1
|
Cipres DT, Cowherd RB, Barry OH, Chen L, Yee LM. Characteristics Associated with Trial of Labor among Patients with Twin Pregnancies. Am J Perinatol 2024; 41:1455-1462. [PMID: 38531392 DOI: 10.1055/a-2295-3329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
OBJECTIVE This study aimed to identify patient and provider factors associated with undergoing trial of labor (TOL) among eligible patients with twin gestations. STUDY DESIGN This retrospective cohort study of patients with twin gestations who received care at a large tertiary care center from 2000 to 2016 included individuals with live pregnancies greater than 23 weeks of gestation and cephalic-presenting twin. Patients with a prior uterine scar or contraindication to vaginal delivery were excluded from analyses. Maternal and clinical characteristics were compared among patients who did and did not undergo TOL. Multivariable logistic regression models included characteristics chosen a priori and those with bivariable associations with p < 0.1. Interactions between parity and other significant variables in the primary models were also investigated. RESULTS Among 1,888 eligible patients, 80.7% (N = 1,524) underwent TOL. Those undergoing TOL were more likely to be younger, multiparous, and have a maternal-fetal medicine physician as the delivering provider (p < 0.01). Hypertensive disorders of pregnancy were less prevalent among patients undergoing TOL (20.2 vs. 27.8%, p < 0.01). In multivariable analysis, advanced maternal age (adjusted odds ratio [aOR]: 0.55, 95% confidence interval [CI]: 0.40-0.74) and nulliparity (aOR: 0.36, 95% CI: 0.25-0.52) conferred a lower odds of TOL, while having a maternal-fetal medicine provider (aOR: 2.74, 95% CI: 1.55-4.83) was associated with higher odds. Interaction analyses demonstrated no significant interaction effects between parity and other characteristics. Among those undergoing a TOL, 76.0% (1,158/1,524) had a successful vaginal delivery of both twins, with 48.1% (557/1,158) having breech extraction of the second twin. CONCLUSION In this cohort of twin gestations with a high frequency of TOL, patient and provider characteristics are associated with attempting vaginal delivery. Variation in provider practices suggests differing skills and comfort with twin vaginal delivery may influence route of delivery decision-making in patients with twins. KEYPOINTS · Most patients with twin pregnancies undergoing TOL had successful vaginal deliveries.. · Having an MFM delivering provider was associated with higher odds of attempting twin TOL.. · Nulliparity and advanced maternal age were associated with lower odds of twin TOL..
Collapse
Affiliation(s)
- Danielle T Cipres
- Department of Obstetrics and Gynecology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Rachael B Cowherd
- Department of Obstetrics and Gynecology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
- Division of Gynecology, Department of Obstetrics and Gynecology, Medical University of South Carolina, Charleston, South Carolina
| | - Olivia H Barry
- Department of Obstetrics and Gynecology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Liqi Chen
- Department of Preventive Medicine (Biostatistics), Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Lynn M Yee
- Department of Obstetrics and Gynecology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| |
Collapse
|
2
|
Yoles I, Sheiner E, Wainstock T. Long term respiratory morbidity of cesarean-delivered second twin compared to their vaginally-delivered sibling: A retrospective population-based cohort study. Pediatr Pulmonol 2023; 58:3542-3548. [PMID: 37721028 DOI: 10.1002/ppul.26688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 08/09/2023] [Accepted: 09/03/2023] [Indexed: 09/19/2023]
Abstract
BACKGROUND Offspring born via cesarean delivery (CD) may be more prone to develope long-term respiratory diseases, compared to those delivered vaginally (VD). In this study, we compared the rates of respiratory diseases between first twins VD and second twins delivered via CD. METHODS This was a retrospective database study. All twin deliveries encompassed at the Soroka University Medical Center, a large tertiary hospital in southern Israel, between 1991 and 2020, in which the first twin was VD and the second via CD were included. Respiratory diseases included respiratory tract diseases such as bronchiolitis and bronchial asthma. The cumulative incidence of respiratory diseases was compared between the twins using Kaplan-Meier survival analysis and multivariable Cox models to adjust for confounding variables. RESULTS A total of 395,408 deliveries occurred during the study period, with 13,402 (3.4%) of all deliveries being twins. Of these, 184 (1.4%) were first twins VD and second twins delivered via CD. The second CD twin was more likely to have a non-reassuring fetal heart rate pattern and an Apgar score less than 7 at 5 min. No other differences were found between the siblings. The incidence of long-term respiratory diseases was not statistically different between the CD and VD siblings (7.6% vs. 9.4%, respectively; OR = 0.54; 95% CI: 0.23-1.26). Similarly, the cumulative incidence of respiratory diseases was not statistically different (Kaplan-Meier, log-rank, p = .59), and in the multivariable analysis which adjusted for birthweight and fetal distress during delivery (adjusted hazard ratio = 1.06; 95% CI: 0.43-26.25). CONCLUSIONS While the immediate outcomes for the CD twin were slightly worse compared to the VD twin, there was no difference in long-term respiratory diseases between the siblings.
