Third-trimester ultrasound for antenatal diagnosis of placenta accreta spectrum in women with placenta previa: results from the ADoPAD study

OBJECTIVE

To evaluate the performance of third-trimester ultrasound for the diagnosis of clinically significant placenta accreta spectrum disorder (PAS) in women with low-lying placenta or placenta previa.

METHODS

This was a prospective multicenter study of pregnant women aged ≥ 18 years who were diagnosed with low-lying placenta (< 20 mm from the internal cervical os) or placenta previa (covering the internal cervical os) on ultrasound at ≥ 26 + 0 weeks' gestation, between October 2014 and January 2019. Ultrasound suspicion of PAS was raised in the presence of at least one of these signs on grayscale ultrasound: (1) obliteration of the hypoechogenic space between the uterus and the placenta; (2) interruption of the hyperechogenic interface between the uterine serosa and the bladder wall; (3) abnormal placental lacunae. Histopathological examinations were performed according to a predefined protocol, with pathologists blinded to the ultrasound findings. To assess the ability of ultrasound to detect clinically significant PAS, a composite outcome comprising the need for active management at delivery and histopathological confirmation of PAS was considered the reference standard. PAS was considered to be clinically significant if, in addition to histological confirmation, at least one of these procedures was carried out after delivery: use of hemostatic intrauterine balloon, compressive uterine suture, peripartum hysterectomy, uterine/hypogastric artery ligation or uterine artery embolization. The diagnostic performance of each ultrasound sign for clinically significant PAS was evaluated in all women and in the subgroup who had at least one previous Cesarean section and anterior placenta. Post-test probability was assessed using Fagan nomograms.

RESULTS

A total of 568 women underwent transabdominal and transvaginal ultrasound examinations during the study period. Of these, 95 delivered in local hospitals, and placental pathology according to the study protocol was therefore not available. Among the 473 women for whom placental pathology was available, clinically significant PAS was diagnosed in 99 (21%), comprising 36 cases of placenta accreta, 19 of placenta increta and 44 of placenta percreta. The median gestational age at the time of ultrasound assessment was 31.4 (interquartile range, 28.6-34.4) weeks. A normal hypoechogenic space between the uterus and the placenta reduced the post-test probability of clinically significant PAS from 21% to 5% in women with low-lying placenta or placenta previa in the third trimester of pregnancy and from 62% to 9% in the subgroup with previous Cesarean section and anterior placenta. The absence of placental lacunae reduced the post-test probability of clinically significant PAS from 21% to 9% in women with low-lying placenta or placenta previa in the third trimester of pregnancy and from 62% to 36% in the subgroup with previous Cesarean section and anterior placenta. When abnormal placental lacunae were seen on ultrasound, the post-test probability of clinically significant PAS increased from 21% to 59% in the whole cohort and from 62% to 78% in the subgroup with previous Cesarean section and anterior placenta. An interrupted hyperechogenic interface between the uterine serosa and bladder wall increased the post-test probability for clinically significant PAS from 21% to 85% in women with low-lying placenta or placenta previa and from 62% to 88% in the subgroup with previous Cesarean section and anterior placenta. When all three sonographic markers were present, the post-test probability for clinically significant PAS increased from 21% to 89% in the whole cohort and from 62% to 92% in the subgroup with previous Cesarean section and anterior placenta.

CONCLUSIONS

Grayscale ultrasound has good diagnostic performance to identify pregnancies at low risk of PAS in a high-risk population of women with low-lying placenta or placenta previa. Ultrasound may be safely used to guide management decisions and concentrate resources on patients with higher risk of clinically significant PAS. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Maternal arterial stiffness in pregnancies affected by Type 1 diabetes mellitus

AIM

There is little information about maternal central haemodynamics and arterial stiffness in pregnancies affected by Type 1 diabetes mellitus. The aim of the current study was to investigate whether maternal arterial stiffness is altered in pregnant women with Type 1 diabetes mellitus compared with women with uncomplicated pregnancies.

METHODS

This was a cross-sectional study involving 37 pregnant women without diabetes and 37 pregnant women with Type 1 diabetes mellitus during the second trimester of pregnancy. Maternal wave reflection (augmentation index) and pulse wave velocity of the carotid-femoral and carotid-radial part of the arterial tree were assessed non-invasively using applanation tonometry.

