Mid-trimester Pregnancy Research Articles

Detection of Congenital Anomalies by Fetal Ultrasonographic Examination across Europe

Objectives: Birth defects are a major health burden. Primary prevention is at present emerging, i.e. folate supplementation. When it is not possible, as is still the case for most birth defects, research is needed to determine how an optimal provision of prenatal diagnosis and use of services can be achieved. Ultrasound scans in the midtrimester of pregnancy are now a routine part of antenatal care in most European countries. The objective of this study was to evaluate the prenatal diagnosis of congenital anomalies by fetal ultrasonographic examination across Europe. Methods: Data from 20 registries of congenital malformations in 12 European countries were included. The prenatal ultrasound screening programs in the countries ranged from no routine screening to 3 fetal scans offered, including 2 for biometric purposes and 1 for search of congenital anomalies, the anomaly scan. Results: There were 8,126 cases with congenital anomalies with an overall prenatal detection rate of 44.3%. Termination of pregnancy was performed in 1,657 cases (21.8%). There was significant variation in the prenatal detection rate between regions with the lowest detection rate in registries of countries without routine fetal screening (Denmark and The Netherlands) and the highest detection rate in registries of countries with at least 1 anomaly scan (France, Germany, Italy, Spain, UK). However, there were large variations among the registries with a high detection rate. There were significant differences in the prenatal detection rate and proportion of induced abortions between isolated anomalies and associated anomalies (chromosomal aberrations, recognized syndromes, and multiple without chromosomal aberrations or recognized syndromes). Conclusions: Prenatal detection rate of congenital anomalies by fetal scan varies significantly between registries of European countries even with the same screening policy. Prenatal detection of congenital anomalies is significantly higher when associated malformations are present. The rate of induced abortions varies between registries of countries even with the same detection rate of congenital anomalies. The variation described may be due to cultural and policy differences.

Detection of Gardnerella vaginalis in the vagina and amniotic fluid using the polymerase chain reaction

Gardnerella aginalis is generally considered a member of the endogenous vaginal flora. It has been isolated in 26]45% of healthy pregnant w x women 1,2 . However, the presence of G. aginalis in the vagina during the second trimester has been associated with an increased risk of preterm labor and preterm premature rupture of w x membranes 3 . G. aginalis is one of the most common microorganisms isolated from the amniotic fluid of patients in preterm labor with intact w x membranes or intra-amniotic infection 4 . Although amniotic fluid traditionally has been considered sterile in pregnant women who are not in labor with intact membranes, recent studies have shown that microbial invasion of the amniotic cavity has occurred in asymptomatic women during the mid-trimester of pregnancy. Microbiological culture with selective media is

Cardiovascular effects of intravaginal misoprostol in the mid trimester of pregnancy

Objective: Our aim was to evaluate the cardiovascular effects of high-dose intravaginal misoprostol administration by means of transthoracic electrical bioimpedance monitoring. Study Design: Healthy women undergoing mid trimester pregnancy interruption with intravaginal misoprostol were eligible for this prospective observational study. Baseline blood pressure was obtained for 1 hour and transthoracic electrical bioimpedance monitoring was performed before misoprostol administration, 600 μg vaginally. Posttreatment assessments were made every 15 minutes for a total of 4 hours, with patients in a left lateral recumbent position. Heart rate, mean arterial pressure, cardiac index, stroke index, systemic vascular resistance index, and end-diastolic volume index were determined. Measurements were averaged for 30-minute intervals and reported as mean ± SD. Statistical analyses included the paired t test and repeated-measures analysis of variance. Results: Nine women consented to have transthoracic electrical bioimpedance monitoring, and no statistically significant changes in any of the measured cardiac parameters for the 4-hour monitoring interval were noted. Direct comparisons between the pretreatment and 2-hour posttreatment intervals (reported time peak of blood misoprostol levels) also revealed no significant differences in the cardiovascular index values. Conclusion: High-dose intravaginal misoprostol in the mid trimester does not alter maternal cardiac function as measured by transthoracic electrical bioimpedance. (Am J Obstet Gynecol 2000;183:1100-2.)

