third trimester. Receiver operating characteristic (ROC) curves for establishing threshold values for fetal renal pelvis volume, AP measurement, fetal kidney volume and renal parenchymal thickness to predict neonatal uropathies were analyzed. Also, sensitivity, specificity, area under the curve (AUC) and likelihood ratios were calculated.

RESULTS

A cut-off point of 1.58 cm³ was identified in the third trimester of pregnancy (AUC 0.865 (95% CI 0.789-0.940), sensitivity 76.3%, specificity 87.4%, LR+ 6.06, LR- 0.27) for measurements with SonoAVC. A cut-off value of 11.5 mm was established in the third trimester of pregnancy (AUC 0.828 (95% CI 0.737-0.918), sensitivity 71.1%, specificity 85.1%, LR+ 4.77, LR- 0.34) for the conventional AP measurement. A cut-off point for fetal kidney volume was calculated at 13.29 cm³ (AUC 0.769 (95% CI 0.657-0.881), sensitivity 71%, specificity 66%, LR+ 2.09, LR- 0.44). For renal parenchymal thickness, a cut-off point of 8.4 mm was established (AUC 0.216 (95% CI 0.117-0.315), sensitivity 31.6%, specificity 32.6%, LR+ 0.47, LR- 2.10).

CONCLUSION

This study demonstrates that 3D fetal renal pelvis volume measurements and AP measurements both have a good and comparable diagnostic performance, fetal renal volume a fair accuracy and renal parenchymal thickness a poor accuracy in predicting postnatal renal outcome.

Maternal HLA-C2 and 14 bp insertion in HLA-G is associated with recurrent implantation failure after in vitro fertilization treatment

The major rate-limiting step in in vitro fertilization (IVF) success appears to be the implantation of the semi-allogeneic embryo into the maternal endometrium. To determine possible risk factors of recurrent failure of embryos to implant, we investigated immunogenetic determinants as level of human leukocyte antigen (HLA) histocompatibility, frequency of killer-cell immunoglobulin-like receptors (KIR) and HLA-C alleles and HLA-G polymorphism. We DNA typed women with recurrent implantation failure (RIF) and their partners for classical HLA Class I, HLA Class II, HLA-G and KIR alleles and compared these results with couples with successful embryo implantation after their first IVF and normal fertile couples. No association was found between RIF and the degree of histocompatibility between partners or sharing of a specific antigen. Also, no significant difference in KIR haplotype or combination of HLA-C group and KIR was observed. We did find a higher frequency of HLA-C2 and a higher frequency of 14 base pair (bp) insertion in HLA-G in women with RIF. Therefore we conclude that the degree of histocompatibility between partners is not a determining factor for the occurrence of RIF. However, presence of the HLA-C2 allotype and the HLA-G allele with a 14 bp insertion is a significant risk factor.

Preservation of human placenta facilitates multicenter studies on the local immune response in normal and aberrant pregnancies

Our standard procedure for phenotypic and functional analysis of immune cells present in the placenta is to isolate leukocytes from the decidua within five hours of the delivery. However, this results in logistical problems with deliveries at night, weekends or in other medical centers. Collecting placentas after complicated pregnancies is even more difficult owing to the low prevalence and the often unscheduled delivery. The aim was to investigate the possibility of preserving the human placenta before phenotypic and functional analysis of decidual lymphocytes. Placentas were obtained after uncomplicated pregnancy. The tissue was divided into two equal parts: decidual lymphocytes from one part were isolated within five hours according to our standard procedure, whereas the other part was preserved in either Celsior(®), a storage solution for solid organ preservation, or phosphate-buffered saline (PBS) for 24h at 4°C before isolation. Overall, the phenotype and functional capacity of decidual lymphocytes isolated within five hours was comparable to decidual lymphocytes isolated after 24-h preservation in Celsior(®) or PBS. Minor differences were found between decidual lymphocytes isolated within five hours and decidual lymphocytes isolated after 24-h preservation in Celsior(®). The results indicate that PBS is sufficient to preserve the placenta for 24h for phenotypical and functional studies. The ability to preserve the placenta will simplify the procedure for the isolation of decidual lymphocytes and makes it easier to analyze tissue from women who deliver during the night, at weekends or in other hospitals, and possibly even women with complicated pregnancies.

