Vaginal progesterone in twin gestation with a short cervix:revisiting an individual patient data systematic review and meta-analysis

OP09.10: Hemodynamic effects of sildenafil administration in an animal model of preeclampsia

Early detection of embryonic malformations by transvaginal and color Doppler sonography.

A total of 834 women with uneventful pregnancies were followed prospectively until the 15th week of gestation by TVS to screen for early embryonic malformations. Twenty-eight embryonic anomalies were detected in this series (3.3%). The median gestational age at diagnosis was 11 (range, 8 to 15) weeks. Two neural tube defects were missed by early TVS screening. Two suspected abdominal wall defects were not confirmed by repeat mid-second trimester abdominal sonography representing 6.7% of all fetal malformations evident by 24 weeks of gestation. The sensitivity and specificity of TVS screening for fetal malformations in this series were 93.3 and 99.7%, respectively. In addition, the role of T…

Prospective risk of stillbirth and neonatal complications in twin pregnancies: systematic review and meta-analysis

Twin pregnancies are at increased risk of stillbirth. Uncomplicated twin pregnancies are commonly delivered earlier to prevent stillbirth; however, there is a risk of neonatal complications associated with being born prior to 39 weeks’ gestation. The optimal gestational age for delivery in twin pregnancies is unknown and likely varies by chorionicity. The present study aimed to determine the prospective risk of stillbirth in women with uncomplicated monochorionic and dichorionic twin pregnancies, and neonatal mortality risks, when delivered beyond 34 weeks of gestation. Data on twin pregnancies that reported rates of stillbirth were obtained from MEDLINE, EMBASE, and Cochrane Library. Separ…

Increased doses of vaginal progesterone for the prevention of preterm birth in twin pregnancies: a randomised controlled double-blind multicentre trial

Objective  Previous trials have shown little benefit for preventing preterm birth in twin pregnancies using 90–200 mg of daily vaginal natural progesterone. Higher doses have not been tested. Our aim was to determine the efficacy and safety of two different daily doses of vaginal natural progesterone (200 and 400 mg), compared with placebo, for preventing preterm birth in unselected twin pregnancies. Design  Randomised controlled double-blind multicentre trial (1:1:1). Setting  The study was carried out in five university centres from Valencia, Murcia and Alicante (Spain). Population  Women with dichorionic diamniotic twin pregnancies. Methods  The women self-inserted two vaginal pessaries …

Doubtful association between TAR syndrome and increased nuchal translucency in the first trimester of pregnancy

EP08.12: Cavum veli interpositi: two cases and clues to differentiate it from a true brain midline cystic lesion

Computerized analysis of normal fetal heart rate pattern throughout gestation.

Objective To analyze the evolution of computerized cardiotocography (cCTG) parameters throughout gestation in a large archive of traces from healthy fetuses. Methods This was a cross-sectional study of the first cCTG record from 4412 singleton fetuses with good pregnancy outcome. Normal ranges of cCTG parameters for 25 to 42 weeks were derived from analysis of only one cCTG record per fetus, and the relationship between the parameters and gestational age was investigated. Results Fetal heart rate (FHR) accelerations, short- and long-term variation overall, duration of episodes of high and low variation and variation in high episodes increased with advancing gestation. In contrast, maternal …

Examination of the fetal brain by transabdominal three-dimensional ultrasound: potential for routine neurosonographic studies

Objective To evaluate the role of transabdominal three-dimensional (3D) ultrasound in the assessment of the fetal brain and its potential for routine neurosonographic studies. Methods We studied prospectively 202 consecutive fetuses between 16 and 24 weeks' gestation. A 3D ultrasound volume of the fetal head was acquired transabdominally. The entire brain anatomy was later analyzed using the multiplanar images by a sonologist who was expert in neonatal cranial sonography. The quality of the conventional planes obtained (coronal, sagittal and axial, at different levels) and the ability of the 3D multiplanar neuroscan to visualize properly the major anatomical structures of the brain were eva…

Additive effect of factors related to assisted conception on the reduction of maternal serum pregnancy-associated plasma protein A concentrations and the increased false-positive rates in first-trimester Down syndrome screening.

