ORIGINAL ARTICLE
Laparoscopic hysterectomy Initial experience ANTON LANGEBAEKKE, OSKARJOHANSKAR AND ARNEURNES From the Department of Obstetrics and Gynecology, Central Hospital of Akershus, Nordbyhagen, Norway
Actu Obstel Gynecol Scand 1992: 71: 226229
Laparoscopic hysterectomy is now being performed in our department in cases where no malignancy is suspected. This study presents the first 10 cases. Indications for hysterectomy were myomas, meno- and metrorrhagia resistant to medical and hysteroscopic treatment, and patients with pain and suspicion of having adenomyosis. No complications have been encountered during the laparoscopic operations, but one patient had a second laparoscopy on the first postoperative day due to postoperative bleeding. Another patient had a postoperative infection leading to a compression of the ureter. This report demonstrates that laparoscopic hysterectomy is a valuable addition to the new procedures in ‘minimal invasive surgery’, but only after long and appropriate training. Key words: laparoscopy; hysterectomy; operative laparoscopy; laser Submitted January 8,1992 Accepted January 22, 1992
Endoscopic surgery is rapidly becoming a popular alternative to traditional operative procedures for a variety of diseases. Kurt Semm in Kiel played an important rBle more than two decades ago in the development of operative laparoscopy (1). In 1987 the French gynecologist Philippe Mouret performed the first laparoscopic cholecystectomy in Lyon (2). To start with this procedure attracted only minor interest but today it has become widespread. It was not surprising that a gynccologist penetrated the general surgical discipline. Operative laparoscopy in gynecology has been progressively well established during the last decade and today most gynecological surgery can be performed using laparoscopic visualization (3, 4). Hysterectomy for benign disease has also been performed laparoscopically (6), and so has pelvic lymphadenectomy. (Querleu D. Laparoscopic pelvic lymphadenectomy. Presented at the Second World Congress of gynecological endoscopy, Clermond-Ferrand, France, 1Y89). These are only some of the indications among ‘the new frontiers’. After introduction of operative laparoscopy with Actu Ohstet Gynccol Scund 71 (1992)
CO, laser in our department during 1988, we have performed more and more complex laparoscopic surgery (5). With increased skill with ‘minimal invasive surgery’ we proceeded to laparoscopic hysterectomy, which was first done in July 1991. We present here the results of our first 10 operations.
Material and methods This report consists of the first ten laparoscopic hysterectomies performed in the Department of Obstetrics and Gynecology, Akershus Central Hospital, Norway. The patients were operated on between July and December 1991. They were all informed that laparoscopy was not the standard procedure in the department, and that a laparotomy might become necessary. The indications for surgery were either myomas (n = 3), or menometrorrhagia unresponsive to medical and hysteroscopic treatment (n = 4), or pelvic pain and endometriosis where medical treatment
Laparoscopic hysterectomy
227
Table 1. Results of laparoscopic hysterectomy in 10 patients Patient no.
Age
Indication
Op. time (min)
Uterine weight (8)
Hospital Complications Diathermy/ (yesho) Endo-Cia stay (days)
1
43 34 44 39 42
myoma dysmenorrhoea menorrhagia menorrhagia dysmenorrhoea myoma family history metrorrhagia dysmenorrhoea dysmenorrhoea
210 110 150 130 85 120 100 100 120 75
203 135 160 150 90 320 99 96 113 80
2 1 2 3 2 5 2 2 3 1
2 3 4 5 6 7 8 9 10
41
51 43 39 38
and laser laparoscopy were unsuccessful and adenomyosis was probable (n = 2). One patient was referred to our hospital from the Norwegian Radium Hospital for prophylactic hysterectomy and bilateral salpingo-oophorectomy because of high incidence of cancer in her family. All the patients underwent preoperative examinations to exclude gynecological malignancies. This consisted of general gynecological examination where we paid attention to the mobility and the size of the uterus, and to pathology of the adnexa. We excluded patients with a previous cesarean section, and also where the size of the uterus was more than that of a 13 week pregnancy. After colposcopy, cervical smear and where indicated biopsies of the cervix uteri were taken. The uterine cavity was examined as indicated by vaginal ultrasonography, hysteroscopy and cytology or histology of the endometrium. An enema was given the night before surgery. All operations were performed under general endotracheal anesthesia following standard preparations for vaginal surgery and possible laparotomy. The triple puncture technique used has been previously described in detail (5). A 12 mm laparoscope (Storz) with laser channel was introduced through the umbilicus, then two 5 mm suprapubic trocar sleeves to permit accessory instruments. The abdominal cavity was examined thoroughly to exclude other patholoTable 11. Pathologic diagnosis of 10 laparoscopic hysterectomies Diagnosis Myoma Normal Adenomyosis Endometriosis
