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.

P-302 How adenomyosis changes throughout pregnancy

Study question

How do the ultrasound characteristics of adenomyosis modify during pregnancy?

Summary answer

Signs of adenomyosis are visible in pregnancy and progressively disappear through gestation; adenomyosis was associated with an increased risk of miscarriage in the 1st trimester.

What is known already

Women with uterine adenomyosis may be asymptomatic (35%) or report menorrhagia (50%), dysmenorrhea (30%) and metrorrhagia (20%). Several authors recently linked this condition to subfertility since many women with “unexplained infertility” were found to have adenomyosis. Being relatively inexpensive and accurate, ultrasound is now considered the imaging modality of choice for diagnosing adenomyosis. Although the increasing interest towards the adenomyosis there are no data on the identification of sign of adenomyosis among pregnant women and evaluating their changes throughout the pregnancy.

Study design, size, duration

This is a retrospective exploratory cohort study conducted between 2016 and 2020 including 254 women of which 66 were diagnosed as having focal or diffuse adenomyosis (according to the MUSA classification) before conception or during the 1st trimester of pregnancy. The remaining 188 women were used as controls.

Participants/materials, setting, methods

Women were included if they had at least one pre-conceptional transvaginal ultrasound scan documenting adenomyosis, at least one scan per trimester and known maternal and neonatal outcomes. Diagnosis of adenomyosis was based on the MUSA classification and the recent consensus classification system for adenomyosis. We evaluated if the signs of adenomyosis were visible later in pregnancy and post-partum. Obstetric and neonatal outcomes were compared between women with or without these signs.

Main results and the role of chance

The globular aspect of the uterus was reported in 79% women with adenomyosis in the 1st trimester: it progressively disappeared, being present in only 38% and 2% women in the 2nd and 3rd trimester respectively and again visible in the post-partum in 65% women. Asymmetrical thickening (30%) and cysts (23%) were reported in the 1st trimester and disappeared during pregnancy. Adenomyosis was associated with miscarriage (OR 5.9 95%CI 2.4-14.9, p &lt; 0.001) also when considering only normal conception (OR 5.1 95%CI 1.8-14.2, p = 0.002) or when correcting for maternal age (aOR 5.9, CI95% 2.3-15.2, p &lt; 0.001). Gestational age at delivery was lower in women with adenomyosis (p = 0.004); Caesarean Sections (CS) rate was higher than in controls (OR 2.5, CI95% 1.3-4.8, p = 0.007) and this was confirmed (OR 2.4 CI95% 1.1-5, p = 0.02) also excluding women with previous CS.

Limitations, reasons for caution

These findings are from a monocentric retrospective study including only patients with known obstetric outcomes diagnosed with adenomyosis. Analysis was not stratified according to the mode of conception because of the small sample size, possibly introducing a bias in pregnancy outcomes.

Wider implications of the findings

Despite their progressive disappearance, signs of adenomyosis can be clinically relevant since associated with an increased risk of miscarriage in the first trimester also when considering only women with normal conception. Adenomyosis per se might have an influence on endometrial molecular expression resulting in impaired implantation and early development.

Trial registration number

not applicable

Development of the Fetal Vermis: New Biometry Reference Data and Comparison of 3 Diagnostic Modalities-3D Ultrasound, 2D Ultrasound, and MR Imaging

BACKGROUND AND PURPOSE

Normal biometry of the fetal posterior fossa rules out most major anomalies of the cerebellum and vermis. Our aim was to provide new reference data of the fetal vermis in 4 biometric parameters by using 3 imaging modalities, 2D ultrasound, 3D ultrasound, and MR imaging, and to assess the relation among these modalities.

MATERIALS AND METHODS

A retrospective study was conducted between June 2011 and June 2013. Three different imaging modalities were used to measure vermis biometry: 2D ultrasound, 3D ultrasound, and MR imaging. The vermian parameters evaluated were the maximum superoinferior diameter, maximum anteroposterior diameter, the perimeter, and the surface area. Statistical analysis was performed to calculate centiles for gestational age and to assess the agreement among the 3 imaging modalities.

