A five century evolution of cervical incompetence as a clinical entity.

Since cervical incompetence was introduced in the English literature in 1678, our understanding and obstetric management of this clinical entity, have changed tremendously over the years. This review shows the historical perspective of the development of cervical incompetence as a distinct clinical entity and an all or nothing phenomenon to cervical incompetence as part of a spectrum leading to preterm delivery, which can express differently in subsequent pregnancies. These changes in our understanding imply consequences for the obstetric management of cervical incompetence. This review focuses on the obstetric management of women considered to be at high risk of preterm delivery due to cervical incompetence, by transvaginal ultrasonographic follow-up of cervical length and transvaginal cervical cerclage.

Evidence-based care of recurrent miscarriage.

Between 0.5 and 1.0% of couples experience recurrent pregnancy loss (RPL), which is defined as three or more consecutive miscarriages. Losses are classified as pre-embryonic (<5 weeks), embryonic (5-10 weeks) or fetal (>10 weeks). Genetic abnormalities are responsible for RPL in 2-4% of these couples. Inadequate progesterone production has been proposed a cause of RPL and progesterone is given to prevent miscarriage, despite a lack of supportive evidence. The factor V Leiden and prothrombin G20210A mutations are common inherited thrombophilias also associated with RPL. Antenatal thromboprophylaxis is sometimes recommended although no data exist regarding efficacy. Antiphospholipid syndrome is known to cause RPL and antenatal thromboprophylaxis reduces the risk of miscarriage. Uterine abnormalities might also result in RPL. About 50% of cases of RPL have no identifiable cause. Alloimmune incompatibility has been proposed as a cause for RPL in these women. The concept of alloimmune-related RPL has not been scientifically validated.

Pregnancy outcome following recurrent spontaneous abortions.

OBJECTIVE: The purpose of the present study was to examine the association between spontaneous consecutive recurrent abortions and pregnancy complications such as hypertensive disorders, abruptio placenta, intrauterine growth restriction and cesarean section (CS) in the subsequent pregnancy. METHODS: A population-based study comparing all singleton pregnancies in women with and without two or more consecutive recurrent abortions was conducted. Deliveries occurred during the years 1988-2002. Stratified analysis, using a multiple logistic regression model was performed to control for confounders. RESULTS: During the study period 154,294 singleton deliveries occurred, with 4.9% in patients with history of recurrent consecutive abortions. Using a multivariate analysis, with backward elimination, the following complications were significantly associated with recurrent abortions-advanced maternal age, cervical incompetence, previous CS, diabetes mellitus, hypertensive disorders, placenta previa and abruptio placenta, mal-presentations and PROM. A higher rate of CS was found among patients with previous spontaneous consecutive recurrent abortions (15.9% versus 10.9%; OR = 1.6; 95% CI, 1.5-1.7; P < 0.001). Another multivariate analysis was performed, with CS as the outcome variable, controlling for confounders such as placenta previa, abruptio placenta, diabetes mellitus, hypertensive disorders, previous CS, mal-presentations, fertility treatments and PROM. A history of recurrent abortion was found as an independent risk factor for CS (OR = 1.2; 95% CI, 1.1-1.3; P < 0.001). About 58 cases of inherited thrombophilia were found between the years 2000-2002. These cases were significantly more common in the recurrent abortion as compared to the comparison group (1.2% versus 0.1%; OR = 11.1; 95% CI, 6.5-18.9; P < 0.001). CONCLUSION: A significant association exists between consecutive recurrent abortions and pregnancy complications such as placental abruption, hypertensive disorders and CS. This association persists after controlling for variables considered to coexist with recurrent abortions. Careful surveillance is required in pregnancies following recurrent abortions, for early detection of possible complications.

Cervical incompetence and the role of emergency cerclage.