Ih*
Number of patients
no no no no no Yes no Yes no no
diathermy diathermy both both both both diathermy diathermy both both
gy. Care was taken to locate the course of the ureter. In six cases, a midline 12 mm trocar was placed halfway between the umbilicus and the symphysis pubis to allow an endoscopic G I A stapler (Endo G I A 30, United States Surgical Corporation, Auto Suture Norway). In the case were the adnexa were removed together with the uterus, the infundibulopelvic vessels were desiccated with bipolar electrocoagulation and then cut with laparoscopic scissors. All other cases were started by coagulating and transecting the round ligament thus opening the broad ligament. The fallopian tube and the uteroovarian ligament were divided after desiccation with bipolar coagulation using 70 watt (Valley Lab Force 2). In 2 cases we used the Endo G I A stapler to divide these structures, but in the other patients the round ligaments were too vast and the anatomy atypical making the ligaments inappropriate for the stapler. We then worked progressively with laparoscopic surgical techniques including aquadissection to develop tissue planes. The bladder was separated from the anterior uterine surface using scissors or CO, laser assisted by aquadissection. For the big vessel hemostasis including the uterine artery and vein, bipolar electrosurgery or Endo-GIA stapler were used. We divided the uterosacral ligament laparoscopically and the transverse cervical ligament by bipolar electrosurgery and scissors or the laser, thus facilitating uterine descent and minimizing vaginal surgery. In half of the cases we opened the vagina with the laser or laparoscopic scissors, whereas in the other patients the opening was done by the vaginal route. The uterus was then removed (in one case with the adnexa attached) through the vagina. The peritoneal cavity was closed with a 0 Dexon purse string suture. The inferior parts of the cardinal ligaments were sutured to the lateral part of the vaginal vault, the vagina itself was closed with a 0 Dexon continuous suture. Inspection by the laparoscope at the end of Acta Ohstet Gynecol Scatid 71
( I 992)
228
A . Langebrekke et al.
the procedure ensured that hemostasis was adequate. In four cases an intraperitoneal drain was inserted through one of the suprapubic incisions unti1 the morning after surgery. All patients received 2 g Ampicillin and 1500 mg Metronidazol IV.
analgesics and, except for one (number 6), they were all eating and walking around. Two patients (nilmbers 2 and lo), were discharged the day after surgery. The 8 cases without complications went back to daily activity from 10 to 21 days after surgery.
Results
Discussion
Table I summarizes the data of the 10 patients. The median age of the patients was 42.5 (range 34-51). We never resorted to laparotomy because of hemostatic or other technical difficulties. Towards the end of the procedure one patient (number 4) developed a massive subcutaneous emphysema. This disappeared during the next 4 hours while she was observed in the intensive care unit. During this time she was on an artificial respirator. There were no complications after extubation, and she was discharged on the third day after the surgery. Total estimated blood loss during the operation did not exceed 150 ml in any case (range 2(&150ml). The blood loss occurred essentially during the vaginal part of the procedure. One patient (number 6) had signs of intraabdominal hemorrhage the day after surgery. A second laparoscopy was performed and 1000 ml blood was aspirated from the abdomen. The origin of the hemorrhage was never found. An intraabdominal drain was inserted for one day, and she went home 5 days after the hysterectomy. One patient (number 8) was readmitted 2 weeks after surgery because of an infection in the left adnexal region. An intravenous pyelogram showed a compression of the ureter. A cystoscopy was performed, and a pig-tail catheter was introduced into the ureter and left in place for 4 weeks. The patient was then given antibiotics for 3 weeks. Two weeks after placement of the catheter the patient had started her daily activities. The late postoperative phase after extraction of the pigtail catheter was uneventful. No intra-abdominal or wound infections were seen in the other patients. N o thromboembolic accidents occurred. All the specimens removed were subjected to pathological examination. The weights of the uteri were registered at the department of pathology and ranged from 90 to 320 grams. There were 4 specimens with myomas, one with superficial endometriosis of the uterus and one with adenomyosis. In 4 cases no pathology was found. The median duration of hospital stay was 2 days (range 1-5). Postoperative pain was minimal. If needed, oral medication was started 6 hours after surgery. The day after surgery there was no need for
