聽歌的風

雖然這次成功懷孕，但是卻發現擔心的事情只有多沒少，我想這也許就是人生吧 (笑)

擔心的事情主要有兩個，一個是流產的機率，另一個則是畸胎的機率；兩個都是難以預測，但是愛操心的我當然會先看看國外的paper，

還好大部分的paper都認為，只要用成熟的精蟲作ICSI，畸胎的比率跟正常懷孕沒有統計上的顯著差別。所以需要用到TESE或ICSI的朋友就不要太擔心了喔!

當然該作的檢查還是要作，除了侵入性的羊膜穿刺，我們想聽台兒診所在作了高層次超音波之後的建議，畢竟羊膜穿刺還是有大約千分之三的流產風險，對於好不容易懷孕的我們，

還是小心一點好。

 

 

  

http://humrep.oxfordjournals.org/cgi/content/full/18/10/2093

在非阻塞無精症案例中使用睪丸切片所取得精蟲作單一精蟲顯微植入的兒童的懷孕結果

^{在全部299個使用睪丸精蟲而懷孕的案例中，83個是非阻塞性無精症病人(其中72個是使用新鮮取出的精蟲，11個是使用冷凍保存的精蟲)。其餘的216個病人則是阻塞性無精症病人(其中189個是使用新鮮取出的精蟲，27個是使用冷凍保存的精蟲) 在全體病人中，25個失去聯絡(8%)，此次研究剩下的274個案例。}

^{平均的懷孕女性年紀為31.4歲(非阻塞性)與32.7歲(阻塞性)，非阻塞性的案例為第一次懷孕的比率較高(76% vs 63%)，但尚無達到統計上的顯著差異。}

^{此次研究結果顯示，這兩個群體在懷孕的結果上並無顯著差異。}

^{在非阻塞群體所產生的61個嬰兒中，58個為活產，有3個為妊娠中終止，1個在生產完死亡。38個嬰兒為單胞胎，14個為雙胞胎，9個為3胞胎。}

^{在阻塞性群體所產生的196個嬰兒中，193個為活產，有3個為妊娠中終止。110個嬰兒為單胞胎，74個為雙胞胎，12個為3胞胎。}

^{所有的群體中，單胞胎的生產中有顯著周數不足的現象，雙胞胎的生產則有早產的現象。}

^{兩個群體中初生兒的體重並無顯著的差異。3個胎兒懷孕中止，一個初生兒在出生後死亡。非阻塞性與阻塞性的早期懷孕致死率分別為66/1000與15/1000}

^{非阻塞性的群體中有4%的初生兒有重大的畸形發生，阻塞性則有3%。非阻塞性的群體中有2%的初生兒有輕微的畸形發生，阻塞性則有4%。} 

^{非阻塞這一組有15/61的胎兒採取了染色體檢驗，其中發現有一個染色體異常(7%)而人工終止了妊娠。在另兩個流產的個案中，進行了染色體的確認發現其中一個也是有異常的情形。在阻塞的這一組，有70/196的胎兒進行了染色體檢驗(應該是羊膜穿刺)，其中有兩個為染色體異常，一為XY錯置情況，另一則為遺傳性的染色體異常。}

^{使用睪丸切片所取得的精蟲來作單一精蟲植入雖然是可行的，但是伴隨的是比用阻塞性無精症所取得精蟲來得較低的受精率及懷孕率。有些研究對於嚴重睪丸衰竭所取得的精蟲有著染色體不正常的較高機率的看法。這是因為這些研究指出不成熟的精蟲可能在交換配子時有可能會產生不完整的情況。}

^{不完整基因交換通常會影響受精以及早期胚胎的發展，但在懷孕晚期會造成的影響也可能會更大。也有一說是不成熟的配子有可能帶著缺乏作用的精蟲中央體而且展現初不正常的原核體凝聚現象。基於種種考量，在荷蘭是禁止使用非阻塞精蟲來進行植入的。}