Objective To analyze whether assisted conceptions need adjustments in first-trimester Down syndrome screening and why modifications in screening markers occur. Design Eleven-year cohort retrospective analysis. Setting Maternal-fetal medicine unit. Patient(s) Two thousand eleven naturally conceived normal singleton pregnancies and 2,042 normal singleton pregnancies achieved with assisted conception: 350 by IUI and 1,692 with IVF (n = 328) or intracytoplasmic sperm injection (ICSI; n=1,364), using nondonor (n = 1,086) or donated ova (n = 606), with fresh (n = 1,432) or frozen (n = 260) embryos. Intervention(s) Comparison of ultrasound and biochemical markers of first-trimester Down syndrome s…

P01.28: Analysis of nuchal translucency measurements in pregnancies achieved by assisted reproduction techniques

EP07.12: Calcar avis: a normal cerebral anatomic structure that can also mimic parenchymal pathology

Correlation between neonatal outcomes of twins depends on the outcome : Secondary analysis of twelve randomised controlled trials

ObjectiveTo estimate the magnitude of the correlation between neonatal outcomes of twins and demonstrate how this information can be used in the design of randomised controlled trials (RCTs) in women with twin pregnancies.DesignSecondary analysis of data from 12 RCTs.SettingObstetric care in multiple countries, 2004-2012.Population or sample4504 twin pairs born to women who participated in RCTs to assess treatments given during pregnancy.MethodsIntraclass correlation coefficients (ICCs) were estimated using log-binomial and linear models.Main outcome measuresPerinatal death, respiratory distress syndrome, bronchopulmonary dysplasia, intraventricular haemorrhage, necrotising enterocolitis, s…

OC2.01: Examination of the fetal brain by three-dimensional ultrasound: potential for routine neurosonographic studies

Objective: To evaluate the role of three-dimensional (3D) ultrasound in the assessment of the fetal brain and its potential for routine neurosonographic studies. Methods: We studied prospectively 202 consecutive brain fetuses between 16 and 24 weeks’ gestation. A 3D-ultrasound volume of the fetal head was acquired transabdominally. The entire brain anatomy was later analyzed by a sonologist expert in neonatal cranial sonography using the multiplanar images. The quality of the conventional planes obtained (coronal, sagittal and axial, at different levels) and the ability to visualize properly the major brain anatomic structures were evaluated. Results: Acceptable rendered cerebral volumes we…

Can antepartum computerized cardiotocography predict the evolution of intrapartum acid-base status in normal fetuses?

Background. To study the relationship between antepartum computerized cardiotocography (cCTG) and the evolution of intrapartum fetal acid-base balance in a low-risk population. Methods. Forty-nine healthy fetuses were prospectively followed up by antepartum cCTG (Oxford System 8002), fetal scalp blood sampling at the onset of the active phase of dilatation (3 cm) and at the beginning of the second stage of labor (10 cm) and study of acid-base status at birth in the umbilical cord. Correlation studies and linear regression analysis were performed. Results. Normal prelabor cCTG was followed by normal fetal acid-base balance in the different study periods. No relationship was found between cCT…

Is avoidance of surgery possible in patients with perimenopausal ovarian tumors using transvaginal ultrasound and duplex color Doppler sonography?

A total of 108 cases of small perimenopausal ovarian tumors (largest diameter, less than 7 cm) were evaluated by transvaginal sonography and duplex color Doppler sonography; 101 had criteria for benignity and 7 for malignancy. All cysts were punctured and aspirated to avoid unnecessary surgery (benign cases) and establish the cytologic diagnosis as well as to avoid the risk of leakage (malignant cases). Recurrence rate of benign punctured cysts was 25% within 1 year of follow up. No difference in recurrent rate was seen between pre- and postmenopausal patients (19 of 56 cases in the premenopausal group, and five of 28 cases in the postmenopausal group). The larger the cyst, the greater the …

The Maternal Cytokine and Chemokine Profile of Naturally Conceived Gestations Is Mainly Preserved duringIn VitroFertilization and Egg Donation Pregnancies

This prospective longitudinal study aimed at comparing maternal immune response among naturally conceived (NC;n=25),in vitrofertilization (IVF;n=25), and egg donation (ED;n=25) pregnancies. The main outcome measures were, firstly, to follow up plasma levels of interleukin (IL) 1beta, IL2, IL4, IL5, IL6, IL8, IL10, IL17, interferon gamma, tumor necrosis factor-alpha (TNFα), transforming growth factor-beta (TGFβ), regulated upon activation normal T-cell expressed and secreted (RANTES), stromal cell-derived factor 1 alpha (SDF1α), and decidual granulocyte-macrophage colony-stimulating factor (GM-CSF) during the three trimesters of pregnancy during the three trimesters of pregnancy; secondly, t…