A t the time of writing, we are not aware of any other Scandinavian report of this treatment. At present relatively few surgeons in Scandinavia utilize operative laparoscopy. In 1985 DeCherney stated that ‘little remains in the reproductive surgeon’s armamentarium that can’t be accomplished through the use of the laparoscope. The advent of endoscopic surgery has made and will continue to make profound changes in our field’ (7). Only after appropriate training in advanced operative laparoscopy can one proceed into more complex surgery. There are useful classifications of laparoscopic procedures according to degree of difficulty (4). Both the surgeon and the patient must be prepared for the possibility of a laparotomy. Laparoscopic hysterectomy was first reported by Reich in USA in 1989 (6). It is among the more complex laparoscopic procedures. Laparoscopic hysterectomy with endoscopic section of uterine arteries and further dissection, including opening of the vagina, is not always necessary especially for a gynecologist trained in vaginal hysterectomy. In our department the traditional way to perform hysterectomy has been the abdominal route. With our experience of laparoscopic surgery over the last four years, we find can divide the uterine vascular pedicles, the uterosacral ligaments, and most of the inferior parts of the cardinal ligaments laparoscopically. In fact this facilitates the uterine descent and minimizes the vaginal surgery. For a surgeon trained in vaginal hysterectomy, the laparoscopy could facilitate the surgery in patients where vaginal hysterectomy usually is contraindicated. This is what we call vaginal hysterectomy assisted by laparoscopy. The size of the uterus is important. We considered a transverse diameter of 8-10 cm as the upper limit. Above that extraction would be difficult without sectioning the uterus. We also selected patients without previous cesarean section during our first 10 operations because of probable scarring o n the anterior part of the uterus. With o u r present experience, we do not think, however, that previous cesarean section would present any major problem. There are several advantages in using the endoG I A stapler. Using this instrument instead of exclusively diathermy, we provoke less necrosis and tissue reaction. We also think that the stapler reduces op-
Acra Ohstet Gynecol Scund 71 (lY92)
Laparoscopic hysterectomy eration time, but we have not yet tested this hypothesis. The stapler is expensive, however. Operating time so far exceeds that of a conventional hysterectomy, even if the very first case is disregarded. We feel, however, that the time will be reduced as we gain further experience. Our initial experience with hysterectomies, is promising. All our patients were satisfied with the procedure and not least with the cosmetic result. It must be underlined that patient safety and successful outcome is dependent on adequate training in progressively complex laparoscopic procedures. The surgeon must also be trained in traditional gynecological surgery by laparotomy. Our series is small and further experience is needed as well as longterm results. Clinical trials will be necessary for a full evaluation of the method.
229
References 1 . Semm K, Mettler L. Technical progress in pelvic surgery via operative laparoscopy. Am J Obstet Gynecol 1980; 138: 121-7. 2. Dubois F, Berthelot G , Levard H. Cholecystectomie par coelioscopie. Nouv Presse med 1989; 18: 98k-2. 3. Gornel V. Operative laparoscopy: time for acceptance. Fertil Steril 1989; 52: 1-1 1. 4. Reich H. New techniques in advanced laparoscopic surgery. Clin Obstet Gynecol 1989; 3: 655-81. 5 . Langebrekke A, Urnes A . Laparoscopic adnexectomy. Actd Obstet Gynecol Scand 1991: in press. 6. Reich H , DeCaprio J , McGlynn F. Laparoscopic hysterectomy. J Gynecol Surg 1989; 5: 213-6. 7. DeCherney AH. The leader of the band is tired. Fertil Steril 1985; 44: 299-302. Address for correspondence:
Acknowledgment We would like to thank the head of our department, BrittIngjerd Nesheim, for providing us with the opportunities to develop our laparoscopic techniques, for encouragement during our work, and for help in preparing this manuscript.
