After 3 years in OBGYN residency program in Israel I decided to pursue a dream and joined the Angelo lab to conduct placental research. I am particularly interested in decidual immune cell populations in normal placentation and in obstetric complications, such as preeclampsia and preterm birth.

Honors & Awards

  • School of Medicine Dean’s Postdoctoral Fellowship, Stanford University (6/30/2018-7/1/2019)

Boards, Advisory Committees, Professional Organizations

  • member, SRI (2018 - Present)

Professional Education

  • Doctor of Medicine, Hebrew University Of Jerusalem (2014)

Lab Affiliations

All Publications

  • Evolution of Immune Sexual Dimorphism in Response to Placental Invasiveness: AResponse to Natri etal. Trends in genetics : TIG Greenbaum, S., Greenbaum, G. 2019

    View details for DOI 10.1016/j.tig.2019.10.009

    View details for PubMedID 31753530

  • Combining Multiplexed Ion Beam Imaging (MIBI) with Convolutional Neural Networks to accurately segment cells in human tissue Greenwald, N., Keren, L., Greenbaum, S., Fong, M., Chaudhry, G., Abraham, Z., Moseley, J., Van Valen, D., Angelo, M. BMC. 2019
  • Group B Streptococcus maternal colonization and respiratory infections in the offspring: lessons learned from an analysis of a population-based cohort with 18-year follow-up. Archives of gynecology and obstetrics Greenbaum, S., Sheiner, E., Wainstock, T., Segal, I., Sergienko, R., Walfisch, A. 2019


    Group B Streptococcus (GBS) early onset disease is a major cause for neonatal morbidity and mortality. We aimed to determine whether maternal GBS and the associated intrapartum antibiotic prophylaxis impacts pediatric long-term respiratory infectious morbidity.A population-based cohort study was conducted, during the years 1991-2013, comparing the incidence of hospitalizations due to common respiratory infections (RI) in offspring of mothers with and without GBS. Univariate analysis and a Cox proportional hazard model were used to estimate un-adjusted and adjusted hazard ratios for pediatric RI risk.During the study period, 173,757 term vaginal deliveries took place, of which 2.4% (4252) were diagnosed as GBS + gravidas. In univariate and multivariate analyses for the entire study period, RI risk was increased in exposed offspring. In a sensitivity analysis investigating study periods with different health policies, both GBS diagnosis rates and pediatric infectious respiratory morbidity rates increased over time, but with no independent association between the two.When analyzing large data sets spanning over long time periods, a special attention must be paid to account for healthcare trends, to avoid erroneous conclusions, as demonstrated here.

    View details for DOI 10.1007/s00404-019-05397-1

    View details for PubMedID 31784813

  • Ecological dynamics of the vaginal microbiome in relation to health and disease. American journal of obstetrics and gynecology Greenbaum, S., Greenbaum, G., Moran-Gilad, J., Weintruab, A. Y. 2018


    The bacterial composition of the vaginal microbiome is thought to be related to health and disease states of women. This microbiome is particularly dynamic, with compositional changes related to pregnancy, menstruation, and disease states such as bacterial vaginosis. In order to understand these dynamics and their impact on health and disease, ecological theories have been introduced to study the complex interactions between the many taxa in the vaginal bacterial ecosystem. The goal of this review is to introduce the ecological principles that are used in the study of the vaginal microbiome and its dynamics, and to review the application of ecology to vaginal microbial communities with respect to health and disease. While applications of vaginal microbiome analysis and modulation have not yet been introduced into the routine clinical setting, a deeper understanding of its dynamics has the potential to facilitate development of future practices, for example in the context of postmenopausal vaginal symptoms, stratifying risk for obstetric complications, and control of sexually transmitted infections.

    View details for PubMedID 30447213

  • Maternal total cell-free DNA in preeclampsia and fetal growth restriction: Evidence of differences in maternal response to abnormal implantation. PloS one Rafaeli-Yehudai, T., Imterat, M., Douvdevani, A., Tirosh, D., Benshalom-Tirosh, N., Mastrolia, S. A., Beer-Weisel, R., Klaitman, V., Riff, R., Greenbaum, S., Alioshin, A., Rodavsky Hanegbi, G., Loverro, G., Catalano, M. R., Erez, O. 2018; 13 (7): e0200360


    Preeclampsia and fetal growth restriction are obstetrical syndromes associated with abnormal placental implantation and changes in the activation status of maternal leukocytes. This study is aimed to determine by a simple, rapid fluorescent assay the changes in maternal serum total cell-free DNA (t-cfDNA) concentrations in women with preeclampsia and those with fetal growth restriction (FGR).A cross-sectional study was conducted measuring maternal serum t-cfDNA concentrations. Women were classified into the following groups: 1) patients with preeclampsia (n = 21); 2) FGR-estimated fetal weight below the 10thpercentile (n = 28); and 3) normal pregnancy (n = 39). Serum samples were directly assayed for t-cfDNA using a rapid fluorescent SYBR Gold assay. Elevated maternal serum t-cfDNA concentrations were defined as a cutoff>850ng/ml. Nonparametric statistics were used for analysis.Women with preeclampsia had a higher median maternal serum concentration (802 ng/ml, 400-2272 ng/ml) than women with a normal pregnancy (499 ng/ml, 0-1892 ng/ml, p = 0.004) and those with FGR (484 ng/ml, 72-2187 ng/ml, p = 0.012). Moreover, even patients with FGR <5th percentile and abnormal Doppler had a lower median maternal serum t-cfDNA than those with preeclampsia (median 487 ng/ml, 144-1971 ng/ml, p = 0.022). The median concentration of t-cfDNA did not differ between women with a normal pregnancy and those with FGR (p = 0.54), as well as those with fetuses <5th percentile and abnormal Doppler (p = 0.7). Women with preeclampsia had a higher proportion of elevated t-cfDNA than those with a normal pregnancy (p = 0.015) and patients with FGR (p = 0.025).Preeclampsia is associated with higher maternal serum t-cfDNA concentration than normal pregnancy or FGR. This observation may reflect an increased systemic activation of the maternal inflammation, rather than placental; this assumption is supported by the fact that we did not observe a significant change in the maternal serum t-cfDNA in patients with placental-mediated FGR.