First trimester biochemical screening for Down's syndrome in singleton pregnancies conceived by assisted reproduction

BACKGROUND: Serum biochemical markers [free betahCG (fbetahCG); pregnancy-associated plasma protein-A (PAPP-A)] used in first trimester Down's syndrome screening have not been fully investigated in pregnancies achieved by assisted reproduction techniques. We present data on pregnancies conceived by all types of assisted reproduction techniques, including pregnancies following ovum donation (OD) and a large sample by ICSI. METHODS: First trimester Down's syndrome screening was performed in 1054 normal singleton pregnancies: natural conception (n = 498), ovulation induction (OS, n = 97), IVF (n = 47), ICSI (n = 222) and OD (n = 190). RESULTS: No differences in maternal levels of fbetahCG and …

474: Cervical length and risk of preterm birth in European women with a twin pregnancy

P01.46: The incidence and characteristics of first-trimester fetal lateral neck cysts

Improved accuracy of hysteroembryoscopic biopsies for karyotyping early missed abortions

Abstract Objective To assess the potential of direct embryo and chorion biopsies obtained by hysteroembryoscopy for karyotyping early missed abortions. Design Clinical prospective descriptive study. Setting Instituto Valenciano de Infertilidad, Valencia, Spain. Patient(s) Sixty-eight women (71 gestational sacs) with missed abortions. The gestational age on ultrasound was 6.3 weeks (range, 4–10 weeks). Intervention(s) Transcervical hysteroembryoscopy before curettage. Main outcome measure(s) Comparison between the cytogenetic results from hysteroembryoscopic biospies and those of the curettage material. Result(s) Hysteroembryoscopic biopsies could be taken in 97.2% of the gestational sacs. D…

Immunohistochemical localization of filaggrin in benign, premalignant and malignant cervical tissue.

Epithelial distribution of filaggrin, a histidine-rich protein related to squamous terminal differentiation, was investigated in 87 cervical biopsies using an avidin-biotin-peroxidase technique with a monoclonal anti-human filaggrin antibody (AKH1). Normal squamous cervical epithelium exhibited a positive homogeneous immunoperoxidase stain in the upper parabasal, intermediate and superficial cell layers. Similar findings were obtained in cervical condylomas, although full-thickness staining was observed in 35.7% of the cases (P < 0.001). Filaggrin expression in CIN was inversely related to the severity of the lesion (P < 0.001). An irregular staining pattern was present in most high-grade C…

First-trimester diagnosis of thrombocytopenia-absent radius (TAR) syndrome in a triplet pregnancy

The role of thrombophilia and thyroid autoimmunity in unexplained infertility, implantation failure and recurrent spontaneous abortion.

The role of thrombophilia and thyroid autoimmunity in unexplained infertility (UI), implantation failure (IF) and recurrent spontaneous abortion (RSA) is controversial and poorly understood.From March, 2004 to January, 2007, 119 women were prospectively included: 32 oocyte donors, 31 patients with UI, 26 with IF and 30 with RSA. The IF and RSA groups presented normal preimplantation genetic screening. Protein C, protein S, antithrombin III, lupus anticoagulant, activated protein C resistance (APCR), immunoglobulin M and G anticardiolipin antibodies, homocystine, Factor V Leiden, prothrombin G20210A mutation, methylentetrahydrofolate reductase C677T mutation, thyroid-stimulating hormone (TSH…

New Insights into the Anterior Complex

&lt;b&gt;&lt;i&gt;Objective:&lt;/i&gt;&lt;/b&gt; To introduce visualization of the germinal matrix (GM), external angle of the frontal horn, and periventricular white matter while evaluating the anterior complex (AC) during basic ultrasound assessment of the fetal brain. &lt;b&gt;&lt;i&gt;Case Presentations:&lt;/i&gt;&lt;/b&gt; This is a retrospective observational study of healthy women with singleton pregnancies, with no increased risk of fetal central nervous system anomalies, attending routine ultrasound screening at 20–32 weeks’ gestation. Seventeen cases are presented in which an abnormal aspect of the GM or external angle of the frontal horn or periventricular white matter on AC eval…

Age and Uterine Receptiveness: Predicting the Outcome of Oocyte Donation Cycles

The impact of advancing age on uterine receptiveness has always been a concern of the medical establishment. Oocyte donation (OD) is the perfect model for ascertaining the extent of this relationship, but the literature is somewhat unreliable, mainly due to the limited samples on which the studies are based and insufficient control of important variables such as embryo quality.The present work was developed in a private infertility clinic.We retrospectively evaluate the results of 3089 OD cycles that ended up in a d 3 embryo transfer. Severe male factor infertility was an exclusion criterion.The impact of patients' age on pregnancy, implantation, and miscarriage rates and obstetric outcome …

P04.29: Is the finding of a central gall bladder an anatomic variant?

