Trimester Spontaneous Miscarriage Research Articles

Manual Vacuum Aspiration Versus Expectant Management for First Trimester Miscarriage: A Randomized Controlled Trial.

Background Miscarriage is one of the common problems encountered in pregnancy. The treatment modalities are expectant, medical, and surgical management. This study compared the effectiveness and safety of manual vacuum aspiration (MVA) with expectant management for first trimester miscarriage. Method This randomized controlled trial was conducted in Teaching Hospital Jaffna, Jaffna, Sri Lanka, and 134 eligible patients with first trimester spontaneous miscarriage were randomized to expectant management (67) and MVA (67). Those allocated to expectant management were managed expectantly for up to two weeks, and those allocated to MVA underwent aspiration under a paracervical block in the ward. The primary outcome was complete evacuation of the uterus, and the secondary outcomes were duration of bleeding, duration of pain, level of pain, need for the second procedure, cervical or uterine injuries, and patient satisfaction. Results Of the 134 eligible women, seven were lost to follow-up and 127 were analyzed. The MVA was superior in achieving complete evacuation compared to expectant management (95.2% vs. 70.3%; p ≤ 0.001). Notably, in both groups, complete evacuation was more readily achievable in incomplete miscarriage than in missed miscarriage. Duration of bleeding (mean days, 1.6 vs. 4.3; p ≤ 0.0001), duration of pain (mean days, 1.0 vs. 4.2; p ≤ 0.0001), and the need for additional surgical procedure in the form of dilatation and curettage (4.8% vs. 29.7%; p ≤ 0.001) were lower in MVA. Patient satisfaction was higher in the MVA group than in the expectant group (93.7% vs. 65.6%; p ≤ 0.001). No statistically significant differences were observed between the groups in terms of blood transfusion and infection. There wasn't any incidence of cervical damage or uterine perforation. Conclusion MVA is an effective and safe treatment method for first trimester miscarriage with higher patient satisfaction.

Maternal and neonatal outcomes following a second trimester dilation and curettage

To evaluate the maternal and neonatal outcomes of pregnancies after a second-trimester dilation and curettage (D&C) following a spontaneous miscarriage. A retrospective analysis of prospectively collected data of women who conceived ≤ 6 months following a spontaneous miscarriage and subsequently delivered in a single tertiary medical center between 2016 and 2021. The maternal and neonatal outcomes of women with second trimester (15-21 weeks) who eventualy underwent curettage were compared to those who had the first trimester (< 14 weeks) D&C. The primary outcome of this study was the rate of preterm birth (< 37 weeks). Secondary outcomes were adverse maternal and neonatal outcomes. Univariate analysis was followed by multiple logistic regression models; adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated. During the study period, 1365 women met the inclusion criteria; of those, 272 (19.9%) women gave birth following second trimester D&C and 1093 (80.1%) following first trimester D&C. Maternal demographic and obstetric characteristics including maternal age, gravidity, parity, number of previous miscarriages, previous cesarean deliveries and obesity rates were similar between the groups. We found no differences between the study groups in any maternal or neonatal parameter examined including preterm birth (5.1% vs. 5.3%, p=0.91), fertility treatments, hypertension disorders of pregnancy, placental complications, mode of delivery and neonatal birth weights (Table 1). This was confirmed on a multivariate analysis as well [aOR 1.02 (0.53–1.94), p = 0.96] for preterm birth (Table 2). History of a second trimester spontaneous miscarriage treated by curretage confers no additional risk than first trimester to pregnancies conceived within six months of the index miscarriage. Further propective studies to strengthen these findings are needed.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Maternal TSH levels at first trimester and subsequent spontaneous miscarriage: a nested case-control study.

Thyroid dysfunction is a frequently found endocrine disorder among reproductively aged women. Subclinical hypothyroidism is the most common condition of thyroid disorders during pregnancy and is defined as manifesting a thyroid-stimulating hormone concentration exceeding the trimester-specific reference value, with a normal free thyroxine concentration. Here, we evaluated the prospective association between spontaneous miscarriage and first-trimester thyroid function. We conducted a case–control study (421 cases and 1684 controls) that was nested. Thyroid-stimulating hormone (TSH), free thyroxine (FT4), thyroid-peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb) status were measured. We found that higher TSH was related to spontaneous miscarriage (OR 1.21; 95% CI, 1.13–1.30, P < 0.001). Compared with women with TSH levels of 0.4–<2.5 mIU/L, the risk of miscarriage was increased in women with TSH levels of 2.5–<4.87 mIU/L (OR 1.47; 95% CI, 1.16–1.87) and TSH greater than 4.87 mIU/L (OR 1.97; 95% CI, 1.22–3.18). After controlling for the confounding factor, TPOAb positivity status and FT4, the results were similar. The present study showed that higher TSH was associated with miscarriage in early pregnancy. In fact, TSH levels between 2.5 and 4.87 mIU/L increased the risk for miscarriage, with TSH greater than 4.87 mIU/L increasing the risk even further.

