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.

Serial cervical-length measurements after first episode of threatened preterm labor improve prediction of spontaneous delivery prior to 37 weeks' gestation.

OBJECTIVE: To assess whether repeat cervical-length (CL) measurement in women discharged from hospital after their first episode of threatened preterm labor can predict their risk of spontaneous preterm birth. METHODS: This was a secondary analysis of a randomized controlled trial of maintenance tocolysis, in which CL was measured on transvaginal ultrasound at the time of hospital discharge and after 2, 4, 8 and 12 weeks, in women who remained undelivered after their first episode of threatened preterm labor. After univariate analysis, multivariate logistic regression analysis was used to assess whether CL < 10 mm at the time of hospital discharge or at any follow-up evaluation could predict spontaneous delivery prior to 37 weeks of gestation. RESULTS: Of 226 women discharged after a diagnosis of threatened preterm labor, 57 (25.2%) delivered spontaneously prior to 37 weeks' gestation. The risk of spontaneous preterm birth was higher among women with CL < 10 mm at hospital discharge compared to those with CL ≥ 10 mm (adjusted odds ratio (aOR), 3.3; 95% CI, 1.2-9.2). Moreover, spontaneous preterm delivery was more common when CL < 10 mm was detected up to 2 weeks (aOR, 2.9; 95% CI, 1.1-7.3) or up to 4 weeks (aOR, 7.3; 95% CI, 2.3-22.8) post discharge, as compared with when CL was persistently ≥ 10 mm. The association was not significant when considering CL measurements at 8 weeks, and there was insufficient information to assess the effect of measurements obtained at 12 weeks. CONCLUSIONS: Women who remain undelivered after their first episode of threatened preterm labor continue to be at high risk of spontaneous preterm birth if their CL is below 10 mm at the time of hospital discharge or at any follow-up visit up to 4 weeks later. CL measurement could be included in the antenatal care of these women in order to stratify their risk of preterm birth, rationalize resource utilization and help clinicians improve pregnancy outcome. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Vaginal delivery in SARS-CoV-2-infected pregnant women in Northern Italy: a retrospective analysis.

OBJECTIVE: To report mode of delivery and immediate neonatal outcome in women infected with COVID-19. DESIGN: Retrospective study. SETTING: Twelve hospitals in northern Italy. PARTICIPANTS: Pregnant women with COVID-19-confirmed infection who delivered. EXPOSURE: COVID 19 infection in pregnancy. METHODS: SARS-CoV-2-infected women who were admitted and delivered from 1 to 20 March 2020 were eligible. Data were collected from the clinical records using a standardised questionnaire on maternal general characteristics, any medical or obstetric co-morbidity, course of pregnancy, clinical signs and symptoms, treatment of COVID 19 infection, mode of delivery, neonatal data and breastfeeding. MAIN OUTCOME AND MEASURES: Data on mode of delivery and neonatal outcome. RESULTS: In all, 42 women with COVID-19 delivered at the participating centres; 24 (57.1%, 95% CI 41.0-72.3) delivered vaginally. An elective caesarean section was performed in 18/42 (42.9%, 95% CI 27.7-59.0) cases: in eight cases the indication was unrelated to COVID-19 infection. Pneumonia was diagnosed in 19/42 (45.2%, 95% CI 29.8-61.3) cases: of these, 7/19 (36.8%, 95% CI 16.3-61.6) required oxygen support and 4/19 (21.1%, 95% CI 6.1-45.6) were admitted to a critical care unit. Two women with COVID-19 breastfed without a mask because infection was diagnosed in the postpartum period: their newborns tested positive for SARS-Cov-2 infection. In one case, a newborn had a positive test after a vaginal operative delivery. CONCLUSIONS: Although postpartum infection cannot be excluded with 100% certainty, these findings suggest that vaginal delivery is associated with a low risk of intrapartum SARS-Cov-2 transmission to the newborn. TWEETABLE ABSTRACT: This study suggests that vaginal delivery may be associated with a low risk of intrapartum SARS-Cov-2 transmission to the newborn.

[The use of RCGO triggers in the obstetric - gynecological procedures: the impact on the reduction of adeverse events. The experience of the Lombardia Region]. / L'utilizzo dei RCOG trigger in area ostetrica - ginecologica e la riduzione degli eventi avversi. L'esperienza della regione Lombardia.

