Aust NZ J Obstet Gynaecol 1992: 32: 2: 120
Pregnancy Outcome Following Preterm Premature Rupture of the Membranes at Less Than 26 Weeks’ Gestation Jennifer Dowd: B Med Sci, MBBS and Michael Permezel: MD, BS, MRCP, MRCOG, FRACOG Royal Women’s Hospital‘ and Department of Obstetrics and Gynaecologx University of Melbourne2
EDITORIAL COMMENT: This careful analysis of 71 cases of premature rupture of the membranes (PROM) in singleton pregnancies without cervical suture reports important findings that will assist those who manage these difficult and important pregnancies. They are often especially important because the patient has had a bad past history of pregnancy wastage and is anxious to receive conservative therapy regardless of the risks (to her and her fetus) and cost (to the community). In Melbourne it has until recently been the rule to advise hospitalization until delivery in women with PROM - now that bed costs are high as in the USA, we have begun to do what has been done for years in the USA - manage these women at home after an initial week or so in hospital i f the drainage of liquor ceases and there is no evidence of infection. In this study 69 of the 71 women remained in hospital but in future a large proportion are likely to be managed (definitely without coitus) at home. In this series 6 of the 71 women had PROM before 20 weeks and there was only I fetal survivor in this group. It should be noted that the series excluded cases in which PROM resulted in delivery before 20 weeks. Therefore this study does not support the editor’s opinion that conservative management is reasonable when PROM occurs before 20 weeks’ gestation, and the fetus is alive and ultrasonographically normal, even when there is oligohydramnios, if the patient agrees with or requests this regimen. Many obstetricians would consider that it isperfectly proper practice to put up an oxytocin drip and deliver the woman with PROMifshe is unwilling to face the clinical and social prospects ahead and the period of gestation is less than . 20 weeks; a 5 in 40 take-home-baby rate when PROM occurs before 24 weeks indicates that conservative therapy has some winners in such cases. A final comment is what constitutes maturity in these cases - when is the battle won?; in this series 2 of the 71 women were induced for ‘maturity’ and figure I shows that this was 33 and 34 weeks respectively. In the editor’s opinion it is wise to allow these pregnancies to go to 37 weeks’ gestation; despite the excellence of modern neonatal care tragic lossesstill occur in infants born between 34-37 weeks’ gestation. Perhaps we could allow pregnancy to continue longer and reduce costs (mother in hospital, baby in special care nursery) if we managed more of these patients at home. We need careful studies to see i f such a regimen is safe enough for the mother and her fetus.
Summary: The outcome of 71 singleton pregnancies where premature rupture of the membranes (PROM) occurred at gestations of less than 26 weeks was assessed retrospectively. The incidence of chorioamnionitis was 39.4% and the overall maternal morbidity rate was 53% but there were no long-term maternal sequelae. The latent period from PROM until delivery ranged from 24 hours after delivery.
RESULTS Seventy-one patients were suitable for the study. The mean gestational age at PROM was 23 weeks (range 17-25 weeks). 23 (32.4%) were nulliparas. There was a preponderance of male fetuses (62.8%). Possible aetiological factors in this group of subjects were as follows. Two (2.8%) patients had experienced PROM in a previous pregnancy and the same number had had a preterm delivery without PROM. Two patients had undergone a Strassman procedure for congenital uterine anomalies. During the pregnancy in question, 14 women (19.7%) had vaginal bleeding prior to 20 weeks and another 6 (8.5%) had bleeding that commenced after 20 weeks but before PROM. Three patients underwent amniocentesis for advanced maternal age (performed at 16 weeks with subsequent PROM at 20, 21 and 21 weeks) and one had a continuing pregnancy in the presence of an intrauterine contraceptive device which could not be removed. Thirty-eight (53.5%) had an uncomplicated history. .............. P E R I N A T A L LOSS
- ALIVE
17
j
Figure 1. Duration of PROM and outcome. Each bar represents a single pregnancy, with the lower end being the gestation of PROM and the upper end the gestation at delivery. 22, 20 18 16 cI 14
3 2
cu l 2
0 10
k $ 8
z
2
0%
n
1-3 4-7 8-14 14-28 28-56 56+ DURATION OF RUPTURED MEMBRANES IN DAYS
H= total number of patients delivering m= number with chorioamnionitis Figure 2. Cumulative rate of delivery and infection.
