An audit of the obstetric outcome of 148 consecutive pregnancies from assisted conception: implications for neonatal services

Preterm birth in singleton pregnancies conceived by in vitro fertilization or intracytoplasmic sperm injection: an overview of systematic reviews

BACKGROUND

The rate of preterm birth of singletons conceived through in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) is increased, being as high as 15% to 16% across Europe and the United States. However, the underlying etiology, phenotype, and mechanisms initiating preterm birth (PTB) are poorly understood.

OBJECTIVE

To quantify the PTB risk and examine supposed etiology in IVF/ICSI singleton pregnancies compared to naturally conceived.

STUDY DESIGN

Overview of reviews including all available systematic reviews with meta-analysis comparing PTB risk in IVF/ICSI and naturally conceived singletons. A comprehensive search of PubMed/MEDLINE, Embase, Scopus, and Cochrane Library databases was performed up to December 31, 2023. Information available on etiology, phenotype, initiation of PTB, and relevant moderators was retrieved and employed for subgroup analyses. Random-effects meta-analysis models were used for pooling effect measures. Estimates were presented as odds ratios (ORs) with 95% confidence intervals (CIs). The extent of overlap in the original studies was measured using the corrected covered area assessment. The quality of the included reviews was evaluated with the AMSTAR 2 tool. The Grading of Recommendations Assessment, Development and Evaluation approach was applied to rate evidence certainty. The protocol was registered on PROspective Register of Systematic Reviews (CRD42023411418).

RESULTS

Twelve meta-analyses (16,522,917 pregnancies; ˃433,330 IVF/ICSI) were included. IVF/ICSI singletons showed a significantly higher PTB risk compared to natural conception (PTB ˂37 weeks: OR: 1.72, 95% CI: 1.57-1.89; PTB<32 weeks: OR: 2.19, 95% CI: 1.82-2.64). Influential analysis reinforced the strength of this association. Subgroup analyses investigating supposed etiology revealed a comparable risk magnitude for spontaneous PTB (OR: 1.79, 95% CI: 1.56-2.04) and a greater risk for iatrogenic PTB (OR: 2.28, 95% CI: 1.72-3.02). PTB risk was consistent in the subgroup of conventional IVF (OR: 1.95, 95% CI: 1.76-2.15) and higher in the subgroup of fresh only (OR: 1.79, 95% CI: 1.55-2.07) vs frozen-thawed embryo transfers (OR: 1.39, 95% CI: 1.34-1.43). There was minimal study overlap (13%). The certainty of the evidence was graded as low to very low.

CONCLUSION

Singletons conceived through IVF/ICSI have a 2-fold increased risk of PTB compared to natural conception, despite the low certainty of the evidence. There is paucity of available data on PTB etiology, phenotype, or initiation. The greater risk increase is observed in fresh embryo transfers and involves iatrogenic PTB and PTB ˂32 weeks, likely attributable to placental etiology. Future studies should collect data on PTB etiology, phenotype, and initiation. IVF/ICSI pregnancies should undertake specialistic care with early screening for placental disorders, cervical length, and growth abnormalities, allowing appropriate timely follow-up, preventive measures, and therapeutic interventions strategies.

Artificial Reproductive Technology - A Risk Factor for Retinopathy of Prematurity

BACKGROUND:

Retinopathy of Prematurity (ROP) is a potentially blinding vasoproliferative disease in premature babies. The presentation and course of ROP are determined by a complex interaction of a series of risk factors, including artificial reproductive technology (ART).

AIM:

To analyse and combine the information relating ART as an independent risk factor for retinopathy of prematurity.

METHODS AND MATERIAL:

The article is systematic review and meta-analysis using RevMan 5. Pubmed, Scopus and Medline were searched for articles from 1990 to 2018.

RESULTS:

Studies suggest that ROP is observed more frequently in ART children. They are more likely to be premature and of low birth weight than those conceived naturally. Results vary from just a tendency to a five-fold increase in risk to develop ROP in ART babies. At the same time, they might develop ROP later, and more mature newborns might be affected.

CONCLUSION:

The data relating ART as a risk factor for ROP is inconclusive, but most studies show at least a tendency. The ART newborns need to be considered as a risk group for ROP and observed with greater suspicion. Even more mature ART newborns might need to be screened in order not to miss any significant pathology.