The last few weeks of pregnancy are critical to a baby's health because important organs, including the brain and lungs, are not completely developed until the end of pregnancy. The adverse events during labor and childbirth can have very serious physical, psychological and financial consequences for the child, the family, health professionals and the whole community. These events can be reduced through interventions aimed at improving the safety and quality of care, based on evidence-based knowledge, guidelines and practices that must be widely and effectively applied. This work reports the experience of the Lombardy Region on improvement actions in the obstetric and gynecological procedures for the reduction of adverse events and sentinel events through the monitoring and management of the RCGS trigger tool.

Bedside diagnosis of two major clinical phenotypes of hypertensive disorders of pregnancy.

OBJECTIVE: To investigate the hypothesis that fetal abdominal circumference (AC) and uterine artery (UtA) Doppler pulsatility index (PI) could be used to select two homogeneous subgroups of women affected by hypertensive disorders of pregnancy (HDP), characterized by the coexistence of maternal hypertension with and without intrauterine growth restriction (IUGR). METHODS: This was a multicenter retrospective study of cases affected by HDP in whom fetal AC and UtA-PI had been measured at admission to fetomaternal medicine units. Maternal characteristics, pregnancy complications and outcome were recorded. These data allowed us to model the characteristics of fetal growth in cases affected by HDP, and to design composite indicators of risk factors for maternal metabolic syndrome and of severity for maternal functional organ damage. RESULTS: Measurements of fetal AC and UtA-PI allowed us to define a group of HDP cases with appropriate-for-gestational-age (AGA) fetuses (HDP-AGA), diagnosed by normal fetal AC and UtA-PI (n = 205), and a group of HDP cases with IUGR fetuses (HDP-IUGR), diagnosed by fetal AC < 5(th) centile and UtA-PI > 95(th) centile (n = 124). Curves fitted to the birth weights of these two groups were significantly different, but gestational age at admission for HDP (< 34 or ≥ 34 weeks) did not show an independent association with birth weight. When birth weight was expressed as a Z-score with respect to local reference charts, the average corresponded to the 6(th) and 48(th) centiles, respectively. The occurrence of HDP-AGA (as compared with HDP-IUGR) was significantly associated with risk factors for maternal metabolic syndrome (odds ratio, 2.79 (95% CI, 1.57-4.97)), independent of gestational age. The same risk factors yielded non-significant odds ratios for the development of late-onset (vs early-onset) HDP. Women with HDP-IUGR had worse clinical outcomes. CONCLUSIONS: This study provides new information based on simple prenatal bedside examinations that might help to differentiate HDP-IUGR from HDP-AGA fetuses. These groups are associated with different fetal growth patterns and risk factors, independent of gestational age at onset of the disease. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Can adverse neonatal outcome be predicted in late preterm or term fetal growth restriction?

OBJECTIVE: To identify independent predictors of adverse neonatal outcome in cases of fetal growth restriction (FGR) at > or = 34 weeks. METHODS: From a cohort of 481 FGR cases delivered at > or = 34 weeks, demographic and obstetric variables, fetal biometry and Doppler indices of the uterine, umbilical and fetal middle cerebral arteries available within 2 weeks of delivery, were related to adverse neonatal outcome, defined as admission to the neonatal intensive care unit for indications other than low birth weight alone. RESULTS: Logistic regression analysis showed that gestational age (GA) at delivery (odds ratio (OR) = 0.59; 95% CI, 0.50-0.70), abdominal circumference (AC) centile (OR = 0.69; 95% CI, 0.59-0.81) and umbilical artery (UA) pulsatility index (PI) centile (OR = 1.02; 95% CI, 1.01-1.04) significantly correlated with adverse neonatal outcome. From this model we calculated a score of adverse neonatal outcome expressed by the formula: (UA-PI centile/3) - (10 x AC centile) + (10 x (40 - GA at delivery in weeks)). Receiver-operating characteristics curve analysis demonstrated that a score of > or = 25 optimally predicted adverse neonatal outcome (sensitivity of 75%, false-positive rate of 18%). Beyond 37.5 weeks, gestational age no longer had an independent impact on outcome. CONCLUSIONS: In late preterm or term FGR, GA at delivery is the most important predictor of adverse neonatal outcome. At > 37.5 weeks, delivery may be the best option to minimize adverse outcome in all FGR cases. At 34-37 weeks, a score based on GA at delivery, UA-PI centile and AC centile optimally predicts adverse neonatal outcome.

Are ultrasonographic myoma characteristics associated with blood loss at delivery?