Gene polymorphisms and HLA-G expression in spontaneous abortions

Abstract Introduction HLA-G and HLA-E are claimed to play a role in establishing maternal–fetal immune tolerance and in maintaining pregnancy. The presence of polymorphism in the HLA-G gene could cause a deficient or excessive expression of the HLA-G and HLA-E molecules. These anomalies could eventually cause pregnancy losses. Materials and methods Clinical study. A total of 90 patients were included in this study. These patients suffered spontaneous abortions between weeks 6 and 11 of pregnancy. We have analysed the most important polymorphisms of the HLA-G gene through different genetic studies and HLA-G and HLA-E expression through immunostaining in human cytotrophoblast cells from first…

Potential pitfalls in fetal neurosonography

Objective To present anatomic variants of the fetal brain and artifacts related to scanning techniques that could be misinterpreted as abnormalities on prenatal neurosonographic studies. Methods The findings were derived from fetal neurosonographic studies performed routinely from 16 to 36 weeks' gestation during the last 3 years, supervised by a sonologist specialized in neonatal cranial sonography. Results The pitfalls were divided into three groups: brain parenchyma, ventricular system and choroid plexus. We provide images of these pseudolesions and clues to their differentiation from true brain pathology. Conclusions Knowledge of misleading images seen on fetal neurosonographic studies …

The influence of oxygen concentration during embryo culture on obstetric and neonatal outcomes: a secondary analysis of a randomized controlled trial.

Abstract STUDY QUESTION Does oxygen concentration during 3-day embryo culture affect obstetric and neonatal outcomes? SUMMARY ANSWER Oxygen concentration during 3-day embryo culture does not seem to affect the obstetric and neonatal outcomes measured. WHAT IS KNOWN ALREADY Atmospheric oxygen appears to be harmful during extended embryo culture. Embryo culture conditions might therefore be a potential risk factor for subsequent fetal development and the health of future children. No data are available concerning the obstetrics and neonatal outcomes after Day 3 transfer of embryos cultured under reduced and atmospheric oxygen tensions. STUDY DESIGN, SIZE, DURATION A secondary analysis of a pr…

An anatomical fetal brain structure and a normal variant mimicking anomalies on routine neurosonographic imaging: report of two cases

We present two cases in which an anatomical structure, the calcar avis, and a normal variant, a bifid choroid plexus, mimicked abnormalities on routine prenatal ultrasound examination. To the best of our knowledge these pitfalls have only been described in neonates. A familiarity with these false images is important to avoid erroneous diagnoses.

Sildenafil citrate improves perinatal outcome in fetuses from pre-eclamptic rats

Please cite this paper as: Herraiz S, Pellicer B., Serra V, Cauli O, Cortijo J, Felipo V, Pellicer A. Sildenafil citrate improves perinatal outcome in fetuses from pre-eclamptic rats. BJOG 2012;119:1394–1402. Objective  To evaluate perinatal outcome after sildenafil citrate (SC) administration at the onset of pregnancy in a rat pre-eclampsia model. Design  In vivo animal experimental study. Setting  Fundacion IVI-Instituto Universitario IVI, Valencia, Spain. Sample Control and pre-eclampsia-induced pregnant Wistar rats exposed to chronic SC administration. Methods  We evaluated the use of SC, which was tested as a potential therapeutic tool to maintain vasodilatation in complicated pregnanc…

Obesity and poor reproductive outcome: the potential role of the endometrium

Objective To analyze the potential role of extraovarian factors such as endometrium in the reproductive outcome of obese patients. Design Retrospective study. Setting University-affiliated infertility clinic, between January 2001 and July 2005. Patient(s) Women undergoing a total of 2656 first ovum donation (OD) cycles with good quality embryos. Intervention(s) The oocyte donors underwent controlled ovarian hyperstimulation, and recipients received a well-established hormonal replacement therapy for endometrial preparation. In vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) was performed according to semen characteristics. All first cycles (n = 2656) of ovum donation us…

The value of the short-term fetal heart rate variation for timing the delivery of growth-retarded fetuses.