Loss of Placental P-Glycoprotein May Be a Common Pathophysiologic Pathway for First Trimester Spontaneous Miscarriages.

P-glycoprotein the highly conserved mammalian adenosine triphosphate-binding cassette transmembrane multidrug protein transporter is involved in peri-implantation events and fetal placental development. Greater expression in early versus late pregnancy and localization in both syncytio- and cytotrophoblast indicate that P-glycoprotein transports substances across the uterine epithelium during early pregnancy and protects the conceptus from toxic substances during implantation and early embryogenesis. We hypothesized that P-glycoprotein is involved in the physiologic maintenance of early pregnancy and that P-glycoprotein dysregulation may be involved in early pregnancy pathologies. First trimester dilation and curettage specimens were selected retrospectively from the archives of the Department of Pathology from spontaneous miscarriages (n = 36) and elective termination of pregnancy (n = 20). Two P-glycoprotein specific monoclonal antibodies JSB1and C219 were used on formalin-fixed, paraffin-embedded 5µ tissue sections. The location, intensity, and percentage of P-glycoprotein chorionic villous immunostaining were semiquantitated. Spontaneous miscarriages demonstrated absence or significant reduction in P-glycoprotein compared to elective terminations; 75% (27/36) showed total absence of P-glycoprotein, 19% (7/36) showed only rare villi with discontinuous immunostaining, and 6% (2/36) showed weak immunostaining. In contrast, 90% of elective terminations (18/20) showed positive immunostaining for P-glycoprotein and only 10% (2/20) showed loss of P-glycoprotein expression (P < .0001). We report a dramatic loss/decrease of P-glycoprotein in first trimester spontaneous miscarriages. This finding in conjunction with the known high expression of P-glycoprotein in normal first trimester placental tissues suggests an important role of P-glycoprotein in the maintenance of early pregnancy.

Optimal Sampling Source and Time for Wet Mount Detection ofTrichomonas vaginalis in Cervical Mucus During ART Cycle Evaluation

Objective Trichomonas vaginalis (TV) is a sexually transmitted parasitic disease with a global presence. Over a period of two years, 44 couples were assessed for cervical mucous (CM) quality/function as part of their infertility evaluation. Thirteen of 44 couples had TV present in periovulatory CM examination. In one case, TV was seen in fluid aspirated from the uterine cavity. The aim of the study was to evaluate the incidence of TV detection in asymptomatic cases during infertility workup. Design Retrospective study. All patients studied were Caucasian with the age range 29 to 39 years. Length of failure to conceive ranged from 1-9 years. Materials and Methods Cervical mucus specimens were aspirated from the external cervical os during the patients’ periovulatory period. Wet mounts were prepared for microscopic analysis. Uterine fluid specimens were collected if indicated during sonography. Results Trichomonas vaginalis trophozoites were always detected in association with white blood cells (WBC) clusters or WBC’s/epithelial cell clusters. In some cases, it would take several minutes to find trophozoites. Furthermore, trophozoites were similar in appearance as compared to WBC’s and could only be detected by the rhythmic movement of their flagella. Trichomonas vaginalis was identified in 14 of the women studied, 6 during IUI treatment, 4 as part of a post coital examination, 3 as part of a midcycle mucous examination and in 1 patient following aspiration of fluid in the fundus of the uterus. All couples testing positive were treated with 2 grams of metronidazole as a one dose treatment. This treatment rendered 13 of 14 couples TV free when CM was evaluated at ovulation in a subsequent cycle. The patient not responding to a single 2 gram dose received 500 mg of metronidazole twice daily for 7 days and subsequently tested negative for TV. Five of the 14 couples have conceived after the discovery of TV. Four patients conceived following metronidazole and one conceived in the ovulatory cycle when TV was detected. Two pregnancies have delivered healthy infants. One pregnancy is in the third trimester and one is in the first trimester. There was one first trimester spontaneous miscarriage of a tetraploid conceptus. Conclusions It is concluded that TV could be present with higher frequency in patients seeking reproductive treatment. It appears that antibiotic treatment enhances the chance for conception in couples so affected. Disclosures Nothing to disclose.