OBJECTIVES: The presence of myomas in pregnancy is associated with greater blood loss at delivery. The aim of this study was to evaluate whether the sonographic characteristics of myomas can predict blood loss at delivery in women with large myomas. METHODS: Among women who underwent second-trimester ultrasound screening at our department between January 1996 and December 2004, 251 had at least one myoma with a mean diameter > or = 5 cm. Number of myomas (single vs. multiple), maximum diameter of the largest myoma, sum of the maximum diameter of each myoma, change in size of myomas between first and last scan, and location in relation to the placenta and to the presenting part of the fetus (above or below) were analyzed in relation to blood loss at delivery and severe postpartum hemorrhage (> or = 1000 mL). RESULTS: Multivariate analysis showed that the presence of multiple myomas was the only parameter independently associated with amount of blood loss at delivery (P = 0.003). The association between the presence of multiple myomas and severe postpartum hemorrhage was of borderline significance for the statistical power of this study (P = 0.08). CONCLUSIONS: In women with large myomas, the presence of multiple tumors is independently associated with heavier blood loss at delivery but not with postpartum hemorrhage of > or = 1000 mL.

Amnioinfusion in preterm PROM: effects on amnion and cord histology.

OBJECTIVE: To investigate the effects of transabdominal amnioinfusion (TA) on the histology of amnion (A) and umbilical cord (UC). STUDY DESIGN: From a cohort of 56 singleton pregnancies with premature rupture of membranes (PROM) at

Very low voltage single drive domain inverted LiNbO(3) integrated electro-optic modulator.

Domain inversion is used in a simple fashion to improve significantly the performance of a waveguide electro-optic modulator in z-cut LiNbO(3). The waveguide arms of the Mach-Zehnder interferometer are placed in opposite domain-oriented regions under the same, narrower and more efficient electrode, so that opposite phase shifts (push-pull effect) can still be achieved despite the arms being subjected to the same electric field. Switching voltages close to 2 V are obtained, which allow 10Gb/s modulation with inexpensive drivers, such as those used for electro-absorption modulators, which deliver driving voltages well below 3V.

Receptors for pituitary adenylate cyclase activating peptides in human pituitary adenomas.

The presence of pituitary adenylate cyclase activating polypeptide (PACAP) receptors coupled to adenylate cyclase was investigated in four types of human pituitary adenomas: three null adenomas and five gonadotropin-, three ACTH-, four GH-, and four PRL-producing adenomas. In all samples, except in prolactinomas, PACAP(1-27) and PACAP(1-38) stimulated adenylate cyclase activity equally well and potently (K(act) around 3 nmol). Vasoactive intestinal polypeptide (VIP) was systematically 100- to 300-fold less potent than both PACAPs. In prolactinomas, PACAP(1-27), PACAP(1-38), and VIP were inactive despite a response of the enzyme to guanosine 5'-triphosphate, Gpp(NH)p, forskolin, and fluoride. [125I-AcHis1]PACAP(1-27) binding was detected in all samples except in prolactinomas. In addition, a detailed analysis of receptors was feasible in all five gonadotropin- and in two ACTH-producing adenomas, confirming the existence of selective PACAP receptors that recognized PACAP(1-27) and PACAP(1-38) with similar high affinity (IC50 0.8-1.5 nmol) and VIP with a low affinity (IC50 100 nmol/L).

Complementation of a yeast delta pkc1 mutant by the Arabidopsis proteinANT.

The Saccharomyces cerevisiae protein kinase C homologue, PKC1, is involved in maintenance of cell integrity during polarized growth. We have used a mutant complementation approach to investigate related signal transduction pathways in higher plants. Here we report the isolation of a cDNA from Arabidopsis thaliana which partially suppresses the lytic defect of a delta pkc1 yeast strain. The encoded protein, ANT, belongs to the AP2-related gene family and is essential for ovule development. Expression in yeast of a LexA-ANT fusion protein activates transcription of a reporter gene from promoters containing lexA operators. Our results support the idea that ANT acts as transcriptional activator in planta.

Mutations in the yeast two pore K+ channel YKC1 identify functional differences between the pore domains.

