Utilidad de la prueba de la fibronectina fetal y de la longitud del cérvix en la predicción del parto prematuro en gestantes sintomáticas

Objective

To evaluate the usefulness of fetal fibronectin and cervical length in predicting preterm birth in women with preterm uterine contractions.

Material and methods

A prospective study was conducted at the Virgen Macarena Hospital in Seville that included 153 pregnant women with suspected preterm labor and intact membranes. Cervical length was measured by transvaginal sonography and a rapid qualitative fibronectin test was performed in the emergency consultation. Women with a negative fibronectin test and cervical length ≥ 30 mm were not hospitalized or treated with tocolytics or corticosteroids.

Results

The mean gestational age at diagnosis was 223,02 ± 19,98 days, and 267,52 ± 14,15 days at delivery. Preterm birth < 37 weeks rate was 23% and 7,4% for deliveries < 35 weeks. There is an association between cervical length < 30 mm and birth < 37 weeks (OR, 3,68; 95% CI, 1,53-8,84), and with delivery in the following 14 days (OR, 3,35; 95% CI, 1,30-21,95). With the association of both tests we gain specificity in predicting preterm birth.

Conclusion

Cervical length is the test with higher specificity (E) and negative predictive value (VPN) for the prediction of preterm birth in women with symptomatic contractions.     

Obstetric and neonatal outcomes of twin pregnancies conceived by assisted reproductive technology compared with twin pregnancies conceived spontaneously: a prospective follow-up study

Objective

To compare the obstetric and neonatal outcomes of twin pregnancies conceived by assisted reproduction technology (ART) with spontaneously conceived (SC) twin pregnancies.

Study design

A prospective cohort study compared all dichorionic twin pregnancies in nulliparous women following fresh in vitro fertilization/intra-cytoplasmic sperm injection (ICSI) or ICSI cycles at Royan Institute (n = 320) with SC dichorionic twin pregnancies in nulliparous women at Arash Women's hospital (n = 170) from January 2008 to October 2010. These pregnancies were followed-up until hospital discharge following delivery. Obstetric and neonatal outcomes of SC and ART twin pregnancies were compared.

Results

Multivariate analysis, adjusted for maternal age and body mass index, revealed that the obstetric outcomes were similar in both groups. However, the risks of very preterm birth [odds ratio (OR) 5.2, 95% confidence interval (CI) 2.1–12.9], extremely low birth weight (OR 2.2, 95% CI 1.0–3.9), admission to a neonatal intensive care unit (OR 2.0, 95% CI 1.2–3.2) and perinatal mortality (OR 2.3, 95% CI 1.2–4.0) were higher in the ART group.

Conclusions

The maternal outcomes of ART dichorionic twins were comparable with those of SC twins. However, despite the same obstetric management, the rates of very preterm birth, extremely low birth weight, admission to a neonatal intensive care unit and perinatal mortality were significantly higher in the ART group.     

Recent oral contraceptive use and adverse birth outcomes

Objective

To examine the possible association between oral contraceptive use and adverse birth outcomes.

Study design

We conducted a population-based cohort study of pregnant women who used oral contraceptives within 3 months before their last menstrual period. Subjects were divided into three groups, according to the interval (0–30, 31–60, and 61–90 days) between the dispensing date and their last menstrual period. For each exposed subject, 4 subjects without exposure to oral contraceptives were individually matched by infant's year of birth and plurality and by mother's age and parity.

Results

Oral contraceptive use within 30 days prior to the last menstrual period was associated with increased risks of very low birth weight (OR: 3.24, 95% CI: 1.18, 8.92), low birth weight (OR: 1.93, 95% CI: 1.17, 3.20), and preterm birth (OR: 1.61, 95% CI: 1.01, 2.55); however, oral contraceptive use 31–90 days prior to the last menstrual period did not increase the risk of low birth weight or preterm birth.

Conclusion

Our results indicate the use of oral contraceptives near the time of conception may be associated with an increased risk of low birth weight and preterm birth.     

