Materials and Methods

This was a retrospective cohort of all multifetal pregnancies complicated by documented PPROM occurring before 26 0/7 weeks and managed by a single group of perinatologists at the University of Utah and Intermountain Healthcare Hospitals between July 4, 2002, and Sept. 1, 2013. These dates were selected based on the availability of centralized data of good quality. Cases were identified through International Classification of Diseases , ninth revision, searches, review of established obstetric databases, and chart review. Data were collected and managed using REDCap (Research Electronic Data Capture) electronic data capture tools hosted at the University of Utah Center for Clinical and Translational Science.

PPROM was confirmed if at least 2 of the following were present: pooling, ferning, nitrazine, visible fetal parts seen on speculum examination without overlying membrane, and/or deepest vertical pocket of fluid on ultrasound examination less than 2 cm. The date and time of membrane rupture was reported by the patient. In cases in which an exact time could not be recalled, the date and time of rupture was designated as the time of rupture confirmation. Because of this limitation, the latency period was rounded to the nearest half-day.

Women declining expectant management, delivering within 12 hours of PPROM, presenting with chorioamnionitis and/or fetal demise of 1 or more fetuses, carrying a pregnancy complicated by twin-twin transfusion syndrome, or carrying 1 or more fetuses with known major structural anomalies, polyhydramnios, and/or aneuploidy were excluded. Those in which an interval delivery was attempted and was achieved longer than 48 hours of latency were also excluded.

Multiples that spontaneously reduced in the first trimester were designated by their reduced state. Neonatal resuscitation was uniformly performed at 24 weeks’ gestation or greater. For neonates delivering at 23 0/7 to 23 6/7 weeks, the decision whether to resuscitate was decided by consensus between the woman, her family, and her provider(s). Neonates delivering at less than 23 0/7 weeks are provided comfort care at our institutions but are not actively resuscitated.

Gestational age was determined by best obstetric estimate per standard criteria, using a combination of last menstrual period dating and ultrasonographic data as appropriate. Chorionicity was determined by ultrasonographic findings and confirmed with placental pathology whenever possible. Maternal and neonatal records were reviewed by a single physician researcher (L.F.W.).

Data collection was deidentified and therefore informed consent was waived. This study was approved by the University of Utah and Intermountain Healthcare Institutional Review Boards.

Neonatal survival without major morbidities was the primary outcome. Composite severe neonatal morbidity was defined as grade III or IV intraventricular hemorrhage, bronchopulmonary dysplasia, pulmonary hypoplasia, necrotizing enterocolitis requiring surgical intervention, retinopathy of prematurity grade 3 or 4, or neonatal death. All morbidities were assessed only in live-born neonates. For higher-order multiple gestations (eg, triplets and greater), comparisons were made between the fetus with ruptured membranes and the first fetus to deliver with intact membranes.

Data were analyzed using STATA version 12.0 (STATACorp, College Station, TX) and followed a within-pregnancy sample approach. If data were available for both multiples of the same pregnancy, the comparison was done using ordinary statistical tests: McNemar test for binary variables, Wilcoxon signed rank for ordered categorical variables, and Student paired-sample t test for continuous variables. If data were missing for one of the paired multiples, such as hospital length of stay when 1 multiple died, a mixed-effects regression model was used, with outcome nested within pregnancies. These models are identical to the ordinary paired-sample statistical tests when no data are missing but can still use the data on the nonmissing multiple to refine the estimates when a portion of the data are missing.

We attempted to capture time-specific probability estimates of death (intrauterine demise and neonatal death), neonatal survival, and neonatal survival without major composite morbidity by stratifying outcomes from each PPROM gestational age group by outcomes during each subsequent 2 week increment divided by the number of patients still being followed up. If there were no events (deaths or diagnoses of morbidity) during a specific time period, the probability from the earlier time interval was carried forward.

Results

We identified 40 multifetal pregnancies with documented PPROM occurring prior to 26 weeks that were managed expectantly. Seven pregnancies were excluded from analysis because of a successful attempt at delayed interval delivery (each pregnancy attained at least 48 hours of latency for the remaining fetuses following delivery of the presenting neonate). Ten pregnancies were excluded from analysis because of the presence of major congenital fetal anomalies/aneuploidy or suspected twin-twin transfusion syndrome. Thus, 23 pregnancies were analyzed, including 22 dichorionic-diamniotic twins and 1 set of trichorionic-quadamniotic quadruplets ( Figure ).