OBJECTIVE: To evaluate the role of emergency cerclage for women who present with a dilated external cervical os and bulging or "hour-glassing" membranes. We examined overall experiences at Kingston General Hospital (KGH) from 2000 to 2004 and conducted a literature review for the period January 1, 1995, to December 31, 2004. METHODS: A search for cerclages placed by operators in Kingston revealed 12 pregnancies in the period between 2000 and 2004. We reviewed the charts for these women and for their infants. We conducted a literature review, using the terms "cerclage," "cervical," "emergent or emergency cerclage," "rescue cerclage," and "incompetent cervix," using an OVID interface to access MEDLINE records. We excluded articles in which the diagnosis of cervical incompetence was made using ultrasound, because its predictive value has not been shown in randomized trials. The most recent review of this type was carried out in 1995; since then, an additional 24 articles have been published that met our inclusion and exclusion criteria. RESULTS: The average time between cerclage placement and delivery at KGH was 7 weeks, which allowed for 10 of 13 infants (one twin pregnancy) to be born at 28 weeks or later. Three infants were born weighing under 1 kg; the 10 remaining infants weighed over 1 kg. Histological data are available for 12 placentas of the 13 infants delivered; 7 infants had a histological diagnosis of chorioamnionitis; none of the blood cultures from any of the infants post-delivery revealed septicemia. The literature review identified 638 women. Where reported, the average prolongation of the pregnancy was 7 weeks plus 1 day. This allowed for 60% of infants (range 26% to 80%) to be born after 28 weeks, with an average neonatal survival of over 70% (range 47.2% to 96%). Preterm premature rupture of membranes complicated an average of 29% of pregnancies (range 1% to 58%), and chorioamnionitis was reported in 5% to 80% of pregnancies. CONCLUSIONS: The KGH data collected and the data available in the literature suggest that emergency cerclage, under ideal circumstances, can significantly prolong pregnancy and increase the chance of viable pregnancy outcome. However, in counselling women about the potential therapeutic benefit of emergency cerclage, the increased risk of chorioamnionitis and its associated risk of fetal inflammatory brain injury, as well as the risk of extending a pregnancy from pre-viability to severe prematurity, should be discussed. A longer-term follow-up than has been carried out here is required for better elucidation of the effect of chorioamnionitis on those infants in childhood and beyond.

The effect of cervical cerclage on the course of labor.

Although it is generally believed that patients with previous cervical cerclage have abnormal labor patterns, there is little evidence to support this belief. We analyzed the pattern of cervical dilatation during labor in 114 women with cervical cerclage by the McDonald procedure who delivered vaginally at term and compared them with 150 normal laboring women. Similar patterns of cervical dilatation were found in both groups and there was no case of cervical dystocia, a commonly cited complication of cervical cerclage.

Plasma oxytocin but not prostaglandin F2 alpha metabolite levels at cerclage may predict preterm delivery.

Plasma oxytocin and prostaglandin F2 alpha metabolite (PGFM) concentrations were measured in 45 patients admitted for cerclage during the second trimester. Samples were collected before, 3 hours after, and 3 days after the Shirodkar procedure. Uterine activity was recorded by external tocography twice daily for 30 minutes. Twenty-eight women with uncomplicated pregnancy and commensurate gestational age served as controls. Cervical length, measured by ultrasonography, was significantly shorter before cerclage (36 +/- 2 mm) than after cerclage (43 +/- 2 mm) or compared with controls (48 +/- 1 mm). Bishop scores ranged from 3-6 (median 4) in the cerclage group and 0-1 (median 0) in controls. Fifteen cerclage patients and one control delivered preterm 5-22 weeks after the procedure. Initial plasma PGFM levels were significantly higher in cerclage patients than in controls. The cerclage procedure caused an immediate rise in plasma PGFM and a subsequent fall below initial levels to control values. Neither the initial levels of PGFM nor the increments 3 hours after cerclage correlated with the outcome of pregnancy. By contrast, plasma oxytocin levels before cerclage were significantly higher in patients who subsequently delivered preterm than in those who delivered at term. Cerclage resulted in a significant fall in plasma oxytocin at 3 hours in patients with preterm delivery, but after 3 days the oxytocin levels had returned to the precerclage values. Patients who had increased uterine contractions had significantly higher plasma oxytocin levels but lower PGFM levels than those without contractions.(ABSTRACT TRUNCATED AT 250 WORDS)

Temporary submucosal cervical cerclage.

A submucosal, easily removable cervical cerclage was placed in 37 patients with cervical incompetence. The perinatal mortality rate compared favorably with reports using other techniques, and the cesarean section rate was not different from that in the overall obstetric population. In view of the absence of any complications, this technique would seem to be the cerclage of choice.

Transabdominal cerclage for fetal wastage due to cervical incompetence.