^{到目前為止，只有一些文獻有探討使用睪丸切片精蟲來施作ICSI的生產結果，Ludwig 2002年研究了229個使用睪丸精子的懷孕個案，結論是使用睪丸精子並不會增加重大畸形的風險，重大畸形的比率，至出生八周為止，為9%(含流產個數)，相較於使用自然射出精蟲來作ICSI的畸形率為8.4%。Bonduelle 2002年對於使用自然射出精蟲與使用睪丸取出精蟲的個案進行研究也未發現兩組之間的畸胎率有顯著的差異 (3.4%, 2477個樣本 vs. 2.9%, 206個樣本)。 Wennerholm 2000年的研究指出31個使用睪丸取出精蟲的出生嬰兒沒有發現重大畸形。以上的研究中，使用睪丸取出精蟲的個案數量偏少，也沒有對阻塞與非阻塞性的差異作比較。只有Palermo 1999年的研究作這兩者之間的差異比較，但此研究無法分辨是臨床上還是病理上的結果。在我們的研究中，發現非阻塞睪丸取出精蟲有4%的畸胎率，而使用阻塞性睪丸取出的精蟲有3%的畸胎率，這項結果與Bonduelle 2002年所得到的結論是一致的，該項研究指出使用ICSI所產出的嬰兒有3.4%的比率為畸胎。}

^{對於懷孕的結果，我們觀察出一個明顯的現象，使用睪丸取出精蟲，會導致單胞胎有較低的懷孕週數而雙胞胎則有較高的早產機率。}

^{此項研究中，我們並沒有將精蟲條件為數目低下、活動力不良且型態不良症或自發性懷孕的情況考慮在內。我們的研究樣本數目還屬不足，無法得到一個決定性的結論。無論如何，我們建議繼續研究使用未成熟精蟲的情況，}

Pregnancy outcome and neonatal data of children born after ICSI using testicular sperm in obstructive and non-obstructive azoospermia

V. Vernaeve^1,3, M. Bonduelle², H. Tournaye¹, M. Camus¹, A. Van Steirteghem¹ and P. Devroey¹

¹ Centre For Reproductive Medicine and ² Center for Medical Genetics, University Hospital, Dutch-speaking Brussels Free University (Vrije Universiteit Brussel), Laarbeeklaan 101, B-1090 Brussels, Belgium

³ To whom correspondence should be addressed. e-mail: valerie.vernaeve@az.vub.ac.be

	Abstract

Top Abstract Introduction Materials and methods Results Discussion References

 
BACKGROUND: Registries on outcome of ICSI pregnancies obtained with testicular sperm do not differentiate between obstructive (OA) and non-obstructive azoospermia (NOA). We evaluated the pregnancy outcome and neonatal data on children born after ICSI using testicular sperm of men with histologically proven OA or NOA. METHODS: Pregnancies obtained after ICSI using testicular sperm of men with defined NOA (n = 70) were compared with those of men with OA (n = 204). RESULTS: Multiple birth rates in NOA and OA couples, respectively, were 21 versus 27% (P = NS), overall preterm delivery rates were 38 versus 26% (NS), and prematurity rates were 24 versus 13% for singletons (NS) and 86 versus 54% for twins (relative risk 1.59, 95% confidence interval 1.04–2.42). Median gestational age for singletons was 38.3 versus 39.3 weeks, respectively (P < 0.05). The low birth weight rates were 34 versus 31%, respectively (NS). The early perinatal mortality rate was 66 versus 15 per 1000 births, respectively, (NS). Major congenital malformations were observed in 4 versus 3%, respectively, of the live born babies (NS). Prenatal karyotypes showed 7% de-novo abnormalities in the NOA group versus 1% in the OA group (NS). CONCLUSIONS: Our data do not show differences between NOA and OA pregnancies except for a strong tendency towards a lower gestational age in singletons and a higher percentage of premature twins in the NOA group. Although our data are based on a limited sample, the differences observed call for further analysis. Given the low pregnancy rates after ICSI with NOA, a multicentre study, differentiating NOA and OA patients, would be recommended.

 

Key words: azoospermia/follow-up/ICSI/pregnancy outcome/testicular sperm

	Introduction

Top Abstract Introduction Materials and methods Results Discussion References

 
Since its introduction in 1992, ICSI has become a popular assisted fertilization technique with a high efficiency in treating severe oligoasthenoteratozoospermia (Palermo et al., 1992). Because ICSI has been considered from the start as a procedure not without risks, several studies have been performed on the follow-up of pregnancies and on children born after ICSI.

The different percentages found in the published studies about major and minor congenital malformations cannot be compared, but overall the data in large and reliable surveys do not indicate a higher rate of malformations in ICSI children than in IVF- or naturally conceived children (Wennerholm et al., 2000a; Bonduelle et al., 2002a). However, the study by Ericson and Källen (2001) found an increased risk of the total malformation rate after IVF which could mainly be explained by maternal factors. Furthermore, the limited available data on ICSI fetal karyotypes reveal that, in comparison with a general neonatal population, there is a slight but increased risk of chromosomal anomalies, predominantly affecting the sex chromosomes (Bonduelle et al., 2002b).