The K+ channel of Saccharomyces cerevisiae encoded by the YKC1 gene includes two pore-loop sequences that are thought to form the hydrophilic lining of the pore. Gating of the channel is promoted by membrane depolarisation and is regulated by the extracellular K+ concentration ([K+]o) both in the yeast and when expressed in Xenopus oocytes. Our previous work showed that substitutions of equivalent residues L293 and A428 within the pore-loops had qualitatively similar effects on both the [K+]o-sensitivity of channel gating and its voltage-dependence. Here, we report that mutations of equivalent residues N275 and N410, N-terminal from the K+ channel signature sequences of the two pores, have very different actions on channel gating and, in this case, are without effect on its voltage-sensitivity. The mutation N410D slowed current activation in a [K+]o-dependent manner and it accelerated deactivation, but without significant effect on the apparent affinity for K+. The N275D mutant, by contrast, had little effect on the [K+]o-sensitivity for activation and it greatly altered the. [K+]o-dependence of current deactivation. Neither mutant affected the voltage-dependence of the steady-state current nor the ability for other alkali cations to substitute for K+ in regulating gating. The double mutant N410D-N275D showed characteristics of N410D in the [K+]o-sensitivity of current activation and of N275D in the [K+]o-sensitivity of deactivation, suggesting that little interaction occurs between pore domains with mutations at these sites. The results indicate that the two pore domains are not functionally equivalent and they suggest that the regulation of gating by external K+ is mediated by K+ binding at two physically distinct sites with different actions.

Extracellular K+ and Ba2+ mediate voltage-dependent inactivation of the outward-rectifying K+ channel encoded by the yeast gene TOK1.

Gating of the yeast K+ channel encoded by the Saccharomyces cerevisiae gene TOK1, unlike other outward-rectifying K+ channels that have been cloned, is promoted by membrane voltage (inside positive-going) and repressed by extracellular K+. When expressed in Xenopus laevis oocytes, the TOK1p current rectified strongly outward, its activation shifting in parallel with the K+ equilibrium potential when the external K+ concentration ([K+]o) was increased above 3 mM. Analysis of the TOK1p current indicated that two kinetic components contributed to the conductance and the voltage sensitivity of the conductance. By contrast, the [K+]o sensitivity of the current was accommodated entirely within the slow-relaxing component; it was diminished near 1 mM [K+]o, and at submillimolar concentrations the voltage dependence of the TOK1p conductance was insensitive to [K+]o. External Rb+, the K+ channel blockers Cs+ and Ba2+--but not Na+, Ca2+ or Mg2+--substituted for K+ in control of TOK1p activation, indicating a specificity in cation interaction with the TOK1p gate. These and additional results indicate that external K+ acts as a ligand to inactivate the TOK1p channel, and they implicate a gating process mediated by a single cation binding site within the membrane electric field, but distinct from the permeation pathway.

Pit-1/GHF-1 expression in pituitary adenomas: further analogy between human adenomas and rat SMtTW tumours.

Adenomas can develop from each cell type of the anterior pituitary. In the normal pituitary, three of these cells types, the GH-, prolactin- and TSH-secreting cells, express the transcription factor Pit-1/GHF-1 which is responsible for prolactin and GH (and probably TSH) cell commitment, differentiation, probably proliferation and gene expression. We have analysed the expression of Pit-1/GHF-1 in a panel of human pituitary adenomas. All GH-, prolactin- and TSH-expressing adenomas studied expressed the Pit-1/GHF-1 factor, as demonstrated by in-situ hybridization and immunocytochemistry. The expression was higher in adenomas than in normal human pituitary. In contrast, ACTH- and LH-FSH-secreting and non-secreting adenomas were negative. Seven transplants of the spontaneous rat prolactinoma SMtTW were also investigated and all were found to be positive. This further stresses the analogy between these tumours and human prolactinomas. Taken together, the data confirm that Pit-1/GHF-1 expression is restricted to GH-, prolactin- and TSH-expressing cells, and the increased expression in adenomas is compatible with a role of Pit-1/GHF-1 in cell proliferation.

Expression of IL-6 mRNA in normal rat and human pituitaries and in human pituitary adenomas.

Cells expressing IL-6 mRNA were detected by in situ hybridization in normal pituitaries. In normal untreated rat pituitary the expression was very low. Within hours after IP administration of liposaccharide, IL-6 mRNA accumulated in the anterior lobe of the pituitary. Production of IL-6 was monitored after dissociation and culture of pituitary cells. High levels (8000 pg/ml) were recovered after 72 hr in culture. In normal human pituitaries, less than 1% of cells expressed IL-6 mRNA or IL-6 receptor mRNA (IL-6-R mRNA). In gonadotropinomas, prolactinomas, and non-functioning adenomas, only rare, scattered positive cells were found for either IL-6 or IL-6-R. In contrast, both genes were highly expressed in ACTH- and GH-secreting tumors at the junction of adenoma and infiltrating fibrous tissue and around blood vessels. The combined expression of IL-6 and IL-6-R suggests that IL-6 acts in an autocrine or in a paracrine way in ACTH and GH adenomas.