Influence of mode of delivery on neonatal mortality and morbidity in spontaneous preterm breech delivery

Objective

To study the association between mode of delivery and neonatal outcome in singleton pregnancy with breech presentation and preterm birth, due to premature labour (PTL) and/or preterm premature rupture of the membranes (pPROM).

Design and methods

Information on preterm (gestational week 25–36) singleton births in breech presentation in Sweden during 1990–2002 was obtained from the Swedish Medical Birth Registry and the Swedish Hospital Discharge Registry. The study groups included 1975 caesarean and 699 vaginal deliveries with a diagnosis of PTL or pPROM, without pregnancy complications implying a high risk of fetal compromise. The rates of infant respiratory distress syndrome (IRDS), intraventricular haemorrhage (IVH), low Apgar scores, and neonatal deaths were compared between infants delivered vaginally and by caesarean section. Odds ratios were calculated with adjustment for gestational age, year of birth, maternal age and parity.

Results

The risk of neonatal death and the risk of an Apgar score below 5 min postnatally were both lower after caesarean delivery (OR 0.4; 95% CI 0.2–0.7, and OR 0.4; 95% CI 0.3–0.7, respectively), whereas the risk of IRDS was increased (OR 2.1; 95% CI 1.4–3.2). A diagnosis of IRDS was not associated with mortality (OR 0.8; 95% CI 0.5–1.5). IVH was not associated with mode of delivery (OR 1.2; 95% CI 0.5–2.8).

Conclusion

The lower neonatal mortality after CS supports a policy of caesarean delivery of the preterm breech.     

Risk factors for preterm premature rupture of membranes in Chinese women from urban cities

Objective

To investigate the prevalence of preterm premature rupture of membranes (PPROM) in urban areas in China and examine the associated risk factors.

Methods

A population-based, prospective study was undertaken in 14 cities in China between January 1, 2011, and January 31, 2012. Women were recruited at their first prenatal-care visit, when maternal characteristics were recorded. Risk factors were analyzed by one-way analysis of variance.

Results

Of 112 439 women included in analyses, 3077 (2.7%) had PPROM. Univariate analysis showed an increased risk of PPROM before 28 weeks of pregnancy in migrant women (odds ratio [OR] 2.25; 95% confidence interval [CI] 1.53–3.30; P < 0.001), in those with a history of recurrent induced abortions (OR 2.75; 95% CI 1.66–4.56; P < 0.001), and in those with a history of preterm birth (OR 3.90; 95% CI 0.77–19.61; P < 0.001). The associations were maintained in multivariate analysis (P < 0.001).

Conclusion

Migration as a result of urbanization, high rates of induced abortion, and preterm birth are potential risk factors for PPROM in Chinese women.     

Examination of the association between male gender and preterm delivery

Objective

To examine possible reasons why a male fetus constitutes a risk factor for preterm delivery.

Study design

Retrospective study of deliveries from hospital database in a UK teaching hospital. The population comprised all deliveries >23 weeks over an 11-year period, excluding multiples, terminations and pregnancies with major abnormalities including indeterminate gender. Obstetric variables and outcomes were initially compared in male and female babies for preterm births in different gestation bands, extreme (<28 weeks), severe (29–32 weeks) and moderate (33–36 weeks). For each, the odds ratios with 95% confidence intervals for preterm delivery were calculated. Then, using binary logistic regression with adjusted odds ratios with 95% confidence intervals, putative causal pathways that might explain the male excess were tested.

Results

75,725 deliveries occurred, of which 4003 (5.3%) were preterm. Males delivered preterm more frequently (OR 1.13, 95% CI 1.06–1.20). This was due to spontaneous (OR 1.30, 95% CI 1.19–1.42) but not iatrogenic (OR 0.96, 95% CI 0.87–1.05) preterm birth. There was an increased risk of pre eclampsia among preterm females. Although males were larger, and male pregnancies were more frequently nulliparous and affected by some other obstetric complications (abruption, urinary tract infection), these did not account for their increased risk. Any effect of growth restriction could not be properly determined.