Lactoferrin in intrauterine infection, human parturition, and rupture of fetal membranes

Objective: Lactoferrin is an iron-binding protein with antimicrobial properties. This study was undertaken to determine whether amniotic fluid concentrations of this protein change with gestational age, infection, labor, and rupture of membranes. Study Design: This cross-sectional study included women who underwent transabdominal amniocentesis (n = 268) in the following groups: (1) mid trimester of pregnancy; (2) preterm labor who delivered at term, preterm labor who delivered preterm with intra-amniotic infection, and preterm labor who delivered preterm without intra-amniotic infection; (3) preterm premature rupture of membranes in the presence or absence of intra-amniotic infection; (4) term with intact membranes not in labor, in labor, and in labor with intra-amniotic infection; and (5) premature rupture of membranes at term not in labor. In addition, lactoferrin concentrations were determined in maternal plasma and cord blood of patients at term not in labor. Lactoferrin concentration was measured with an immunoassay. Results: (1) Lactoferrin was detectable in 85.4% (229/268) of amniotic fluid samples, not detectable in all fluid obtained in the mid trimester, and detectable in all maternal and cord plasma samples. (2) The concentration of lactoferrin increased with advancing gestational age ( r = 0.68; P < .0001). (3) Intra-amniotic infection was associated with significant increases in amniotic fluid lactoferrin concentrations in patients with preterm labor (no intra-amniotic infection median, 1641.2 ng/mL; range, <1.24-35,090.0 ng/mL; vs intra-amniotic infection median, 3833.6 ng/mL; range, 746.0-47,020.0 ng/mL; P < .001), term labor (no intra-amniotic infection median, 2085.8 ng/mL; range, 425.0-23,230.0 ng/mL; vs intra-amniotic infection median, 5627.0 ng/mL; range, <1.24-19,220.0 ng/mL; P < .001), and preterm premature rupture of membranes (no intra-amniotic infection median, 2190 ng/mL; range, <1.24-7456.1 ng/mL; vs intra-amniotic infection median, 3449.3 ng/mL; range, <1.24-83,600.0; P < .01). (4) Spontaneous labor at term but not preterm was associated with a significant decrease in amniotic fluid lactoferrin concentration ( P < .05). (5) Spontaneous term parturition was associated with a significant increase in umbilical cord plasma lactoferrin concentration ( P < .005). Conclusion: (1) Intra-amniotic infection was consistently associated with dramatically increased concentrations of lactoferrin in amniotic fluid. (2) Term parturition was associated with a significant increase in lactoferrin concentration in the fetal compartment (umbilical cord blood) and a decrease in the amniotic compartment. We propose that lactoferrin is part of the repertoire of host defense mechanisms against intra-amniotic infection. (Am J Obstet Gynecol 2000;183:904-10.)

Evidence for the participation of interstitial collagenase (matrix metalloproteinase 1) in preterm premature rupture of membranes

Objective: Rupture of membranes is thought to result from the effects of physical forces in localized areas of the membranes weakened by the degradation of structural collagens. Matrix metalloproteinases are enzymes that degrade extracellular matrix components and have been implicated in membrane rupture. The objective of this study was to determine whether spontaneous rupture of membranes is associated with a change in the amniotic fluid concentration of interstitial collagenase (matrix metalloproteinase 1 [MMP-1]), a major collagenase. Study Design: A cross-sectional study was conducted to determine MMP-1 concentrations in amniotic fluid from 353 women in the following categories: (1) term with intact membranes not in labor and in labor, (2) preterm labor who delivered at term, (3) preterm labor who delivered preterm without microbial invasion of the amniotic cavity, (4) preterm labor who delivered preterm with microbial invasion of the amniotic cavity, (5) preterm premature rupture of membranes with and without microbial invasion of the amniotic cavity, (6) term premature rupture of membranes not in labor and in labor, and (7) mid trimester of pregnancy. Microbial invasion of the amniotic cavity was determined by an amniotic fluid culture positive for microorganisms. MMP-1 concentrations in amniotic fluid were determined by means of sensitive and specific immunoassays. Results: (1) MMP-1 was detectable in 81.3% of amniotic fluid samples (287/353), and its concentrations increased with advancing gestational age ( r = 0.4; P < .001). (2) Preterm premature rupture of membranes was associated with a significant increase in the median amniotic fluid concentration of MMP-1 ( P = .02). (3) Women with term premature rupture of membranes had a significantly lower amniotic fluid MMP-1 concentration than those with intact membranes at term not in labor ( P < .001). (4) Microbial invasion of the amniotic cavity in patients in preterm labor with intact membranes and in patients with preterm premature rupture of membranes was also associated with significant increases in the median amniotic fluid MMP-1 concentrations ( P < .05 and P < .01, respectively). (5) Patients with preterm premature rupture of membranes and microbial invasion of the amniotic cavity had a significantly higher median amniotic fluid MMP-1 concentration than those with intact membranes and microbial invasion of the amniotic cavity ( P = .01). (6) Neither term nor preterm parturition was associated with changes in amniotic fluid MMP-1 concentrations ( P = .6 and P = .3, respectively). Conclusion: (1) Collagenase 1 (MMP-1) is a physiologic constituent of amniotic fluid. (2) Preterm premature rupture of membranes (in both the presence and absence of infection) was associated with an increase in the amniotic fluid MMP-1 concentrations. (3) Neither term nor preterm parturition was associated with a significant increase in the amniotic fluid concentration of MMP-1. (Am J Obstet Gynecol 2000;183:914-20.)