From 1978-1986, nine transabdominal cervicoisthmic cerclage procedures were performed on eight patients at the University of California, San Francisco. In six of the patients, the decision to perform the procedure was based on failed transvaginal cerclages. In five of these six cases, the cervix had deep traumatic defects. In the remaining two patients, the cervix was extremely short. Before the procedure, the eight patients had 25 pregnancies lasting beyond the first trimester, with 20 fetal losses (fetal salvage rate 20%). After the transabdominal procedure, the eight patients had 13 pregnancies resulting in eight term births, three premature births (at approximately 36 weeks' gestation), and two fetal losses (salvage rate 85%). All infants were delivered by cesarean section. The transabdominal cerclage may increase the fetal salvage rate in selected women when poor obstetric outcome is related to failed transvaginal cerclage and/or an anatomically defective cervix.

Diagnosis of impending late abortion.

PIP: During the years 1966 to 1972, 19 pregnant women, all but 1 in the midtrimester, reported to the outpatient clinic because of urinary symptoms. 13 were multigravidas, 6 were secundigravidas. Their chief complaint was urinary urgency and frequency of 2 or 3 days duration only. There was no dysuria or fever. 11 also complained of a pressure sensation in the lower abdomen. 3 reported a pink watery vaginal discharge. Their urinary symptoms were found to be related to the passive dilation of the cervix without uterine contractions. 16 were not too advanced to be treated by emergency cerclage using an Ethicon Mersileve band in a McDonald type procedure. Patients were confined to bed for 2-3 days and oral antibiotics given. Symptoms subsided and all but 1 of these women so treated had vaginal deliveries at term. When urinary tract symptoms appear in the second trimester of pregnancy without evidence of urinary infection, a high index of suspicion and careful attention to the meager symptoms is necessary to make early diagnosis of a dilating cervix. Timely surgical treatment can result in fetal salvage. The single most important traumatic factor in cervical incompetence is thought to be the forceful dilation of the cervix when articial abortion is performed. In 10 of these women curettage had artificially terminated the preceeding pregnancy. In 2 others artificial abortion had been followed by 1 or 2 premature deliveries. In only 4 of the 19 cases were there no previous traumas to the uterus. It is assumed therefore that cervial incompetence, late spontaneous abortion, and premature delivery will become more common in those countries which recently liberalized their abortion laws.^ieng

The incidence of preterm labor and specific risk factors.

A retrospective review of patients at high risk for preterm delivery because of twin gestation, uterine malformation, incompetent cervix, or previous preterm delivery was carried out to assess the rates of preterm labor and spontaneous preterm birth. Among the 119 patients with multifetal gestation, 46% had preterm labor and 36% delivered before 37 weeks' gestation. In the 58 patients with an anomalous uterus, the rate of preterm labor was 19%, and 14% had early deliveries. Of those with incompetent cervices (115), one-fourth had preterm labor and 17% had an early birth. When a history of one or more preterm deliveries was present, the preterm labor rate ranged from 41-68%, with an early delivery rate of 30-47%. Prophylactic tocolytic therapy did not prolong gestations significantly. Maternal smoking did not have an adverse effect on the incidence of preterm labor except in twin pregnancies, for which early delivery was more likely. The percentages for preterm delivery are slightly lower than those found in the literature; this may be attributable to improvement in preterm birth prevention efforts including patient education, more frequent examinations, home uterine activity monitoring, and daily nursing contact.

Reproductive performance after conventional metroplasty: an evaluation of 102 cases.

OBJECTIVE: To evaluate the influence of conventional metroplasty on reproductive performance of symmetric uterine anomalies and determine the complications of these procedures. DESIGN: A retrospective clinical analysis of consequently operated 102 women. SETTING: Institutional. PATIENTS AND PARTICIPANTS: One hundred two patients with bicornuate and septate uterus and a history of late recurrent abortion and/or preterm delivery were included in this study. INTERVENTIONS: Jones, Strassman, and Tompkins procedures for metroplasty and McDonald operation for cervical cerclage. MAIN OUTCOME MEASURE: The fetal survival rate has increased from 3.7% before operation to 75.0% afterwards. In only two patients uterine rupture was observed. RESULTS: Conventional metroplasty improves the fetal survival rate in women with symmetric uterine anomalies. CONCLUSIONS: Our results confirm the view that conventional metroplasty seems to be an operation of choice in women with symmetric uterine anomalies and a history of recurrent late abortion and preterm delivery. However, uterine rupture and postoperative infertility may be potential complications.