Collapse
Affiliation(s)
- Israel Yoles
- Department of Obstetrics and Gynaecology, Soroka University Medical Centre, Beer-Sheva, Israel
- Clalit Health Services, The Central District, Rishon Le Tzion, Israel
| | - Eyal Sheiner
- Department of Obstetrics and Gynaecology, Soroka University Medical Centre, Beer-Sheva, Israel
| | - Tamar Wainstock
- Department of Public Health, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| |
Collapse
|
3
|
Mo GN, Cheng YW, Caughey AB, Yee LM. Disparities in Trial of Labor among Women with Twin Gestations in the United States. Am J Perinatol 2023; 40:214-221. [PMID: 33878771 DOI: 10.1055/s-0041-1727228] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
OBJECTIVE The aim of the study is to examine clinical and demographic factors associated with trial of labor (TOL) among women with twin gestations eligible for a vaginal delivery. STUDY DESIGN This was a population-based cohort study of women giving birth to twin gestations in the United States (2012-2014). Inclusion criteria for the analysis included live births greater than 23 weeks' gestation and a cephalic presenting twin. Women with prior cesarean delivery were excluded. Women were categorized by whether they underwent a TOL. Clinical and demographic characteristics associated with TOL status were evaluated using multivariable logistic regression analyses. Secondary analyses with stratification by parity and by second twin presentation were performed. RESULTS Of 90,000 women eligible for inclusion, a minority (39.3%) underwent TOL. Women who had a greater gestational age at delivery were more likely to have a TOL. In contrast, several demographic factors were associated with decreased likelihood of TOL, including maternal age >35 years and identifying as Hispanic or Asian compared with non-Hispanic White. No differences in odds of TOL were observed for women who were identified as non-Hispanic Black versus non-Hispanic White, nor were other demographic factors such as marital status, insurance status, or educational attainment associated with undergoing TOL. Clinical factors associated with decreased odds of TOL included nulliparity, obesity, and hypertensive disorders of pregnancy. Results did not substantively change when stratified by parity or second twin presentation, nor did findings differ in the subgroup who delivered at 32 weeks of gestation or greater. CONCLUSION In this large population of women with twins who were eligible for a TOL, a minority of individuals attempted a vaginal delivery. Demographic and clinical factors such as older maternal age, Asian or Hispanic racial or ethnic identification, nulliparity, and obesity are associated with decreased odds of undergoing TOL. KEY POINTS · Understanding disparities in trial of labor among patients with twins is key to promoting equity.. · Older maternal age and identifying as Hispanic or Asian were associated with lower odds of TOL.. · Nulliparity, obesity, and hypertension were associated with decreased odds of TOL..