RESULTS

Pregnant women with normal pregnancies and Type 1 diabetes mellitus had similar augmentation index (3.7 +/- 12.8 vs. 5.1 +/- 12.6%, P = 0.6), even after adjusting for possible confounders. Within the group of diabetic women, augmentation index was associated with duration of diabetes (P = 0.003, r(2) = 0.22) but not with glycated haemoglobin. Pulse wave velocities were similar between the two groups of women (carotid-femoral: 5.6 +/- 0.9 vs. 5.7 +/- 1.1 m/s, P = 0.4; carotid-radial: 7.4 +/- 1.2 vs. 7.8 +/- 1 m/s, P = 0.1). In the diabetic women there was no significant association between the pulse wave velocities and either duration of diabetes or glycated haemoglobin.

CONCLUSIONS

Pregnancy in women with Type 1 diabetes mellitus is not associated with altered maternal systemic arterial stiffness. However, maternal wave reflections increase with the duration of diabetes.

Antepartum amnioinfusion: a review

OBJECTIVE

Antepartum amnioinfusion is a relatively recent procedure introduced with fetal medicine techniques. It is usually indicated for severe oligohydramnios in order to avoid the related complications such as pulmonary hypoplasia, the deforming effects of oligohydramnios, variable fetal heart rate decelerations and intraventricular hemorrhage. Antepartum amnioinfusion is also employed to improve ultrasound visualization in cases with oligohydramnios. Our objective was to evaluate the benefits and complications related to this procedure which is still less commonly used compared to intrapartum amnioinfusion, and whose risks are therefore not well established.

STUDY DESIGN

Reports of study designs identified from searches of MEDLINE, PUBMED, the Cochrane Collaboration, specialized databases and bibliographies of review articles were identified. Studies in women who underwent amnioinfusion between 1987 and 2002 were included.

RESULTS AND CONCLUSIONS

Amnioinfusion seems to offer several benefits, in terms of both prenatal diagnosis and favorable perinatal outcome. Most clinical experiences report that amnioinfusion is safe, both for the mother and for the fetus. However, randomized control-group studies subdivided on the basis of the cause of oligohydramnios (e.g. premature rupture of membranes, fetal growth restriction, obstructive uropathy and renal agenesis) could help to determine the advantages and risks linked to this procedure. Prospective randomized studies should therefore be encouraged, to clarify any possible doubts regarding the procedure, before it can be introduced into routine practice in the management of oligohydramnios.

Uterine artery Doppler at 11 + 0 to 13 + 6 weeks in the prediction of pre-eclampsia

OBJECTIVE

To determine the performance of screening for pre-eclampsia (PET) by maternal characteristics and uterine artery pulsatility index (PI) at 11 + 0 to 13 + 6 weeks' gestation.

METHODS

In women with singleton pregnancies attending for routine care at 11 + 0 to 13 + 6 weeks' gestation we recorded maternal variables and measured the uterine artery PI. We identified 107 cases that subsequently developed PET and 5041 that were unaffected by PET, gestational hypertension or delivery of newborns with birth weight below the 10(th) centile. A multivariate Gaussian model was fitted to the distribution of log multiples of the median (MoM) PI in the PET and unaffected groups. Likelihood ratios for log MoM PI were computed and used together with maternal variables to produce patient-specific risks for each case. Predicted detection rates (DR) and false-positive rates (FPR) were calculated by taking the proportions with risks above a given risk threshold.

RESULTS

In the unaffected group log MoM PI was influenced by maternal ethnic origin, body mass index, previous history of PET and fetal crown-rump length. In the prediction of PET significant contributions were provided by log MoM PI, ethnic origin, body mass index and previous and family history of PET. For an FPR of 10% the DRs of all PET and PET leading to delivery before 34 weeks' gestation by log MoM PI and maternal variables were 61.7% and 81.8%, respectively.

CONCLUSION

Maternal variables together with uterine artery PI at 11 + 0 to 13 + 6 weeks' gestation provide sensitive prediction of the development of PET, especially of severe early-onset PET.

Frontomaxillary facial angle in chromosomally normal fetuses at 11 + 0 to 13 + 6 weeks

OBJECTIVE

To establish the normal range of the frontomaxillary facial (FMF) angle at 11 + 0 to 13 + 6 weeks of gestation.

METHODS

In this prospective study, three-dimensional (3D) volumes of the fetal head were obtained from 500 pregnancies before fetal karyotyping by chorionic villus sampling (CVS), after screening by fetal nuchal translucency (NT) thickness and maternal serum free beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) at 11 + 0 to 13 + 6 weeks. Only cases with a normal karyotype were included in this study. The FMF angle was measured off-line. In a subgroup of 150 cases the FMF angle was measured using 2D ultrasound before obtaining a 3D volume. In 50 cases the 3D volumes were used to measure the FMF angle by the same examiner twice and by another examiner once.

