Maturity testing with preterm premature rupture of the membranes

A transcervical amniotic fluid collector: a new medical device for the assessment of amniotic fluid in patients with ruptured membranes

AIM

To describe a new device for the transcervical collection of amniotic fluid (AF) in patients with ruptured membranes, and to compare the concentration of proteins in fluid retrieved by transabdominal amniocentesis and the transcervical AF collector.

STUDY DESIGN

Paired AF samples were collected in patients with preterm prelabor rupture of membranes (PROM) (n=11) by transabdominal amniocentesis and with the transcervical AF collector (Yoon's AF Collector™). Three proteins known to have high concentrations in AF [α-fetoprotein (AFP), β-human chorionic gonadotrophin (β-hCG), and prolactin] were measured.

RESULTS

(1) There was a significant correlation between the concentrations of analytes in AF obtained by transabdominal amniocentesis and by the transcervical AF collector (r=0.94, P<0.001 for AFP; r=0.96, P<0.001 for β-hCG; r=0.72, P<0.05 for prolactin); (2) Bland-Altman plots showed no evidence of heteroscedasticity between transabdominal or transcervical AF concentrations of these markers.

CONCLUSIONS

There was a strong correlation between the concentrations of proteins in AF collected by amniocentesis or with the transcervical device.

A prospective population-based study of 598 cases of PPROM between 24 and 34 weeks' gestation: description, management, and mortality (DOMINOS cohort)

OBJECTIVE(S)

Description of mothers' characteristics, obstetricians' practices, and PPROM-linked mortality in all 81 maternity hospitals in the Rhône-Alpes Region, over a period of 2 years.

STUDY DESIGN

Prospective cohort study of 598 women with PPROM between 24 and 34 weeks' gestation, leading to 680 births. At time of PPROM, collection of mothers' socio-economic characteristics, medical and obstetric histories and PPROM circumstances. Collection of perinatal management, neonates' medical status and postnatal referral.

RESULTS

The birth rate after PPROM between 24 and 34 weeks' gestation was 0.47% (95% CI: 0.42-0.48). Sixty percent of PPROM occurred before 32 weeks' gestation and 98% of births before 37 weeks. The incidence of previous PPROM was 14.3%. Antibiotics, corticosteroids, and tocolytics were given to 82, 78, and 52% of women, respectively. The rate of antibiotics and antenatal corticosteroids varied with gestational age (lower rates for antibiotics just after the limit of viability (23-24 weeks) and after 32 weeks, higher rates of corticosteroids between 26 and 30 weeks). The PPROM-birth interval became shorter as gestation advanced. The incidence of C-section was 58.7% (n = 270), C-section before labour being the most frequent mode of delivery. Sixty-seven percent of neonates were born in Level-3 hospitals. The overall neonatal mortality rate at 28 days decreased with gestational age at PPROM, and was 17.2% (16/93), 3% (6/200), and 0.41% (1/241) at 24-27, 28-31 and 32-33 weeks of PPROM, respectively.

CONCLUSION(S)

After PPROM, antibiotics and antenatal corticosteroids were widely used in our cohort, and C-section rates were elevated. With that up-to-date management, the perinatal mortality rate was less than 3% following PPROM after 28 weeks' gestation.

Preterm premature rupture of membranes: diagnosis, evaluation and management strategies

Preterm premature rupture of the membranes (PPROM) is responsible for one-third of all preterm births and affects 120,000 pregnancies in the United States each year. Effective treatment relies on accurate diagnosis and is gestational age dependent. The diagnosis of PPROM is made by a combination of clinical suspicion, patient history and some simple tests. PPROM is associated with significant maternal and neonatal morbidity and mortality from infection, umbilical cord compression, placental abruption and preterm birth. Subclinical intrauterine infection has been implicated as a major aetiological factor in the pathogenesis and subsequent maternal and neonatal morbidity associated with PPROM. The frequency of positive cultures obtained by transabdominal amniocentesis at the time of presentation with PPROM in the absence of labour is 25-40%. The majority of amniotic fluid infection in the setting of PPROM does not produce the signs and symptoms traditionally used as diagnostic criteria for clinical chorioamnionitis. Any evidence of infection by amniocentesis should be considered carefully as an indication for delivery. Documentation of amniotic fluid infection in women who present with PPROM enables us to triage our therapeutic decision making rationally. In PPROM, the optimal interval for delivery occurs when the risks of immaturity are outweighed by the risks of pregnancy prolongation (infection, abruption and cord accident). Lung maturity assessment may be a useful guide when planning delivery in the 32- to 34-week interval. A gestational age approach to therapy is important and should be adjusted for each hospital's neonatal intensive care unit. Antenatal antibiotics and corticosteroid therapies have clear benefits and should be offered to all women without contraindications. During conservative management, women should be monitored closely for placental abruption, infection, labour and a non-reassuring fetal status. Women with PPROM after 32 weeks of gestation should be considered for delivery, and after 34 weeks the benefits of delivery clearly outweigh the risks.

Testing for fetal lung maturation: a biochemical "window" to the developing fetus

Fetal lung maturity testing represents a major milestone in perinatology. This article critically evaluates specific controversies regarding the methodologies used to measure pulmonary surfactant in AF and how well each of these techniques performs both in principle and application. The clinical utility of fetal lung maturity testing as it applies to particularly difficult complications of pregnancy is discussed. These technical and clinical issues are framed by the scientific and empiric evidence that is used as the rationale for such testing and its implementation in the effective management of preterm delivery.