Today, ICSI is also widely used for patients with azoospermia even when severe testicular failure is present. Since there is increasing evidence that in these patients spermatozoa have an increased chromosomal aneuploidy rate (Bernardini et al., 2000; Martin et al., 2000; Levron et al., 2001; Mateizel et al., 2002), follow-up of the pregnancies obtained after the use of testicular sperm from these patients is very important. Few studies involving a small number of patients have been published on the outcome of pregnancies and the health of children born after ICSI with testicular sperm (Aytoz et al., 1998; Wennerholm et al., 2000b; Bonduelle et al., 2002a; Ludwig et al., 2002). Furthermore, a distinction between normal spermatogenesis and spermatogenetic failure is lacking.

The aim of this study is to analyse the pregnancy outcome and neonatal outcome of children born after ICSI with testicular sperm in patients with obstructive and non-obstructive azoospermia.

	Materials and methods

Top Abstract Introduction Materials and methods Results Discussion References

 
All pregnant patients whose male partner had a testicular sperm recovery for ICSI in the period from January 1994 to December 2000 were included in this retrospective, cohort study. The two study cohorts were defined according to testicular histology. The non-obstructive azoospermia (NOA) group included patients with complete or incomplete maturation arrest, complete or incomplete germ cell aplasia (Sertoli cell-only) and tubular sclerosis and atrophy. All these patients had absolute azoospermia (i.e. no spermatozoa were found in any of the semen analyses after centrifugation at high speed), but had sperm found after testicular biopsy. Klinefelter’s syndrome patients were excluded from this study.

Pregnancies obtained after ICSI with both fresh and frozen testicular spermatozoa were included in the study.

Technical procedures, including testicular sperm recovery, ovarian stimulation protocols, micro-injection procedure, embryo culture and transfer, and luteal phase support, have been described previously (Verheyen et al., 1995; Tournaye et al., 1997; Joris et al., 1998; Van Steirteghem et al., 1998).

A rise in serum HCG on two consecutive occasions from 11 days after transfer indicated pregnancy. Each pregnancy with at least one sac revealed by ultrasonography 5 weeks after transfer was considered as a clinical pregnancy. If there was no sac, the pregnancy was considered subclinical. Gestational age was calculated as the time between the beginning of the last menstrual period and the date of birth of the child. The last menstrual period was calculated by adding 15 days to the date of embryo transfer.

We evaluated both early (before 20 weeks of gestation) and late (20 weeks of gestation) pregnancy outcome in the NOA and obstuctive azoospermia (OA) cohorts.

Abortion was defined as pregnancy loss before 20 weeks of gestational age, and preterm delivery was defined as delivery of a live born or stillborn infant before 37 weeks of gestational age. A live born or stillborn infant weighing <2500 g at birth was considered a low birth weight infant. A live born or stillborn infant weighing <1500 g at birth was considered a very low birth weight infant. The death of a fetus of at least 20 weeks’ gestation before delivery was defined as intrauterine death, and the death of an infant during the first week following delivery was defined as early neonatal death. The early perinatal mortality rate was expressed as the sum of stillbirths and early neonatal deaths per 1000 births.

Major malformation was defined as those malformations causing death or functional impairment, or requiring surgical correction. The remaining malformations were considered minor malformations.

Since all outcome measures were not available for all patients, calculations were performed on appropriate data subsets.

Comparisons of the NOA and OA groups for qualitative variables were performed using a Fisher exact test. A Mann–Whitney test was used when data were not normally distributed. A P-value of <0.05 was considered to be statistically significant. Additional relative risk (RR) with corresponding 95% confidence interval (CI) was calculated whenever relevant.

This study was approved by our institutional review board.

	Results

Top Abstract Introduction Materials and methods Results Discussion References

 
In all, 299 pregnancies obtained with testicular sperm were evaluated. Eighty-three pregnancies were obtained with testicular sperm from NOA patients (72 pregnancies were obtained after the use of fresh sperm and 11 pregnancies with frozen-thawed sperm). Two hundred and sixteen pregnancies were obtained with testicular sperm from OA patients (189 pregnancies were obtained after the use of fresh sperm and 27 pregnancies with frozen-thawed sperm). In all, 25 patients were lost for follow-up (8%): 13 (16%) in the NOA and 12 (6%) in the OA group (P = 0.006). Data for analysis were thus available for a total of 274 pregnancies (70 in the NOA group and 204 in the OA group). Six patients were pregnant more than once in the NOA group (9%) compared with 28 in the OA group (14%) (P = 0.3).