RESULTS

The mean FMF angle decreased with crown-rump length (CRL) from 84.3 degrees at CRL 45 mm to 76.5 degrees at CRL 84 mm. There was no significant association between the FMF angle and fetal NT or serum PAPP-A or beta-hCG. In the volumes with paired measurements, the difference between two measurements by the same or two sonographers was < 5% in 95% of the cases. In the cases with paired 3D and 2D ultrasound measurements, the difference in FMF angles was < 8% in 95% of the cases.

CONCLUSIONS

At 11 + 0 to 13 + 6 weeks the FMF angle decreases with fetal CRL but is not related to fetal NT or serum biochemistry. The measurement is reproducible and the results obtained by 3D and 2D ultrasound are similar.

Transabdominal antepartum amnioinfusion

OBJECTIVES

The purpose of our study was to evaluate whether transabdominal antepartum amnioinfusion is associated with maternal complications during pregnancy and at childbirth.

METHODS

Fifty-three pregnant women, hospitalized for oligohydramnios and submitted to transabdominal antepartum amnioinfusion between 16 and 34 weeks' gestational age, were compared with a historic group of 42 pregnant women treated conservatively.

RESULTS

The study population was divided into two groups of women with ruptured and unruptured membranes (Groups A and B, respectively). The latency period between time of admission and term of pregnancy was more favorable in amnioinfused patients (Group A: 22 vs. 11 days; Group B: 30 vs. 9 days), and none of the maternal adverse events under study was significantly more common in amnioinfused patients. By contrast, maternal temperature over 38 degrees C was more frequent among controls than among amnioinfused patients with ruptured membranes (23% vs. 4%); so was the number of cesarean sections for fetal distress in Group B (50 vs. 11%).

CONCLUSIONS

Antepartum amnioinfusion does not appear to induce greater complications than conservative treatment for oligohydramnios, with or without premature rupture of membranes. On the contrary, this procedure seems to offer several benefits to pregnant women.

[Amnioinfusion: techniques, indications, and controlled retrospective study of 55 cases]

Amnioinfusion is a relatively recent procedure introduced among fetal medicine techniques. Its applications focus on two different methods: transcervical and transabdominal. The first procedure usually is carried out during "intrapartum amnioinfusion" to prevent or treat fetal heart rate (FHR) decelerations related to oligohydramnios or to dilute thick meconium staining of the amniotic fluid. The latter method used during "antepartum amnioinfusion" is usually indicated for severe oligohydramnios in order to avoid the complications related such as pulmonary hypoplasia, deforming effects of oligohydramnios, variable FHR decelerations and intraventricular hemorrhages. Antepartum amnioinfusion, also used to improve ultrasound visualisation in presence of oligohydramnios, is less employed as compared to intrapartum amnioinfusion, therefore its risks are not well established. In order to study possible adverse effects on the mother or foetus, fifty five patients affected by oligohydramnios at 17th-34th week of gestational age were submitted to antepartum amnioinfusion (1-5 procedures) and were matched retrospectively with forty seven women with the same characteristics treated with the conservative and expectant management. The trend of pregnancy was the same for both groups in relation to maternal fever > 38 degrees (10.9% in the amnioinfused group vs 17.0% in control group ns), leukocyte count > 18,000/mm3 (25.5% vs 21.3%, ns), C-reactive protein > 10 ng/ml (10.9% vs 6.4%, ns). The latency period between admission and delivery was significantly longer in the amnioinfused group than in the control one [21 (range 1-98) vs 9 days (range 0-72); p < 0.001] and the frequency of Apgar score < 7 at the 5th min was less represented in the amnioinfused group than in the control group (32.3% vs 66.6%; p < 0.001). In conclusion, it was interesting to note that antepartum amnioinfusion seems to increase the latency period between premature rupture of membranes and delivery, but it remains to clarify if this procedure is as much safe for the fetus as for the mother.

Doppler velocimetry and non stress test in severe fetal growth restriction

OBJECTIVE

The aim of our study was to evaluate the efficacy of Doppler velocimetry and cardiotocography in surveillance of the fetus affected by severe fetal growth retardation (FGR) and hence their capacity in predicting adverse perinatal outcome. This could therefore permit the timing of delivery thus reducing perinatal morbidity and mortality.