Adverse obstetric outcome in women with a history of infertility: A retrospective study

Women with a history of infertility are associated with a higher incidence of adverse pregnancy outcome. This retrospective study reviewed 105 women with a known history of infertility; of these 105 women, 77 (73%) conceived spontaneously and 28 (27%) had assisted conception. Our finding confirms higher perinatal complications; relative ratios (RR) for pre-eclampsia was 4.6 (95% CI=2.1-9.9), intrauterine growth restriction 4.8 (95% CI=1.9-12.0), gestational diabetes 1.8 (95% CI=0.5-5.8), pre-term premature rupture of membrane 2.3 (95% CI=0.6-8.8) and pre-term labour 2.6 (95% CI=1.1-5.9). We postulate that women with a history of infertility are at high risk of such obstetric complications and may benefit from intensified antenatal care.

Restoration of endocrine function and fertility with orthotopic tubal-ovarian allotransplant as the anatomical-functional unit in rabbits

The aim of this study was to re-establish endocrine and reproductive function in tubal-ovariectomized rabbits using orthotopic tubal-ovary allotransplants (OT-OA). Fifty-five New Zealand White nonconsanguineous rabbits were used and allocated into five experimental groups: Each group comprised donors submitted to right salpingo-oophorectomy that served as the donated allograft. In group 1 no cyclosporin (CsA) was administered and rabbits were submitted to left salpingo-oophorectomy (LSO). Group 2 was the allotransplant group and did not receive CsA. Group 3 was the allotransplant group with CsA. They were submitted to bilateral salpingo-oophorectomy followed by OT-OA. CsA of 10 mg/kg/day was administered to rabbits for the first 21 days and 5 mg/kg/day for the remainder of the study. Group 4 received CsA just as for group 3 and was submitted to LSO. During the study the following were measured: estradiol (E2), progesterone (P4), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and histopathological study of the uteri, tubes, and ovaries. Groups 1, 3, and 4 showed a significant increase in serum E2 and P4 levels corresponding to the second week of gestation, compared to group 2 (p < .05). Group 2 showed a significant increase in serum LH and FSH levels during week 10 compared to serum LH and FSH levels in groups 1, 3, and 4 (p < .05). In group 3, three rabbits did not reject the allotransplant, one rabbit became pregnant, and endocrine function was re-established in two rabbits. It can be concluded that OT-OA together with CsA administration re-establishes endocrine function and fertility.

Obstetric outcome of twin pregnancies conceived by in vitro fertilization and ovulation induction compared with those conceived spontaneously

OBJECTIVE

To compare the obstetric characteristics of twin pregnancies conceived by in vitro fertilization (IVF) and ovulation induction with those conceived spontaneously.

DESIGN

Case control study.

SETTING

Tertiary Medical Center.

PATIENTS

All twin deliveries that were achieved by IVF (n=558) and ovulation induction (n=478) from January 1988 through December 2002 were evaluated. Each group was compared with a control group that conceived spontaneously (n=3694) and was delivered during the same period.

INTERVENTIONS

Ovulation induction, IVF-ET.

MAIN OUTCOME MEASURES

Obstetrical complications.

RESULTS

Multivariate analysis showed that patients who conceived with the assistance of IVF and ovulation induction had a significantly higher risk for gestational diabetes mellitus (odds ratio [OR]=2.41, 95% confidence interval [CI]=1.77-3.29 and OR=1.71, CI=1.2-2.42, respectively), cesarean section (OR=2.17, 95% CI=1.74-2.70 and OR=1.76, CI=1.43-2.16, respectively), and a lower gestational age at birth in the IVF group (OR=0.91, 95% CI=0.88-0.94), compared with their controls.

CONCLUSIONS

After controlling for maternal age, and nulliparity we demonstrated that twin pregnancies conceived with the assistance of IVF and ovulation induction are at increased risk for gestational diabetes mellitus, and delivery by cesarean section. In addition, IVF conceived pregnancies have a lower gestational age at birth.

