Targeted therapy for threatened preterm labor based on sonographic measurement of the cervical length: a randomized controlled trial

OBJECTIVE

False positive diagnosis of preterm labor is common. As a consequence, medications including corticosteroids to promote fetal lung maturity and tocolysis are prescribed unnecessarily. We tested the hypothesis that management of threatened preterm labor based on measurement of cervical length by ultrasonography can reduce the number of women who receive inappropriate treatment.

METHODS

Forty-one women with threatened preterm labor for whom a clinical decision was made to prescribe antenatal corticosteroids and tocolysis were randomized to have their cervical length measured by transvaginal ultrasound (n=21) or to receive therapy as planned (n=20). Fourteen women in the ultrasound group had a cervix longer than 15 mm and the therapy was withheld, while the other seven with a short cervix were managed in the same way as the control group.

RESULTS

Three women (14%) in the ultrasound group were treated inappropriately with antenatal corticosteroids because they remained undelivered for more than a week. This compared favorably with the control group where 18 out of 20 (90%) received corticosteroids unnecessarily (relative risk (RR) 0.16; 95% confidence interval (CI), 0.05-0.39). Tocolysis was given to only seven women (33.3%) in the ultrasound group compared with 20 (100%) in the control group (RR 0.3; 95% CI, 0.15-0.54). There were no babies in either group who were born prematurely without being given a full course of antenatal corticosteroid therapy.

CONCLUSION

Women with threatened preterm labor and cervical length more than 15 mm should not receive tocolysis. The issue of the safety of withholding corticosteroid therapy in this clinical scenario warrants further study.

Outcome of antenatally diagnosed sacrococcygeal teratomas: single-center experience (1993-2004)

AIMS

Sacrococcygeal teratomas (SCTs) are the commonest neonatal tumors with an incidence of approximately 1:30,000. There are few large single-center series and even fewer describing both their antenatal and postnatal course. We report the outcome of all fetuses investigated at a tertiary fetal medicine center with this diagnosis.

METHOD

Demographic details were obtained from a prospectively maintained database. Patient records were examined for additional data including antenatal and postnatal interventions. Data were described as median (range).

RESULTS

Forty-one SCTs were diagnosed antenatally during the period 1993 to 2004. Twelve were excluded from subsequent analysis (single antenatal visit or attending for second opinion [n = 6] and termination of pregnancy [n = 6]). Twelve underwent fetal intervention (laser vessel ablation [n = 4], alcohol sclerosis [n = 3], cyst drainage [n = 2], amniodrainage [n = 2], vesicoamniotic shunt [n = 1]) for fetal hydrops and polyhydramnios to aid in delivery and to prevent obstructive uropathy developing in the fetus. Of these, 3 died in utero and 9 survived to be born (median gestational age, 33 weeks [27-37 weeks]). A further 3 died in the neonatal period. There are 6 long-term survivors (50%) from this group. Seventeen infants, without intervention, were born at median gestational age 38 weeks (26-40 weeks). One infant with severe cardiac anomalies died on the day of birth. All surviving infants had definitive excisional surgery at a median of 2 days (1-16 days). Current median follow-up of survivors is 39 months (8-86 months). There have been no recurrences. One child has mild constipation, and 3 are awaiting cosmetic revision of their scars.

CONCLUSIONS

The overall survival of antenatally diagnosed SCT is approximately 77%, with the development of hydrops and others requiring in utero intervention carrying a poor prognosis. Otherwise, the outcome after surgical excision is excellent.

Current consequences of prenatal diagnosis of congenital diaphragmatic hernia

BACKGROUND

Today, the diagnosis of congenital diaphragmatic hernia (CDH) can readily be made in the prenatal period during screening ultrasound examination. Patients ought to be referred to rule out associated anomalies, and in isolated cases, prognosis is poor when the liver is intrathoracic and the lung-to-head ratio (LHR) is less than 1. In these patients, prenatal intervention aiming to reverse pulmonary hypoplasia can be considered.

