The association of in vitro fertilization and perinatal morbidity

In recent years, there has been increasing concern regarding the safety of in vitro fertilization (IVF) because of the potential health impact on these infants. Multiple pregnancy contributes the vast majority of morbidity associated with IVF and, initially, many thought that adverse outcomes after IVF were solely attributable to the high incidence of twin pregnancies. More recently, multiple studies have suggested that IVF singleton pregnancies may be at increased risk for preterm birth, low birth weight, congenital anomalies, perinatal mortality, and several other pregnancy-related complications compared with unassisted singleton pregnancies. We have focused this review on the increased risk of adverse outcomes in IVF singleton conceptions compared with that of unassisted conceptions. The available evidence evaluating the association between IVF and low birth weight, preterm delivery, placental abruption, preeclampsia, congenital anomalies, and perinatal mortality in singleton pregnancies is summarized. In addition, data reporting an increased risk of congenital and chromosomal anomalies after IVF are presented.     

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.     

Compartment syndrome after gynecologic laparoscopy: systematic review of the literature and establishment of normal values for postoperative serum creatine kinase and myoglobin levels

Purpose

The worldwide prevalence of adverse pregnancy outcomes (APOs) in singleton pregnancies after in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) is suggested to vary; however, a complete overview is missing. The aim of this review is to estimate the worldwide prevalence of APOs associated with IVF/ICSI singleton pregnancies.

Methods

PubMed, Google Scholar, Cochrane Libraries, and Chinese databases were searched for studies assessing APOs among IVF/ICSI singleton births through March 2016. The prevalence estimates were summarized and analyzed by meta-analysis.

Results

Fifty-two cohort studies, with 181,741 IVF/ICSI singleton births and 4,636,508 spontaneously conceived singleton births, were selected for analysis. Among IVF/ICSI singleton pregnancies, pooled estimates were 10.9% [95% confidence interval (CI) 10.0–11.8] for preterm birth, 2.4% (95% CI 1.9–3.0) for very preterm birth, 8.7% (95% CI 7.4–10.2) for low birth weight, 2.0% (95% CI 1.5–2.6) for very low birth weight, 7.1% (95% CI 5.5–9.2) for small for gestational age, 1.1% (95% CI 0.9–1.3) for perinatal mortality, and 5.7% (95% CI 4.7–6.9) for congenital malformations. The IVF/ICSI singleton pregnancies have higher prevalence of APOs compared with those conceived naturally (all P = 0.000). Significant differences in different continents, countries, income groups, and type of assisted conception were found.

Conclusions

The IVF/ICSI singleton pregnancies are at a higher prevalence of adverse perinatal outcomes compared with those conceived naturally. Important geographical differences were found. Yet, population-wide prospective APO registries covering the entire world population for IVF/ICSI pregnancies are needed to determine the exact perinatal prevalence.

     

Hydatid of Morgagni: a possible underestimated cause of unexplained infertility

Objectives

To assess the risk of spontaneous and iatrogenic preterm delivery in singleton pregnancies when comparing in vitro fertilization (IVF) pregnancies with intracytoplasmic sperm injection (ICSI) pregnancies.

Study design

A national population-based cohort study using Norwegian Medical Birth Register data during 1999 through 2006 was designed. The cohort included 5824 singleton pregnancies after IVF and ICSI treatment. Multinomial logistic regression analyses were used to calculate risk estimates.

Results

There were no differences in maternal complicating factors such as pre-eclampsia, hypertension and diabetes between the IVF and ICSI pregnancies. However, IVF pregnancies had a 60% increased risk of moderately (32^+0days-36^+6days gestational weeks) iatrogenic preterm delivery (OR: 1.6, 95%CI: 1.1-2.2) and a 40% increased risk of iatrogenic preterm delivery <37 weeks (OR: 1.4, 95%CI: 1.02-1.9) compared to ICSI pregnancies.

Conclusion

IVF pregnancies were at increased risk of moderately iatrogenic preterm delivery when compared to ICSI pregnancies.     