Restoration of endocrine function and fertility with a tubo-ovarian autotransplant as the anatomical-functional unit in rabbits using a vascular microsurgical technique

Infertility has been considered a global public health problem in many countries worldwide. Our objective was to restore endocrine function and fertility in tubal-oophorectomized rabbits using an orthotopic tubal-ovarian vascularized autotransplant model as the anatomical-functional unit while employing a microvascular surgical technique. Twenty New Zealand white (NZW) sexually mature female rabbits and four male NZW rabbits of proven fertility were divided into two study groups. In group I (n = 10), a left salpingo-oophorectomy was performed. Group II (n = 10) was subjected to a bilateral salpingo-oophorectomy, plus a right orthotopic tubal-ovarian autotransplant. Our testing variables were vascular and tubal-anastomoses permeability, estradiol (E2) and progesterone (P4) serum levels, pregnancy, number of offspring, histopathological study of the uteri, fallopian tubes, and ovaries. One hundred percent immediate permeability of the tubal anastomoses was achieved, while late permeability was found to be 64%. Immediate permeability of vascular anastomoses was 90%, and late permeability was recorded at 80%. E2 serum levels in both groups at different times showed no statistically significant differences. In the case of P4, a small difference was found during pregnancy, especially greater in the control group (P < .05). In the autotransplanted group, four rabbits became pregnant (44%). Endocrine function and fertility were restored in the rabbits with the tubal-ovarian transplant as the anatomical-functional unit. The use of isotransplants and allotransplants should be considered a therapeutic alternative in the infertile woman with irreparable bilateral tubal damage, ovarian dysgenesis, surgical absence of ovaries and fallopian tubes, or when the conventional IVF/TE in these cases has been unsuccessful.

Perinatel outcomes of singleton pregnancies achieved by in vitro fertilization: a systematic review and meta-analysis

OBJECTIVE

To determine whether the incidence of adverse obstetric outcomes is higher in singleton pregnancies achieved by in vitro fertilization (IVF) than in spontaneously conceived singletons matched for maternal age.

METHODS

We used comprehensive search strategies to search MEDLINE and EMBASE databases. We selected case-control and cohort studies that compared singleton pregnancies conceived by IVF or intracytoplasmic sperm injection (ICSI) with spontaneously conceived singletons (matched for maternal age [case-control studies] or controlled for maternal age [cohort studies]). Two reviewers independently assessed titles, abstracts, and study quality and extracted data. Statistical analysis was performed with Review Manager for Windows (Version 4.2, Oxford, UK). We performed meta-analysis of dichotomous data, using odds ratios (ORs) as measures of effect size, with a random effects model. We followed the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines for meta-analysis of observational studies.

RESULTS

Singleton pregnancies resulting from IVF have increased rates of poor obstetric outcome, compared with spontaneously conceived singletons matched for maternal age, with increases in perinatal mortality (OR 2.40; 95% confidence interval [CI] 1.59-3.63), preterm birth at < 33 weeks' gestation (OR 2.99; 95% CI 1.54-5.80), preterm birth at < 37 weeks' gestation (OR 1.93; 95% CI 1.36-2.74), very low birth weight (< 1500 g) (OR 3.78; 95% CI 4.29-5.75), small for gestational age (OR 1.59; 95% CI 1.20-2.11), and congenital malformations (OR 1.41; CI 1.06-1.88).

CONCLUSIONS

IVF singleton pregnancies have increased rates of poor obstetric outcome, compared with spontaneously conceived singletons matched for maternal age.

Perinatal outcomes of in vitro fertilization twins: a systematic review and meta-analyses

OBJECTIVE

Uncontrolled studies suggest that in vitro fertilization twins have increased rates of preterm birth and low birth weight and would warrant increased antenatal monitoring. The objective of this meta-analysis was to determine whether the incidence of poor obstetric outcomes is higher for in vitro fertilization twins than for spontaneously conceived twins who were matched for maternal age.