A study of the relationship between placenta growth factor and gestational age, parturition, rupture of membranes, and intrauterine infection

Objective: Placenta growth factor is a potent angiogenic factor produced by the human placenta that has been implicated in the pathogenesis of preeclampsia and intrauterine growth restriction. Placenta growth factor belongs to the vascular endothelial growth factor family and is capable of inducing proliferation, migration, and activation of endothelial cells. The objective of this study was to determine the relationship between amniotic fluid concentration of placenta growth factor and gestational age, parturition (term and preterm), spontaneous rupture of the membranes, and intra-amniotic infection. Study Design: Amniotic fluid samples obtained from 273 pregnant patients were assayed in the following clinical groups: midtrimester pregnancy, preterm labor who delivered at term, preterm labor without microbial invasion of the amniotic cavity who delivered preterm, preterm labor with microbial invasion of the amniotic cavity, term not in labor, term in labor, term with microbial invasion of the amniotic cavity, preterm premature rupture of membranes with and without microbial invasion of the amniotic cavity, and term with premature rupture of membranes without microbial invasion of the amniotic cavity. The placenta growth factor concentrations were determined by an immunoassay that is both sensitive and specific. Results: Placenta growth factor was detectable in 96.3% (263/273) of samples. Amniotic fluid placenta growth factor concentration decreased with advancing gestational age (r = –0.42; P <.001). Amniotic fluid placenta growth factor concentrations were significantly higher in women in midtrimester pregnancy than in those at term not in labor (midtrimester pregnancy: median, 43.1 pg/mL; range, 22.9-69.8 pg/mL; vs term not in labor: median, 28.7 pg/mL; range, 16.1-82.7 pg/mL; P <.01). Neither term nor preterm parturition was associated with a change in amniotic fluid placenta growth factor concentrations. Term premature rupture of membranes was associated with a significant decrease in amniotic fluid placenta growth factor concentration (term premature rupture of membranes: median, 16.5 pg/mL; range <5.2-195.1 pg/mL; vs term intact membranes: median, 28.7 pg/mL; range, 16.1-822.7 pg/mL; P <.005). Preterm premature rupture of membranes was not associated with changes in amniotic fluid placenta growth factor concentrations. Intra-amniotic infection in preterm labor, term labor with intact membranes, and preterm premature rupture of membranes were not associated with changes in amniotic fluid placenta growth factor concentrations. Conclusion: Placenta growth factor is a physiologic constituent of amniotic fluid. Amniotic fluid concentrations of placenta growth factor decrease with advancing gestational age. Neither parturition nor infection affects amniotic fluid placenta growth factor concentrations. (Am J Obstet Gynecol 2000;182:1633-7.)

Evaluation of the prenatal diagnosis of limb reduction deficiencies. EUROSCAN Study Group.