Risk of preterm delivery in relation to maternal low birth weight

OBJECTIVE: We examined the relationship between maternal low birth weight and preterm delivery risk. METHODS: Information concerning maternal birth weight was collected during in-person interviews. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI). Preterm delivery cases were studied in aggregate, in subgroups (spontaneous preterm labor, preterm premature rupture of membranes, medically induced preterm delivery, moderate preterm delivery [gestational age at delivery 34-36 weeks], and early preterm delivery [gestational age at delivery<34 weeks]). RESULTS: After adjusting for confounders, women weighing<2,500 g at birth had a 1.54-fold increased risk of preterm delivery versus women weighing=2,500 g (95% CI 0.97-2.44). Maternal low birth weight was associated with a 2-fold increased risk of spontaneous preterm delivery (95% CI 1.03-3.89), but weakly associated with preterm premature rupture of membranes (OR=1.44; 95% CI 0.67-3.09) and medically induced preterm delivery (OR=1.10; 95% CI 0.43-2.82). Maternal low birth weight was more strongly associated with early preterm delivery (OR=1.94) than with moderate preterm delivery (OR=1.46). Women weighing<2,500 g at birth and who became obese (pre-pregnancy body mass index, =30 kg/m2) before pregnancy had a 3.65-fold increased risk of preterm delivery (95% CI 1.33-10.02) versus women weighing=2,500 g at birth and who were not obese prior to pregnancy (<30 kg/m2). CONCLUSIONS: Results confirm earlier findings linking maternal low birth weight with future risk of preterm delivery.     

Risk factors for postpartum hemorrhage requiring transfusion in cesarean deliveries for Japanese twins: comparison with those for singletons

Objective

The aim of this study was to identify the factors associated with the increased risk of postpartum hemorrhage requiring transfusion in Japanese twin pregnancies in comparison with those in Japanese singleton pregnancies.

Methods

We reviewed the obstetric records of all singleton and twin deliveries after 22?weeks’ gestation at the Japanese Red Cross Katsushika Maternity Hospital from 2003 through 2011. Potential risk factors for transfusion due to hemorrhage after cesarean delivery were selected according to previous studies of postpartum hemorrhage or transfusion or both after delivery: maternal age, parity, previous cesarean deliveries, history of infertility therapies such as in vitro fertilization, gestational age at delivery, neonatal birth weight, placenta previa, uterine myoma ≥6?cm, hypertensive disorders, placental abruption, emergency cesarean deliveries and general anesthesia.

Results

Using multiple logistic regression, the independent risk factors for postpartum hemorrhage requiring transfusion in singleton pregnancies were preterm delivery [odds ratio (OR) 2.40, 95?% confidence interval (CI) 1.2–4.6, p?<?0.01], placenta previa (OR 8.08, 95?% CI 3.9–16, p?<?0.01) and placental abruption (OR 12.8, 95?% CI 2.3–76, p?<?0.01). In twin pregnancies, however, the independent risk factors for postpartum hemorrhage requiring transfusion were gestational age at ≥41?weeks (OR 8.20, 95?% CI 1.3–40, p?<?0.01) and hypertensive disorders (OR 5.45, 95?% CI 2.2–14, p?<?0.01).

Conclusions

The factors associated with postpartum hemorrhage requiring transfusion in cesarean deliveries of twins seemed to be different from those in singleton cesarean deliveries.     

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 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.     

Maternal risks and perinatal outcome in a Danish national cohort of 1005 twin pregnancies: the role of in vitro fertilization