STUDY DESIGN

Medline and EMBASE were searched with comprehensive search strategies. Case-control and cohort studies of twins who were conceived by in vitro fertilization or in vitro fertilization/intracytoplasmic sperm injection, with the transfer of fresh embryos or cryopreserved (frozen) in women with infertility, and/or whose partners were subfertile or infertile, compared with naturally (spontaneously) conceived twins who were matched for maternal age (case-control studies) or which were controlled for it (cohort studies). Two reviewers independently assessed titles, abstracts, and study quality and extracted the data. Statistical analysis was performed with commercial statistical software. Dichotomous data were meta-analyzed with odds ratios as measures of effect size, and continuous data was meta-analyzed with mean differences. Interstudy variation was incorporated with the assumption of a random effects model for the treatment effect.

RESULTS

Compared with spontaneously conceived twins who were matched for maternal age, in vitro fertilization twins have an increased risk of preterm birth between 32 and 36 weeks of gestation (odds ratio, 1.48; 95% CI, 1.05-2.10), and an elevated risk of preterm birth at <37 weeks of gestation when parity is also matched for an odds ratio of 1.57 (95% CI, 1.01-2.44). There was an increased rate of cesarean delivery among in vitro fertilization twins (odds ratio, 1.33; 95% CI, 1.06-1.67). There were no significant differences in incidences of perinatal death, low birth weight infants, or congenital malformations.

CONCLUSION

In vitro fertilization twins have increased rates of preterm birth compared with spontaneously conceived twins who were matched for maternal age, despite the fact that their outcomes would be expected to be better because of the decreased proportion of monochorionic twins.

Obstetric outcome in women with subfertility

BACKGROUND

It has been suggested that a history of subfertility is associated with increased obstetric and perinatal risks. It is unclear if the cause is inherent characteristics in the women or the fertility treatment.

OBJECTIVES

To compare the obstetric and perinatal risks of singleton pregnancies in women with a history of subfertility in comparison with the general population.

DESIGN

Population cohort.

SETTING

Aberdeen, Scotland.

POPULATION

Cases were women attending the Fertility Clinic between 1989 and 1999 who subsequently went on to have singleton pregnancies. Controls included the general population of women who delivered singletons over the same period.

METHODS

We performed a retrospective cohort study to investigate the obstetric outcome of singleton pregnancies in women with subfertility. The general population of women who delivered singletons over the same period served as controls.

MAIN OUTCOME MEASURES

Obstetric and perinatal complications in singleton pregnancies.

RESULTS

Maternity records were available for a total of 1437 subfertile women and 21,688 controls. Subfertile women were older [mean (SD) age: 31 (4.7) years vs 27 (5.4) years, P < 0.01] and more likely to be primiparous (70% vs 65%, P < 0.001). After adjusting for age and parity, subfertile women were at increased risk of pre-eclampsia (OR 1.9, 95% CI 1.5-2.5), placenta praevia (OR 3.9, 95% CI 2.2-7.0) and placental abruption (OR 1.8, 95% CI 1.1-3.0), and more likely to undergo induction of labour (OR 1.5, 95% CI 1.3-1.6), caesarean section (OR 2.1, 95% CI 1.8-2.4) and instrumental delivery (OR 2.2, 95% CI 1.8-2.6), and deliver low birthweight (OR 1.4, 95% CI 1.3-1.7) and preterm (OR 1.7, 95% CI 1.2-2.2) infants. There were no differences between treatment-related and treatment-independent pregnancies.

CONCLUSION

Subfertile women are at higher risk of obstetric complications, which persist after adjusting for age and parity.

Increased risk of preterm birth in singleton pregnancies resulting from in vitro fertilization–embryo transfer or gamete intrafallopian transfer: A meta-analysis

OBJECTIVE

To perform a systematic review of the literature to determine whether singleton pregnancies resulting from IVF-ET/GIFT are at higher risk for preterm birth (<37 weeks).

DESIGN

Literature search and systematic review.

SETTING

Medical school.

INTERVENTION(S)

A MEDLINE search (1965-2000) was performed using the terms "premature labor," "infertility," "pregnancy complications," "gonadotropins," "pregnancy outcome," "preterm delivery," and "in vitro fertilization." Criteria for inclusion were English language, original research article, study patients conceived using IVF-ET (with or without intracytoplasmic sperm injection) or GIFT, pregnancy outcome reported compared with a control group (e.g., naturally conceived singletons at their hospital or a national reference), and prematurity clearly defined. Incomplete articles (e.g., abstracts), reports of other studies, and studies that failed to separate multiple from singleton gestations were excluded.