Chorionic plate expression patterns of the maspin tumor suppressor protein in preeclamptic and egg donor placentas

Maspin is a serine protease inhibitor involved in regulating human placental trophoblast cell migration. Maspin has not been studied in preeclampsia (PE) or relative to the maternal-fetal immunological relationship, both of which may involve altered trophoblast migration. We examined maspin expression in placentas from in vitro fertilization (IVF) and egg donor (ED) pregnancies with and without PE. Exclusive to the chorionic plate, the number of maspin-positive extravillous trophoblasts was significantly decreased in IVF-PE vs. IVF (p = 0.005) and ED vs. IVF (p = 0.013). These data suggest maspin expression may be influenced by PE and/or the immunological dynamics of pregnancy.

Meeting report of the first conference of the International Placenta Stem Cell Society (IPLASS)

The International Placenta Stem Cell Society (IPLASS) was founded in June 2010. Its goal is to serve as a network for advancing research and clinical applications of stem/progenitor cells isolated from human term placental tissues, including the amnio-chorionic fetal membranes and Wharton's jelly. The commitment of the Society to champion placenta as a stem cell source was realized with the inaugural meeting of IPLASS held in Brescia, Italy, in October 2010. Officially designated as an EMBO-endorsed scientific activity, international experts in the field gathered for a 3-day meeting, which commenced with "Meet with the experts" sessions, IPLASS member and board meetings, and welcome remarks by Dr. Ornella Parolini, President of IPLASS. The evening's highlight was a keynote plenary lecture by Dr. Diana Bianchi. The subsequent scientific program consisted of morning and afternoon oral and poster presentations, followed by social events. Both provided many opportunities for intellectual exchange among the 120 multi-national participants. This allowed a methodical and deliberate evaluation of the status of placental cells in research in regenerative and reparative medicine. The meeting concluded with Dr. Parolini summarizing the meeting's highlights. This further prepared the fertile ground on which to build the promising potential of placental cell research. The second IPLASS meeting will take place in September 2012 in Vienna, Austria. This meeting report summarizes the thought-provoking lectures delivered at the first meeting of IPLASS.

Induction versus expectant monitoring for intrauterine growth restriction at term: randomised equivalence trial (DIGITAT)

OBJECTIVE

To compare the effect of induction of labour with a policy of expectant monitoring for intrauterine growth restriction near term.

DESIGN

Multicentre randomised equivalence trial (the Disproportionate Intrauterine Growth Intervention Trial At Term (DIGITAT)).

SETTING

Eight academic and 44 non-academic hospitals in the Netherlands between November 2004 and November 2008.

PARTICIPANTS

Pregnant women who had a singleton pregnancy beyond 36+0 weeks' gestation with suspected intrauterine growth restriction.

INTERVENTIONS

Induction of labour or expectant monitoring.

MAIN OUTCOME MEASURES

The primary outcome was a composite measure of adverse neonatal outcome, defined as death before hospital discharge, five minute Apgar score of less than 7, umbilical artery pH of less than 7.05, or admission to the intensive care unit. Operative delivery (vaginal instrumental delivery or caesarean section) was a secondary outcome. Analysis was by intention to treat, with confidence intervals calculated for the differences in percentages or means.

RESULTS

321 pregnant women were randomly allocated to induction and 329 to expectant monitoring. Induction group infants were delivered 10 days earlier (mean difference -9.9 days, 95% CI -11.3 to -8.6) and weighed 130 g less (mean difference -130 g, 95% CI -188 g to -71 g) than babies in the expectant monitoring group. A total of 17 (5.3%) infants in the induction group experienced the composite adverse neonatal outcome, compared with 20 (6.1%) in the expectant monitoring group (difference -0.8%, 95% CI -4.3% to 3.2%). Caesarean sections were performed on 45 (14.0%) mothers in the induction group and 45 (13.7%) in the expectant monitoring group (difference 0.3%, 95% CI -5.0% to 5.6%).

CONCLUSIONS

In women with suspected intrauterine growth restriction at term, we found no important differences in adverse outcomes between induction of labour and expectant monitoring. Patients who are keen on non-intervention can safely choose expectant management with intensive maternal and fetal monitoring; however, it is rational to choose induction to prevent possible neonatal morbidity and stillbirth.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial number ISRCTN10363217.

Labour and neonatal outcome in small for gestational age babies delivered beyond 36+0 weeks: a retrospective cohort study

OBJECTIVE

Small for gestational age (SGA) is associated with increased neonatal morbidity and mortality. At present, evidence on whether these pregnancies should be managed expectantly or by induction is lacking. To get insight in current policy we analysed data of the National Dutch Perinatal Registry (PRN).