Ultrasound scans in the mid-trimester of pregnancy are now a routine part of antenatal care in most European countries. Using data from registries of congenital anomalies a study was undertaken in Europe. The objective of the study was to evaluate prenatal detection of limb reduction deficiencies (LRD) by routine ultrasonographic examination of the fetus. All LRDs suspected prenatally and all LRDs (including chromosome anomalies) confirmed at birth were identified from 20 Congenital Malformation Registers from the following 12 European countries: Austria, Croatia, Denmark, France, Germany, Italy, Lithuania, Spain, Switzerland, The Netherlands, UK and Ukrainia. These registries are following the same methodology. During the study period (1996-98) there were 709,030 births, and 7,758 cases with congenital malformations including LRDs. If more than one LRD was present the case was coded as complex LRD; 250 cases of LRDs with 63 (25.2%) termination of pregnancies were identified including 138 cases with isolated LRD, 112 with associated malformations, 16 with chromosomal anomalies and 38 non chromosomal recognized syndromes. The prenatal detection rate of isolated LRD was 24.6% (34 out of 138 cases) compared with 49.1% for associated malformations (55 out of 112; p<0.01). The prenatal detection of isolated terminal transverse LRD was 22.7% (22 out of 97), 50% (3 out of 6) for proximal intercalary LRD, 8.3% (1 out of 12) for longitudinal LRD and 0 for split hand/foot; for multipli-malformed children with LRD those percentages were 46.1% (30 out of 65), 66.6% (6 out of 9), 57.1% (8 out of 14) and 0 (0 out of 2), respectively. The prenatal detection rate of LRDs varied in relation with the ultrasound screening policies from 20.0% to 64.0% in countries with at least one routine fetal scan.

Evaluation of prenatal diagnosis of cleft lip with or without cleft palate and cleft palate by ultrasound: experience from 20 European registries

Ultrasound scans in the mid-trimester of pregnancy are now a routine part of antenatal care in most European countries. Using data from registries of congenital anomalies a study was undertaken in Europe. The objective of the study was to evaluate prenatal detection of cleft lip with or without cleft palate (CL(P)) and cleft palate (CP). All CL(P) and CPs suspected prenatally and identified at birth in the period 1996-98 were registered from 20 Congenital Malformation Registers from the following European countries: Austria, Croatia, Denmark, France, Germany, Italy, Lithuania, Spain, Switzerland, The Netherlands, UK, Ukraine. These registries followed the same methodology. A total of 709,027 births were covered; 7758 cases with congenital malformations were registered. Included in the study were 751 cases reported with facial clefts: 553 CL(P) and 198 CP. The prenatal diagnosis by transabdominal ultrasound of CL(P) was made in 65/366 cases with an isolated malformation, in 32/62 cases with chromosomal anomaly, in 30/89 cases with multiple malformations and in 21/36 syndromic cases. The prenatal diagnosis of CP was made in 13/198 cases. One hundred pregnancies were terminated (13%); in 97 of these the cleft was associated with other malformations.

Evaluation of prenatal diagnosis of cleft lip/palate by foetal ultrasonographic examination

Ultrasound scans in the midtrimester of pregnancy are now a routine part of antenatal care in many countries. This type of screening procedure can detect serious foetal anomalies. Thanks to our registry of congenital anomalies a study was undertaken. The objective of the study was to evaluate prenatal detection of cleft lip (palate)(CL/P) by routine ultrasonographic examination of the foetus in 265 679 consecutive pregnancies from 1979 to 1998. The percentage of prenatal detection of CL/P was low. For isolated malformation (foetuses with only CL/P) the detection rate was low: 17.8 %; however, this detection rate increased from 5.3 % during the period 1979–1988 to 26.5 % during the period 1989–1998, for foetuses with associated malformations (foetuses with CL/P and one or more additional major malformations) these detection rates were 34.6, 13.3 and 50.0 %, respectively. In foetuses with associated malformations with CL/P this detection rate was higher for chromosomal abnormalities with CL/P and for non-syndromic, non-chromosomal multiply malformed children with CL/P than for non-chromosomal recognized syndromes with CL/P.