MAIN OUTCOME MEASURE(S)

Summary of relative risks of preterm birth.

RESULT(S)

Twenty-seven articles met all inclusion/exclusion criteria and were analyzed by meta-analysis. The random-effects summary relative risk of preterm birth in singleton pregnancies resulting from IVF-ET/GIFT was 1.98 (95% confidence interval, 1.77-2.22).

CONCLUSION(S)

The risk of preterm birth in singleton pregnancies resulting from IVF-ET/GIFT is twice that of natural conceived pregnancies.

Cause and risk of stillbirth in twin pregnancies: a retrospective audit

BACKGROUND

The epidemiology of twin pregnancies complicated by stillbirth of one or both fetuses is a scarcely examined area. The risk of perinatal death in twin pregnancies is increased 2-5 times compared to singletons, and the identification of preventable risk factors becomes increasingly important as the number of multiple pregnancies is rising. We report the causes of death in twin pregnancies and their respective risk factors.

METHODS

Twin pregnancies (n = 54) complicated by antepartum or intrapartum stillbirth of one or both twins (n = 68) and twin pregnancies with normal outcome (n = 103) in the counties of Oslo and Akershus, Norway, from 1986 to 1995 were included. The cases were classified and compared to the controls in multiple logistic regression analyses with regard to risk factors.

RESULTS

The risk of stillbirth increased with monochorionicity, non-Western origin and assisted reproduction techniques (ART). The cases could be divided into eight different groups according to the primary diagnosis. The groups did not fit any of the existing cause-of-death classifications used on singleton stillbirths.

CONCLUSIONS

The identification of monochorionic gestation should be made early in pregnancy to designate the level of risk. Assisted reproduction techniques leading to a high incidence of twins should be avoided. Health care professionals in the immigrant population should address the detrimental effects of consanguinity on reproductive outcome. We emphasize the need of a new cause-of-death classification for twin stillbirths.

Pregnancy complications, obstetric risks, and neonatal outcome in singleton and twin pregnancies after GIFT and IVF

PURPOSE

In vitro fertilization (IVF) and to a lower extent gamete intra-fallopian transfer (GIFT) have become routine infertility treatments in industrialized countries. Our purpose is to compare the obstetric and neonatal characteristics of singleton and twin pregnancies after GIFT and IVF with those conceived spontaneously.

METHODS

This case-control study was conducted in a tertiary care medical center. The 322 singleton and 78 twin pregnancies after GIFT or IVF from 1991 through 1996 were evaluated and compared with each other, and with a control group that conceived spontaneously and matched for parity, maternal and gestational age. Statistical significance of differences was assessed by chi(2) test or two-tailed Fisher exact test. Continuous variables were compared by the paired t-test.

RESULTS

Pregnancy-induced hypertension (PIH) and vaginal bleeding were significantly more frequent maternal complications in the GIFT/IVF singleton groups compared to controls. In twin pregnancies the rate of cesarean sections, vaginal bleeding and preterm labor were more common after GIFT/IVF but did not reach statistical significance. Assisted reproduction was associated with low birth weight only in twin pregnancies when controlled for confounding variables, however perinatal outcome was comparable. There was no significant difference in the outcome measures between GIFT and IVF pregnancies.

CONCLUSION

After controlling for parity, maternal and gestational age, singleton pregnancies conceived by GIFT/IVF are at increased obstetrical risk, however the perinatal outcome is comparable despite a lower average birth weight.

Obstetric outcome among women with unexplained infertility after IVF: a matched case-control study

BACKGROUND

Infertility itself and also assisted reproductive treatment increase the incidence of some obstetric complications. Women with unexplained infertility are reported to be at an increased risk of intrauterine growth restriction during pregnancy, but not for other perinatal complications.

METHODS

A matched case-control study was performed on care during pregnancy and delivery, obstetric complications and infant perinatal outcomes of 107 women with unexplained infertility, with 118 clinical pregnancies after IVF or ICSI treatment. These resulted in 90 deliveries; of these, 69 were singleton, 20 twin and one triplet. Two control groups were chosen from the Finnish Medical Birth Register, one group for spontaneous pregnancies (including 445 women and 545 children), matched according to maternal age, parity, year of birth, mother's residence and number of children at birth, and the other group for all pregnancies after IVF, ICSI or frozen embryo transfer treatment (FET) during the study period (including 2377 women and 2853 children).