METHODS

We used data of all nulliparae between 2000 and 2005 with a singleton in cephalic presentation beyond 36+0 weeks, with a birth weight below the 10th percentile. We analysed two groups of pregnancies: (I) with isolated SGA and (II) with both SGA and hypertensive disorders. Onset of labour was related to route of delivery and neonatal outcome.

RESULTS

Induction was associated with a higher risk of emergency caesarean section (CS), without improvement in neonatal outcome. For women with isolated SGA the relative risk of emergency CS after induction was 2.3 (95% Confidence Interval [CI] 2.1 to 2.5) and for women with both SGA and hypertensive disorders the relative risk was 2.7 (95% CI 2.3 to 3.1).

CONCLUSION

Induction in pregnancies complicated by SGA at term is associated with a higher risk of instrumental deliveries without improvement of neonatal outcome. Prospective studies are needed to determine the best strategy in suspected IUGR at term.

[Delayed cord clamping in the interest of the newborn child]

The importance of delayed cord clamping, both for the preterm and for the term newborn, for the prevention ofneonatal anaemia (during the neonatal period and/or at the age of3 months) and furthermore to reduce the need of blood transfusions, has recently been demonstrated in controlled clinical studies and meta-analyses. Physiological and pathophysiological factors also provide a rationale for delayed cord clamping: neonatal blood volume may increase by 32% if cord clamping is delayed until the umbilical cord has completely stopped pulsating. A slow transition, involving closure of the ductus arteriosus and the foramen ovale cordis and gradual filling of the neonatal systemic circulation, contributes to the opening of the alveoli due to perfusion of the alveolar capillaries. No disadvantages, such as polycythaemia or hyperbilirubinaemia, have been described with regard to preterm neonates, whereas the incidence of intracranial haemorrhages is reduced. Also for the mother, no disadvantages of late clamping have been determined. As a standard procedure, the baby's umbilical cord should not be clamped until at least 3 minutes have passed. One should wait at least 30 seconds during the birth of children for whom a more active approach is necessary. Of all people, these children will benefit from a good Hb level.

[Need for blood transfusion in premature infants in 2 Dutch perinatology centres particularly determined by blood sampling for diagnosis]

OBJECTIVE

Determination of factors related to the need for transfusion in premature infants.

DESIGN

Descriptive.

METHOD

The need for transfusion in premature infants was determined in 2 academic centres: University Medical Center Utrecht and Leiden University Medical Center, The Netherlands. The data had been acquired in another study. The factors under study were: hospital, pregnancy duration, birth weight, gender, time of clamping of the umbilical cord, total volume of blood sampled for diagnostic purposes, number of days of mechanical ventilation, total duration of admission and duration of the admission to the Neonatal Intensive care unit. Both hospitals followed the national interdisciplinary practice guideline 'Blood transfusion'.

RESULTS

The total volume ofsampled blood for diagnosis, the duration of the mechanical ventilation and the admission period were related to a greater need for transfusion. On the other hand, the chance of transfusions diminished with longer pregnancy duration or increased birth weight. The difference in need for blood transfusion between both centres was significant. The total volume of transfused erythrocytes showed a strong correlation with the volume sampled for diagnostic procedures.

CONCLUSION

Anaemia in neonates is strongly related to the amount of blood taken for diagnostic procedures. Alternatives for blood transfusions in premature infants, and consequently for the reduction of the number of donors per child, are to be sought in delayed clamping of the umbilical cord, use of erythropoietin and use ofautologous umbilical cord blood.

Differential Distribution of CD4+CD25bright and CD8+CD28− T-cells in Decidua and Maternal Blood During Human Pregnancy

During pregnancy several maternal and fetal mechanisms are established to prevent a destructive immune response against the allogeneic fetus. Despite these mechanisms, fetus specific T-cells persist throughout gestation but little is known about the regulation of these T-cells. Recently, CD4(+)CD25(+) regulatory T-cells have been identified in human decidua. Human decidua forms the maternal part of the fetal-maternal interface and is subdivided in two distinct regions: the decidua (d.) basalis and the decidua (d.) parietalis. The aim of this study was to determine the distribution of specific T-cell subsets in d. basalis and d. parietalis in early and term pregnancy, with a special emphasis on the presence of CD4(+)CD25(bright) (regulatory) T-cells and CD8(+)CD28(-) (suppressor) T-cells. In addition, we compared phenotypic characteristics of decidua derived T-cell subsets with maternal peripheral blood (mPBL) T-cells and T-cells from non-pregnant controls. We identified significantly higher percentages of CD4(+)CD25(bright) and CD8(+)CD28(-) T-cells in decidua compared to peripheral blood suggesting an important role for these T-cell subsets locally at the fetal-maternal interface. The major differences in T-cell subset distribution and the presence of additional phenotypic differences between T-cells in d. basalis, d. parietalis and mPBL may reflect specific immunomodulatory functions of these T-cell subsets at these different sites during pregnancy.