Collapse
Affiliation(s)
- Gina N Mo
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Yvonne W Cheng
- Division of Maternal-Fetal Medicine, California Pacific Medical Center, San Francisco, California
| | - Aaron B Caughey
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Oregon Health & Science University, Portland, Oregon
| | - Lynn M Yee
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| |
Collapse
|
4
|
Twin birth: The maternal experience. SEXUAL & REPRODUCTIVE HEALTHCARE 2022; 33:100766. [PMID: 36027723 DOI: 10.1016/j.srhc.2022.100766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 08/01/2022] [Accepted: 08/15/2022] [Indexed: 11/21/2022]
Abstract
OBJECTIVE Twin birth is a special setting for women giving birth, and the experience of childbirth can be different from singleton birth. The objective of this study was to evaluate and compare the childbirth experiences of twin mothers and singleton mothers. We also aimed to identify the risk factors of a negative childbirth experience in the whole study population. METHODS All live diamniotic twin deliveries in the study hospital of at least 35+0 weeks of gestation with a plan of vaginal birth were included in this matched groups study from August 2015 to August 2019. For every twin birth, two singleton birth controls were selected and matched with parity, the actual mode of birth, and gestational weeks at birth. Six weeks after birth, a Childbirth Experience Questionnaire (CEQ) was sent to mothers, and 72 twin mothers and 126 singleton mothers returned the questionnaire. RESULTS The twin mothers' overall childbirth experience was positive. They reported a significantly lower opportunity to choose the birthing position (p < 0.001). Otherwise, there were no differences in the CEQ mean total scores between the study groups. Intrapartum cesarean section raised the risk of a negative childbirth experience and there was a high level of satisfaction with midwifery care among the whole study population. CONCLUSION The overall maternal experience in planned vaginal twin birth was positive. Twin mothers felt less often able to choose their birthing position, otherwise the childbirth experience did not differ from that of singleton mothers.
Collapse
|
5
|
Chen J, Shen H, Chen YT, Chen CH, Lee KH, Torng PL. Experience in different modes of delivery in twin pregnancy. PLoS One 2022; 17:e0265180. [PMID: 35275972 PMCID: PMC8916635 DOI: 10.1371/journal.pone.0265180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 02/24/2022] [Indexed: 11/18/2022] Open
Abstract
Background/purpose
Vaginal delivery, compared with Cesarean delivery, remains a less chosen mode of delivery for twin pregnancy. We studied the maternal and perinatal outcomes of twin pregnancy with different modes of delivery.
Methods
A retrospective study with data collected from a regional hospital, including vital twin pregnancies delivered at gestational age of 32 weeks and above. Medical charts were reviewed for prenatal conditions and postpartum outcomes.
Results
Ninety-eight pairs of twins were included and 44.9% were delivered via vaginal delivery. Women in the vaginal delivery group were significantly younger (32.5 ±4.3 years versus 34.8 ±4.6 years, p < 0.01), multiparous (34.1% versus 18.5%) and with more twins in vertex-vertex presentation (70.5% versus 33.3%) compared with women in the Cesarean delivery group. There were no differences between maternal postpartum complications and neonatal outcomes in both groups. The outcomes showed longer inter-twin delivery time interval (5.7 ± 5.6 versus 1.5 ± 0.9 min, p < 0.01), less estimated blood loss (198.7 ± 144.1 versus 763.2 ± 332.3 mL, p < 0.01), and shorter maternal hospital stay (3.0 ± 0.5 versus 5.7 ± 0.5 days, p< 0.01) in the vaginal delivery group. Twenty newborns had Apgar score below seven at birth. Logistic regression analysis revealed that low Apgar score was independently related to younger maternal age, maternal obstetric diseases and fetal non-vertex presentation. Gestational weeks and mode of delivery were not related to low Apgar score.
Conclusion
With careful case selection, vaginal delivery could be safely performed in twin pregnancies with less estimated blood loss and better recovery than Cesarean delivery.