Conclusions

Being male carries an increased risk of spontaneous but not iatrogenic preterm birth. The reasons behind this remain obscure.     

Independent effects of pregnancy induced hypertension on childhood development: a retrospective cohort study

Objective

To assess whether maternal hypertension in pregnancy was independently associated with additional support needs in children.

Study design

Retrospective cohort study using linkage of birth records of all singleton deliveries occurring in primigravidae between 1995 and 2008 in Aberdeen Maternity and Neonatal Databank with the Support Needs System (SNS) dataset in Grampian. Crude and adjusted odds ratios with 95% confidence intervals of having a record in SNS in the presence of maternal pregnancy induced hypertension were calculated using logistic regression taking account of confounders such as preterm birth and low birth weight.

Results

After adjusting for confounding factors, neither pre-eclampsia {Adj OR 0.80 (95% CI 0.60, 1.07)} nor gestational hypertension {Adj OR 1.16 (95% CI 0.99, 1.36)} showed statistically significant associations with additional support needs. An association of pre-eclampsia with cerebral palsy seen on univariate analysis also disappeared on adjusting for confounders {Adj OR 1.26 (95% CI 0.43, 3.68)}. Birth before 32 weeks gestation and birthweight below 1500 g were independently associated with additional support needs in children.

Conclusions

While maternal hypertension was not found to be independently associated with special needs in children, very preterm birth and very low birthweight showed an association.     

Do poor responders have poor perinatal outcomes? A retrospective analysis of 1386 assisted reproductive technology cycles

Objective

The purpose of this study was to evaluate whether poor responder women have adverse perinatal outcomes compared to normo responders following assisted reproductive technology (ART).

Encuesta SEGO. Tratamiento de la amenaza de parto pretérmino en los hospitales españoles

Objective

To determine how threatened preterm labor is treated in Spanish hospitals.

Material and method

Under the aegis of the Spanish Society of Obstetrics and Gynecology, an Internet questionnaire on basic aspects of the treatment of threatened preterm labor was sent to 41 Spanish hospitals (37 public and four private hospitals).

Results

All hospitals use tocolysis in threatened preterm labor before 34th weeks. The most widely used tocolytic agent is atosiban (73,7%), followed by betamimetics (21.9%) and nifedipine (4.9%). Only 7.3% of the hospitals use tocolytics in threatened preterm labor after 34 weeks. All the hospitals use corticosteroids to accelerate lung maturation: 92.7% use betamethasone and 7.3% prefer dexamethasone. In 90% of the hospitals, steroid therapy is not repeated. In multiple pregnancies, the same steroid dose as that used in single pregnancies is administrated in all centers.

Conclusions

The most widely used tocolytic agent in Spanish hospitals is atosiban and the preferred corticosteroid is betamethasone.     

Factores etiopatogénicos de la prematuridad en el hospital universitario Sant Joan de Déu de Barcelona

Objective

To determine the rate of preterm births in 2010 at the Sant Joan de Déu University Hospital in Barcelona, and classify them according to the main cause by using a mapping algorithm to establish the main etiological causes of preterm birth.

Subjects and methods

All preterm births at less than 37 weeks’ gestation occurring in the Sant Joan de Déu University Hospital in 2010 (n = 396) were reviewed and assigned to a group according to their primary etiology.

Results

The preterm birth rate was 9.8%. Inflammatory causes accounted for 36% of all preterm births followed by idiopathic causes (29%). In preterm deliveries of multiple gestations, inflammatory causes accounted for 44%.

Conclusions

Inflammatory causes are the main etiology of preterm births and are more common in multiple gestations.     

Risk factors and perinatal outcomes associated with idiopathic small for gestational age Taiwanese newborns

Objective

To determine risk factors and perinatal outcomes associated with small for gestational age (SGA) neonates among healthy pregnant women.