[Breech presentation at term: the caesarean section that is routinely advised is ultimately not safe for the child]

Recently, the results have become available on both the neonatal and the maternal outcome of deliveries after randomisation in the Term breech trial. At 2 years, in contrast to the original results in which perinatal death and serious neonatal morbidity were higher in the planned vaginal delivery group, no differences were evident in the combined outcdme variable, including death after delivery and neurodevelopmental delay. There were also no apparent differences between the two groups in neurodevelopmental abnormalities as screened by the ASQ postal enquiry. These are the most important findings that should be discussed with the parents during counselling regarding the mode of delivery of a foetus in breech presentation.

Factor VIII levels and the risk of pre-eclampsia, HELLP syndrome, pregnancy related hypertension and severe intrauterine growth retardation

OBJECTIVE

Recently, acquired as well as genetic prothrombotic factors are associated with thrombotic events. These factors have also been related to conditions of uteroplacental insufficiency such as pre-eclampsia, HELLP syndrome and severe intrauterine growth restriction (IUGR). The aim of this study was to determine whether elevated factor VIII levels are associated with uteroplacental insufficiency, in particular pre-eclampsia, HELLP syndrome or pregnancy-induced hypertension and intrauterine growth retardation.

METHODS

Plasma samples of 75 women with a history of pregnancy complicated by pre-eclampsia, HELLP syndrome, pregnancy induced hypertension or intrauterine growth restriction were tested for factor VIII:C (FVIII:C) levels at a minimum of 10 weeks post-partum. Laboratory results were compared to factor VIII:C levels found in a healthy control group of 272 women.

RESULTS

Mean factor VIII:C levels were similar at 123 IU/dl in both the patient group and the controls. In a logistic regression model, after adjusting for age and blood group, no effect of factor VIII:C levels on the risk of pregnancy complications was observed, with the exception of IUGR with (OR 2.9, CI 1.0-8.7) or without hypertension (OR 2.0, CI 0.7-6.4).

CONCLUSION

If the elevated level of factor VIII would be the sole factor responsible for the increased risk observed, one would expect to find an effect of blood group on risk as well (blood group being an important determinant of FVIII:C). While no such effect could be shown a causal relationship between elevated levels of factor VIII and conditions of uteroplacental insufficiency such as pre-eclampsia, HELLP syndrome, pregnancy-induced hypertension and IUGR is not very likely.

Intervention Rates after Elective Induction of Labor Compared to Labor with a Spontaneous Onset

INTRODUCTION

Elective induction of labor has become a widely used procedure in obstetrics. A number of studies have shown an increased incidence of operative deliveries. The objective of this study was to evaluate the rate of interventions in our hospital, including operative delivery.

METHODS

A matched cohort study in which labor of 122 electively induced women and 122 women with labor with a spontaneous onset were analyzed retrospectively. These women were matched for parity and gestational age.

RESULTS

Pain relief, fetal scalp blood sampling and operative deliveries were recorded more frequently in the electively induced labor group. Cesarean delivery was found in 15% of women with induced labor, and in 1% of labors with a spontaneous onset (relative risk 18 (95% CI 2.4-132.7)). No differences were found in neonatal outcomes.

CONCLUSIONS

Elective induction of labor leads to increased intervention rates during labor. The rate of cesarean delivery is high, particular in nulliparous women and multiparous women without a previous vaginal birth.

Low dose sulprostone for termination of second and third trimester pregnancies

OBJECTIVE

The purpose of this study is to assess the effectiveness and safety of sulprostone (nalador) for labour induction in the event of foetal death or foetal malformations.

STUDY DESIGN

Retrospective analysis of 284 women with intrauterine foetal death (n=137), or foetal abnormalities (n=147), who underwent labour induction with sulprostone in a continuous dose of 1microg/min intravenously.

RESULTS

All but three women had a successful vaginal delivery. The median induction-expulsion interval was significantly shorter (12h) in the foetal death group compared to the foetal malformation group (25h). Two uterine ruptures were recorded, one in a woman with a uterine anomaly, and one in a woman with a previous caesarean section. There were no other complications. Gestational age had a significant influence on spontaneous expulsion of the placenta: before 24 weeks 55%, and after 24 weeks 82% spontaneous expulsion. For the chance of a neonate born with signs of life, parity was the only significant determinant.