RESULTS

Among singletons, no difference was found in the mean birthweight, and the incidence of low birthweight (<2500 g) was comparable with that of the control groups. No differences were found in gestational duration, major congenital malformations or perinatal mortality among the groups studied. Among singletons in the study group, there were more term breech presentations (10.1%) compared with both spontaneously conceiving women and all IVF women (P < 0.01). The rate of pregnancy-induced hypertension was significantly lower among singletons in the study group (P < 0.05) compared with other IVF singletons. The multiple pregnancy rate was 23.3% in the study group. The obstetric outcome of the IVF twins was similar to both control groups.

CONCLUSIONS

The overall obstetric outcome among couples with unexplained infertility treated with IVF was good, with similar outcome compared with spontaneous pregnancies and IVF pregnancies generally.

The impact of an assisted conception unit on the workload of a general gynaecology unit

The burden placed on a hospital by the presence of an assisted conception unit has been emphasised only in terms of its impact on neonatal services. This paper examines the previously neglected subject of the gynaecological workload generated by a tertiary fertility centre that provides treatments by assisted conception. As many IVF units operate independently this additional workload may not be appreciated. It has, however, significant practical and financial implications for neighbouring hospitals and trusts. This is of particular relevance in view of the move towards more uniform health service funding of assisted conception throughout the United Kingdom.

Risk of cranial ultrasound abnormalities in very-low-birth-weight infants conceived with assisted reproductive techniques

OBJECTIVE

To evaluate risks of cranial ultrasound abnormalities among very-low-birth-weight (VLBW) infants conceived with fertility therapy (ovulation induction only or with assisted reproductive techniques [ART]) and of multiple gestation pregnancies.

STUDY DESIGN

The incidences of cranial ultrasound abnormalities in 1473 VLBW infants conceived with and without fertility therapy and born of multiple versus singleton pregnancies were compared, using logistic regression models.

RESULTS

Infants conceived with ART were less likely to have intraventricular hemorrhage (IVH). Twins and triplets had risks of cranial ultrasound abnormalities similar to those of singletons. Twins and triplets conceived with ART were at lower risk of IVH.

CONCLUSION

VLBW infants conceived with ART do not appear to be at increased risk of cranial ultrasound abnormalities. Likewise, twins and triplets were not at increased risk of these abnormalities.

Review of unexplained infertility and obstetric outcome: a 10 year review

BACKGROUND

Increased maternal and fetal risks have been reported in pregnancies following unexplained infertility. Our aims were to examine the obstetric and perinatal outcome of singleton pregnancies in couples with unexplained infertility and explore the impact of fertility treatment.

METHODS

Women with unexplained infertility were identified from the Aberdeen Fertility Clinic Database. Their unit numbers were matched against the Aberdeen Maternity and Neonatal Databank (AMND) in order to extract obstetric records of those women with subsequent pregnancy outcomes. The general obstetric population served as a control group.

RESULTS

Women with unexplained infertility were older [30.8 versus 27.9 years, 95% confidence interval (CI) for difference = +2.4 to +3.4] and more likely to be primiparous (59 versus 40%, 95% CI = +1.3 to +1.9). After adjusting for age and parity they had a higher incidence of pre-eclampsia, abruptio placentae, preterm labour, emergency Caesarean section and induction of labour in comparison with the general population (P < 0.05). Perinatal outcome did not differ between women with unexplained infertility and those of the general population. The multiple pregnancy rate was 5.4% higher following fertility treatment than in women who conceived spontaneously (95% CI = +2.8 to +9.7).

CONCLUSIONS

Women with unexplained infertility are at higher risk of obstetric complications which persist even after adjusting for age, parity and fertility treatment. The reasons are however unclear and merit further study.

Are singleton assisted reproductive technology pregnancies at risk of prematurity?

PURPOSE

Our purpose was to determine the risk of premature delivery among singleton pregnancies derived from assisted reproduction technology (ART).