Methods

A retrospective cohort study was conducted of 49 945 women who gave birth at Chang Gung Memorial Hospital, Taipei, Taiwan, after 24 weeks of pregnancy. Idiopathic SGA newborns (n = 3398) were characterized by a birth weight below the 10th percentile for mean weight corrected for GA and fetal sex.

Results

Risk factors for idiopathic SGA newborns included hypercoiling of the umbilical cord (adjusted odds ratio [aOR], 3.3; 95% confidence interval [CI], 1.6–7.0); prior fetal death (aOR, 2.8; 95% CI, 2.0–3.9); primiparity (aOR, 1.5; 95% CI, 1.4–1.7); adolescent pregnancy (aOR, 1.5; 95% CI, 1.2–2.0), low prepregnancy weight (aOR, 1.6; 95% CI, 1.5–1.8), low prepregnancy body mass index (aOR, 1.1; 95% CI, 1.0–1.3); short stature (aOR, 1.3; 95% CI, 1.1–1.4); and entangled umbilical cord (aOR, 1.1; 95% CI, 1.0–1.3). Idiopathic SGA newborns correlated with increased risk of adverse perinatal outcomes, including fetal death, low Apgar scores, oligohydramnios, placental abruption, and admission to the neonatal intensive care unit.

Conclusion

Some risk factors for idiopathic SGA newborns were modifiable, suggesting potential implications for public health.     

Prevalence and risk factors related to preterm birth in Brazil

Background

The rate of preterm birth has been increasing worldwide, including in Brazil. This constitutes a significant public health challenge because of the higher levels of morbidity and mortality and long-term health effects associated with preterm birth. This study describes and quantifies factors affecting spontaneous and provider-initiated preterm birth in Brazil.

Methods

Data are from the 2011–2012 “Birth in Brazil” study, which used a national population-based sample of 23,940 women. We analyzed the variables following a three-level hierarchical methodology. For each level, we performed non-conditional multiple logistic regression for both spontaneous and provider-initiated preterm birth.

Results

The rate of preterm birth was 11.5 %?, (95 % confidence 10.3 % to 12.9 %) 60.7 % spontaneous - with spontaneous onset of labor or premature preterm rupture of membranes - and 39.3 % provider-initiated, with more than 90 % of the last group being pre-labor cesarean deliveries. Socio-demographic factors associated with spontaneous preterm birth were adolescent pregnancy, low total years of schooling, and inadequate prenatal care. Other risk factors were previous preterm birth (OR 3.74; 95 % CI 2.92–4.79), multiple pregnancy (OR 16.42; 95 % CI 10.56–25.53), abruptio placentae (OR 2.38; 95 % CI 1.27–4.47) and infections (OR 4.89; 95 % CI 1.72–13.88). In contrast, provider-initiated preterm birth was associated with private childbirth healthcare (OR 1.47; 95 % CI 1.09–1.97), advanced-age pregnancy (OR 1.27; 95 % CI 1.01–1.59), two or more prior cesarean deliveries (OR 1.64; 95 % CI 1.19–2.26), multiple pregnancy (OR 20.29; 95 % CI 12.58–32.72) and any maternal or fetal pathology (OR 6.84; 95 % CI 5.56–8.42).

Conclusion

The high proportion of provider-initiated preterm birth and its association with prior cesarean deliveries and all of the studied maternal/fetal pathologies suggest that a reduction of this type of prematurity may be possible. The association of spontaneous preterm birth with socially-disadvantaged groups reaffirms that the reduction of social and health inequalities should continue to be a national priority.

     

Teenage pregnancy and the influence of paternal involvement on fetal outcomes

Study Objective

We sought to assess the impact of paternal involvement on adverse birth outcomes in teenage mothers.

Design

Using vital records data, we generated odds ratios (OR) and 95% confidence intervals (CI) to assess the association between paternal involvement and fetal outcomes in 192,747 teenage mothers. Paternal involvement status was based on presence/absence of paternal first and/or last name on the birth certificate.