CONCLUSIONS

The use of intravenous sulprostone in a low continuous dose is both effective and safe. In addition, this study does not support former opinions that smoking and advanced maternal age are contraindications.

The severity of immune fetal hydrops is predictive of fetal outcome after intrauterine treatment

OBJECTIVE

This study was undertaken to test the hypothesis that the degree of immune fetal hydrops predicts outcome in red blood cell-alloimmunized pregnancies.

STUDY DESIGN

In an 11-year period, 213 fetuses received 599 intrauterine transfusions. The outcome of 208 pregnancies, including two pairs of twins, was analyzed in a retrospective study. Eighty fetuses demonstrated ultrasonographic signs of hydrops at the start of treatment; 42 of these were classified as mildly hydropic and 38 were classified as severely hydropic. Reversal of hydrops as a result of treatment, survival, and neonatal morbidity was studied.

RESULTS

The overall survival rate of fetuses with hydrops was 78%. Of the fetuses with mild hydrops, 98% survived, whereas in cases of severe hydrops the survival rate was 55%. Intrauterine reversal of hydrops occurred in 65% of the fetuses with hydrops. The reversal rate was 88% in fetuses with mild hydrops and 39% in fetuses classified as severely hydropic. After reversal of hydrops, almost all of the fetuses survived (98%), whereas in cases of persistent hydrops outcome was unfavorable, with a survival rate of 39% for all fetuses and 26% for fetuses classified as severely hydropic.

CONCLUSION

In contrast with severe hydrops, there is a high rate of reversal of mild hydrops after adequate treatment. In our study 98% of fetuses survived after reversal of hydrops. To improve the outcome of red blood cell-alloimmunized pregnancies, early diagnosis of fetal anemia and referral to a specialized center are important; these steps enable the start of intrauterine treatment when hydrops is absent or still mild.

Association of stress during delivery with increased numbers of nucleated cells and hematopoietic progenitor cells in umbilical cord blood

OBJECTIVE

Umbilical cord blood can be used as a source of bone marrow repopulating cells for allogeneic stem cell transplantation. Large variations in the frequencies of white blood cells and hematopoietic progenitor cells have been found for umbilical cord blood. These variations may be due in part to specific circumstances during labor and delivery.

STUDY DESIGN

In this study we analyzed the relationship between stress factors occurring during parturition and the frequencies of nucleated cells, leukocyte subsets, CD34(+) cells, and hematopoietic progenitor cells, as determined in semisolid medium cultures of umbilical cord blood.

RESULTS

We observed that a prolonged first stage of labor resulted in increases in the numbers of nucleated cells, granulocytes, CD34(+) cells, and hematopoietic progenitor cells in umbilical cord blood. Evaluation of parameters that indicate stress of the infant during delivery demonstrated higher numbers of nucleated cells, granulocytes, CD34(+) cells, and hematopoietic progenitor cells in umbilical cord blood from children with lower venous pH.

CONCLUSION

Longer duration stress during delivery increased the numbers of nucleated cells, granulocytes, CD34(+) cells, and hematopoietic progenitor cells, possibly by causing mobilization of various cell populations by endogenous cytokines. As long as umbilical cord blood harvesting does not interfere with the delivery, umbilical cord blood collected after stressful deliveries may provide optimal units for hematopoietic stem cell transplantation.

Benefits and risks of fetal red-cell transfusion after 32 weeks gestation

OBJECTIVE

To compare the outcome after intrauterine transfusion (IUT) between fetuses treated before and those treated after 32 weeks gestation.

SETTING

National referral center for intrauterine treatment of red-cell alloimmunization in The Netherlands.

STUDY DESIGN

Retrospective evaluation of an 11 year period, during which 209 fetuses were treated for alloimmune hemolytic disease with 609 red-cell IUTs. We compared fetal and neonatal outcome in three groups: fetuses only treated before 32 weeks gestation (group A, n=46), those treated both before and after 32 weeks (group B, n=117), and those where IUT was started at or after 32 weeks (group C, n=46).

RESULTS

Survival rate was 48% in group A, 100% in group B, and 91% in group C. Moreover, fetuses in group A were hydropic significantly more often. Short-term perinatal loss rate after IUT was 3.4% in the 409 procedures performed before 32 weeks and 1.0% in the 200 procedures performed after 32 weeks gestation.

CONCLUSION

Perinatal losses were much more common in fetuses only treated before 32 weeks gestation. Two procedure-related perinatal losses in 200 IUT after 32 weeks remain a matter of concern because of the good prospects of alternative extrauterine treatment.