Spontaneous first trimester miscarriage rates per woman among parous women with 1 or more pregnancies of 24 weeks or more

BackgroundThe purpose of this study was to quantify spontaneous first trimester miscarriage rates per woman among parous women. A vast amount of data has accumulated regarding miscarriage rates per recognized pregnancy as well as about recurrent miscarriage. This is the second study of miscarriage rates per woman in a parous population and the first study of recurrent and non-recurrent, spontaneous first trimester miscarriage rates per woman in a large parous population.MethodsExtraction of the following variables from all delivery room admissions from both Hadassah Medical Centers in Jerusalem Israel, 2004–2014: # of first trimester spontaneous miscarriages, # live births; # living children; age on admission, pre-pregnancy height and weight, any smoking this pregnancy, any alcohol or drug abuse this pregnancy, blood type, history of ectopic pregnancy, history of cesarean surgery (CS) and use of any fertility treatment(s).ResultsAmong 53,479 different women admitted to labor and delivery ward, 43% of women reported having had 1 or more first trimester spontaneous miscarriages; 27% reported having had one, 10% two, 4% three, 1.3% four, 0.6% five and 0.05% reported having 6–16 spontaneous first trimester miscarriages. 18.5% had one or more first trimester miscarriages before their first live birth. Eighty-one percent of women with 11 or more living children experienced one or more first trimester miscarriages. First trimester miscarriage rates rose with increasing age, increasing parity, after previous ectopic pregnancy, after previous cesarean surgery, with any smoking during pregnancy and pre-pregnancy BMI ≥30.ConclusionsMiscarriages are common among parous women; 43% of parous women report having experienced one or more first trimester spontaneous miscarriages, rising to 81% among women with 11 or more living children. One in every 17 parous women have three or more miscarriages. Depending on her health, nutrition and lifestyle choices, even a 39 year old parous woman with a history of 3 or more miscarriages has a good chance of carrying a future pregnancy to term but she should act expediently.

Abdominal tuberculosis and spontaneous miscarriage

We present a case report of a 23-year-old Pakistani woman who had a second trimester spontaneous miscarriage while visiting her family in the Kingdom of Saudi Arabia. A dilatation and...

Relationship of Torch Profile in First Trimester Spontaneous Miscarriage

Background TORCH is a group of organisms like Toxoplasma, Rubella, Cytomegalo virus and Herpes simplex virus. These groups of organisms causing infections in pregnant lady leads to various degree of adverse pregnancy outcomes in the form of spontaneous abortion, preterm delivery, intrauterine growth restriction, severe congenital defect with syndromic babies. So, to observe the relationship of TORCH infection in first trimester spontaneous miscarriage in our population and to treat them, this study was performed.Materials and Methods A total of 103 patients with spontaneous abortion meeting inclusion criteria were taken in the study. TORCH profile was sent for those patients and observed the sero-prevalance for IgM and IgG. Thereafter organism was identified and the results were interpreted.Results Out of total 103 patients enrolled 58.25 % of patients were sero-positive for TORCH complex. IgM or IgG Sero-positive for Toxoplasma, Rubella, Cytomegalo virus and Herpes Simplex virus were 11.65% /17.47% ;7.76% / 43.68%; 19.41% / 41.74% and 31.06% / 54.36% respectively.Conclusion In the present study on analyzing the association of TORCH antibodies in women with spontaneous abortion, infection with Herpes simplex virus was most commonly associated.Journal of Nobel Medical College Vol.5(2) 2016; 17-21

The incidence of aneuploidy in differentiated blastocysts from patients with no prior first trimester spontaneous miscarriages or failed in vitro fertilization cycles

The incidence of aneuploidy in differentiated blastocysts from patients with no prior first trimester spontaneous miscarriages or failed in vitro fertilization cycles

Risk of first trimester spontaneous miscarriage among singleton gestations following ICSI and its relation to underlying cause of infertility