The mean age of the women was 31.4 years (95% CI, 29.7–33.0) versus 32.7 years (95% CI, 31.8–33.6) in the NOA and OA group, respectively. Primigravidae were more common in the NOA group (51 out of 67 with known gestational status versus 127 out of 203 with known status, i.e. 76 versus 63%), but statistical significance was not reached (P = 0.053). The parity was not statistically different between the two cohorts.

There were no statistical significant differences with respect to the outcome of the pregnancies in the two groups studied (Table I).

 

View this table: [in this window] [in a new window]   Table I. Outcome of the pregnancies in non-obstructive and obstructive azoospermia

 
Of the 61 children in the NOA group, 58 were live born, three were stillborn and one died in the immediate post-partum period. Thirty-eight children were from singleton pregnancies, 14 were from twin pregnancies and nine were from triplet pregnancies.

Of the 196 children in the OA group, 193 were live born and three were stillborn. One-hundred and ten children were from singleton pregnancies, 74 were from twin pregnancies and 12 were from triplet pregnancies.

There was a strong tendency towards a lower gestational age among the singletons and a higher percentage of preterm twins in the NOA group. The gestational age at birth and percentages of preterm deliveries are summarized in Table II

 

View this table: [in this window] [in a new window]   Table II. Gestational age at birth, preterm deliveries and birth weight of the children in non-obstructive and obstructive azoospermia

 
No differences were observed between both groups regarding the birth weight of the children. The results of birth weights of the non-obstructive and obstructive groups are summarized in Table II.

Three fetuses died in utero after 20 weeks in both groups, and one infant died in the early neonatal period in the NOA group. The early perinatal mortality rate was thus 66 per 1000 births (n = 4) and 15 per 1000 (n = 3) in the NOA and OA group, respectively (RR: 4.3, 95% CI 0.8–23.7).

Major malformations were present in 4% of the liveborn children (n = 2 out of 54 with a known result) obtained with testicular sperm of NOA men versus in 3% in children of OA men (n = 5 out of 188 with a known result) (RR: 1.4, 95% CI 0.19–7.8). One polymalformative syndrome was present in a stillborn child of the NOA group. The minor malformation rate in live born children in the NOA and OA group was 2% (n = 1 out of 54 with a known result) versus 4% (n = 8 out of 188 with a known result) (RR: 0.4, 95% CI 0.02–3.27) (Table III).

 

View this table: [in this window] [in a new window]   Table III. Major and minor malformations in live born children after ICSI with testicular sperm of men with non-obstructive and obstructive azoospermia

 
Fifteen of the 61 fetuses had a prenatal karyotype in the NOA group; one trisomy 18 was observed (7%) and the pregnancy was terminated. Two karyotypes were performed on miscarriage tissue and one trisomy 22 was observed. Seventy of the 196 OA fetuses were tested prenatally (36%); an abnormal karyotype was obtained in two (3%): one de-novo 46,XY inv7(q22;q34) abnormality (1%) and one inherited karyotype abnormality [45,XX der(13,14)(q10;q10)] (RR: 4.7, 95% CI 0.31–70.45).

 

	Discussion

Top Abstract Introduction Materials and methods Results Discussion References

 
At present, ICSI with testicular sperm from NOA patients is possible but results in lower fertilization and pregnancy rates than with sperm from men with OA (Vernaeve et al., 2003). There are some concerns when spermatozoa from men with severe testicular failure are used for ICSI. These spermatozoa are known to show a higher chromosomal aneuploidy rate (Bernardini et al., 2000; Martin et al., 2000; Levron et al., 2001; Mateizel et al., 2002). It is assumed that genomic imprinting may be less complete when immature gametes are used (Tesarik and Mendoza, 1996). Incomplete imprinting is unlikely to impair fertilization and early development, but developmental anomalies might become manifest at birth or even later in life. Furthermore, immature gametes may contain dysfunctional sperm centrosome and may show abnormal decondensation of the male pronucleus (Hewitson et al., 2002). As a result of all these concerns, the use of testicular spermatozoa from men with NOA has been banned in The Netherlands.

