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FETAL VIABILILTY IN MULTIPLE PREGNANCY
183
"epoch" of breathing activity ended when less than three valid breaths occurred within this timeframe. We, however, considered fetuses to be breathing only if an episode of movements was continuous for at least 60 s during a 30 min observation period, which was extended for up to 2 h if no such episodes were seen. A breath-to-breath interval of more than 6 s was taken to indicate cessation of breathing. Our definition has been used extensively before and emphasises the importance of sustained respiratory effort for a defined time.2,5,6 Although Castle and Tumbulf suggested 20 s or more may be sufficient, most investigators use at least 30 or 60 S.2,5,6,8,9 "Breathing activity" may occur before death in utero from a variety of insults, but usually as gasps or brief episodes of abnormal breathing."* Moessinger and colleagues’ use of a short period such as 6 s could include such activity and we believe this could be incorrectly interpreted as "FBM present". Indeed, in our series, fetuses who subsequently died of pulmonary hypoplasia did make breathing movements which we interpreted as gasps, as none of these episodes were sustained for a 60 s period with a breath-tobreath interval of less than 6 s. Our results suggest that "sustained" breathing activity rather than the short epochs described by Moessinger et al is important for continuing antenatal lung growth in cases of oligohydramnios due to PROM. ANNE GREENOUGH Department of Child Health, MARGARET BLOTT King’s College School of K. NICOLAIDES Medicine-and Dentistry, STUART CAMPBELL London SE5 9PJ 1. Blott M,
Greenough A. Oligohydramnios in the second trimester of pregnancy: Fetal breathing and normal lung growth. Early Hum Devel (in press). 2 Roberts AD, Griffin D, Mooney R, Cooper DJ, Campbell S. Fetal activity in 100 normal third trimester pregnancies. Br J Obstet Gynaecol 1980; 87: 480-84. 3. Cooney TP, Thurlbeck WM. Pulmonary hypoplasia in Down’s syndrome. N Engl J Med 1982; 207: 1170-73.
Emery JL, Mithal A. The alveoli in the terminal respiratory unit of man during late intrauterine life and childhood. Arch Dis Child 1960; 35: 544-47. 5. Manning FA, Platt LD, Sipos L. Antepartum fetal evaluation: Development of a fetal biophysical profile. Am J Obstet Gynecol 1980; 136: 787-95. 6. Vintzileos AM, Campbell WA, Ingardia CJ, Nochimson DJ. The fetal biophysical profile and its predictive value. Obstet Gynecol 1983; 62: 271-78. 7. Castle BM, Turnbull AC. The presence or absence of fetal breathing movements predicts the outcome of preterm labour. Lancet 1983; ii: 471-73. 8. Vintzileos AM, Campbell WA, Nochimson DJ, Weinbaum PJ. Fetal breathing as a predictor of infection in premature rupture ofthe membranes. Obstet Gynecol 1986; 4.
67: 813-17.
Manning FA, Platt LD. Fetal breathing movements and the abnormal contraction stress test. Am J Obstet Gynecol 1979; 133: 590-93. 10. Patrick JE, Dalton KJ, Dawes GS. Breathing patterns before detah in fetal lambs. Am J Obstet Gynecol 1976; 125: 73-78. 9.