MID-TRIMESTER MTP USING ENDOCERVICAL PGE2 GEL AND SERIAL INTRAMUSCULAR CARBOPROST

60 cases of mid-trimester pregnancy were terminated using endocervical PGE2 gel (for achieving cervical priming) followed by serial intramuscular injections of carboprost. In this prospective study, 56 cases were multiparae with gestational age varying between 15-22 weeks. The induction-abortion-interval was 8.4h ± 0.8h with a success rate of 100%. The incidence of incomplete abortion was 5% and check curettage was performed in 16.6% cases. Gastrointestinal side effects were common. Vomiting occurred in 42% cases and diarrhoea in 50%. Febrile morbidity was seen in 8.3% cases. There were no complications of the procedure. The method was highly acceptable to the patients being non-invasive and allowing ambulation throughout. This method of elective mid-trimester abortion is an effective alternative to the other commonly used methods like extra-amniotic ethacridine lactate or intra-amniotic hypertonic saline instillation.

Second-trimester uterine evacuation: A comparison of intra-amniotic (15S)-15-methyl-prostaglandin F2α and intravaginal misoprostol

Objective: Our purpose was to compare the efficacy, safety, and adverse effects of intra-amniotically administered (15S)-15-methyl-prostaglandin F 2α and intravaginally administered misoprostol for second-trimester uterine evacuation. Study Design: Fifty-one patients were randomly assigned to receive either a single 2.5-mg intra-amniotic injection of (15S)-15-methyl-prostaglandin F 2 α (n = 26) or two 200-μg intravaginal doses of misoprostol (n = 25) at 12-hour intervals. The primary outcome measured was evacuation of the uterus within 24 hours. Results: The mean time from initiation of termination to uterine evacuation was less in the prostaglandin group than in the misoprostol group (17.5 ± 8.6 hours vs 22.3 ± 12.5 hours), but this was not statistically significant ( P > .05). The rate of successful fetal evacuation at 24 hours was significantly higher in the prostaglandin group than in the misoprostol group (88% vs 60%, P = .02). The complete-abortion rate and the incidence of adverse effects were similar in both groups. Conclusion: The use of an intra-amniotic injection of (15S)-15-methyl-prostaglandin F 2α for midtrimester pregnancy termination is safe and is associated with a greater number of successful uterine evacuations within 24 hours, without an increase in adverse effects, than intravaginal administration of misoprostol. (Am J Obstet Gynecol 1999;181:1057-61.)

R-188. C-reactive protein in midtrimester pregnancy and in the post-abortum period

R-188. C-reactive protein in midtrimester pregnancy and in the post-abortum period

Coagulation and fibrinolysis in viable mid-trimester pregnancies of normal, intrauterine growth retardation, chromosomal anomalies and hydrops fetalis and their eventual obstetric outcome.

A total of 71 pregnant women diagnosed by ultrasound to have viable fetus in late mid- trimester pregnancies of normal, IUGR, hydrops fetalis and chromosomal anomalies were studied for their coagulation, fibrinolytic and inhibitor levels with association on eventual obstetrics outcome. A hypercoagulable state was observed in all the pregnancies studied. However, higher hypercoagulation evidenced by significantly raised prothrombin formation and clot elasticity together with higher levels of D-dimer, uPA antigen and PAI-1 than observed in normal pregnancy suggests a hyperfibrinolytic/inhibitor state in hydrops fetalis pregnancy associated with bad obstetric outcome. In IUGR pregnancy associated with good outcome further enhanced clot elasticity was seen whilst no significant differences were observed in pregnancy with chromosomal anomalies when compared to uncomplicated normal pregnancy. Our study suggests that in hydrops fetalis pregnancy, further enhanced prothrombin formation and hyperfibrinolysis/inhibitor at late mid-trimester is associated with a poor obstetric outcome.

Extra-amniotic balloon with PGE 2 versus extra-ovular Foley catheter with PGF 2α in mid-trimester pregnancy termination

Objective: The objective of this study was to compare the efficacy and side effects of two methods of mid-trimester labor induction, extra-amniotic balloon with intracervical prostaglandin (PG) E 2 (0.5 mg×2) vs. extra-ovular Foley catheter with intrauterine PGF 2α (1 mg/h ×6). Methods: A cohort of 32 and 36 cases indicated for mid-trimester termination was enrolled and managed with extra-amniotic balloon and extra-ovular Foley catheter methods, respectively. Outcomes of induction-to-delivery interval, induction failure, and occurrence of side effects were assessed. Results: There were no statistical differences in maternal age, parity, gestational age or fetal birth weight between the two groups. Compared with the extra-ovular Foley catheter with PGF 2α group, the induction-to-delivery interval was significantly shorter in the extra-amniotic balloon plus PGE 2 group. There was no significant difference in side effects and major complications developed in either groups. Conclusions: The extra-amniotic balloon with intracervical PGE 2 is more efficient in reducing the induction-to-delivery interval for termination of mid-trimester pregnancies than the extra-ovular Foley catheter with intrauterine PGF 2α.