METHODS

We present our current algorithm for counselling patients presenting with CDH. Patients with a poor prognosis are offered percutaneous fetal endoluminal tracheal occlusion (FETO) with a balloon, inserted at 26 to 28 weeks. We report on the evolution of technique and results in a consecutive homogeneous case series and compare outcome in cases with similar severity managed in the postnatal period.

RESULTS

Within a period of 28 months, FETO was performed between 26 and 28 weeks in 24 fetuses with severe left-sided CDH. Under general (n = 5), epidural (n = 17) or local (n = 2) anesthesia, the balloon was successfully positioned at first surgery (23/24) with a mean operation time of 20 minutes (range, 3-60 minutes). There were no serious maternal complications or direct fetal adverse effects. In the first 2 weeks after FETO, LHR increased from 0.7 to 1.7. Premature prelabour rupture of the membrane (PPROM) occurred in 16.7% and 33.3% at 28 and 32 weeks or earlier, respectively. Gestational age at delivery was 33.5 weeks. Patency of airways was restored either in the prenatal (n = 12) or perinatal period (n = 12). Early (7 days) and late (28 days) survival, and survival at discharge were 75% (18/24), 58.3% (14/24) and 50% (12/24), respectively. Half of nonsurvivors (n = 6) died of pulmonary hypoplasia and hypertension, in combination with PPROM and preterm delivery (n = 4) and balloon dislodgement (n = 2), which coincided with a short tracheal occlusion (TO) period (12 days). In the other 6, TO period was comparable to that in the 12 survivors (47 vs 42 days, respectively). In that group of 6 babies, only 2 died of pulmonary problems. Late neonatal survival (28 days) was higher with prenatal vs perinatal balloon retrieval 83.3% vs 33.3% (P = .013). In a multicentre study validating the criteria, survival till discharge in 37 comparable cases was 9% (3/32) and 13% (5/37) of parents opted for termination.

CONCLUSION

Fetuses with isolated left-sided CDH, liver herniation, and LHR of less than 1 have a poor prognosis. Percutaneous FETO is minimally invasive and may improve the outcome in these highly selected cases. Airways can be restored before birth, allowing vaginal delivery and return to the referring tertiary unit and may improve survival rate. The procedure carries a risk for PPROM, although that may decrease with experience.

Optimized real-time quantitative PCR measurement of male fetal DNA in maternal plasma

BACKGROUND

Circulating fetal DNA (cfDNA) in maternal plasma has been measured to investigate its possible relationship with pregnancy-related disorders, including fetal trisomy 21 and preeclampsia. The circulating concentrations of single-copy fetal genes, however, are close to the detection limits of PCR methods.

METHODS

We optimized a protocol for the real-time quantitative PCR amplification of the multicopy sequence DYS14 on the Y-chromosome. This was compared with an established real-time PCR assay for the single-copy SRY gene.

RESULTS

By probit regression analysis, the measurements of male DNA by the DYS14 assay had a 10-fold lower detection limit (0.4 genome equivalents) than did measurements of SRY. For plasma samples from women in the first trimester of pregnancy, imprecision (CV) was 2%-22% when amplifying DYS14 compared with 26%-140% for SRY.

CONCLUSIONS

The low copy numbers of fetal DNA in plasma of women in the first trimester of pregnancy cannot be measured precisely when targeting single-copy sequences. Better results are obtained by amplifying a sequence that is present in multiple copies per male genome.

A link between high serum levels of human chorionic gonadotrophin and chorionic expression of its mature functional receptor (LHCGR) in Down's syndrome pregnancies