Study objective: To assess the association between the first trimester miscarriage rates among women undergoing intracytoplasmic sperm injection (ICSI) and underlying etiology of infertility. Design: Prospective cohort study. Setting: Ain Shams University maternity hospital. Materials and methods: The study included women who became pregnant with singleton preg- nancy following ICSI as a treatment for different causes of infertility. Women were followed up throughout the first trimester of pregnancy up to 12 weeks' gestation (10 weeks after the day of embryo transfer). Main outcome measure: First trimester miscarriage rate. Results: Two hundred and thirty four pregnant young women were included in the study, 164 (70.9%) women miscarried. The causes of infertility among these women were as follows: 41 (25%) mild male factor infertility, 40 (24.4%) severe male factor infertility, 45 (27.44%) tubal fac- tor, 7 (4.27%) polycystic ovarian syndrome, 3 (1.83%) endometriosis, 20 (12.19%) unexplained and

Paternal factors in spontaneous first trimester miscarriage

Objectives : To determine whether paternal factors i.e., age, tobacco use and genital tract infection increase the risk for spontaneous first trimester miscarriage. Methodology : This case control study was conducted in the Department of Obstetrics & Gynaecology, Unit V / IV, Dow Medical College & Lyari General Hospital, Dow University of Health Sciences, Karachi, Pakistan. Duration of study was two and half years, from Nov, 2007 to Apr, 2010. Inclusion criteria were pregnant women with age 20 - 35 years irrespective of parity. Exclusion criteria were known medical illness in either partner, induced abortion and recurrent miscarriages. Studied paternal factors were age, tobacco use and genital tract infection. Data was computed using SPSS version 16. Significance of paternal factors was determined by Logistic Regression Analysis. Results : Total cases studied were 200, while there were 400 controls. Mean maternal age was 27.6±4.9 years in cases and 26.5±4.5 years in controls. Mean paternal age was 35.5±6.2 years in cases and 32.3±5.4 years in controls. Paternal age was >35 years in 54.5% cases and 16.8% controls. Spearman Bivariate correlation revealed paternal age > 35 years (p=0.000) and genital tract infection (p=0.043) as significant factors. Only paternal age >35 years (p=0.000) remained significant in Final Model after entering into logistic regression. Paternal age beyond 35 years was found to be significantly related to first trimester spontaneous miscarriages.

Seroepidemiology of Toxoplasma Gondii Infection in Women with First Trimester Spontaneous Miscarriage in Qena Governorate, Egypt

To determine seroprevalence and risks factors for T. gondii in women with early miscarriage, Sera of 76 women were analyzed infection by indirect enzyme linked immunosorbent assay (ELISA). Seropositive cases were further examined histopathologically for evidence of Toxoplasma gondii organisms. Demographic data were obtained from participants to gather information on risk factors. Of 76 women with spontaneous abortion screened for Toxoplasma-specific IgG and IgM antibodies with ELISA, 35 were IgG seropositive, of which, 14 samples were IgM seropositive. Therefore, seropositivity rates of 46.1% (95% CI: 35.1%, 57.3%), and 18.4% (95% CI: 10.89%, 28.32%) for IgG and IgM, respectively were found. These indicate that, 27.6 % (21 cases) of studied women (IgG+/IgM-) were immune to toxoplasmosis and 53.94 %(41 cases) were susceptible to primary infection (IgG-/IgM-). Mean while acute toxoplasmosis (IgG+/IgM+) was 18.4 %( 14 cases) with one case (1.3%) confirmed for recent infection as she had Tachyzoites on histopathology study. On the basis of multivariate logistic regression, living in a rural area was found to be the only independent predictor of toxoplasmosis (OR=3.800, CI= 1.100-10.813, p=0.034). The seroprevalence of T. gondii infection in women with first trimester abortion in Qena governorate of Egypt is high. Pregnant women living in rural area are at a higher risk for acquiring infection during pregnancy. Antenatal screening of pregnant women and educational program about risks for Toxoplasmosis in rural areas is needed.

Evolución obstétrica de paciente afectada de síndrome de Ehlers-Danlos

Ehlers-Danlos syndrome (EDS) is a group of connective tissue disorders characterised by tissue fragility and joint hypermobility. Although it is rarely associated with pregnancy, some types may have severe maternal complications. We report our experience of a 35-year-old patient suffering from a classic EDS, who had a successful pregnancy at 38 weeks, and first trimester spontaneous miscarriage of a twin pregnancy.