Fertility and pregnancy outcome after treatment for cervical intraepithelial neoplasia.

Fertility and pregnancy outcomes are important concerns of reproductive-age women undergoing treatment for cervical intraepithelial neoplasia (CIN). Despite this concern, very few controlled studies are examining this relationship. With the exception of large-cone biopsies, no evidence confirms that commonly used treatment modalities for CIN have a detrimental effect on fertility. Some CIN treatments are reported to be associated with preterm deliveries, low birth weight, and an increase in instrumental deliveries. Because smoking and low socioeconomic status are also associated with CIN, the value of any study not controlling for these factors is limited. Large-cone biopsies are associated with increased numbers of preterm deliveries and midtrimester pregnancy losses. The relationship of smaller-cone biopsies to preterm delivery is controversial. Cryotherapy does not affect pregnancy outcome, but the evidence is limited. Stronger evidence shows no difference in pregnancy outcome after laser surgery or electrosurgical loop excision. To be valuable, future studies should control for smoking and socioeconomic factors.

How accurate is fetal biometry in the assessment of fetal age?

OBJECTIVE: The purpose of the study was to assess the accuracy of fetal biometry in the midtrimester of pregnancy in the assignment of fetal age. STUDY DESIGN: A total of 152 singleton, 67 twin, and 19 triplet gestations resulting from in vitro fertilization with ultrasonographic fetal biometry from 14 to 22 weeks made up the study population. A gestational age prediction equation was derived from singletons with the use of stepwise linear regression. This equation was compared with 38 previously published equations and then applied to the twin and triplet populations. RESULTS: Head circumference was the best predictor of gestational age (random error [SD] 3.77 days). Addition of abdominal circumference and femur length to head circumference improved the accuracy of the dating equation (random error 3.35 days). Most dating formulas had systematic errors of <1 week. The systematic error was –0.32 day for averaging the singleton-based predictions for twins and –1.26 days for triplets. CONCLUSIONS: Gestational age assessment with the use of fetal biometry from 14 to 22 weeks is accurate for singleton, twin, and triplet gestations. (Am J Obstet Gynecol 1998;178:678-87.)

Preterm premature rupture of membranes and the associated risk for placental abruption. Inverse correlation to gestational length.

To evaluate the association between prolonged premature rupture of membranes (PROM) and placental abruption, especially during midtrimester pregnancy. A retrospective hospital based study of 83 women with PROM occurring between 14 and 32 weeks of gestation and where active expectant management was undertaken. Increased frequency of placental abruption was found in patients with early rupture of membranes. The incidence was 50% and 44% when rupture of the membranes occurred before 20 weeks or between 20-24 weeks of pregnancy, respectively. When PROM occurred during gestational ages of 29-32 weeks, the incidence was 13%. Patients with antepartum bleeding, both before (relative risk 34) and after rupture of the membranes (relative risk 38) had a significantly higher risk for placental abruption (p<.001) than women without bleeding prior to delivery. The overall neonatal survival rate was 87%. No neonatal deaths were considered to be directly caused by asphyxia due to placental abruption. Using active expectant management and strict routines it seems possible to minimize the risk for perinatal asphyxia and mortality. The clinician should be aware of the significant association between preterm premature rupture of membranes and the risk for subsequent placental abruption, especially in patients with early midtrimester PROM and history of bleedings before rupture of membranes or bleedings during the latency period.