 

Few publications so far have addressed the obstetric and neonatal outcome of children born after ICSI using testicular sperm. The study by Ludwig et al. (2002) analysed the outcome of 229 pregnancies in which testicular sperm was used and found no additional risk of major malformations in children born after the use of testicular spermatozoa. The major malformation rate, up to 8 weeks after birth, in this study was 9% based on live born and stillborn children and including spontaneous and induced abortions, compared wth 8.4% in ICSI with ejaculated spermatozoa. Bonduelle et al. (2002a) examined the outcome of malformation rates and found no differences, up to 8 weeks after birth, between ejaculated (3.4%, n = 2477) and testicular sperm (2.9%, n = 206). The study performed by Wennerholm et al. (2000b) found no major malformations in the 31 children born after the use of testicular sperm for ICSI. In these studies, the subgroups of testicular sperm are small and no discrimination is made between OA and NOA. Only the study by Palermo et al. (1999) differentiated between these two subgroups, although it was not clear whether it was done on a clinical or a histopathological basis. In the 34 pregnancies obtained after the use of testicular sperm, eight were classified as obstructive and 26 as non-obstructive. Similarly, in this study, the prevalence of congenital malformation did not vary in relation to the sample origin (or the cause of azoospemia). In our study, we found a malformation rate of 4% after the use of testicular sperm of NOA patients and 3% after the use of testicular sperm of OA patients. These rates are comparable with the rates observed in the study by Bonduelle et al. (2000a) where a 3.4% major malformation rate was found in ICSI children after the use of ejaculated sperm, using the same methodology and definitions as in this study.

With regards to the pregnancy outcome, we observed a strong tendency towards lower gestational age among the singletons and a higher percentage of premature twins in the NOA group, when comparing two different subgroups of azoospermic patients.

In this study we did not include a historical control group such as oligoasthenoteratozoospermic patients or spontaneous conceptions. The sample size of our current data set would be too small to draw any valid conclusion. However, given our findings and the concerns about the use of immature testicular spermatozoa from men with spermatogenetic failure, further study is recommended. In view of the low pregnancy rate after ICSI in NOA, a multicentre study in which a distinction is made between azoospermic patients with OA and those with NOA is suggested.

 

	Acknowledgements

 
We would like to thank the clinical, paramedical and laboratory staff of the Centre for Reproductive Medicine and the Centre for Medical Genetics, Professor Collins and Dr. Efstratios Kolibianakis for statistical help, and Mrs. Ines Devolder of the Language Education Centre of our University for editing our manuscript. The work was supported by grants of the Fund for Scientific Research-Flanders (FWO-Vlaanderen) and an unrestricted educational grant from Organon International.

 

	References

Top Abstract Introduction Materials and methods Results Discussion References

 
Aytoz, A., Camus, M., Tournaye, H., Bonduelle, M., Van Steirteghem, A. and Devroey, P. (1998) Outcome of pregnancies after intracytoplasmic sperm injection and the effect of sperm origin and quality on this outcome. Fertil. Steril., 70, 5000–5005.

Bernardini, L., Gianaroli, L., Fortini, D., Conte, N., Magli, C., Cavani, S., Gaggero, G., Tindiglia, C., Ragni, N. and Venturini, P.L. (2000) Frequency of hyper-, hypohaploidy and diploidy in ejaculated, epididymal and testicular germ cells of infertile patients. Hum. Reprod., 15, 2165–2172.[Abstract/Free Full Text]

Bonduelle, M., Liebaers, I., Deketelaere, V., Derde, M.P., Camus, M., Devroey, P. and Van Steirteghem, A. (2002a) Neonatal data on a cohort of 2889 infants born after ICSI (1991–1999) and of 2995 infants born after IVF (1983–1999). Hum. Reprod., 17, 671–694.[Abstract/Free Full Text]

Bonduelle, M., Van Assche, E., Joris, H., Keymolen, K., Devroey, P., Van Steirteghem. A. and Liebaers, I. (2002b) Prenatal testing in ICSI pregnancies: incidence of chromosomal anomalies in 1586 karyotypes and relation to sperm parameters. Hum. Reprod., 17, 2600–2614.[Abstract/Free Full Text]

Ericson, A. and Källen, B. (2001) Congenital malformations in infants born after IVF: a population-based study. Hum. Reprod., 16, 504–509.[Abstract/Free Full Text]

Hewitson, L., Simerly, C. and Schatten, G. (2002) Fate of sperm components during assisted reproduction: implication for infertility. Hum. Fertil., 5, 111–116.