Human chorionic gonadotrophin (hCG) is released from placental trophoblasts and is involved in establishing pregnancy by maintaining progesterone secretion from the corpus luteum. Serum hCG is detected in the maternal circulation within the first 2-3 wks of gestation and peaks at the end of the first trimester before declining. In Down's syndrome (DS) pregnancies, serum hCG remains significantly high compared to gestation age-matched uncompromised pregnancies. It has been proposed that increased serum hCG levels could be due to transcriptional hyper-activation of the CGB (hCG beta) gene, or an increased half life of glycosylated hCG hormone, or both. Another possibility is that serum hCG levels remain high due to reduced availability of the hormone's cognate receptor, LHCGR, leading to lack of hormone utilization. We have tested this hypothesis by quantifying the expression of the hCG beta (CGB) RNA, LHCGR RNA and LHCGR proteins in chorionic villous samples. We demonstrate that chorionic expression of hCG beta (CGB) mRNA directly correlates with high serum hCG levels. The steady-state synthesis of LHCGR mRNA (exons 1-5) in DS pregnancies was significantly higher than that of controls, but the expression of full-length LHCGR mRNA (exons 1-11) in DS was comparable to that of uncompromised pregnancies. However, the synthesis of high molecular weight mature LHCGR proteins was significantly reduced in DS compared to uncompromised pregnancies, suggesting a lack of utilization of circulating hCG in DS pregnancies.

Fetal intervention for congenital diaphragmatic hernia: the European experience

Fetuses with CDH presenting with liver herniation and a lung area-to-head circumference ratio of less than 1.0 have a high chance for neonatal death due to pulmonary hypoplasia. Fetal tracheal occlusion (TO) prevents egress of lung liquid, which triggers lung growth. In animal experiments, we were able to develop a minimally invasive technique for Fetoscopic Endoluminal Tracheal Occlusion (FETO) with a detachable balloon. In 2001, we demonstrated feasibility of FETO by percutaneous access in fetuses with severe CDH. In a retrospective multicenter review, we obtained LHR measurements and position of the liver in 134 cases of isolated left-sided CDH between 24 and 28 weeks. Eleven patients (8%) with LHR < 1.4 opted for termination. Overall survival of liveborn babies was 47% (58/123). LHR and position of the liver correlated both to survival. Combination of both variables predicted neonatal outcome better: liver up and LHR < 1.0 predicted a survival of 9%. When LHR < 0.6, there were no survivors irrespective of liver position. We could successfully perform endotracheal placement of the balloon in 20 cases at a median gestational age of 26 weeks. The mean duration of the operation was 22 (range 5-54) minutes. In 11 (55%) of these patients, there was postoperative prelabor (ie, <37 weeks) amniorrhexis. Membranes ruptured before 32 weeks in 35%, with a decreasing trend as experience increased. Ultrasound scans after FETO demonstrated an increase in the echogenicity of the lungs within 48 hours and improvement in the LHR from a median 0.7 (range 0.4-0.9) before FETO to 1.8 (range 1.1-2.9) within 2 weeks after surgery. The median gestation at delivery was 33.2 (range 27-38) weeks, and in 14 (70%) this occurred after 32 weeks. Surgical repair of the diaphragmatic hernia could be done in 13 babies, and in all but 1 the defect was extensive and required the insertion of a patch. Survival to discharge was 50%. These 10 long-term surviving babies are now aged 7 to 26 (median 19) months without known neurologic morbidity. Eight babies died in the neonatal period due to complications of the underlying disease. Two nonsurvivors died from other causes but with appropriately developed lungs. Improved survival coincided with increasing experience, in turn related to reduced incidence of postoperative amniorrhexis, later delivery, and a change in the policy on the timing of removal of the balloon from intrapartum to the prenatal period. Survival in eligible contemporary controls was 1/12 (8%). The presence of liver herniation and a low lung-to-head ratio (LHR <1.0) is a good predictor of poor prognosis at different tertiary centers around the world. Severe CDH may be successfully treated with FETO, which is minimally invasive and may improve postnatal survival.

Definitive surgical management of antenatally diagnosed exomphalos

BACKGROUND/PURPOSE

The management of exomphalos is controversial with many centers in the United Kingdom and elsewhere advocating a conservative nonsurgical approach for the larger examples. Nevertheless, this approach is not without problems or complication. The aim of the study was to ascertain the outcome of all infants with an antenatally diagnosed exomphalos treated recently at our institution using a policy of aggressive abdominal wall closure.

METHODS

This is a retrospective review of all infants with exomphalos treated from January 1995 to September 2002.