METHODS

Ninety-five singleton ART pregnancies and 190 matched spontaneous pregnancies were assessed for preterm delivery rates, pregnancy complications, and cesarean section rates in a retrospective study at an academic medical center.

RESULTS

Among the ART singleton deliveries group (n = 95), 19 (20%) were preterm, which was statistically significantly higher than the 4% (8 of 190) found in the control group. Among the pregnancies achieved by intracytoplasmic sperm injection (ICSI) in the severe male-factor infertility subgroup (n = 22), only one preterm delivery occurred (4.5%).

CONCLUSIONS

Singleton ART pregnancies are at an increased risk of preterm delivery compared to singleton pregnancies after spontaneous conception. The higher rate may be attributed to various infertility cofactors, such as uterine malformations, previous operative procedures that involved cervical dilatation, and a history of pelvic infection. This is supported by the finding that ICSI-derived pregnancies in couples with strict male-factor infertility are not at an increased risk of preterm delivery.

In vitro fertilisation and stage 3 retinopathy of prematurity

PURPOSE

To re-examine the risk of children born by assisted conception developing stage 3 retinopathy of prematurity (ROP) and to define whether the risk of ROP varies with the method of assisted conception.

METHODS

This was a retrospective study carried out between December 1995 and December 1998 of infants in a single neonatal unit serving the Brent and Harrow area of North West Thames requiring screening and treatment of ROP. The infants screened were identified from the ROP screening database. Those conceived by in vitro fertilisation (IVF) and other forms of assisted conception were identified by reviewing the neonatal notes and the maternal obstetric records. Birth weight, gestational age and the type of assisted conception were recorded. The presence or absence of any stage of ROP, its location and severity and the cases requiring treatment were recorded.

RESULTS

One hundred and seventy-nine infants fulfilled the screening criteria during this period. Acute ROP was detected in 32.4% (58 infants) and stage 3 ROP developed in 15.6% (28 infants). Twenty-one infants (11.7%) were born after assisted conception, with 12 (6.7%) being conceived by IVF. The others were conceived on clomiphene (8) or after intrauterine insemination (1). Assisted conception accounted for 21.4% of all those reaching stage 3 disease and 28.6% of those infants requiring treatment. Of the 12 infants conceived by IVF, 41.6% (5 infants) developed acute ROP which progressed to threshold ROP in all infants (100%). Of the assisted conception babies requiring treatment for ROP, 83.3% were conceived by IVF. The other child had been conceived on clomiphene. The gestational age and birth weight of the IVF infants reaching stage 3 ROP were 26.6 +/- 0.89 weeks and 937 +/- 170.2 g. The gestational age and birth weight in the rest of the infants reaching stage 3 ROP were lower than in those conceived by assisted conception (25.739 +/- 1.13 weeks and 735.29 +/- 117.70 g); however, this did not approach statistical significance (p = 0.35 and p = 0.13, respectively).

CONCLUSIONS

In this study 11.7% of the group requiring screening were conceived by assisted conception. Of all babies requiring treatment for ROP, 28.6% were born after assisted conception. Of the assisted conception group, 83.3% were conceived by IVF. Assisted conception using IVF rather than other techniques appears to be the major risk factor for the development of threshold ROP. We would advise increased vigilance when screening babies conceived by the IVF methods of assisted conception.

Assessment of separate contributions to perinatal mortality of infertility history and treatment: a case-control analysis

BACKGROUND

Few studies have described the perinatal risks associated with infertility, other than for infertility treated by in-vitro fertilisation or gamete intrafallopian transfer. The aim of this analysis was to estimate the risks of perinatal death associated with treated and untreated infertility.

METHODS

A population-based case-control study of perinatal deaths was carried out in Leicestershire Health District over the period 1990-94, during which 60,922 babies were delivered. Of these, 567 perinatal deaths were associated with 542 women. 972 mothers were randomly selected as controls. Medical, obstetric, and social data were collected for cases and controls from the medical notes and interviews with the women. The relative risks of perinatal death associated with treated and untreated infertility before the index pregnancy were estimated as odds ratios by means of unconditional logistic regression analysis.