Pregnancy and Uterine Anomalies

ABSTRACT Congenital uterine malformations are known to have a higher incidence of infertility, repeated first trimester spontaneous miscarriages, fetal intrauterine growth restriction, fetal malposition, preterm labor, retained placenta and increased cesarean section rate. The actual incidence of uterine malformation is unknown, since many women do not have any symptoms. They are estimated to occur in 0.4% (0.1-3%) of the general population and in 4% of infertile women, and in patients with repeated spontaneous miscarriages the figures fluctuate between 3 and 38%. The discrepancy among different publications stems from their use of different diagnostic techniques, heterogenous population samples and clinical diversity of Mullerian anomalies.

The role of embryopathology in the study of first trimester spontaneous miscarriage

The study of first trimester spontaneous miscarriage is the object of increasing attention not only for clinicians but also for patients and their family. Embryopathology concerns the study of pathologic conditions and malformations like early development failure, development alterations and true malformative lesions. It is well known that the most severe genetic abnormalities emerge as an interruption in embryogenesis and that the most complex developmental abnormalities caused by external factors - like infections, toxic and environmental agents - have their onset in the early stages of embryo formation and are often also the cause of pregnancy loss. In order to improve the monitoring of at risk couples we have expanded the study of basic research with those of research applied to human pathology. The role of embryopathology is fundamental to understand the timing at which the embryo development failure and its subsequent death actually occur and the main defect in embryo formation underlying development abnormalities. From 1994 to 2010 we examined 256 early spontaneous abortions in which an intact gestational sac was present. The introduction of acrylic resin embedding technique in 1995 added many advantages such as the possibility of obtaining semi-thin and uniformly thick sections with better histological and cytostructural details, assuring the almost total absence of coartation, and the preservation of antigenic properties. This technique therefore permits improvement in morphological obervation in order to reinterpret the classification of spontaneous aborted embryo. This enables a better definition of the real stage and time when development was interrupted. That is the basis to understand the role of external factor as a cause of pregnancy loss.

Basal follicle-stimulating hormone as a predictor of fetal aneuploidy

To determine whether an elevated basal FSH concentration is an independent predictor of fetal aneuploidy, as measured in spontaneous abortions (SAB). Retrospective study. Academic reproductive endocrinology and infertility center. All women with karyotypes of chorionic villi isolated from first trimester spontaneous miscarriages at the time of dilation and curettage from 1999 to 2006. The highest basal serum FSH level in the year preceding dilation and curettage was recorded. Monitoring of early pregnancy. Fetal karyotype. A total of 177 spontaneous miscarriages with karyotypes (70 euploid and 107 aneuploid) were identified, of which 53% were conceived by IVF. The aneuploid cohort consisted of trisomic (87%), teraploid (9.3%), and monosomic (3.7%) gestations. Using logistic regression analysis, basal FSH was not found to be independently predictive of an aneuploid gestation in our data set. Our data do not support the hypothesis that an elevated basal FSH concentration is associated with an increase in fetal aneuploidy. Our findings suggest that the association between diminished ovarian reserve and SAB may result from nonkaryotypic factors.

A randomised trial of surgical, medical and expectant management of first trimester spontaneous miscarriage

Medical management and expectant care have been considered possible alternatives to surgical evacuation of the uterus for first trimester spontaneous miscarriage in recent years. To compare the effectiveness and safety of medical and expectant management with surgical management for first trimester incomplete or inevitable miscarriage. Forty women were recruited following diagnosis of incomplete or inevitable miscarriage, and randomised to surgical, medical or expectant care via an off-site, computerised enrollment system. The primary outcome was the effectiveness of medical (vaginal misoprostol) and expectant management relative to surgical evacuation, assessed at 10-14 days and 8 weeks post-recruitment. Infection, pain, bleeding, anxiety, depression, physical and emotional recovery were assessed also. Analysis was by intention-to-treat. Effectiveness at 8 weeks was lower for medical (80.0%) and expectant (78.6%) than for surgical management (100.0%). Two women in the medical group had confirmed infections. Bleeding lasted longer in the expectant group than in the surgical group. There were no significant differences in pain, physical recovery, anxiety or depression between the groups. 54.6%, 42.9% and 57.1% of the surgical, medical and expectant groups respectively would opt for the same treatment again. Expectant care appears to be sufficiently safe and effective to be offered as an option for women. Medical management might carry a higher risk of infection than surgical or expectant care.