Risk factors for neonatal intraventricular haemorrhage in spontaneous prematurity at 32 weeks gestation or less.

In this study we aimed to establish which clinical and histopathological factors are associated with early-onset neonatal intraventricular haemorrhage (IVH) in non-iatrogenic preterm delivery before 32 weeks of gestation. We retrospectively reviewed all singleton pregnancies delivered before 32 weeks of gestation after spontaneous onset of preterm labour or preterm membrane rupture during the period January 1993 to June 1997. Clinical and histopathological data in cases with IVH diagnosed at neonatal cranial ultrasound within 72 h of birth (n = 17) were compared with those of neonates not experiencing this complication (non-IVH) (n = 54). Histological lesions analysed were those of acute inflammation and those on a uteroplacental vascular basis. Statistical methods included the Wilcoxon rank sum test, Fisher's exact test, and logistic regression analysis. A P<0.05 was considered significant.IVH and non-IVH groups were not significantly different in birthweight, gestational age at delivery, cord pH at birth, rates of 5-min Apgar score below 7, caesarean delivery, diagnosis of clinical chorioamnionitis or antenatal administration of steroids. Respiratory distress syndrome was more frequently diagnosed in the IVH than non-IVH group (64 per cent versus 33 per cent, P=0.02). Placental acute inflammatory or uteroplacental vascular lesions were present in 100 per cent of IVH neonates versus 22 per cent of non-IVH cases (P<0.001). Logistic regression analysis demonstrated that only respiratory distress syndrome (P = 0.04) and histological evidence of acute placental inflammation (P = 0.02) were significantly and independently associated with IVH. Histopathological evidence of acute inflammatory placental lesions is the best predictor of occurrence of neonatal IVH.

Ureteropelvic junction obstruction in utero and ex utero.

Seventy cases of ureteropelvic junction obstruction, bilateral or unilateral, were followed prospectively throughout gestation and postnatally for an average of 2.3 years. Cases of ureteropelvic junction obstruction with a renal pelvis dilated less than 1 cm uniformly did well; those with a pyelectasis more than 2 cm, both bilateral and unilateral, had a favorable outcome in approximately three-quarters. Surprisingly, pelvis dilatation between 1-2 cm had a better outcome if bilateral than if unilateral.

Alterations in the retinoblastoma pathway of cell cycle control in parathyroid tumors.

Mutations in proto-oncogenes and tumor suppressor genes have been associated with tumor development and/or progression in many neoplasms. It has been reported that parathyroid tumors have deletions affecting the retinoblastoma gene (RB), and overexpression of cyclin D1 (Cyc D1). The aim of the present study was to evaluate the alterations in the components of the pRB pathway in parathyroid adenomas and parathyroid aggressive tumors, including patterns of expression of pRB, Cyc D1, and p16/INK4A. Paired normal and tumor DNA from 6 parathyroid adenomas and 5 aggressive tumors were analyzed for loss of heterozygosity (LOH) at the RB locus. The expression of pRB, Cyc D1 and p16 was studied in 4 adenomas and 5 aggressive tumors. RB LOH was found in 1 of 6 adenomas, and in 1 of 2 informative aggressive tumors. Immunohistochemical analysis revealed undetectable pRB in 4 of 5 aggressive tumors and presence of pRB in all adenomas. Conversely, Cyc D1 expression was found in 3 of 4 aggressive tumors, but was undetectable in the adenomas. Expression of p16 was identified only in one aggressive tumor. Thus, alterations in the pRB pathway seem to prevail in the aggressive form of parathyroid neoplasms. Our results warrant further investigation of these cell cycle regulators in order to determine their potential role as tumor markers in parathyroid tumors.

Prenatal management of twin gestation. Experience with a new protocol.

We carried out a prospective cohort study to evaluate the usefulness of a specific protocol of prenatal management of twin pregnancy to decrease the incidence of prematurity in the population. The protocol particularly stressed the importance of early recognition of uterine contractile activity and early work leave (from 28 weeks' gestation). The outcome of 39 consecutive twin pregnancies that used the protocol over a five-year period was compared with the outcome of 76 twin pregnancies followed by private practitioners and delivered at our department. The two groups were comparable with respect to maternal age, parity, gestational age at diagnosis, socioeconomic level and educational level. The incidence of preterm delivery was significantly lower in the study group than in the control group. Even more significant was the difference in the incidence of severe prematurity (less than 34 weeks' gestation) between the two groups. The use of a protocol like ours, which does not include prolonged hospitalization, home bed rest or tocolytic treatment, is recommended.