FETAL VIABILILTY IN MULTIPLE PREGNANCY
SIR,-Dr Stabile and colleagues (Nov 28, p 1237) report that early ultrasound examination will identify a large proportion of pregnancies destined to continue when spontaneous abortion threatens. At 5-8 weeks, identification of a live fetus rarely results in spontaneous abortion. We have observed the effect of identification of the fetal heart at 5-8 weeks in multiple gestations resulting from in-vitro fertilisation. After transfer of 3 or 4 embryos all patients were offered ultrasound examination, primarily to identify the number of embryos implanted and to aid diagnosis of ectopic pregnancy. Multiple gestation sacs (2-4) were observed at 6-8 weeks’ gestation in 106 patients between September, 1984, and April, 1987. 5 patients had no demonstrable live fetus in any sac (all twin sacs). All miscarried and were excluded from further analysis. Of the 101patients in which one or more fetal hearts were identified, 98 (97%) have either now delivered one or more live infants or have one or more ongoing pregnancies above 28 weeks’ gestation. A fetal heart was identified in 178 gestation sacs. 172 (96 6%) of these are either ongoing (containing a live fetus over 28 weeks’ gestation, n = 38) or have resulted in delivery of a live infant (n= 134). A fetal heart was not identified in 53 sacs (22-9% of the total). 52 of these resulted in the demise of the sac and 1(19 %) in a live birth. The number of fetal hearts seen was less than the number of gestation sacs in 31 % patients with 2 sacs, 53 % patients with 3 sacs
miscarried a live fetus. The miscarriage rate was similar to the group in which all sacs contained a live fetus (7-8%). That an empty sac does not affect eventual outcome is therefore true for higher order
pregnancies too. The positive reassurance of ongoing pregnancy when a fetal heart is identified by ultrasonography at 6-8 weeks can be extended to multiple pregnancies where 2-4 sacs are present. Academic Department of Obstetrics and Gynaecology, King’s College School of Medicine and Dentistry, London SE5 8RX
JULIAN S. PAMPIGLIONE
Hallam Medical Centre, London WIN 5LR
BRIDGETT A. MASON LIMITATIONS OF GIFT
SIR,-We have completed more than 1700 gamete intrafallopian (GIFT) operations and consider this treatment to be an important part of any comprehensive fertility service. However, despite the promotion of GIFT as a simpler alternative to in-vitro fertilisation (IVF) for use in district general hospitals, we are cautious in recommending it as a first option for most patients with open fallopian tubes who are resistant to conventional treatment. GIFT may fail to fulfil the hopes of both specialists and infertile couples. transfer
The main difference between GIFT and IVF is that fertilisation in vivo rather than in vitro. Both require the same organisational work-up. There are advantages to GIFT in patients with a record of fertilisation (ie, a previous pregnancy or IVF) but there are limitations to GIFT alone in those in whom fertilisation has not been proven, especially when sperm counts are thought to be equivocal or suboptimum. GIFT should, ideally, be undertaken in conjunction with, rather than in isolation from, IVF. If the technical skill needed to handle gametes and culture media that is necessary with GIFT is available then IVF is also possible. The use of both techniques together provides a clearer understanding of the nature of difficult cases of infertility and their management. This has particular relevance to some patients with "unexplained" infertility or endometriosis and in some with polycystic ovaries who have failed to conceive by alternative means. They may have lower fertilisation and pregnancy occurs
potential. We do not recommend GIFT as the primary treatment in patients with suboptimum sperm counts. Analysis of our first 1000 procedures shows that GIFT with poor sperm has a significantly reduced chance of success. Similarly, there are limitations to GIFT in certain groups if no more than four oocytes are transferred. Your Oct 24 editorial refers to IVF and GIFT as if they were totally separate entities. They are not. If the ability to do both is not available some patients treated unsuccessfully by GIFT may remain unaware of the cause of their infertility and of its potential resolution. The question whether fertilisation is possible will not have been answered. GIFT is a welcome addition to a range of fertility options but it is no panacea. It is not ideal to use this method of assisted reproduction on an empirical basis without the provision of IVF.
.
and all
patients with 4 sacs.