Anton Langebrekke Department of Gynecology and Obstetrics Central Hospital of Akershus 1474 Nordbyhagen Norway
Acta Obstet Gynecol Scand
71 (1992)
Laparoscopic hysterectomy Initial experience ANTON LANGEBAEKKE, OSKARJOHANSKAR AND ARNEURNES From the Department of Obstetrics and Gynecology, Central Hospital of Akershus, Nordbyhagen, Norway
Actu Obstel Gynecol Scand 1992: 71: 226229
Laparoscopic hysterectomy is now being performed in our department in cases where no malignancy is suspected. This study presents the first 10 cases. Indications for hysterectomy were myomas, meno- and metrorrhagia resistant to medical and hysteroscopic treatment, and patients with pain and suspicion of having adenomyosis. No complications have been encountered during the laparoscopic operations, but one patient had a second laparoscopy on the first postoperative day due to postoperative bleeding. Another patient had a postoperative infection leading to a compression of the ureter. This report demonstrates that laparoscopic hysterectomy is a valuable addition to the new procedures in ‘minimal invasive surgery’, but only after long and appropriate training. Key words: laparoscopy; hysterectomy; operative laparoscopy; laser Submitted January 8,1992 Accepted January 22, 1992
Endoscopic surgery is rapidly becoming a popular alternative to traditional operative procedures for a variety of diseases. Kurt Semm in Kiel played an important rBle more than two decades ago in the development of operative laparoscopy (1). In 1987 the French gynecologist Philippe Mouret performed the first laparoscopic cholecystectomy in Lyon (2). To start with this procedure attracted only minor interest but today it has become widespread. It was not surprising that a gynccologist penetrated the general surgical discipline. Operative laparoscopy in gynecology has been progressively well established during the last decade and today most gynecological surgery can be performed using laparoscopic visualization (3, 4). Hysterectomy for benign disease has also been performed laparoscopically (6), and so has pelvic lymphadenectomy. (Querleu D. Laparoscopic pelvic lymphadenectomy. Presented at the Second World Congress of gynecological endoscopy, Clermond-Ferrand, France, 1Y89). These are only some of the indications among ‘the new frontiers’. After introduction of operative laparoscopy with Actu Ohstet Gynccol Scund 71 (1992)
CO, laser in our department during 1988, we have performed more and more complex laparoscopic surgery (5). With increased skill with ‘minimal invasive surgery’ we proceeded to laparoscopic hysterectomy, which was first done in July 1991. We present here the results of our first 10 operations.
Material and methods This report consists of the first ten laparoscopic hysterectomies performed in the Department of Obstetrics and Gynecology, Akershus Central Hospital, Norway. The patients were operated on between July and December 1991. They were all informed that laparoscopy was not the standard procedure in the department, and that a laparotomy might become necessary. The indications for surgery were either myomas (n = 3), or menometrorrhagia unresponsive to medical and hysteroscopic treatment (n = 4), or pelvic pain and endometriosis where medical treatment
Laparoscopic hysterectomy
227
Table 1. Results of laparoscopic hysterectomy in 10 patients Patient no.
Age
Indication
Op. time (min)
Uterine weight (8)
Hospital Complications Diathermy/ (yesho) Endo-Cia stay (days)
1
43 34 44 39 42
myoma dysmenorrhoea menorrhagia menorrhagia dysmenorrhoea myoma family history metrorrhagia dysmenorrhoea dysmenorrhoea
210 110 150 130 85 120 100 100 120 75
203 135 160 150 90 320 99 96 113 80
2 1 2 3 2 5 2 2 3 1
2 3 4 5 6 7 8 9 10
41
51 43 39 38
and laser laparoscopy were unsuccessful and adenomyosis was probable (n = 2). One patient was referred to our hospital from the Norwegian Radium Hospital for prophylactic hysterectomy and bilateral salpingo-oophorectomy because of high incidence of cancer in her family. All the patients underwent preoperative examinations to exclude gynecological malignancies. This consisted of general gynecological examination where we paid attention to the mobility and the size of the uterus, and to pathology of the adnexa. We excluded patients with a previous cesarean section, and also where the size of the uterus was more than that of a 13 week pregnancy. After colposcopy, cervical smear and where indicated biopsies of the cervix uteri were taken. The uterine cavity was examined as indicated by vaginal ultrasonography, hysteroscopy and cytology or histology of the endometrium. An enema was given the night before surgery. All operations were performed under general endotracheal anesthesia following standard preparations for vaginal surgery and possible laparotomy. The triple puncture technique used has been previously described in detail (5). A 12 mm laparoscope (Storz) with laser channel was introduced through the umbilicus, then two 5 mm suprapubic trocar sleeves to permit accessory instruments. The abdominal cavity was examined thoroughly to exclude other patholoTable 11. Pathologic diagnosis of 10 laparoscopic hysterectomies Diagnosis Myoma Normal Adenomyosis Endometriosis