AUST.AND N.Z. JOURNAL OF OBSTETRICS
122
The mean latent period from PROM until delivery was 20 days (range 12 hours to 77 days) (figure 1). Ten of the 71 patients (14.1%) delivered within 24 hours of PROM, 20 (28.2%) within 72 hours, 29 (40.8%) within one week, 39 (54.9%) within 2 weeks and 52 (73%) within 4 weeks (figure 2). Chorioamnionitis developed in 28 (39.4%) patients. Twenty one (75%) of these patients grew potential pathogens on antenatal genital tract cultures but only in 5 was there documented neonatal infection. Amongst the 43 patients without clinical evidence of chorioamnionitis there were 7 cases of neonatal infection (all of whom had positive genital tract cultures). Twentyone patients grew a potential pathogen with neither evidence of neonatal infection nor chorioamnionitis. The results of genital tract cultures are given in table 1. Table 1. Bacterial Isolates and Frequency of Infection Organism
n
Maternal infections Neonatal infections
14 Group B Strep. 12 Mixed anaerobes E. Coli 11 7 Mycoplasnia 6 Staph aureus 2 Ur Urealyticum Klebsiella 1 Group D Strep. 2 Peptostreptococcus 1 Anaerobic Strep. 1 1 Haemophilus infl. I Gram neg. rods I Candida albicans 1 Strep. pneurno. Group C Strep. 1
There was no increase in risk of developing chorioamnionitis with an increasing latent period (X2 = 5.4, p
Pregnancy Outcome Following Preterm Premature Rupture of the Membranes at Less Than 26 Weeks’ Gestation Jennifer Dowd: B Med Sci, MBBS and Michael Permezel: MD, BS, MRCP, MRCOG, FRACOG Royal Women’s Hospital‘ and Department of Obstetrics and Gynaecologx University of Melbourne2
EDITORIAL COMMENT: This careful analysis of 71 cases of premature rupture of the membranes (PROM) in singleton pregnancies without cervical suture reports important findings that will assist those who manage these difficult and important pregnancies. They are often especially important because the patient has had a bad past history of pregnancy wastage and is anxious to receive conservative therapy regardless of the risks (to her and her fetus) and cost (to the community). In Melbourne it has until recently been the rule to advise hospitalization until delivery in women with PROM - now that bed costs are high as in the USA, we have begun to do what has been done for years in the USA - manage these women at home after an initial week or so in hospital i f the drainage of liquor ceases and there is no evidence of infection. In this study 69 of the 71 women remained in hospital but in future a large proportion are likely to be managed (definitely without coitus) at home. In this series 6 of the 71 women had PROM before 20 weeks and there was only I fetal survivor in this group. It should be noted that the series excluded cases in which PROM resulted in delivery before 20 weeks. Therefore this study does not support the editor’s opinion that conservative management is reasonable when PROM occurs before 20 weeks’ gestation, and the fetus is alive and ultrasonographically normal, even when there is oligohydramnios, if the patient agrees with or requests this regimen. Many obstetricians would consider that it isperfectly proper practice to put up an oxytocin drip and deliver the woman with PROMifshe is unwilling to face the clinical and social prospects ahead and the period of gestation is less than . 20 weeks; a 5 in 40 take-home-baby rate when PROM occurs before 24 weeks indicates that conservative therapy has some winners in such cases. A final comment is what constitutes maturity in these cases - when is the battle won?; in this series 2 of the 71 women were induced for ‘maturity’ and figure I shows that this was 33 and 34 weeks respectively. In the editor’s opinion it is wise to allow these pregnancies to go to 37 weeks’ gestation; despite the excellence of modern neonatal care tragic lossesstill occur in infants born between 34-37 weeks’ gestation. Perhaps we could allow pregnancy to continue longer and reduce costs (mother in hospital, baby in special care nursery) if we managed more of these patients at home. We need careful studies to see i f such a regimen is safe enough for the mother and her fetus.
Summary: The outcome of 71 singleton pregnancies where premature rupture of the membranes (PROM) occurred at gestations of less than 26 weeks was assessed retrospectively. The incidence of chorioamnionitis was 39.4% and the overall maternal morbidity rate was 53% but there were no long-term maternal sequelae. The latent period from PROM until delivery ranged from 24 hours after delivery.
RESULTS Seventy-one patients were suitable for the study. The mean gestational age at PROM was 23 weeks (range 17-25 weeks). 23 (32.4%) were nulliparas. There was a preponderance of male fetuses (62.8%). Possible aetiological factors in this group of subjects were as follows. Two (2.8%) patients had experienced PROM in a previous pregnancy and the same number had had a preterm delivery without PROM. Two patients had undergone a Strassman procedure for congenital uterine anomalies. During the pregnancy in question, 14 women (19.7%) had vaginal bleeding prior to 20 weeks and another 6 (8.5%) had bleeding that commenced after 20 weeks but before PROM. Three patients underwent amniocentesis for advanced maternal age (performed at 16 weeks with subsequent PROM at 20, 21 and 21 weeks) and one had a continuing pregnancy in the presence of an intrauterine contraceptive device which could not be removed. Thirty-eight (53.5%) had an uncomplicated history. .............. P E R I N A T A L LOSS
- ALIVE
17
j
Figure 1. Duration of PROM and outcome. Each bar represents a single pregnancy, with the lower end being the gestation of PROM and the upper end the gestation at delivery. 22, 20 18 16 cI 14
3 2
cu l 2
0 10
k $ 8
z
2
0%
n
1-3 4-7 8-14 14-28 28-56 56+ DURATION OF RUPTURED MEMBRANES IN DAYS
H= total number of patients delivering m= number with chorioamnionitis Figure 2. Cumulative rate of delivery and infection.
AUST.AND N.Z. JOURNAL OF OBSTETRICS
122
The mean latent period from PROM until delivery was 20 days (range 12 hours to 77 days) (figure 1). Ten of the 71 patients (14.1%) delivered within 24 hours of PROM, 20 (28.2%) within 72 hours, 29 (40.8%) within one week, 39 (54.9%) within 2 weeks and 52 (73%) within 4 weeks (figure 2). Chorioamnionitis developed in 28 (39.4%) patients. Twenty one (75%) of these patients grew potential pathogens on antenatal genital tract cultures but only in 5 was there documented neonatal infection. Amongst the 43 patients without clinical evidence of chorioamnionitis there were 7 cases of neonatal infection (all of whom had positive genital tract cultures). Twentyone patients grew a potential pathogen with neither evidence of neonatal infection nor chorioamnionitis. The results of genital tract cultures are given in table 1. Table 1. Bacterial Isolates and Frequency of Infection Organism
n
Maternal infections Neonatal infections
14 Group B Strep. 12 Mixed anaerobes E. Coli 11 7 Mycoplasnia 6 Staph aureus 2 Ur Urealyticum Klebsiella 1 Group D Strep. 2 Peptostreptococcus 1 Anaerobic Strep. 1 1 Haemophilus infl. I Gram neg. rods I Candida albicans 1 Strep. pneurno. Group C Strep. 1
There was no increase in risk of developing chorioamnionitis with an increasing latent period (X2 = 5.4, p