Retained products of gestation in miscarriage: An evaluation of transvaginal ultrasound criteria for diagnosing an “empty uterus”

The purpose of this study was to compare clinical outcomes of conservative management versus surgical evacuation of retained products of gestation after misoprostol treatment for first trimester spontaneous miscarriage using less restrictive transvaginal ultrasound criteria for diagnosing "empty uterus," which were managed conservatively. This was a prospective, randomized, controlled trial. Forty-six patients who had sonographic features previously regarded as significant retained products of gestation after misoprostol treatment, ie, homogenous intrauterine dimension of more than 11 cm 2 in combined transverse and sagittal plane, or those with heterogeneous intrauterine contents were consented to randomization. The short-term complication rates of those managed conservatively were significantly higher than surgical evacuation ([9/24] 37.5% vs [0/21] 0%, P < .05). Our previously reported transvaginal ultrasound criteria of homogenous intrauterine dimension of less than 11 cm 2 in combined transverse and sagittal planes for defining "empty uterus," which requires no further treatment, cannot be "relaxed" without incurring additional complications.

Child-bearing beyond age 50: pregnancy outcome in 59 cases "a concern?".

To study maternal and perinatal outcomes in healthy women aged 50 years and older. This study was of 59 clinical pregnancies, of which 10 ended in first trimester spontaneous miscarriage (and were excluded from further studies) and 58 live births. This retrospective review of 58 live births in 49 essentially healthy women (mean [SE] age, [52+/-2.5] years; range 50-55 years), with no chronic medical conditions (of which 28 were primigravids). Pregnancy outcomes were ascertained by chart review and telephone follow-up. Of the 58 live births, 41 were singletons, and 7 were twins, and 1 triplet, for which the mean+/-SE gestational age at delivery were 38.1 weeks +/-0.4, 36.2 weeks +/-0.1 and 34.1 weeks respectively. Birth weights (mean +/- SE) were 3,201 g+/-10, 2,252 g+/-4 and 1,998+/-95 g respectively. Mean Apgar score +/- SE at 1 and 5 min were 9.2+/-0.8 and 8.8+/-0.6 respectively. Total cesarean deliveries were 73% (36/49). Of singletons 68% (28) were delivered by cesarean section as were all multiples. The incidence of pre-eclampsia was 30.6%: mild pre-eclampsia 20.4% (10/49), severe pre-eclampsia 10.2% (5/49). Gestational diabetes required insulin in all 19.5% of women. Anemia was noted in 6.5%. Appropriately screened women, aged 50 years or older, can deliver successfully. During pregnancy, they appear to be at increased risk of pre-eclampsia and gestational diabetes. A significant majority can expect to deliver via cesarean.

Placental trophoblast from successful human pregnancies expresses the tolerance signaling molecule, CD200 (OX-2).

Th1 cytokine-dependent abortions in the CBA x DBA/2 mouse model have been linked to down-regulation of expression of the CD200 (OX-2) 'tolerance' signal on trophoblast and in decidua prior to onset of the abortion process. Abortions could be prevented by administration of a soluble CD200. Is CD200 expressed on trophoblast in successful human pregnancy? As one cannot easily obtain trophoblasts in large quantities from successful human pregnancies in the first trimester prior to the onset of the abortion process at 6 weeks gestation, we examined as a first step, trophoblast isolated from term placentae (i.e. successful pregnancies). CD9- trophoblasts were isolated by affinity column and stained for intracellular cytokeratin, and surface CD200 using PE-anti-human CD200 monoclonal antibody. mRNA was extracted from CD9+ and CD9- cells and tested by reverse transcription-polymerase chain reaction for CD200 mRNA. CD9- placental cells were separated by velocity sedimentation and test for CD200-dependent suppression of an allogeneic human mixed lymphocyte culture where cytotoxic T cell (CTL) generation, and Thl --> Th2 cytokine production shift were measured. CD9- but not CD9+ placental cell populations contained cells with mRNA for CD200, both a normal length transcript and a truncated transcript. Flow cytometry showed a CD200+ cytokeratin+ moderate-to-large-sized cell population compatible with trophoblasts and a smaller subset of cytokeratin- cells that expressed CD200 at normal and at high levels. The moderate-sized population proved most potent at inhibiting CTL generation and caused a Th1 --> Th2 cytokine shift. These effects were blocked by monoclonal anti-CD200. A subpopulation of cytokeratin+ placental trophoblasts express bioactive CD200 able to alter maternal immune responses in a favorable (Th2 > Th1) direction. Two populations of CD200+ small- and medium-small-sized cytokeratin- placental cells remain to be identified. Studies of karyotyped first trimester elective termination and spontaneous miscarriage tissues are needed.