Study enrollment

GA , gestational age; IQR , interquartile range; LOS , length of stay; NICU , neonatal intensive care unit; PPROM , preterm premature rupture of membranes; PROM , premature rupture of membranes.

Wong. Expectantly managed multiples with PPROM prior to 26 weeks. Am J Obstet Gynecol 2015 .

Demographic and clinical characteristics are shown in Table 1 . Approximately 44% of the women were multiparous. Of these, none had a history of PPROM in a prior pregnancy. Two women had a history of cervical insufficiency: 1 had a prophylactic cerclage at 13 weeks with subsequent PPROM at 25.4 weeks, and the other had a physical examination that indicated cerclage (because of the presence of amniotic membranes beyond the external os) at 19.0 weeks and subsequent PPROM at 21.4 weeks.

Overall, the median gestational age at PPROM was 22.9 weeks (interquartile range [IQR], 20.7–24.1 weeks); the majority (17 of 23, 74%) occurred prior to 24 weeks’ gestation. Three cases of PPROM occurred in the nonpresenting multiple. Seventeen of 18 pregnancies reaching 23 weeks desired full resuscitation, and 11 of these were delivered at 24 weeks or longer. The majority (15 of 17, 88.2%) received antenatal corticosteroids, and 16 of 17 (94.1%) received latency antibiotics. One woman received magnesium sulfate for fetal neuroprophylaxis. The quadruplet pregnancy resulted in no surviving neonates following PPROM at 22 6/7 weeks and spontaneous labor with subsequent delivery at 23 3/7 weeks; neonatal resuscitation was not performed for any of the 4 neonates.

Overall neonatal outcomes are shown in Table 2 . Of the 46 neonates, 4 experienced antepartum demise, 3 experienced an intrapartum demise, 9 suffered neonatal demise because of severe prematurity without attempted resuscitation, and 10 died in the neonatal intensive care unit. Thus, 20 (43%) survived to hospital discharge. Only 8 neonates (17%) survived to hospital discharge without severe neonatal morbidity. Of these 8 neonates, 5 had intact membranes and 3 had ruptured membranes.

Tables 3–5 stratify outcomes by gestational age at PPROM and the current gestational age of the pregnancy. Generally, chances of death (intrauterine demise and neonatal death) decrease with increasing gestational age of PPROM and increasing latency ( Table 3 ). Overall, the chance of a woman with PPROM at 18 0/7 to 19 6/7 weeks having a surviving neonate is 37.5%, and her chance of having a surviving neonate without major composite morbidity is 25.0%.

Although there is a significant improvement in the probability of neonatal survival with increasing gestational age at the time of PPROM, the improvement in the probability of a surviving neonate without composite morbidity is only modest (83.0% and 33.3% of women with PPROM at 24 0/7 to 25 6/7 weeks, respectively). Intact survival was more likely with an increasing gestational age of delivery and occurred for 50% (5 of 10) of women who remained undelivered with viable pregnancies at 28 weeks and 75% (3 of 4) of women who remained undelivered with viable pregnancies at 30 weeks.

When neonatal outcomes are stratified by membrane status, we found that neonates with rupture of membranes (ROM) were more likely to experience intrauterine demise ( Table 6 ). Outcomes of the ruptured and unruptured neonate for the subset of 17 pregnancies reaching at least 23 0/7 weeks and desiring full resuscitation were similar (data not shown). For this subset, intrauterine demise or neonatal death complicated 8 of 17 multiples with ROM and 6 of 17 with intact membranes ( P = .486), and severe composite morbidity affected 11 of 14 multiples with ROM and 11 of 16 multiples with intact membranes ( P = .144). The median length of hospital stay for the surviving multiple with ROM was 98 days (IQR, 72–111 days) and 92 days (IQR, 46–139 days) for the surviving multiple with intact membranes ( P = .579).

Table 6

Only gold members can continue reading. Log In or Register to continue

Share this:

• Click to share on Twitter (Opens in new window)
• Click to share on Facebook (Opens in new window)

Related

Related posts:

1. Impact of prolapse meshes on the metabolism of vaginal extracellular matrix in rhesus macaque
2. Impact of intrauterine tobacco exposure on fetal telomere length
3. Reply
4. Computed tomography-guided preoperative localization of abdominal wall endometrioma

Stay updated, free articles. Join our Telegram channel

Join