Setting

Data were obtained from vital records data from singleton births in Florida between 1998 and 2007.

Participants

The study population consisted of 192,747 teenage mothers ≤ 20 years old with live single births in the State of Florida.

Main Outcome Measures

Low birth weight, very low birth weight, preterm birth, very preterm birth, small for gestational age (SGA), neonatal death, post-neonatal death, and infant death.

Results

Risks of SGA (OR = 1.06; 95% CI: 1.03-1.10), low birth weight (OR = 1.19; 95% CI: 1.15-1.23), very low birth weight (OR = 1.53; 95% CI: 1.41-1.67), preterm birth (OR = 1.21; 95% CI: 1.17-1.25), and very preterm birth (OR = 1.49; 95% CI: 1.38-1.62) were elevated for mothers in the father-absent group. When results were stratified by race, black teenagers in the father-absent group had the highest risks of adverse birth outcomes when compared to white teenagers in the father-involved group.

Conclusions

Lack of paternal involvement is a risk factor for adverse birth outcomes among teenage mothers; risks are most pronounced among African-American teenagers. Our findings suggest that increased paternal involvement can have a positive impact on birth outcomes for teenage mothers, which may be important for decreasing the racial disparities in infant morbidities. More studies assessing the impact of greater paternal involvement on birth outcomes are needed.     

Complicaciones maternas a corto plazo en pacientes con cesárea

Objective

To determine whether patients who undergo cesarean section are at higher risk of complications than those who have a vaginal birth and to describe the complications observed.

Subjects and methods

We reviewed the clinical records of 1017 patients who gave birth at the Materno- Vall d’Hebron Maternity and Child Hospital in the first trimester of 2007.

Results

For a cesarean rate of 22%, the incidence of maternal complication was 18%, while for vaginal birth the incidence was 6% (RR 3.1, 95% CI 2.4-15.1). The most frequent complications were wound infection (7.5%), transfusions (5.3%) and hemorrhage (3.1%); endomyometritis was more common in the group with vaginal births (1.6% vs. 1.3%).

Conclusions

Cesarean section is associated with a three times higher risk of complications than vaginal birth. The lower incidence of endomyometritis after cesarean sections may be a consequence of antibiotic prophylaxis, but further studies are required to draw firm conclusions on this topic.     

The safety of quinolones—A meta-analysis of pregnancy outcomes

Objective

We conducted a meta-analysis of all published data in order to evaluate the risk for birth defects, stillbirths, preterm births and low birth weight following exposure to quinolones in the first trimester of pregnancy.

Study design

Medline, Embase, Scopus, Biological Abstracts and Proquest Thesis Dissertation databases were searched. Other papers and abstracts were located from the retrieved articles’ references, meeting booklets, internet web sites and books on teratology.

Results

Five studies met the inclusion criteria. The summary odds ratio for all the included studies was 1.05 (95% CI 0.90–1.22) for major malformations, 2.6 (95% CI 0.36–18.67) for stillbirths, 1.15 (95% CI 0.69–1.91) for preterm births and 0.73 (95% CI 0.30–1.79) for low birth weight. In an additional analysis including only fluoroquinolones (nalidixic acid was removed), the summary odds ratio for major malformations remained non-significant (1.11, 95% CI 0.57–2.15).

Conclusions

The use of quinolones during the first trimester of pregnancy does not appear to represent an increased risk for major malformations recognized after birth, stillbirths, preterm births or low birth weight.     

Prevalence and risk factors of bacterial vaginosis during the first trimester of pregnancy in a large French population-based study

Objectives

Bacterial vaginosis is a risk factor for preterm delivery. Its prevalence and risk factors in Europe are not well known. Our objective was to assess both in early pregnancy.

Study design

As part of the PREMEVA randomized controlled trial, this population-based study included 14,193 women screened before 14 weeks’ gestation for bacterial vaginosis in the 160 laboratories of the Nord-Pas-de-Calais region in France. Bacterial vaginosis was defined by a Nugent score ≥ 7. Data were collected about maternal tobacco use, age, education, and history of preterm birth. We estimated the prevalence of bacterial vaginosis and used a multilevel logistic regression model to identify significant risk factors for it.