Early therapy for the incompetent cervix in patients with habitual abortion.

From a thorough evaluation of 66 couples with habitual abortion (HA), 42 were found to have a widened uterine isthmus at hysterosalpingography (HSG) as their only abnormality. First trimester cervical effacement occurred in 90% of these patients. A combination of medical (progesterone [P]), and surgical (McDonald cerclage) begun during the first trimester resulted in successful term pregnancy in 35 of the 36 HA patients (97%) who were treated. The results of this study suggest that (1) functional cervical incompetence may play a major role in HA; (2) a widened uterine isthmus at HSG and first trimester cervical effacement are clinical signs that may define this group of HA; (3) early recognition and therapy for the incompetent cervix can interrupt the progression of events leading to the loss of an otherwise normally developing fetus; and (4) increased perinatal morbidity demands continuous antepartum assessment of fetoplacental integrity in these patients.

Reproductive outcome after hysteroscopic metroplasty in women with septate uterus and otherwise unexplained infertility.

OBJECTIVE: To evaluate the reproductive outcome of hysteroscopic metroplasty performed in women with septate uterus and otherwise unexplained primary infertility. DESIGN: Prospective, observational study. SETTING: Tertiary center for reproductive medicine. PATIENT(S): Sixty-one patients with uterine septa and otherwise unexplained primary infertility. INTERVENTION(S): Hysteroscopic division of the uterine septum. MAIN OUTCOME MEASURE(S): Reproductive outcome after hysteroscopic metroplasty. RESULT(S): Of 61 women, 25 (41%) conceived within 8-14 (mean 11.2) months after hysteroscopic metroplasty. Of these, 18 (29.5% of the total group) had live births (13 carried to term and 5 had preterm deliveries), and 7 (11.5% of the total group) had spontaneous abortions. Cervical cerclage was performed in 9 women; only 1 (11.1%) of these patients and 4 (44.4%) of the 9 who did not have a cerclage had preterm deliveries. Twelve of the 18 women (66.6%) who had live births were delivered by cesarean section. CONCLUSION(S): Women with uterine septum and otherwise unexplained infertility might benefit from hysteroscopic metroplasty.

The cervix and prematurity: aetiology, prediction and prevention.

Preventing preterm delivery remains a major challenge for the 21st century. The cervix plays a fundamental role in supporting a pregnancy and preventing ascending infection from the lower genital tract. Infection is associated with early preterm delivery in about half of cases. Whatever the aetiology of preterm delivery, dilation of the cervix is a common endpoint, and transvaginal scanning of the cervix now provides a good predictor of early preterm delivery in both high- and low-risk women. Changes in the cervix are related to the detection of fetal fibronectin in the vagina, which is also an accurate predictor of delivery. However, the role of intervention in at-risk women is unclear. Elective cerclage is only effective in a minority of women, and the evidence to support its use is limited. It is currently being evaluated whether indicated cerclage, dictated by ultrasound findings, is beneficial.

Management of cervical cerclage after preterm premature rupture of membranes.

The optimal management of preterm premature rupture of membranes (PPROM) in a patient with a cerclage is controversial. The issues are whether the latency period between rupture of membranes and delivery is decreased if the cerclage is removed and whether there is an increased rate of maternal or neonatal infection if the cerclage is kept in place. The data are sparse in directing management of women with prophylactic cerclages placed earlier in their pregnancies who rupture membranes. Latency seems to be increased if the cerclage is kept in place, but maternal and neonatal infectious morbidity is increased also. In women at early gestational ages, keeping the cerclage in place may be warranted until labor ensues. In more advanced gestations, it seems preferable to immediately remove the cerclage upon diagnosis of PPROM.

Prematurity prevention: who is at risk?