OBJECTIVE: To assess the clinical value of the short-term fetal heart rate variation (STV) for timing the delivery of severely growth-retarded fetuses, many associated with pre-eclampsia. DESIGN: Retrospective cohort study. SETTING: John Radcliffe Maternity Hospital, Oxford, UK. POPULATION: Two hundred and fifty-seven fetuses with a birthweight less than third percentile and a last computerised cardiotocography performed within 24 h of delivery. METHODS: Analysis of the relationship between antepartum STV and the perinatal outcome. MAIN OUTCOME MEASURES: Stillbirth rate and the acid-base status at birth. RESULTS: There were no stillbirths or neonatal deaths (NNDs) within 24 h in the study p…

Doubtful association between progesterone therapy and fetal nuchal translucency

Radicales libres de oxígeno y su relación con enfermedades específicas del embarazo

Resumen De forma reciente se han publicado estudios que relacionan los radicales libres de oxigeno con enfermedades especificas del embarazo. En el parto pretermino, el oxido nitrico puede estar involucrado en la quiescencia fisiologica del utero y la colagenolisis asociada con el reblandecimiento tisular del cervix. Respecto a la rotura prematura de membranas, se conoce que la fuerza del amnios deriva del colageno; que su degradacion es controlada por las metaloproteinasas de la matriz, y que una alteracion del balance entre los pro y los antioxidantes aumenta la actividad de estas ultimas. En la preeclampsia, la placentacion defectuosa produce vasoconstriccion, con baja perfusion placenta…

Reactivity of isolated human chorionic vessels: analysis of some influencing variables

The aim of the study was to determine whether 24 h of cold storage of samples, mode of delivery, and gestational age influenced in vitro human chorionic vascular reactivity (35 arteries and 34 veins). The following groups were compared: (i) fresh versus 24-h cold-stored (4 °C in Krebs–Henseleit solution) chorionic vascular rings from normal term placentas, (ii) fresh chorionic vascular rings from normal term placentas obtained after vaginal delivery versus those obtained after elective caesarean section, and (iii) fresh chorionic vascular rings from normal term placentas versus those obtained from preterm deliveries. Isometric recording of the concentration–response curve to KCl (5–120 mM)…

First-trimester reversed end-diastolic flow in the umbilical artery is not always an ominous sign

We report five cases of first-trimester reversed end-diastolic flow in the umbilical artery. Diagnoses were performed between 8 and 12 gestational weeks. All but one case appeared as a transient early finding. Second-trimester fetal demise occurred in two cases. One case delivered at 32 weeks with severe growth restriction but recovered well. The other two cases had a good pregnancy outcome. Our experience suggests that this early Doppler finding is not always an ominous sign.

P09.25: 2D/3D ultrasound diagnosis of ectrodactyly at 14 weeks of gestation

Effectiveness of progestogens to improve perinatal outcome in twin pregnancies : an individual participant data meta-analysis

Background In twin pregnancies, the rates of adverse perinatal outcome and subsequent long-term morbidity are substantial, and mainly result from preterm birth (PTB). Objectives To assess the effectiveness of progestogen treatment in the prevention of neonatal morbidity or PTB in twin pregnancies using individual participant data meta-analysis (IPDMA). Search strategy We searched international scientific databases, trial registration websites, and references of identified articles. Selection criteria Randomised clinical trials (RCTs) of 17–hydroxyprogesterone caproate (17Pc) or vaginally administered natural progesterone, compared with placebo or no treatment. Data collection and analysis I…

Haemodynamic effects of long-term administration of sildenafil in normotensive pregnant and non-pregnant rats

Please cite this paper as: Pellicer B, Herraiz S, Cauli O, Rodrigo R, Asensi M, Cortijo J, Serra V, Morcillo E, Felipo V, Simon C, Pellicer A. Haemodynamic effects of long-term administration of sildenafil in normotensive pregnant and non-pregnant rats. BJOG 2011;118:615–623. Objective  To determine the effects of chronic administration of sildenafil citrateon healthy pregnant rats. Design In vivo animal experimental study. Setting  Fundacion IVI–Instituto Universitario IVI, Valencia, Spain. Sample  Pregnant and non-pregnant Wistarrats exposed to chronic administration of sildenafil. Methods  Placental cross-barrier and feto-maternal relationship levels, maternal blood pressure, and haemody…