Ih*
Number of patients
no no no no no Yes no Yes no no
diathermy diathermy both both both both diathermy diathermy both both
gy. Care was taken to locate the course of the ureter. In six cases, a midline 12 mm trocar was placed halfway between the umbilicus and the symphysis pubis to allow an endoscopic G I A stapler (Endo G I A 30, United States Surgical Corporation, Auto Suture Norway). In the case were the adnexa were removed together with the uterus, the infundibulopelvic vessels were desiccated with bipolar electrocoagulation and then cut with laparoscopic scissors. All other cases were started by coagulating and transecting the round ligament thus opening the broad ligament. The fallopian tube and the uteroovarian ligament were divided after desiccation with bipolar coagulation using 70 watt (Valley Lab Force 2). In 2 cases we used the Endo G I A stapler to divide these structures, but in the other patients the round ligaments were too vast and the anatomy atypical making the ligaments inappropriate for the stapler. We then worked progressively with laparoscopic surgical techniques including aquadissection to develop tissue planes. The bladder was separated from the anterior uterine surface using scissors or CO, laser assisted by aquadissection. For the big vessel hemostasis including the uterine artery and vein, bipolar electrosurgery or Endo-GIA stapler were used. We divided the uterosacral ligament laparoscopically and the transverse cervical ligament by bipolar electrosurgery and scissors or the laser, thus facilitating uterine descent and minimizing vaginal surgery. In half of the cases we opened the vagina with the laser or laparoscopic scissors, whereas in the other patients the opening was done by the vaginal route. The uterus was then removed (in one case with the adnexa attached) through the vagina. The peritoneal cavity was closed with a 0 Dexon purse string suture. The inferior parts of the cardinal ligaments were sutured to the lateral part of the vaginal vault, the vagina itself was closed with a 0 Dexon continuous suture. Inspection by the laparoscope at the end of Acta Ohstet Gynecol Scatid 71
( I 992)
228
A . Langebrekke et al.
the procedure ensured that hemostasis was adequate. In four cases an intraperitoneal drain was inserted through one of the suprapubic incisions unti1 the morning after surgery. All patients received 2 g Ampicillin and 1500 mg Metronidazol IV.
analgesics and, except for one (number 6), they were all eating and walking around. Two patients (nilmbers 2 and lo), were discharged the day after surgery. The 8 cases without complications went back to daily activity from 10 to 21 days after surgery.
Results
Discussion
Table I summarizes the data of the 10 patients. The median age of the patients was 42.5 (range 34-51). We never resorted to laparotomy because of hemostatic or other technical difficulties. Towards the end of the procedure one patient (number 4) developed a massive subcutaneous emphysema. This disappeared during the next 4 hours while she was observed in the intensive care unit. During this time she was on an artificial respirator. There were no complications after extubation, and she was discharged on the third day after the surgery. Total estimated blood loss during the operation did not exceed 150 ml in any case (range 2(&150ml). The blood loss occurred essentially during the vaginal part of the procedure. One patient (number 6) had signs of intraabdominal hemorrhage the day after surgery. A second laparoscopy was performed and 1000 ml blood was aspirated from the abdomen. The origin of the hemorrhage was never found. An intraabdominal drain was inserted for one day, and she went home 5 days after the hysterectomy. One patient (number 8) was readmitted 2 weeks after surgery because of an infection in the left adnexal region. An intravenous pyelogram showed a compression of the ureter. A cystoscopy was performed, and a pig-tail catheter was introduced into the ureter and left in place for 4 weeks. The patient was then given antibiotics for 3 weeks. Two weeks after placement of the catheter the patient had started her daily activities. The late postoperative phase after extraction of the pigtail catheter was uneventful. No intra-abdominal or wound infections were seen in the other patients. N o thromboembolic accidents occurred. All the specimens removed were subjected to pathological examination. The weights of the uteri were registered at the department of pathology and ranged from 90 to 320 grams. There were 4 specimens with myomas, one with superficial endometriosis of the uterus and one with adenomyosis. In 4 cases no pathology was found. The median duration of hospital stay was 2 days (range 1-5). Postoperative pain was minimal. If needed, oral medication was started 6 hours after surgery. The day after surgery there was no need for