Obstetric outcome of elderly low-risk nulliparae

OBJECTIVE

To compare referrals and reasons for referral during pregnancy and labor, mode of delivery and obstetric outcome of first births in women 35 years and older with women 20-30 years old.

METHODS

A prospective cohort study was performed of 146 elderly and 306 younger nulliparae in seven independent midwives' practices in and around Amsterdam.

RESULTS

No significant differences in referrals were found between the two compared groups. After selection during pregnancy, obstetric outcome was not different between the groups. A higher percentage of episiotomies was found in the elderly group, compared to the younger group.

CONCLUSIONS

After proper selection during pregnancy, the elderly nullipara under the care of a midwife does not have an increased risk of fetal distress or other emergency factors, compared to the younger nullipara. However, high referral rates during labor - both of younger and older women - were observed in this study.

Neurodevelopmental outcome at three years of age after fetal 'brain-sparing'

Intrauterine growth restriction (IUGR), occurring preterm, may be related to impaired neurodevelopmental outcome. We measured neurodevelopmental outcome (Hempel examination) at the age of three years in a cohort of infants born between 26 and 33 weeks in 1989. Fetuses were studied haemodynamically, using Doppler ultrasound. The ratio between the umbilical and the cerebral artery Pulsatility Index (U/C ratio) was calculated. This is a measure of redistribution of fetal blood preferentially to the brain and this may be a marker of fetal adaptation to placental insufficiency. Impaired fetal growth was also measured by the fetal growth ratio. Neonatal cranial ultrasound was performed to document intracranial haemorrhages and/or ischaemia. From the original cohort of 106 infants, 96 (91%) infants were examined at three years. After adjustment for obstetric variables, adverse Hempel outcome was related to neonatal cranial ultrasound abnormality and low head circumference at three years. Neither the U/C ratio nor fetal growth were independently associated with Hempel outcome. Fetal 'brain-sparing' in IUGR appears to be a benign adaptive mechanism preventing severe brain damage.

Placental anatomy, fetal demise and therapeutic intervention in monochorionic twins and the transfusion syndrome: new hypotheses

OBJECTIVE

Monochorionic twins with circulatory sharing have an incompletely understood response to acute hemodynamic events. We relate placental vascular anatomy with, first, the response to (a) acute fetal demise and (b) laser interrupted placental anastomoses and, second, the efficacy of current and possibly future therapeutic interventions in twin-twin transfusion syndrome.

DESIGN

Hemodynamic response to acute fetal demise and laser interrupted anastomoses is analysed using the model previously developed for monochorionic twins. Efficacy of therapeutic interventions in twin-twin transfusion syndrome is analysed by combining the estimated incidence of placental anastomotic patterns with three previously proposed pathophysiologic mechanisms.

RESULTS

Fetal demise may cause sequelae for the co-twin in all anastomotic patterns except unidirectional arteriovenous and single venovenous anastomoses which are predicted to be hemodynamically harmless. In twin-twin transfusion syndrome, laser interruption of all anastomoses mitigates further transfusion. This is of benefit for the twins in equally but not in unequally shared placentas. Analysis predicts that approximately 75% fetal survival could be achieved interrupting only arteriovenous anastomoses. Amniocentesis may only prolong pregnancies that lack progressively increasing discordance, assuming that placental anastomoses remain patent following polyhydramnios. This proposed mechanism of action predicts current therapeutic efficacy accurately and could explain the significantly higher reported serious morbidity compared with laser (15/81 = 19+/-5% versus 4/146=3%, P=0.00004). However, if therapeutic interventions could match the syndrome's individual placental anatomy, the analysis suggests approximately 10-15% laser related mortality (premature rupture of membranes) and <3% severe morbidity could possibly become achievable goals.

CONCLUSION

Our predictions allow clinical testing. This information may contribute to an improved management of monochorionic twins.

Twin-twin transfusion syndrome. Three possible pathophysiologic mechanisms

OBJECTIVE

To propose a classification of twin-twin transfusion syndrome based upon three categories of placental anastomotic patterns.

STUDY DESIGN

A mathematical model developed to compute fetal blood volume in monochorionic twins combines fetoplacental circulation with net fetofetal transfusion along placental anastomoses. We included (1) unequal cotyledonic sharing, assuming that smaller fractions cause smaller twins with lower blood pressure, and (2) significantly decreasing anastomotic resistance, combining Poiseuille's law with placental anastomotic growth. Fetoplacental compensatory mechanisms were not studied.