Collapse
Affiliation(s)
- Jung Chen
- Department of Obstetrics and Gynecology, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Hung Shen
- Department of Obstetrics and Gynecology, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Yi Teng Chen
- Department of Obstetrics and Gynecology, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chin-Ho Chen
- Department of Obstetrics and Gynecology, Hsin-Chu Br, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Kuang-Han Lee
- Department of Obstetrics and Gynecology, Hsin-Chu Br, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Pao-Ling Torng
- Department of Obstetrics and Gynecology, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
- Department of Obstetrics and Gynecology, Hsin-Chu Br, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
- * E-mail:
| |
Collapse
|
6
|
Retrospective evaluation of attempted vaginal deliveries in dichorionic twin pregnancies. Arch Gynecol Obstet 2020; 303:1461-1468. [PMID: 33222039 PMCID: PMC8087563 DOI: 10.1007/s00404-020-05882-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 11/04/2020] [Indexed: 11/08/2022]
Abstract
Purpose Numbers of planned cesarean deliveries are increasing in twin pregnancies, despite the lack of evidence for this approach, and the second twin is thought to be at risk for a poorer outcome. The aim of this study was to examine whether twins have a poorer outcome if an attempted vaginal delivery is changed to a cesarean section or combined delivery. Methods This retrospective data analysis included all women with dichorionic twin pregnancies attempting vaginal delivery over a 10-year period. Outcome parameters for the first and second twins relative to their mode of birth were compared. A correlation model between the interdelivery time interval and Apgar scores was calculated. Subgroup analyses assessing the birth mode of the first and second twins were conducted. Results A total of 248 women were enrolled in the study. The second twins had significantly lower values for outcome parameters, such as umbilical artery cord pH and Apgar scores in comparison with the first twins (P < 0.01). The subgroup analysis of birth modes in first and second twins showed a significantly poorer outcome in the cesarean section and combined delivery group (P < 0.05). The interdelivery time interval was significantly longer in the second twin cesarean section group (P < 0.01). There was no significant correlation between the interdelivery time intervals and Apgar scores (P > 0.05). Conclusion Although outcome parameters were significantly lower in second twins and twins born via secondary cesarean section, the clinical relevance of this appears to be negligible.
Collapse
|
7
|
Dathan-Stumpf A, Winkel K, Stepan H. Delivery of Twin Gestation (≥ 32.0 Weeks): The Vaginal Route as a Practicable and Safe Alternative to Cesarean Section. Geburtshilfe Frauenheilkd 2020; 80:1033-1040. [PMID: 33012835 PMCID: PMC7518932 DOI: 10.1055/a-1181-8737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 05/19/2020] [Indexed: 01/20/2023] Open
Abstract
Objective
The appropriate delivery mode for twins is discussed controversially in the literature. The aim of this study was to investigate delivery modes and short-term neonatal outcomes of twin pregnancies delivered in University Hospital Leipzig.
Material and Methods
A total of 274 twin pregnancies (32.0 to 39.4 weeks of gestation) delivered between 2015 and 2017 were analyzed retrospectively with regard to the planned and final delivery mode as well as neonatal outcomes. The inclusion and exclusion criteria for vaginal delivery were comparable to those of the Twin Birth Study.
Results
The spontaneous birth rate for births planned as vaginal deliveries was 78.5%; the rate of secondary cesarean section was 19.4%. The final total cesarean rate was 58.8%, and the rate of vaginal deliveries was 41.2%. Vertex or non-vertex position of the second twin had no significant effect on neonatal outcome or mean delivery interval between the birth of the first and second twin. Chorionicity, neonatal weight and gender had no significant impact on delivery mode. However, successful vaginal delivery was associated with higher gestational age and both fetuses in vertex position. The combined neonatal outcome for both twins was significantly worse if they were delivered by cesarean section compared to spontaneous birth. In addition, the leading twin in monochorionic/diamniotic (MC/DA) pregnancies was intubated more frequently after cesarean delivery and had significantly lower Apgar scores.
Conclusion
Vaginal delivery in twin pregnancies is a practicable and safe option in specific defined conditions and when the appropriate infrastructure and clinical experience is available.