    View details for DOI 10.1371/journal.pone.0200360

    View details for PubMedID 30001403

    View details for PubMedCentralID PMC6042756

  • Cesarean Delivery and Childhood Malignancies: A Single-Center, Population-Based Cohort Study. The Journal of pediatrics Greenbaum, S., Sheiner, E., Wainstock, T., Segal, I., Ben-Harush, M., Sergienko, R., Walfisch, A. 2018; 197: 292–96.e3


    Rising rates of cesarean deliveries worldwide prompt the evaluation of long-term morbidity to the offspring. In this retrospective cohort study, we evaluated whether cesarean delivery influences the development of childhood malignancies. We identified an association of cesarean delivery with acute lymphoblastic leukemia in children, suggesting prudence in the recommendation of cesarean delivery for nonmedically indicated cases.

    View details for DOI 10.1016/j.jpeds.2017.12.049

    View details for PubMedID 29398059

  • Underlying mechanisms of retained placenta: Evidence from a population based cohort study. European journal of obstetrics, gynecology, and reproductive biology Greenbaum, S., Wainstock, T., Dukler, D., Leron, E., Erez, O. 2017; 216: 12–17


    To determine risk factors for retained placenta, and to identify supporting epidemiologic evidence for the three previously-proposed mechanisms: (i) invasive placentation, (ii) placental hypo-perfusion, and (iii) inadequate uterine contractility.A retrospective population-based cohort study.Israeli population in the southern district.Data were analyzed from a tertiary hospital database, between 1989 and 2014, using univariate tests and generalized estimating equation (GEE) multivariable models.Prevalence of retained placenta.The study population included 205,522 vaginal deliveries of which 4.8% (n=9870) were complicated with retained placenta. Previous intra-uterine procedures and placenta-related pregnancy complications were found to be significant risk factors for retained placenta (history of cesarean section aOR=8.82, 95%CI 8.35-9.31; history of curettage aOR=12.80, 95%CI 10.57-15.50; pre-eclampsia aOR=1.25, 95%CI 1.14-1.38; delivery of a small for gestational age neonate aOR=1.08, 95%CI 1.01-1.16; stillbirth aOR=2.34, 95%CI 1.98-2.77). During labour, the risk for retained placenta was increased in presence of arrest of dilatation (aOR=2.03, 95%CI 1.08-3.82) or arrest of descent (aOR=1.55, 95%CI 1.22-1.96). Infections of the uterine cavity during labour were also found to be strongly associated with increased risk of retained placenta (endometritis aOR=2.21, 95%CI 1.64-2.97; chorioamnionitis aOR=3.35, 95% CI 2.78-4.04).Supporting epidemiologic evidence were found for all three underlying mechanisms. In addition, there is evidence to suggest that intrauterine infection and inflammation may also be a possible pathology associated with retained placenta.Risk factors for retained placenta support previously proposed mechanisms in a large cohort study.

    View details for DOI 10.1016/j.ejogrb.2017.06.035

    View details for PubMedID 28692888

  • Cerebral Palsy-Trends in Epidemiology and Recent Development in Prenatal Mechanisms of Disease, Treatment, and Prevention. Frontiers in pediatrics Stavsky, M., Mor, O., Mastrolia, S. A., Greenbaum, S., Than, N. G., Erez, O. 2017; 5: 21


    Cerebral palsy (CP) is the most common motor disability in childhood. This syndrome is the manifestation of intrauterine pathologies, intrapartum complications, and the postnatal sequel, especially among preterm neonates. A double hit model theory is proposed suggesting that an intrauterine condition along with intrapartum or postnatal insult lead to the development of CP. Recent reports demonstrated that treatment during the process of preterm birth such as magnesium sulfate and postnatal modalities such as cooling may prevent or reduce the prevalence of this syndrome. Moreover, animal models demonstrated that postnatal treatment with anti-inflammatory drugs coupled with nanoparticles may affect the course of the disease in pups with neuroinflammation. This review will describe the changes in the epidemiology of this disease, the underlying prenatal mechanisms, and possible treatments that may reduce the prevalence of CP and alter the course of the disease.

    View details for DOI 10.3389/fped.2017.00021

    View details for PubMedID 28243583

    View details for PubMedCentralID PMC5304407

  • Escalating placenta invasiveness: repeated placenta accreta at the limit of viability. International journal of women's health Greenbaum, S., Khashper, A., Leron, E., Ohana, E., Meirovitz, M., Hershkovitz, R., Erez, O. 2016; 8: 119–23


    Placenta percreta is an obstetric condition in which the placenta invades through the myometrium. This is the most severe form of placenta accreta and may result in spontaneous uterine rupture, a rare complication that threatens the life of both mother and fetus. In this case report, we describe a 32-year-old woman in her fourth pregnancy, diagnosed with repeated placenta accreta, which was eventually complicated by spontaneous uterine rupture at 24 weeks' gestation. This patient had a history of abnormal placentation in prior pregnancies and previous uterine injuries. This case demonstrates a pattern of escalating placental invasiveness, and raises questions regarding the process of abnormal placentation and the manifestation of uterine rupture in scarred uteri.

    View details for DOI 10.2147/IJWH.S100321

    View details for PubMedID 27143953

    View details for PubMedCentralID PMC4846064