METHODS

53 women with high risk pregnancies, all suffering from various pathologies such as gestational hypertension, preeclampsia, HELLP syndrome, Antithrombin III deficit, and in whom FGR (fetal abdominal circumference < 2.5th percentile for gestational age) diagnosed between the 24th and 35th week of gestational age, were retrospectively enrolled in the study. Doppler velocimetry was carried out on the main vascular districts - both arterial [umbilical artery (UA), middle cerebral artery (MCA), aorta (Ao) and uterine artery] and venous [umbilical vein (UV), ductus venosus (DV), inferior vena cava (IVC)]. Also evaluated was the amniotic fluid index (AFI). Daily non stress tests (NST) were conducted at least thrice a day for an overall period of not shorter than 60 min. Also considered were the methods of delivery and the perinatal outcome, e.g. gestational age at birth, perinatal mortality, incidence resuscitation, etc.

RESULTS

The 53 patients studied were subdivided into three groups on the basis of the initial velocimetric exam of the umbilical and uterine arteries. Group A was comprised of those with altered waveforms of the UA, Group B those with altered waveforms on the uterine artery while Group C contained those with altered waveforms both of the UA and uterine artery. The period of study for group C was on average six days (p < 0.05) while for groups A and B they were on average 10 and 22 days, respectively. Group C also presented higher incidences of altered waveforms in the venous compartment, i.e. absent or reversed end diastole (ARDEF) was observed in 89% of the cases versus 0% and 7.6% observed in Group A and B, respectively. Altered waveforms in the DV and pulsations in the UV were both observed in Group C while the same was not observed in either group A or B. The NST did not show any substantial difference between the groups - only as the appearance of decelerations present in over half the cases in all groups at the end of the study. Group C also presented higher incidences in adverse perinatal outcome as compared to groups A and B such as as low birth weight (868 g vs 1,324 g & 1,397 g, p < 0.001), neonatal resuscitation (52.6% vs 0% & 7.6% p = 0.001), longer periods of admission to neonatal intensive care unit (67 days vs 32 & 33 p < 0.001) and perinatal mortality (36% vs 0 & 0, p < 0.05). The velocimetric indices which appear to better predict perinatal mortality are those related to the venous compartment giving a diagnostic accuracy of 92.8% (KI > 0.75) in case of pulsations in the UV, 86.6% (KI > 0.75) with alterations on the DV, and of 78.5% (KI > 0.40) for those on the IVC. Cardiotocography revealed to be less capable in predicting perinatal mortality giving a diagnostic accuracy of 66.6% (KI > 0.40) with a non reactive, non variable NST.

CONCLUSION

The data presented show that velocimetric modifications in the fetal venous compartment constitute a relevant prognostic sign in the prediction of perinatal mortality and neonatal resuscitation. The further the vessels compromised are from the heart, the higher is the relative risk for perinatal mortality, equal to 5.0 (95% C.I. = 0.61-40.9) with alterations on the IVC, of 8.2 (95% CI = 1.04-61.5) when they involve the DV, and of 18.0 (95% = 2.44-133) when pulsations are obtained on the UV.

Chemically assisted dissection of tissues: an interesting support in abdominal myomectomy

BACKGROUND

The aim of this study was to verify the efficacy of sodium-2-mercaptoethanesulfonate (mesna) in the chemical separation of tissues in abdominal myomectomies when used with the traditional mechanical separation techniques.

STUDY DESIGN

In a prospective, randomized study, 58 women underwent abdominal myomectomy. In 29 of these, we used mesna for highlighting and separating tissues, and in the other 29 we used saline solution for the same purposes. The variables evaluated included the number of myomas removed, the volume of the biggest myoma, and the total volume of the myomas removed in every intervention. We also recorded operating time, the length of hospital stay, the degree of procedure difficulty, perioperative blood loss, operative complications, and cost.

RESULTS

The operation was significantly shorter in the mesna group (p < 0.05) even though the volume and the number of myomas were larger. The degree of difficulty evaluated by the surgeon at the end of every operation was not significantly different in the two groups. The reduction in hemoglobin 24 hours after operation was significantly less in the patients treated with mesna (p = 0.006), but this difference was probably altered by the increase in hematocrit levels.

CONCLUSIONS

Because of its ability as a chemical dissector, mesna may be a useful aid in this type of benign gynecologic operation. Larger studies to confirm this are needed.