Collapse
Affiliation(s)
| | | | - Holger Stepan
- University Hospital Leipzig, Department of Obstetrics, Leipzig, Germany
| |
Collapse
|
8
|
Orbach-Zinger S, Razinsky E, Bizman I, Firman S, Gat R, Davis A, Ashwal E, Shmueli A, Vaturi M, Gabbay-Benziv R, Eidelman LA. Perioperative noninvasive cardiac output monitoring in parturients with singleton and twin pregnancies undergoing cesarean section under spinal anesthesia with prophylactic phenylephrine drip: a prospective observational cohort study. J Matern Fetal Neonatal Med 2018; 32:3980-3985. [DOI: 10.1080/14767058.2018.1480604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Affiliation(s)
- S. Orbach-Zinger
- Department of Anesthesia, Rabin Medical Center, Beilinson Hospital, Petah Tikva, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - E. Razinsky
- Department of Anesthesia, Rabin Medical Center, Beilinson Hospital, Petah Tikva, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - I. Bizman
- Department of Anesthesia, Rabin Medical Center, Beilinson Hospital, Petah Tikva, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - S. Firman
- Department of Anesthesia, Rabin Medical Center, Beilinson Hospital, Petah Tikva, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - R. Gat
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Helen Schneider Hospital for Women, Obstetrics and Gynecology, Rabin Medical Center, Petah Tikva, Israel
| | - A. Davis
- Department of Anesthesia, Rabin Medical Center, Beilinson Hospital, Petah Tikva, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - E. Ashwal
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Helen Schneider Hospital for Women, Obstetrics and Gynecology, Rabin Medical Center, Petah Tikva, Israel
| | - A. Shmueli
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Helen Schneider Hospital for Women, Obstetrics and Gynecology, Rabin Medical Center, Petah Tikva, Israel
| | - M. Vaturi
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Cardiology, Rabin Medical Center, Beilinson Hospital, Petah Tikva, Israel
| | - R. Gabbay-Benziv
- Obstetrics and Gynecology, Hillel Yaffe Medical Center, Hadera, Israel
| | - L. A. Eidelman
- Department of Anesthesia, Rabin Medical Center, Beilinson Hospital, Petah Tikva, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
9
|
Ylilehto E, Palomäki O, Huhtala H, Uotila J. Term twin birth - impact of mode of delivery on outcome. Acta Obstet Gynecol Scand 2017; 96:589-596. [PMID: 28240343 DOI: 10.1111/aogs.13122] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 02/16/2017] [Indexed: 11/30/2022]
Abstract
INTRODUCTION The main aims of this study were to compare maternal and neonatal outcomes in term twin birth according to the planned mode of delivery and to study the effects of chorionicity and inter-twin delivery time on neonatal outcome. MATERIAL AND METHODS A single-center cohort study of 495 women with twin deliveries at ≥37+0 weeks of gestation. Term twin deliveries were divided into a trial of labor group (TOL, 69.3%) and a planned cesarean section (CS) group (30.7%). The primary outcomes were maternal and neonatal morbidity. RESULTS 80.8% of women attempting TOL achieved vaginal birth. In the TOL group, mothers had less bleeding [median 500 mL (range 150-2700 mL) vs. 950 mL (range 150-3500 mL), p < 0.001) and fewer surgical complications (3.2% vs. 8.6%, p = 0.011), whereas second twins more often had five-minute Apgar scores of <7 (5.0% vs. 0%, p = 0.002) or umbilical artery pH < 7.05 (5.7% vs. 0%, p = 0.003), compared with the planned CS group. There was a slight, non-significant tendency for more NICU admissions in the TOL group, yet the need for NICU treatment was infrequent in the whole study material. Outcomes among dichorionic (DC) second twins were similar to those in the whole material, but among monochorionic (MC) second twins there were no differences between the TOL and planned CS groups. In secondary analysis, a five-minute Apgar score <7 occurred significantly more often in the DC group among second twins if the inter-twin delivery time exceeded 30 min. CONCLUSIONS TOL is a good option for women with twin pregnancy at term, regardless of chorionicity. Active management of labor for the second twin is important, also in DC births. Maternal outcomes were more favorable with TOL and although low Apgar scores and low umbilical blood pH may be more frequent after TOL - especially with the second twin - serious neonatal morbidity is rare and does not differ from that after planned CS.
Collapse
Affiliation(s)
- Elina Ylilehto
- School of Medicine, University of Tampere, Tampere, Finland.,Department of Obstetrics and Gynecology, Tampere University Hospital, Tampere, Finland
| | - Outi Palomäki
- Department of Obstetrics and Gynecology, Tampere University Hospital, Tampere, Finland
| | - Heini Huhtala
- School of Health Sciences, University of Tampere, Tampere, Finland
| | - Jukka Uotila
- School of Medicine, University of Tampere, Tampere, Finland.,Department of Obstetrics and Gynecology, Tampere University Hospital, Tampere, Finland
| |
Collapse
|
10
|
Maruotti G, Saccone G, Morlando M, Martinelli P. First-trimester ultrasound determination of chorionicity in twin gestations using the lambda sign: a systematic review and meta-analysis. Eur J Obstet Gynecol Reprod Biol 2016; 202:66-70. [DOI: 10.1016/j.ejogrb.2016.04.023] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 04/21/2016] [Indexed: 11/16/2022]
|