Results

Among the 14,193 women assessed before 14 weeks’ gestation, the prevalence of bacterial vaginosis was 7.1% (95% CI: 6.6–7.5%). In the multivariate analysis, smoking during pregnancy tobacco (adjusted OR: 1.38; 95% CI: 1.19–1.60), maternal age 18–19 years (adjusted OR: 1.40; 95% CI: 1.01–1.93), and educational level (completed only primary school: adjusted OR: 1.77; 95% CI: 1.35–2.31; completed only secondary school: adjusted OR: 1.27; 95% CI: 1.10–1.48) were independent risk factors for bacterial vaginosis. History of preterm delivery was not an independent risk factor of bacterial vaginosis: adjusted OR: 1.15; 95% CI: 0.90–1.47.

Conclusion

In a large sample of women in their first trimester of pregnancy in France, the prevalence of bacterial vaginosis was lower than rates reported in other countries, but risk factors were similar: young age, low level of education, and tobacco use during pregnancy. These results should be considered in future strategies to reduce preterm delivery.     

Advanced maternal age and adverse perinatal outcomes in an Asian population

Objective

To investigate (1) whether there is an increasing trend in the mean maternal age at the birth of the first child and in the group of women giving birth at age 35 or older, and (2) the association between advanced maternal age and adverse perinatal outcomes in an Asian population.

Study design

We conducted a retrospective cohort study involving 39,763 Taiwanese women who delivered after 24 weeks of gestation between July 1990 and December 2003. Multivariable logistic regression was used to adjust for potential confounding variables.

Results

During the study period, the mean maternal age at the birth of the first child increased from 28.0 to 29.7 years, and the proportion of women giving birth at age 35 or older increased from 11.4% to 19.1%. Compared to women aged 20–34 years, women giving birth at age 35 or older carried a nearly 1.5-fold increased risk for pregnancy complications and a 1.6–2.6-fold increased risk for adverse perinatal outcomes. After adjusting for the confounding effects of maternal characteristics and coexisting pregnancy complications, women aged 35–39 years were at increased risk for operative vaginal delivery (adjusted odds ratio [OR] 1.5, 95% confidence interval [CI] 1.2–1.7) and cesarean delivery (adjusted OR 1.6, 95% CI 1.5–1.7), while women aged 40 years and older were at increased risk for preterm delivery (before 37 weeks of gestation) (adjusted OR 1.7, 95% CI 1.3–2.2), operative vaginal delivery (adjusted OR 3.1, 95% CI 2.0–4.6), and cesarean delivery (adjusted OR 2.6, 95% CI 2.2–3.1). In those women who had a completely uncomplicated pregnancy and a normal vaginal delivery, advanced maternal age was still significantly associated with early preterm delivery (before 34 weeks of gestation), a birth weight <1500 g, low Apgar scores, fetal demise, and neonatal death.

Conclusion

In this population of Taiwanese women, there is an increasing trend in the mean maternal age at the birth of the first child. Furthermore, advanced maternal age is independently associated with specific adverse perinatal outcomes.     

Factors associated with maternal near-miss morbidity and mortality in Kowloon Hospital,Suzhou, China

Objective

To investigate factors associated with acute maternal morbidity and mortality in Kowloon Hospital, Suzhou, China.

Methods

Data from cases of near-miss and maternal death between January 2008 and December 2012 were reviewed retrospectively. Maternal characteristics and related factors were identified, and multiple regression analysis was used to calculate adjusted odds ratios (aORs) and 95% confidence intervals (CIs).