RESULTS

First, unidirectional arteriovenous anastomoses produce steadily increasing fetal discordance by small anastomotic blood flow. Second, arteriovenous plus compensating anastomoses (venoarterial, arterioarterial, venovenous) produce fetal discordance followed by a dynamic steady state of minimal net fetofetal transfusion and large anastomotic flow. This circumstance mitigates further discordant growth. Third, unequal cotyledonic sharing plus superficial compensating anastomoses (arterioarterial, venovenous) produce fetal discordance followed by a steady state of equal fetal growth and small anastomotic flow. The model predictions include spontaneous disappearance and reversal of discordance. Serial measurement of fetal growth patterns and anastomotic flow could identify the syndrome's underlying pathophysiology.

CONCLUSION

Testing the model predictions by relating clinical presentation with placental anatomy could increase our understanding and direct diagnostic and therapeutic strategies to match the underlying placental anatomy.

Elderly nulliparae in midwifery care in Amsterdam

OBJECTIVE

to compare labour complications, after an uncomplicated pregnancy, of first births in women 35 years and older with women 20-30 years old.

DESIGN

an explorative prospective cohort study.

SETTING

four independent midwives' practices in Amsterdam.

PARTICIPANTS

a group of 49 elderly nulliparae was compared with a group of 99 younger nulliparae.

MEASUREMENTS AND FINDINGS

percentage of referrals and reasons for referral during pregnancy and labour, mode of delivery and obstetric outcome.

KEY CONCLUSIONS

no significant differences in referrals were found between the two compared groups. Obstetric-outcome was not different between the groups, except for a lower birthweight in the elderly group. A trend is seen for a raised percentage of referrals during labour in the older group. This is almost completely explained by a failure to progress during first and second stages of labour. Related to this was a trend for an increased incidence of caesarean section in the older group of women.

IMPLICATIONS FOR PRACTICE

after selection, the elderly nullipara, under the care of a midwife, does not have an increased risk of fetal distress or other emergency factors compared to the younger nullipara. However, the referral rates during labour, both of younger and older women, are high.

Fetal brain sparing is associated with accelerated shortening of visual evoked potential latencies during early infancy

OBJECTIVE

Our purpose was to assess the effects that fetal growth restriction exerts on the myelination of the developing brain.

STUDY DESIGN

Fetal haemodynamic centralization, an adaptive strategy to growth restriction caused by placental insufficiency, was determined by Doppler ultrasonography. Infants with a raised ratio between umbilical artery pulsatility index and cerebral artery pulsatility index are severely growth restricted. Visual evoked potentials give information on the degree of brain myelination. Shortening of visual evoked potential latencies is a normal feature of myelination. In a consecutive series of 105 Neonates, visual evoked potentials were recorded at the corrected ages of 6 months and 1 years. Correction for possible confounders, such as cranial ultrasonographic findings, gestational age, and head circumference, was performed.

RESULTS

At 6 months, infants with a raised umbilical artery/cerebral artery pulsatility index ratio have shorter visual evoked potential latencies. Opposite of neonates with a normal umbilical artery/cerebral artery ratio, they show no postnatal maturational shortening of visual evoked potential latencies.

CONCLUSION

Accelerated neurophysiologic maturation, found in infants with a high umbilical artery/cerebral artery ratio, might be the result of a beneficial adaptive process to severe fetal growth restriction.

Neonatal cerebral circulation in relation to neurosonography and neurological outcome: a pulsed Doppler study

In the pathogenesis of neonatal intracranial pathology and adverse neurologic outcome, severe instability of the neonatal cerebral circulation might play an important role. To examine this hypothesis the relationship was explored between intracranial pathology as detected by neurosonography during the first week of life, changes in cerebral blood flow velocity (CBFV) as measured by Doppler ultrasound in the same period and neurologic outcome, as measured by standardized tests during the first year of life. A group of 128 infants born after a pregnancy duration between 25 2/7 and 32 6/7 weeks was studied. In 40% of the infants, the time of occurrence of both types of intracranial pathology was within 1 hour after birth. No relation could be demonstrated between this occurrence and CBFV. Also after the appearance of intracranial pathology no specific changes in CBFV were seen. CBFV was associated with neurological outcome at term age. However, CBFV did not predict outcome of neurological examination at 6 and 12 months of corrected age. Intracranial hemorrhages were associated with abnormal neurological outcome at all assessments. Ischemic lesions were only associated with adverse outcome at 12 months of age.