In these
patients only 2 out of 36 (6%)
Fertility & IVF Unit, Humana Hospital Wellington, London NW8 9LE
IAN CRAFT PETER R. BRINSDEN ERIC G. SIMONS PAUL M. LEWIS
NEEDLE SIZE AND RISK OF MISCARRIAGE AFTER
AMNIOCENTESIS
SiR,—In our randomised controlled trial of genetic amniocentesis in low-risk women1 we stated that an 18G needle (outer diameter 1-2 mm) was used. Others2" have correlated this needle size with the 1 -0 % miscarriage rate (95 % confidence interval 0-3-1-5) we found. We now know that the amniocenteses were done with a 20G needle (1-0 mm). Embarrassing though it is we felt that this information had to be made available because we found a higher miscarriage rate after amniocentesis than most other workers had done. Ours is the only randomised controlled trial to have been published and, with the above amendment, it now fulfils all the
"epoch" of breathing activity ended when less than three valid breaths occurred within this timeframe. We, however, considered fetuses to be breathing only if an episode of movements was continuous for at least 60 s during a 30 min observation period, which was extended for up to 2 h if no such episodes were seen. A breath-to-breath interval of more than 6 s was taken to indicate cessation of breathing. Our definition has been used extensively before and emphasises the importance of sustained respiratory effort for a defined time.2,5,6 Although Castle and Tumbulf suggested 20 s or more may be sufficient, most investigators use at least 30 or 60 S.2,5,6,8,9 "Breathing activity" may occur before death in utero from a variety of insults, but usually as gasps or brief episodes of abnormal breathing."* Moessinger and colleagues’ use of a short period such as 6 s could include such activity and we believe this could be incorrectly interpreted as "FBM present". Indeed, in our series, fetuses who subsequently died of pulmonary hypoplasia did make breathing movements which we interpreted as gasps, as none of these episodes were sustained for a 60 s period with a breath-tobreath interval of less than 6 s. Our results suggest that "sustained" breathing activity rather than the short epochs described by Moessinger et al is important for continuing antenatal lung growth in cases of oligohydramnios due to PROM. ANNE GREENOUGH Department of Child Health, MARGARET BLOTT King’s College School of K. NICOLAIDES Medicine-and Dentistry, STUART CAMPBELL London SE5 9PJ 1. Blott M,
Greenough A. Oligohydramnios in the second trimester of pregnancy: Fetal breathing and normal lung growth. Early Hum Devel (in press). 2 Roberts AD, Griffin D, Mooney R, Cooper DJ, Campbell S. Fetal activity in 100 normal third trimester pregnancies. Br J Obstet Gynaecol 1980; 87: 480-84. 3. Cooney TP, Thurlbeck WM. Pulmonary hypoplasia in Down’s syndrome. N Engl J Med 1982; 207: 1170-73.
Emery JL, Mithal A. The alveoli in the terminal respiratory unit of man during late intrauterine life and childhood. Arch Dis Child 1960; 35: 544-47. 5. Manning FA, Platt LD, Sipos L. Antepartum fetal evaluation: Development of a fetal biophysical profile. Am J Obstet Gynecol 1980; 136: 787-95. 6. Vintzileos AM, Campbell WA, Ingardia CJ, Nochimson DJ. The fetal biophysical profile and its predictive value. Obstet Gynecol 1983; 62: 271-78. 7. Castle BM, Turnbull AC. The presence or absence of fetal breathing movements predicts the outcome of preterm labour. Lancet 1983; ii: 471-73. 8. Vintzileos AM, Campbell WA, Nochimson DJ, Weinbaum PJ. Fetal breathing as a predictor of infection in premature rupture ofthe membranes. Obstet Gynecol 1986; 4.
67: 813-17.
Manning FA, Platt LD. Fetal breathing movements and the abnormal contraction stress test. Am J Obstet Gynecol 1979; 133: 590-93. 10. Patrick JE, Dalton KJ, Dawes GS. Breathing patterns before detah in fetal lambs. Am J Obstet Gynecol 1976; 125: 73-78. 9.