Results

During the study period, there were 18 104 deliveries, 69 near-miss cases, and 3 maternal deaths. Women who had no health insurance (aOR, 4.55; 95% CI, 0.87–21.8), had fewer than 6 prenatal consultations (aOR, 6.76; 95% CI, 0.76–45.8), were part of a migrant population (aOR, 2.34; 95% CI, 0.45–24.9), or delayed seeking healthcare (aOR, 4.76; 95% CI, 0.89–13.6) had a greater risk of near-miss morbidity or death. Admission to intensive care (aOR, 6.75; 95% CI, 0.89–34.6) and blood transfusion within 30 min (aOR, 3.79; 95% CI, 0.65–8.67) were protective factors in disease progression.

Conclusion

The factors associated with maternal near-miss morbidity and mortality were closely related to health insurance and socioeconomic status, suggesting that the government should take an active role in the community in preventing morbidity and mortality in pregnancy.     

Predictors of unknown HIV serostatus at the time of labor and delivery in Kampala,Uganda

Objective

To determine factors associated with an unknown HIV serostatus among pregnant women admitted in labor to Mulago Hospital, Kampala, Uganda.

Methods

In total, 665 pregnant women admitted to Mulago Hospital were interviewed about their sociodemographic characteristics, obstetric history, access to prenatal care, fears regarding HIV testing, and knowledge about modes of mother-to-child-transmission (MTCT). Knowledge of the HIV serostatus was assessed by self-report and verified by prenatal card review.

Results

The prevalence of unknown HIV serostatus at the time of labor was 27.1%. Factors associated with an unknown HIV serostatus included high parity (odds ratio [OR] 1.9; 95% confidence interval [CI], 1.16–3.14), preterm delivery (OR 2.60; 95% CI, 1.06–6.34), prenatal care at a private clinic (OR 12.87; 95% CI, 5.68–29.14), residence more than 5 km from the nearest prenatal clinic (OR 2.86; 95% CI, 1.18–17.9), high knowledge about MTCT (OR 0.25; 95% CI, 0.07–0.86), and fears related to disclosing the test result to the partner (OR 3.60; 95% CI, 1.84–7.06).

Conclusion

The high prevalence of unknown HIV serostatus among women in labor highlights the need to improve accessibility to HIV testing services early during pregnancy to be able to take advantage of antiretroviral therapy.     

Neonatal outcome and birth defects in 6623 singletons born following minimal ovarian stimulation and vitrified versus fresh single embryo transfer

Objective

To compare neonatal outcome between children born after vitrified versus fresh single-embryo transfer (SET).

Study design

Retrospective, single-centre cohort study of 6623 delivered singletons following 29,944 single-embryo transfers. Patients underwent minimal ovarian stimulation/natural cycle IVF followed by SET of fresh or vitrified-warmed (using Cryotop, Kitazato) cleavage-stage embryos or blastocysts. Outcome measures were gestational age at delivery, birth weight, birth length, low birth weight (LBW), small for gestational age (SGA) and large for gestational age (LGA) infants, perinatal mortality and minor/major birth defects (evaluated by parent questionnaire).

Results

Gestational age (38.6 ± 2 versus 38.7 ± 1.9 weeks) and preterm delivery rate (6.9% versus 6.9%, aOR: 0.96 95%CI: 0.76–1.22) in singletons born after the transfer of vitrified embryos were comparable to those born after the transfer of fresh embryos. Children born after the transfer of vitrified embryos had a higher birth weight (3028 ± 465 versus 2943 ± 470 g, p < 0.0001) and lower LBW (8.5% versus 11.9%, aOR: 0.65 95%CI: 0.53–0.79) and SGA (3.6% versus 7.6% aOR: 0.43 95%CI: 0.33–0.56) rates. Total birth defect rates (including minor anomalies) (2.4% versus 1.9%, aOR: 1.41 95%CI: 0.96–2.10) and perinatal mortality rates (0.6% versus 0.5%, aOR: 1.02 95%CI: 0.21–4.85) were comparable between the vitrified and fresh groups.

Conclusions

Vitrification of embryos/blastocysts did not increase the incidence of adverse neonatal outcomes or birth defects following single embryo transfer.