FINDINGS

65 (10%) of cases and 34 (3.5%) of the controls had infertility before the index pregnancy. History of infertility in the index pregnancy, irrespective of treatment, increased the risk of perinatal death (odds ratio 2.9 [95% CI 1.8-4.5]). The population attributable risk fraction for perinatal death related to infertility was 6.2% (3.4-9.0). 45 (54%) of the deaths, even in the untreated group, were associated with immaturity. Compared with women without infertility, women with untreated infertility were at increased risk of perinatal death (3.3 [1.6-6.8]). The risk of perinatal death associated with multiple births did not explain this finding. Similarly, treated infertility also increased the risk of perinatal death (2.7 [1.5-4.7]); the risks associated with multiple births explained some, but not all, of this excess. In Leicestershire, the overall underlying risk of a mother experiencing at least one perinatal death over the study was 9.0 per 1000 women. For women who experience infertility, this risk increases by about 18 per 1000 (6-30).

INTERPRETATION

Counselling for women before any form of infertility treatment should include discussion of the risks of perinatal death. Our results would benefit from confirmation. However, we advocate that at antenatal booking a history of infertility, irrespective of treatment, should be sought, because these women have a significantly increased risk of perinatal death, particularly associated with prematurity.

Is the obstetric outcome of in vitro fertilized singleton gestations different from natural ones? A controlled study

OBJECTIVE

To determine whether singleton IVF pregnancies carry adverse maternal or fetal outcome when compared with naturally conceived gestations.

DESIGN

An analysis of the obstetric outcome of singleton IVF pregnancies in comparison with matched, naturally conceived singleton controls.

SETTING

In vitro fertilization unit and obstetric service at a tertiary medical center.

PATIENT(S)

Two hundred sixty consecutive singleton IVF pregnancies and 260 naturally conceived singleton controls matched 1:1 for maternal age, parity, ethnic origin, and location and date of delivery.

INTERVENTION(S)

In vitro fertilization-ET.

MAIN OUTCOME MEASURE(S)

The rate of antenatal obstetric complications, nonvertex presentation, cesarean section, preterm labor, low birth weight, small and very small for gestational age, neonatal intensive care unit admissions, and perinatal mortality.

RESULT(S)

The rates of most antenatal complications were similar in both groups. Urinary tract infection was the only complication diagnosed significantly more frequently after IVF (7.3% versus 1.2%); however, the rates of severe urinary tract infection necessitating hospitalization were similar. The incidence of nonvertex presentation was also similar. The cesarean section rate was significantly higher among IVF patients (41.9% versus 15.5%). The rates of preterm labor, low birth weight, small and very small for gestational age, neonatal intensive care unit admissions, and perinatal mortality were comparable.

CONCLUSION(S)

When controlling for maternal age, parity, ethnic origin, and location and date of delivery, singleton IVF pregnancies do not carry an increased risk for prematurity, low birth weight, or maternal or fetal complications. Still, these pregnancies are associated with a high rate of cesarean sections.

The neonatal consequences and neonatal cost of reducing the number of embryos transferred following IVF

This clinical audit project examined the effects of change of policy between 1990 and 1993 transferring an average two (maximum three for particular cases) embryos to women undergoing IVF in the West of Scotland programme. All women who achieved clinical pregnancy in 1990 (92 women) and 1993 (93 women) as a result of the IVF programme were included in the study. The hospital records of women via the programme were analysed. The results of the study showed that there was a significant reduction in the rate of multiple pregnancy, preterm birth and low birth weight babies in the 1993 group (new policy). The cost of neonatal intensive care in 1993 for babies born following IVF was about nine times lower than that in 1990 (old policy). This study concluded that a policy of transferring two embryos (or three for particular cases) to women in an IVF programme, had improved the perinatal outcome and reduced the cost of the neonatal service for those babies.

Assisted conception and retinopathy of prematurity

This study was performed to assess the workload imposed by treatment for infertility on a retinopathy of prematurity (ROP) screening programme. We reviewed the records of all babies born between August 1991 and December 1994 as a result of treatment in the Assisted Conception Unit of this hospital, and of all babies screened for ROP over the same period. Of the babies born after assisted conception treatment, 20% fulfilled the ROP screening criteria. ROP of any stage was present in 23% of all the assisted conception babies screened. This group also accounted for a large proportion of those reaching stage 3 disease and of those requiring treatment.