A t the time of writing, we are not aware of any other Scandinavian report of this treatment. At present relatively few surgeons in Scandinavia utilize operative laparoscopy. In 1985 DeCherney stated that ‘little remains in the reproductive surgeon’s armamentarium that can’t be accomplished through the use of the laparoscope. The advent of endoscopic surgery has made and will continue to make profound changes in our field’ (7). Only after appropriate training in advanced operative laparoscopy can one proceed into more complex surgery. There are useful classifications of laparoscopic procedures according to degree of difficulty (4). Both the surgeon and the patient must be prepared for the possibility of a laparotomy. Laparoscopic hysterectomy was first reported by Reich in USA in 1989 (6). It is among the more complex laparoscopic procedures. Laparoscopic hysterectomy with endoscopic section of uterine arteries and further dissection, including opening of the vagina, is not always necessary especially for a gynecologist trained in vaginal hysterectomy. In our department the traditional way to perform hysterectomy has been the abdominal route. With our experience of laparoscopic surgery over the last four years, we find can divide the uterine vascular pedicles, the uterosacral ligaments, and most of the inferior parts of the cardinal ligaments laparoscopically. In fact this facilitates the uterine descent and minimizes the vaginal surgery. For a surgeon trained in vaginal hysterectomy, the laparoscopy could facilitate the surgery in patients where vaginal hysterectomy usually is contraindicated. This is what we call vaginal hysterectomy assisted by laparoscopy. The size of the uterus is important. We considered a transverse diameter of 8-10 cm as the upper limit. Above that extraction would be difficult without sectioning the uterus. We also selected patients without previous cesarean section during our first 10 operations because of probable scarring o n the anterior part of the uterus. With o u r present experience, we do not think, however, that previous cesarean section would present any major problem. There are several advantages in using the endoG I A stapler. Using this instrument instead of exclusively diathermy, we provoke less necrosis and tissue reaction. We also think that the stapler reduces op-
Acra Ohstet Gynecol Scund 71 (lY92)
Laparoscopic hysterectomy eration time, but we have not yet tested this hypothesis. The stapler is expensive, however. Operating time so far exceeds that of a conventional hysterectomy, even if the very first case is disregarded. We feel, however, that the time will be reduced as we gain further experience. Our initial experience with hysterectomies, is promising. All our patients were satisfied with the procedure and not least with the cosmetic result. It must be underlined that patient safety and successful outcome is dependent on adequate training in progressively complex laparoscopic procedures. The surgeon must also be trained in traditional gynecological surgery by laparotomy. Our series is small and further experience is needed as well as longterm results. Clinical trials will be necessary for a full evaluation of the method.
229
References 1 . Semm K, Mettler L. Technical progress in pelvic surgery via operative laparoscopy. Am J Obstet Gynecol 1980; 138: 121-7. 2. Dubois F, Berthelot G , Levard H. Cholecystectomie par coelioscopie. Nouv Presse med 1989; 18: 98k-2. 3. Gornel V. Operative laparoscopy: time for acceptance. Fertil Steril 1989; 52: 1-1 1. 4. Reich H. New techniques in advanced laparoscopic surgery. Clin Obstet Gynecol 1989; 3: 655-81. 5 . Langebrekke A, Urnes A . Laparoscopic adnexectomy. Actd Obstet Gynecol Scand 1991: in press. 6. Reich H , DeCaprio J , McGlynn F. Laparoscopic hysterectomy. J Gynecol Surg 1989; 5: 213-6. 7. DeCherney AH. The leader of the band is tired. Fertil Steril 1985; 44: 299-302. Address for correspondence:
Acknowledgment We would like to thank the head of our department, BrittIngjerd Nesheim, for providing us with the opportunities to develop our laparoscopic techniques, for encouragement during our work, and for help in preparing this manuscript.
Anton Langebrekke Department of Gynecology and Obstetrics Central Hospital of Akershus 1474 Nordbyhagen Norway
Acta Obstet Gynecol Scand
71 (1992)