Effect of fetal brainsparing on the early neonatal cerebral circulation

The effect of antenatal brainsparing on subsequent neonatal cerebral blood flow velocity (CBFV) was studied in very preterm infants. CBFV was determined, using a pulsed Doppler technique, both in the fetal and neonatal period. Neonatally, blood pressure and transcutaneous carbon dioxide tension (TcPCO2) was monitored simultaneously; daily cranial ultrasound examinations were performed. In infants with evidence of brainsparing a higher mean value of CBFV and a different pattern of changes of CBFV during the first week of life was demonstrated compared with infants with normal fetal cerebral haemodynamics. No differences were found in blood pressure and TcPCO2. The incidence of intracranial haemorrhages and of ischaemic echo-dense lesions was also the same for both groups. In a multivariate statistical model gestational age, antepartum brainsparing, and TcPCO2 all contributed significantly in explanation of variation in CBFV. It is speculated that a different setting of cerebral autoregulation related to differences in gestational age or to brainsparing might explain the difference in changes found in neonatal CBFV.

The "brain-sparing" effect: antenatal cerebral Doppler findings in relation to neurologic outcome in very preterm infants

OBJECTIVE

Our purpose was to study the relationship between fetal cerebral circulation and neurologic outcome.

STUDY DESIGN

In 117 high-risk fetuses (gestational age 25 to 33 weeks) flow velocity waveforms were recorded from the umbilical and medial cerebral arteries. The ratio between umbilical and cerebral pulsatility indexes was calculated. A ratio above a predefined tolerance limit was used as an index for the "brain-sparing" effect. Neonatal neurosonography and neurologic examination were used as outcome parameters.

RESULTS

Antenatally raised ratios are associated with poor obstetric outcome (fetal death and fetal growth retardation). The incidence of intracranial hemorrhages and ischemic lesions was not different for infants with a normal or raised prenatal ratio. The incidence of neurologic abnormalities was the same for both ratio groups.

CONCLUSIONS

The "brain-sparing" effect is a mechanism to prevent fetal brain hypoxia rather than a sign of impending brain damage.

Intra-observer and inter-observer reliability of the pulsatility index calculated from pulsed Doppler flow velocity waveforms in three fetal vessels

OBJECTIVE

Study of the intra observer and inter observer reliability of the pulsatility index, calculated from pulsed Doppler recordings of three fetal vessels.

DESIGN

Flow velocity waveforms (FVW) were recorded from the umbilical artery, the fetal descending aorta and the fetal internal carotid artery. Intra-observer reliability was assessed in six fetuses; ten repeated measurements were performed by one observer. Inter-observer reliability was studied in 14 fetuses; two observers performed two repeated measurements in each fetus.

SETTING

A tertiary referral hospital.

SUBJECTS

High risk pregnancies with a gestational age ranging from 29 to 42 weeks.

MAIN OUTCOME MEASURES

Analysis of variance with repeated measurements and a graphical method were used for data analysis. Intra-observer repeatability was expressed as Intraclass Correlation Coefficient (IntraCC). Inter-observer agreement was expressed as Interclass Correlation Coefficient (InterCC).

RESULTS

IntraCC for umbilical artery, descending aorta and internal carotid artery were 0.91, 0.78, and 0.54, respectively. InterCC values for these vessels were 0.39, 0.45 and 0.34, respectively. No systematic differences between the two observers except for the fetal descending aorta, were apparent. IntraCC decreased remarkable when fetuses with absent end diastolic velocities were excluded from the analysis.

CONCLUSION

The pulsatility index (PI) used for fetal measurements has a poor reliability. This is of serious concern when clinical use of FVW measurements is considered as a diagnostic tool.

Fetal and neonatal cerebral circulation: a pulsed Doppler study

We studied the relation between the fetal cerebral circulation and changes in the cerebral circulation directly after birth. With a combined real time ultrasound/pulsed Doppler technique flow velocity waveforms from the fetal umbilical- and carotid-circulation were monitored. Pulsatility Index (PI) was computed and the ratio between Umbilical PI and Carotid PI was calculated. Flow velocity waveforms of the cerebral circulation before birth were related to anterior cerebral artery flow velocity waveforms recorded immediately after birth. The study shows that changes in flow velocity waveforms associated with the intra uterine brain-sparing effect are related to poor obstetrical outcome. Furthermore is shown that the brain-sparing effect in the fetal period is associated with higher PI values in the cerebrovascular circulation in the neonatal period. It is suggested that changes in these PI values, representing changes in cerebrovascular resistance, might be indicative of cerebral ischemia in the neonate.