Tissue inhibitor of metalloproteinase-1 and tissue inhibitor of metalloproteinase-2 expression in human amnion mesenchymal and epithelial cells

OBJECTIVE: This study was conducted to define the cellular site of expression of tissue inhibitor of metalloproteinase-1 and tissue inhibitor of metalloproteinase-2 in human amnion by an evaluation of the levels of messenger ribonucleic acids in separated amnion epithelial and mesenchymal cells and to ascertain whether amnion epithelial and mesenchymal cells maintained in culture continue to express tissue inhibitor of metalloproteinase messenger ribonucleic acids. STUDY DESIGN: Human placentas and fetal membranes were obtained immediately after delivery. Amnion tissue was separated from chorion laeve and either frozen immediately (–80° C) or processed by differential enzymatic treatment to separate the epithelial and mesenchymal cells, which were frozen (−80° C) or else plated and maintained in monolayer culture. The levels of tissue inhibitor of metalloproteinase types 1 and 2 messenger ribonucleic acid were evaluated by Northern analyses of total ribonucleic acid extracted from amnion tissue, freshly separated epithelial and mesenchymal cells, and epithelial and mesenchymal cells in monolayer culture. RESULTS: Tissue inhibitor of metalloproteinase types 1 and 2 messenger ribonucleic acids were detected by Northern analysis in freshly isolated amnion tissues from midtrimester and term pregnancies. The major species of tissue inhibitor of metalloproteinase-1 messenger ribonucleic acid was 0.9 kb in length; a minor species of approximately 3.5 kb also was present. Tissue inhibitor of metalloproteinase-2 messenger ribonucleic acids of 3.5 and 1.0 kb and of similar intensity were also detected. The levels of type 1 messenger ribonucleic acid were not different in amnion tissues obtained at term or during the midtrimester of pregnancy. The levels of tissue inhibitor of metalloproteinase type 2 messenger ribonucleic acids in amnion tissue most commonly were greater at term than in tissues obtained during the midtrimester. The level of type 1 messenger ribonucleic acid in mesenchymal cells was appreciably greater than that in epithelial cells, and this difference was maintained during culture of these cells. The level of type 2 messenger ribonucleic acid was similar in both cell types and was maintained during culture. The levels of type 1 or 2 messenger ribonucleic acids were not affected by treatment of amnion epithelial or mesenchymal cells in culture with a variety of test agents, including steroid hormones, cytokines, and growth factors. CONCLUSION: The amnion mesenchymal cells are the primary source of tissue inhibitor of metalloproteinase-1 in human amnion, whereas both cell types have the potential to produce tissue inhibitor of metalloproteinase-2. (Am J Obstet Gynecol 1997;176:915-21.)

Interobserver variability of midtrimester fetal nuchal thickness

Objective: To assess the interobserver variability of ultrasound measured fetal nuchal thickness (NT). Study design: NT was measured in 103 consecutive early midtrimester pregnancies (13–18 weeks) by three ultrasonographists with different levels of expertise, in our Prenatal Diagnosis Unit. Measurements were obtained prior to amniocentesis, blindly in relation to other examiners' values. The Lin's concordance correlation coefficient and the Kappa statistics were used to assess concordance between observed values. Results: Mean differences between pairs of observers ranged from 0.44 to 0.57 mm. A higher concordance correlation between measurements was obtained between the more experienced observers ( r = 0.77 versus r = 0.51). When assigning cases with a NT ≥ 5 mm to a group at risk for Down's syndrome, a high concordance between experienced ultrasonographists was observed (98% agreement; κ = 0.90). Conclusion: Interobserver variability in NT was acceptable between experienced ultrasonographists.

The role of Ureaplasma urealyticum in adverse pregnancy outcome.

We investigated Ureaplasma urealyticum genital tract colonization rates in an Australian population to determine whether colonization was associated with adverse pregnancy outcome. Women attending an antenatal clinic were evaluated for lower genital tract colonization at their first antenatal visit (162 women) and at 28 weeks' gestation (120 women). Placentas from 92 women were cultured. U. urealyticum was the predominant isolate from the lower (57.4%) and upper (17.4%) genital tract in this population of pregnant women. U. urealyticum was a persistent colonizer during mid-trimester of pregnancy (in 88% of women colonized) whereas M. hominis, G. vaginalis, and Group B streptococcus were present as transient flora of the lower genital tract. Lower genital tract colonization during pregnancy was not directly associated with adverse pregnancy outcome. However preterm delivery in afebrile, asymptomatic women, could possibly be associated with chorioamnionitis (4 of 16 preterm births). Screening of women with a history of preterm birth may prevent upper genital tract infections and preterm delivery.