Progestogens to prevent preterm birth in twin pregnancies:an individual participant data meta-analysis of randomized trials

Abstract Background Preterm birth is the principal factor contributing to adverse outcomes in multiple pregnancies. Randomized controlled trials of progestogens to prevent preterm birth in twin pregnancies have shown no clear benefits. However, individual studies have not had sufficient power to evaluate potential benefits in women at particular high risk of early delivery (for example, women with a previous preterm birth or short cervix) or to determine adverse effects for rare outcomes such as intrauterine death. Methods/design We propose an individual participant data meta-analysis of high quality randomized, double-blind, placebo-controlled trials of progestogen treatment in women with …

P03.04: The influence of mode of conception, fetal gender and twin pregnancy in the development of cerebral structures: a fetal brain 3D ultrasound study

Should Vanishing Twin Pregnancies Be Systematically Excluded From Cell-Free Fetal DNA Testing?

Objective To demonstrate the feasibility of cell-free DNA (cfDNA) testing in vanishing twin (VT) pregnancies in routine clinical practice. Methods Our study included 24 874 singleton and 206 VT consecutive pregnancies. Cell-free DNA was analyzed by massively parallel sequencing. Both aneuploidy analysis (chromosomes 13,18, 21, X, and Y) and fetal fraction estimation were performed according to an Illumina algorithm. Contaminant DNA contribution from the demised co-twin was studied in detail. Results VT pregnancies exhibited a higher prevalence of screen-positive cases (5.8% vs 2.5%), sex discrepancies (10.2% vs 0.05%), and false positive rates (FPR) (2.6% vs 0.3%) than singleton pregnancies…

Obstetric and perinatal outcome of babies born from vitrified oocytes.

Objective To assess outcomes after oocyte vitrification on obstetric and perinatal outcomes compared with those achieved with fresh oocytes. Design Retrospective cohort study. Setting Private university-affiliated IVF center. Patient(s) Children born after use of vitrified oocytes (1,027 from 804 pregnancies) and fresh oocytes (1,224 from 996 pregnancies). Singleton and multiples pregnancies from own and donated ova were included. Intervention(s) Oocyte vitrification by the Cryotop method. Main Outcome Measure(s) Pregnancy, delivery, and neonatal outcomes. Result(s) Vitrification had no clinically relevant adverse effects on obstetric and perinatal outcomes after adjusting for potential con…

The effect of gestational age and cervical length measurements in the prediction of spontaneous preterm birth in twin pregnancies : an individual patient level meta-analysis

OBJECTIVE: To assess the effect of gestational age (GA) and cervical length (CL) measurements at transvaginal ultrasound (TVUS) in the prediction of preterm birth in twin pregnancy. DESIGN: Individual patient data (IPD) meta-analysis. SETTING: International multicentre study. POPULATION: Asymptomatic twin pregnancy. METHODS: MEDLINE and EMBASE searches were performed and IPD obtained from authors of relevant studies. Multinomial logistic regression analysis determined probabilities for birth at ≤28(+0) , 28(+1) to 32(+0) , 32(+1) to 36(+0) , and ≥36(+1) weeks as a function of GA at screening and CL measurements. MAIN OUTCOME MEASURES: Predicted probabilities for preterm birth at ≤28(+0) , 2…

Vaginal progesterone decreases preterm birth and neonatal morbidity and mortality in women with a twin gestation and a short cervix: an updated meta‐analysis of individual patient data

Objective To assess the efficacy of vaginal progesterone for the prevention of preterm birth and neonatal morbidity and mortality in asymptomatic women with a twin gestation and a sonographic short cervix (cervical length ≤ 25 mm) in the mid-trimester. Methods This was an updated systematic review and meta-analysis of individual patient data (IPD) from randomized controlled trials comparing vaginal progesterone with placebo/no treatment in women with a twin gestation and a mid-trimester sonographic cervical length ≤ 25 mm. MEDLINE, EMBASE, POPLINE, CINAHL and LILACS (all from inception to 31 December 2016), the Cochrane Central Register of Controlled Trials, Research Registers of ongoing tr…