RESULTS

There were 35 infants, all of whom underwent surgery. These were separated into 3 groups: group A (all exomphalos minor) underwent primary closure (n = 11), group B (exomphalos major) underwent primary closure (n = 13), and group C (exomphalos major) underwent staged closure involving a silo (n = 11). Infants in group C had a lower birth weight (P = .05) and were less mature (P = .06). They required longer periods of ventilation (P < .001), a longer hospital stay (P = .001), and a longer period to achieve full enteral feeds (P < .001). Overall survival was 34 (97%) of 35 infants. One premature infant who was born with a ruptured exomphalos sac (birth weight, 862 g) died of nonsurgical complications (sepsis and respiratory failure) early after the creation of a silo.

CONCLUSIONS

An aggressive surgical approach in infants with exomphalos is a safe option resulting in effective abdominal wall closure. This requires a skilled multidisciplinary approach and possibly greater resources than other options.

Placental expression of interferon-gamma (IFN-gamma) and its receptor IFN-gamma R2 fail to switch from early hypoxic to late normotensive development in preeclampsia

The inability of the mother to switch from T helper cell type 1 (Th1) to Th2 cytokine profiles at the fetal-maternal interface has been proposed as one of the primary causes of miscarriage, intrauterine growth restriction (IUGR), and preeclampsia (PE). The Th1 [interferon-gamma (IFN-gamma), TNF-alpha, and IL-12] and Th2 (IL-4 and IL-10) cytokines have opposite effects on human pregnancy. Leukemia inhibitory factor (LIF) promotes embryo implantation and sustains pregnancy, whereas IFN-gamma and TNF-alpha are detrimental to pregnancy. Both IFN-gamma and LIF are produced by maternal cells and tissues at the fetal-maternal interface, whereas the IFN-gamma receptors (IFN-gamma R1 and IFN-gamma R2) and LIF receptor are abundantly expressed on the surface of placental trophoblasts. The effect of IFN-gamma on T lymphocyte activation is influenced by the relative membrane density of its two receptors, particularly IFN-gamma R2. In this study we report that in PE (25-40 wk gestation) and PE complicated by IUGR, IFN-gamma R2 protein expression is severely down-regulated and is similar to that observed in early placenta (7-10 wk gestation) developing under low O(2) tension. IFN-gamma production was found to be inversely related to the IFN-gamma R2 protein expression, and LIF receptor protein expression in PE mimicked that in early placental development. These results show that in PE, placental trophoblasts fail to establish an early to late switch with respect to IFN-gamma and IFN-gamma R2 expression. This supports the hypothesis that trophoblasts control the polarization of maternal immune effectors and cytokine profiles at the fetal-maternal interface that could be subject to oxidative stress in PE.

Respiratory function in pregnancy at sea level and at high altitude

OBJECTIVE

To determine the effect of pregnancy on respiratory function in a non-Caucasian group and determine whether there was an interaction between pregnancy and altitude of residence.

DESIGN

Prospective cross sectional study.

SETTING

Antenatal clinics in Peru, at sea level in Lima and at high altitude in Cerro de Pasco.

SAMPLE

Peruvian women with singleton pregnancies; 122 living at sea level and 192 living at 4300 m altitude in the Peruvian Andes. At each location, 19 non-pregnant women were also studied.

METHODS

Respiratory function was measured in pregnant and non-pregnant women living at sea level and at 4300 m.

MAIN OUTCOME MEASURES

Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow rate (PEFR), total lung capacity (TLC), inspiratory capacity (IC), residual volume (RV), expiratory residual volume (ERV) and functional residual capacity (FRC).

RESULTS

At sea level, RV and TLC were higher in the third compared with the first trimester (P < 0.05). At high altitude, FEV1 (P < 0.01), ERV (P < 0.01) and FRC (P < 0.01) were lower in the third compared with the first trimester. Pregnant and non-pregnant women at high altitude were 4 cm shorter (P < 0.0001) and had larger lung volumes (P < 0.01); their total lung capacities were approximately 1 L greater than women living at sea level (P < 0.0001).

CONCLUSION

These results suggest that the effect of pregnancy on the respiratory function of healthy women is influenced by altitude of residence.