RESULTS

The number of fetuses in the study group was 193, 172, and 151 for 2D ultrasound, 3D ultrasound, and MR imaging, respectively. The mean and median gestational ages were 29.1 weeks, 29.5 weeks (range, 21-35 weeks); 28.2 weeks, 29.05 weeks (range, 21-35 weeks); and 32.1 weeks, 32.6 weeks (range, 27-35 weeks) for 2D ultrasound, 3D ultrasound, and MR imaging, respectively. In all 3 modalities, the biometric measurements of the vermis have shown a linear growth with gestational age. For all 4 biometric parameters, the lowest results were those measured by MR imaging, while the highest results were measured by 3D ultrasound. The inter- and intraobserver agreement was excellent for all measures and all imaging modalities. Limits of agreement were considered acceptable for clinical purposes for all parameters, with excellent or substantial agreement defined by the intraclass correlation coefficient.

CONCLUSIONS

Imaging technique-specific reference data should be used for the assessment of the fetal vermis in pregnancy.

The transvaginal probe as a uterine manipulator: a new technique to simplify transabdominal chorionic villus sampling in cases with difficult access to the trophoblast

OBJECTIVES

To evaluate the efficacy of using the transvaginal probe to manipulate the uterus and change the position of the trophoblast, and to simplify access to the chorionic villus under difficult conditions.

METHODS

One thousand five hundred and thirty-nine procedures were performed in our centre in 1524 pregnant women from September 2006 to September 2009. In 90 of these, a difficult access to the trophoblast was observed and uterine manipulation under continuous ultrasound guidance with a double needle technique, was applied to obtain the sample. Of these, 86 samples were taken from singleton pregnancies and 4 from two bichorionic twin pregnancies

RESULTS

One thousand five hundred and thirty-nine transabdominal chorionic villus sampling (TA-CVS) procedures were conducted on 1524 pregnant women. As many as 1449 were performed without manipulation with the transvaginal probe and in 90 cases the manipulation was carried out. In 89 cases, access to the trophoblast was difficult and the uterus was manipulated, which enabled an adequate TA-CVS to be performed with a single aspiration. In one case, TA-CVS was not performed due to significant pelvic pain in a patient with a fixed, retroflexed uterus and a previous history of endometriosis.

CONCLUSIONS

Uterine manipulation with the transvaginal probe may be a useful solution in cases where TA-CVS is limited by difficult access to the trophoblast.

[Ovulation induction in anovulatory women]

Ovulation induction therapy is administered to stimulate follicular growth and induce ovulation in anovulatory infertile women. In anovulatory women with polycystic ovary syndrome, the treatment of choice is clomiphene citrate, whereas in clomiphene nonresponders, gonadotrophins are given as secondary therapy. Currently, insulin-sensitizing agents are used in the treatment of polycystic ovary syndrome to restore menstrual cyclicity. In selected patients, laparoscopic drilling has also been suggested. In anovulatory patients affected with hypogonadotropic hypogonadism, treatment is based on gonadotrophin replacement therapy or pulsatile gonadotrophin-releasing hormone infusion. In ovulation induction therapy the clinician's attention should be directed at restoring normal ovary function. When pharmacotherapy is required, monofollicular growth should be induced to reduce the risk of multiple pregnancy.

Anti-Müllerian hormone measurement on any day of the menstrual cycle strongly predicts ovarian response in assisted reproductive technology

BACKGROUND

Recently, a new marker, the anti-Müllerian hormone (AMH), has been evaluated as a marker of ovarian response. Serum AMH levels have been measured at frequent time-points during the menstrual cycle, suggesting the complete absence of fluctuation. The aim of this study was to evaluate whether serum AMH measurement on any day of the menstrual cycle could predict ovarian response in women undergoing assisted reproductive technology (ART).

METHODS

This study included 48 women attending the IVF/ICSI programme. Blood withdrawal for AMH measurement was performed in all the patients independently of the day of the menstrual cycle.

RESULTS

Women in the lowest AMH quartile (<0.4 ng/ml) were older and required a higher dose of recombinant FSH than women in the highest quartile (>7 ng/ml). All the cancelled cycles due to absent response were in the group of the lowest AMH quartile, whereas the cancelled cycles due to risk of ovarian hyperstimulation syndrome (OHSS) were in the group of the highest AMH quartile. This study demonstrated a strong correlation between serum AMH levels and ovarian response to gonadotrophin stimulation.

CONCLUSION

For the first time, clinicians may have a reliable serum marker of ovarian response that can be measured independently of the day of the menstrual cycle.