Previous preterm birth, previous preterm labor, regular uterine activity, uterine distention, and preterm cervical change are factors that are most often present in patients treated for preterm labor or in patients delivered prematurely. In addition to their frequency, their severity is also the highest in terms of patient risk. These factors usually are easily identified, and an appropriate management plan can be implemented to decrease the incidence of preterm births or to at least increase the fetal time in utero. Antenatal bleeding, chronic urinary tract infections, smoking, and maternal age are also associated with preterm labor. Although these factors are not present as often, they have the potential to precipitate preterm labor and preterm delivery. When they are identified, it is necessary to utilize the appropriate therapeutic measures commensurate to the number and/or the degree of the risk factors. Vaginal microbiology, maternal hematocrit, substance abuse, and coitus are factors that are undergoing active investigation in regards to precipitating preterm birth. They are frequently seen in normal pregnancies, but recently have been associated with a greater likelihood for preterm labor and preterm birth. Unequivocal evidence of this association is currently unavailable; however, more and more investigations are reporting a significant association of these factors with preterm births. The relative degree of risk and the optimal management plans for dealing with these factors also await further definition and refinement. We know that there is no surveillance technique, or combination of techniques, that will identify all patients who will eventually deliver preterm. In many reports, despite the diligent attention to many of the earlier-mentioned risk factors, almost two of three patients who have delivered preterm had no easily identified risk factor. In addition, many patients delivered preterm report no perception of uterine activity (Garbaciak JA, Desch C, unpublished data). Other investigators have concluded that because most of the potentially preventable births occur in groups that present with marked cervical dilatation, it may be difficult to lower significantly the preterm birth rate below the current levels. Despite the sometimes dismal outlook regarding the prevention of preterm labor and delivery, the multiple investigators that have reported certain successes in their study populations should give us hope and encourage us to apply those techniques that appear appropriate and effective in our individual populations and patients. We can see and measure successful outcomes only if we are willing to look and aggressively to attempt to decrease untoward perinatal events.(ABSTRACT TRUNCATED AT 400 WORDS)

Uterine surgical approaches to reduce prematurity.

Success rates of up to 80% can be expected after surgical treatment of abnormal uteri. A careful investigation should be conducted to verify that other causes of prematurity are not present prior to surgical intervention.

Management of a triplet pregnancy with two anencephalic fetuses and polyhydramnios.

The occurrence of a triplet pregnancy discordant for anencephaly is rare and its management presents a clinical dilemma. We report what appears to be the first case of a triplet pregnancy with two anencephalic fetuses complicated by premature contractions and severe polyhydramnios. Its management, which results a healthy newborn weighing 1385 g is discussed.

Cervical cerclage in delayed interval delivery in a multifetal pregnancy: a review of seven case series.

OBJECTIVE: To examine whether cervical cerclage after the first delivery prolongs the inter-delivery interval in delayed interval deliveries. STUDY DESIGN: We identified 66 case reports and case series of delayed interval delivery published between 1880 and 2002. We selected seven case series that identified all cases of delayed interval delivery in their institutions during a specified period. RESULTS: Despite routine use of broad-spectrum prophylactic antibiotics, the average incidence of clinical intrauterine infection after the first delivery was 36% (95% confidence interval (CI): 26-46%). The incidence of maternal sepsis was 4.9% (95% CI: 0.2-9.6%). Studies in which cerclage was infrequently used reported a shorter inter-delivery interval compared to studies where cerclage was used in all cases (median is equal to 9 days versus 26 days, respectively, P<0.001) despite similar gestational ages at the first delivery, types of antibiotics, tocolytics, and incidence of infection. After controlling for other factors, the use of cerclage did not significantly increase the risk of intrauterine infection (adjusted relative risk=1.1, 95% CI: 0.4-3.5). CONCLUSION: Cervical cerclage after the first delivery is associated with a longer inter-delivery interval without increasing the risk of intrauterine infection.

Transvaginal cervicoisthmic cerclage as an alternative to the transabdominal technique.

OBJECTIVES: To analyse the foetal outcome after transvaginal cervicoisthmic cerclage, to determine whether it is a valid alternative to the reference transabdominal technique. STUDY DESIGN: Description of the vaginal operative technique, retrospective review of 20 cervicoisthmic cerclage patients from 1990 to 2000. RESULTS: In the curative group of women with a history of late pregnancy losses or premature deliveries and usually previous failed classical cervical cerclage, the foetal survival rate improved from 18% before cerclage to 79% after cerclage. No operative complications were reported. In the prophylactic group, typically characterised by the absence of the cervix as a consequence of surgery for invasive cervical cancers, the foetal survival rate was 83% after cerclage. CONCLUSIONS: The transvaginal cervicoisthmic cerclage allows a high foetal survival rate without complications in highly selected patients with poor obstetrical history. Because of its simplicity, this technique should replace the transabdominal route for surgeons experienced in vaginal surgery.