FETAL VIABILILTY IN MULTIPLE PREGNANCY
SIR,-Dr Stabile and colleagues (Nov 28, p 1237) report that early ultrasound examination will identify a large proportion of pregnancies destined to continue when spontaneous abortion threatens. At 5-8 weeks, identification of a live fetus rarely results in spontaneous abortion. We have observed the effect of identification of the fetal heart at 5-8 weeks in multiple gestations resulting from in-vitro fertilisation. After transfer of 3 or 4 embryos all patients were offered ultrasound examination, primarily to identify the number of embryos implanted and to aid diagnosis of ectopic pregnancy. Multiple gestation sacs (2-4) were observed at 6-8 weeks’ gestation in 106 patients between September, 1984, and April, 1987. 5 patients had no demonstrable live fetus in any sac (all twin sacs). All miscarried and were excluded from further analysis. Of the 101patients in which one or more fetal hearts were identified, 98 (97%) have either now delivered one or more live infants or have one or more ongoing pregnancies above 28 weeks’ gestation. A fetal heart was identified in 178 gestation sacs. 172 (96 6%) of these are either ongoing (containing a live fetus over 28 weeks’ gestation, n = 38) or have resulted in delivery of a live infant (n= 134). A fetal heart was not identified in 53 sacs (22-9% of the total). 52 of these resulted in the demise of the sac and 1(19 %) in a live birth. The number of fetal hearts seen was less than the number of gestation sacs in 31 % patients with 2 sacs, 53 % patients with 3 sacs
miscarried a live fetus. The miscarriage rate was similar to the group in which all sacs contained a live fetus (7-8%). That an empty sac does not affect eventual outcome is therefore true for higher order
pregnancies too. The positive reassurance of ongoing pregnancy when a fetal heart is identified by ultrasonography at 6-8 weeks can be extended to multiple pregnancies where 2-4 sacs are present. Academic Department of Obstetrics and Gynaecology, King’s College School of Medicine and Dentistry, London SE5 8RX
JULIAN S. PAMPIGLIONE
Hallam Medical Centre, London WIN 5LR
BRIDGETT A. MASON LIMITATIONS OF GIFT
SIR,-We have completed more than 1700 gamete intrafallopian (GIFT) operations and consider this treatment to be an important part of any comprehensive fertility service. However, despite the promotion of GIFT as a simpler alternative to in-vitro fertilisation (IVF) for use in district general hospitals, we are cautious in recommending it as a first option for most patients with open fallopian tubes who are resistant to conventional treatment. GIFT may fail to fulfil the hopes of both specialists and infertile couples. transfer
The main difference between GIFT and IVF is that fertilisation in vivo rather than in vitro. Both require the same organisational work-up. There are advantages to GIFT in patients with a record of fertilisation (ie, a previous pregnancy or IVF) but there are limitations to GIFT alone in those in whom fertilisation has not been proven, especially when sperm counts are thought to be equivocal or suboptimum. GIFT should, ideally, be undertaken in conjunction with, rather than in isolation from, IVF. If the technical skill needed to handle gametes and culture media that is necessary with GIFT is available then IVF is also possible. The use of both techniques together provides a clearer understanding of the nature of difficult cases of infertility and their management. This has particular relevance to some patients with "unexplained" infertility or endometriosis and in some with polycystic ovaries who have failed to conceive by alternative means. They may have lower fertilisation and pregnancy occurs
potential. We do not recommend GIFT as the primary treatment in patients with suboptimum sperm counts. Analysis of our first 1000 procedures shows that GIFT with poor sperm has a significantly reduced chance of success. Similarly, there are limitations to GIFT in certain groups if no more than four oocytes are transferred. Your Oct 24 editorial refers to IVF and GIFT as if they were totally separate entities. They are not. If the ability to do both is not available some patients treated unsuccessfully by GIFT may remain unaware of the cause of their infertility and of its potential resolution. The question whether fertilisation is possible will not have been answered. GIFT is a welcome addition to a range of fertility options but it is no panacea. It is not ideal to use this method of assisted reproduction on an empirical basis without the provision of IVF.
.
and all
patients with 4 sacs.
In these
patients only 2 out of 36 (6%)
Fertility & IVF Unit, Humana Hospital Wellington, London NW8 9LE
IAN CRAFT PETER R. BRINSDEN ERIC G. SIMONS PAUL M. LEWIS
NEEDLE SIZE AND RISK OF MISCARRIAGE AFTER
AMNIOCENTESIS
SiR,—In our randomised controlled trial of genetic amniocentesis in low-risk women1 we stated that an 18G needle (outer diameter 1-2 mm) was used. Others2" have correlated this needle size with the 1 -0 % miscarriage rate (95 % confidence interval 0-3-1-5) we found. We now know that the amniocenteses were done with a 20G needle (1-0 mm). Embarrassing though it is we felt that this information had to be made available because we found a higher miscarriage rate after amniocentesis than most other workers had done. Ours is the only randomised controlled trial to have been published and, with the above amendment, it now fulfils all the