Joris, H., Nagy, Z., Van de Velde, H., De Vos, A. and Van Steirteghem, A. (1998) Intracytoplasmic sperm injection: laboratory set-up and injection procedure. Hum. Reprod., 13 (Suppl. 1), 76–86.[Abstract/Free Full Text]

Levron, J., Aviram-Goldring, A., Madgar, I., Raviv, G., Barkai, G. and Dor, J. (2001) Sperm chromosome abnormalities in men with severe male factor infertility who are undergoing in vitro fertilization with intracytoplasmic sperm injection. Fertil. Steril., 76, 479–484.[CrossRef][Web of Science][Medline]

Ludwig, M. and Katalinic, A. (2002) Malformation rate in fetuses and children conceived after ICSI: results of a prospective cohort study. Reprod. Biomed. Online, 5, 171–178.[Medline]

Martin, R.H., Greene, C., Rademaker, A., Barclay, L., Ko, E. and Chernos, J. (2000) Chromosome analysis of spermatozoa extracted from testes of men with non-obstructive azoospermia. Hum. Reprod., 15, 1121–1124.[Abstract/Free Full Text]

Mateizel, I., Verheyen, G., Van Assche, E., Tournaye, H., Liebaers, I. and Van Steirteghem, A. (2002) FISH analysis of chromosome X, Y and 18 abnormalities in testicular sperm from azoospermic patients. Hum. Reprod., 17, 2249–2257.[Abstract/Free Full Text]

Palermo, G., Joris, H., Devroey, P. and Van Steirteghem, A.C. (1992) Pregnancies after intracytoplasmic injection of single spermatozoon into an oocyte. Lancet, 340, 17–18.[CrossRef][Web of Science][Medline]

Palermo, G., Schlegel, P.N., Hariprashad, J.J., Ergun, B., Mielnik, A., Zaninovic, N., Veeck, L.L. and Rosenwaks, Z. (1999) Fertilization and pregnancy outcome with intracytoplasmic sperm injection for azoospermic men. Hum. Reprod., 14, 741–748.[Abstract/Free Full Text]

Tesarik, J. and Mendoza, C. (1996) Genomic imprinting abnormalities: a new potential risk of assisted reproduction. Mol. Hum. Reprod., 2, 295–298.[Free Full Text]

Tournaye, H., Camus, M., Vandervorst, M., Nagy, Z., Joris, H., Van Steirteghem, A. et al. (1997) Surgical sperm retrieval for intracytoplasmic sperm injection. Int. J. Androl., 20 (Suppl. 3), 69–73.

VanSteirteghem, A., Nagy, P., Joris, H., Janssenswillen, C., Staessen, C., Verheyen, G., Camus, M., Tournaye, H. and Devroey, P. (1998) Results of intracytoplasmic sperm injection with ejaculated, fresh and frozen-thawed epididymal and testicular spermatozoa. Hum. Reprod., 13 (Suppl. 1), 134–42.

Verheyen, G., De Croo, I., Tournaye, H., Pletincx, I., Devroey, P. and Van Steirteghem, A.C. (1995) Comparison of four mechanical methods to retrieve spermatozoa from testicular tissue. Hum. Reprod., 10, 2956–2959.[Abstract/Free Full Text]

Vernaeve, V., Tournaye, H., Osmanagaoglu, K., Verheyen, G., Van Steirteghem, A. and Devroey, P. (2003) Intracytoplasmic sperm injection with testicular spermatozoa is less successful in men with nonobstructive azoospermia than in men with obstructive azoospermia. Fertil. Steril., 79, 529–533.[CrossRef][Web of Science][Medline]

Wennerholm, U.-B., Bergh, C., Hamberger, L., Lundin, K., Nilsson, L., Wikland, M. and Källén, B. (2000a) Incidence of congenital malformations in children born after ICSI. Hum. Reprod., 15, 944–948.[Abstract/Free Full Text]

Wennerholm, U.-B., Bergh, C., Hamberger, L., Westlander, G., Wikland, M. and Wood, M. (2000b) Obstetric outcome of pregnancies following ICSI, classified according to sperm origin and quality. Hum. Reprod., 15, 1189–1194.[Abstract/Free Full Text]

Submitted on November 16, 2002; resubmitted on May 12, 2003; accepted on June 18, 2003.