Factors associated with preterm birth in women undergoing cervical cerclage.

OBJECTIVES: Cervical cerclage is used to manage women at high risk of late miscarriage (LM) and spontaneous preterm birth (PTB) due to factors such as history of cervical insufficiency (CI), uterine anomaly, cervical surgery and ultrasound (US) diagnosed cervical shortening. Urinary tract infection (UTI) and subsequent pyelonephritis, and bacterial infection are associated with PTB, but their role in PTB after cervical cerclage is unknown. We examined the relationship between UTI and bacterial vaginosis (BV), fetal fibronectin (fFN) test and PTB in women undergoing elective- or US-indicated cervical cerclage. We also investigated whether fetal fibronectin (fFN) test were useful to predict PTB. STUDY DESIGN: This is a single center, retrospective study of singleton pregnant women at PTB clinic, University College London Hospital (UCLH, 2005-2015) who underwent elective or US-indicated cervical cerclage. Women were tested for UTI and BV before cerclage placement and received mid-gestation fFN testing. Patient data were extracted from the PTB clinic database and electronic records. Statistical analyses used Pearson's chi-square and Mann-Whitney U tests. P values were corrected by Bonferroni method as required. RESULTS: 267 singleton pregnant women attended our clinic with completed birth outcome. Of those, 32.2% (86/267) delivered prematurely. All women with UTI or BV received antibiotic treatment. Women with a UTI before cerclage placement were more likely to deliver preterm when compared to those with negative MSU culture (OR 3.39, 95%CI 1.24-9.27, p = 0.04). Their gestational age at delivery were also lower than those with negative MSU result (36+6, IQR 31+4-38+2week vs 38+1, IQR 36+1-39+5-week, p = 0.05). However, UTI after cerclage placement or BV either before or after cerclage placement were not associated with PTB. Women who had a positive fFN result were more likely to deliver preterm (OR 3.85, 95% CI 1.81-8.41, p = 0.0007). CONCLUSIONS: The presence of a UTI before cervical cerclage is associated with a higher rate of PTB in women who receive a cervical cerclage, even when treated. We did not find an association between pre or post-cerclage BV or post-cerclage UTI and PTB. Further research is needed to elucidate the link between UTI and PTB in women undergoing cervical cerclage.

Relationship among maternal serum endocrinology, placental karyotype, and intervillous circulation in early pregnancy failure.

OBJECTIVE: To evaluate the relationship among maternal serum endocrinology, placental karyotype, and intervillous blood flow in missed miscarriage. DESIGN: Cross-sectional study of maternal serum, transvaginal ultrasound/Doppler, and placental cytogenetic and immunohistochemical investigations. SETTING: Tertiary care academic hospital. PATIENT(S): One hundred fifty-two women with missed miscarriage between 7 and 13 weeks of gestation. INTERVENTION(S): Ultrasound features, placental intervillous circulation findings on color Doppler imaging, and maternal serum level of alpha-fetoprotein (AFP), beta-hCG, E(2), P, and inhibin A were compared retrospectively with placenta karyotype and hCG immunochemistry. MAIN OUTCOME MEASURES: Data were analyzed according to karyotype results, presence or absence of an intervillous circulation, and delay between fetal demise and evacuation. RESULT(S): The presence of intervillous blood flow and serum concentrations of the different hormones were independent of placental karyotype. Serum beta-hCG and P were significantly higher in cases with intervillous blood flow. No difference in immunostaining for beta-hCG was found between placental tissues from normal pregnancies and missed miscarriages, but significantly higher villous beta-hCG content was found on Western blotting in miscarriage with a recent fetal demise. CONCLUSION(S): The excessive entry of maternal blood inside the placenta in the early stage of most miscarriages is unrelated to conceptus karyotype, and hCG features may reflect a temporary attempt of the trophoblast to stabilize after the initial oxidative insult.

Trophoblastic oxidative stress in relation to temporal and regional differences in maternal placental blood flow in normal and abnormal early pregnancies.

Onset of the maternal-placental circulation was studied by Doppler ultrasonography in 65 pairs of age-matched normal and abnormal pregnancies. In normal pregnancies intervillous blood flow increased with gestational age, being detected in 9 of 25 cases at 8 to 9 weeks but in 18 of 20 at 12 to 13 weeks (P = 0.001). By contrast, in abnormal pregnancies flow was detected in nearly all cases (22 of 25) at 8 to 9 weeks (P < 0.001). In addition, regional differences were observed between the groups. Early flow was restricted to the peripheral regions of most normal placentas (P < 0.001), whereas in missed miscarriages it was most common in central regions or throughout the placenta (P < 0.05 and P < 0.001, respectively). Immunoreactivity for heat shock protein 70 and nitrotyrosine residues was greater in samples from peripheral than from central regions of normal placentas (P = 0.028 and P = 0.019, respectively), and from missed miscarriages compared to controls (P = 0.005 and P = 0.001, respectively). Our results indicate that oxidative damage to the trophoblast, induced by premature and widespread onset of the maternal placental circulation secondary to shallow trophoblast invasion, is a key factor in early pregnancy loss. High oxygen concentrations in the periphery of normal early placentas may similarly induce local regression of the villi, leading to formation of the chorion laeve.

Collection of villous tissue under ultrasound guidance to improve the cytogenetic study of early pregnancy failure.

BACKGROUND: The cytogenetic study of spontaneous miscarriage has been limited by poor karyotype success rates obtained from cell culture after surgical evacuation of retained products of conception. The aim of this study was to assess the effect of improving the method of collection of villous tissues at the time of surgery on the karyotype success rate of cell culture. METHODS: Villous samples were obtained prospectively from a cohort of 170 spontaneous miscarriages at the beginning of the surgical procedure using small biopsy forceps guided into the placenta by ultrasound imaging. This was compared with a retrospective series of 1191 spontaneous miscarriages, cultured in the same laboratory, following conventional collection of the sample from the aspiration recipient after surgery. RESULTS: In the prospective series, six (3.5%) of the original samples were classified by the laboratory as 'decidua only' as compared with 162 (13.6%) in the retrospective series. The karyotype success rate was 94.5% in the prospective series compared with 83.7% in the retrospective series. The karyotype results revealed a chromosome abnormality rate of 65.8% in the prospective group and 64% in the retrospective group with a similar distribution in both groups. CONCLUSIONS: Our data show that a karyotype can be obtained from clean villous material collected at the time of surgical evacuation of miscarriage. Thus, it is not justified to subject women to transabdominal chorionic villus sampling to achieve a high karyotype success rate.