BACKGROUND: Twin pregnancies constitute 25% of all in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) pregnancies. There is a lack of knowledge on maternal risks and perinatal outcome of IVF/ICSI twin pregnancies. METHODS: National survey by questionnaire (n = 1769). The study population consisted of all IVF/ICSI twin mothers (n = 266) and the two control groups of all IVF/ICSI singleton mothers (n = 764) and non-IVF/ICSI twin mothers (n = 739) who delivered in Denmark in 1997. The response rate was 89% among IVF twin mothers and overall 81%. RESULTS: In terms of maternal risks and perinatal outcome no significant differences were observed between IVF/ICSI twin and non-IVF/ICSI twin pregnancies after stratification for maternal age and parity. Nevertheless, IVF/ICSI twin mothers were more frequently on sick leave (OR 2.5, 95% CI 1.5-4.0) and hospitalized (OR 1.9, 95% CI 1.3-2.8) during pregnancy. Compared with IVF/ICSI singleton pregnancies, IVF/ICSI twin pregnancies were characterized by a higher incidence of preeclampsia (OR 2.4, 95% CI 1.5-4.2) and a higher frequency of sick leave (OR 6.8, 95% CI 4.4-10.5) and hospitalizations during pregnancy (OR 3.5, (95% CI 2.5-4.9); moreover, mean birthweight (p < 0.001) and gestational age (p < 0.001) were lower. No differences were observed in the incidence of pregnancy-induced hypertension and gestational diabetes between IVF/ICSI twin and singleton pregnancies. CONCLUSION: Although this population study indicates that maternal risks in IVF/ICSI twin pregnancies are comparable with non-IVF/ICSI twin pregnancies, the IVF/ICSI twin mothers were more likely to be on sick leave or hospitalized during pregnancy. Furthermore, maternal risks were higher and obstetric outcome poorer in IVF/ICSI twin vs. IVF/ICSI singleton pregnancies.     

Perinatal outcome of quadruplet pregnancies in relation to chorionicity.

OBJECTIVE: To compare the perinatal outcome of quadruplets in relation to chorionicity. PATIENTS AND METHODS: In this retrospective study, the maternal, neonatal and chorionicity data were collected from 24 sets of quadruplet pregnancies delivered between January 1985 and December 2001. Perinatal and neonatal data were evaluated in relation to chorionicity. RESULTS: Sixteen pregnancies were quadra-chorionic quadramniotic (QC) and eight had at least one monochorionic pair (TC). The median gestational age at delivery was 31 weeks (23 to 34 weeks) with overall perinatal mortality rate of 177 per 1000 total birth. Delivery before 30 weeks (OR 89; 95% CI 9 to 607; P<0.01) and discordant birth weight of >25% (OR 7.6; 95% CI 2 to 29; P<0.01) had independent effects on perinatal loss rate. The perinatal loss was five fold higher in TC quadruplets than those of QC (OR 5.1; 95% CI 1.7 to 15.4; P<0.001). This was attributed to higher risk of very low birth weight (69 vs 13%; P<0.01), delivery before 30 weeks (63 vs 13%; P<0.001) in TC quadruplets compared to QC gestation. CONCLUSIONS: The quadruplets with MC pair have 5 times higher perinatal mortality than quadra-chorionic quadruplet pregnancies owing to preterm delivery and discordant birth weight.     

First trimester vaginal bleeding and adverse pregnancy outcomes among Chinese women: from a large cohort study in China

Objectives: To examine the effect of first trimester vaginal bleeding on adverse pregnancy outcomes including preterm delivery, low birth weight and small for gestational age. Methods: This is a prospective population-based cohort study. A questionnaire survey was conducted on 4342 singleton pregnancies by trained doctors. Binary logistic regression was used to estimate risk ratios (RRs) and 95% con?dence intervals (95% CI). Results: Vaginal bleeding occurred among 1050 pregnant women, the incidence of vaginal bleeding was 24.2%, 37.4% of whom didn’t see a doctor, 62.6% of whom saw a doctor for vaginal bleeding. Binary logistic regression demonstrated that bleeding with seeing a doctor was significantly associated with preterm birth (RR 1.84, 95% CI 1.25–2.69) and bleeding without seeing a doctor was related to increased of low birth weight (RR 2.52, 95% CI 1.34–4.75) and was 1.97-fold increased of small for gestational age (RR 1.97, 95% CI 1.19–3.25). Conclusions: These results suggest that first trimester vaginal bleeding is an increased risk of low birth weight, preterm delivery and small for gestational age. Find ways to reduce the risk of vaginal bleeding and lower vaginal bleeding rate may be helpful to reduce the incidence of preterm birth, low birth weight and small for gestational age.     

Recurrence of preterm birth in singleton and twin pregnancies

OBJECTIVE: To assess recurrence of preterm birth and its impact on an obstetric population. METHODS: Women with consecutive births at our hospital beginning with their first pregnancy were identified (n = 15,945). The first pregnancy was categorized as delivered between 24 and 34 weeks' gestation or 35 weeks or beyond, singleton or twin, and spontaneous or induced. The risk of preterm delivery in these same women during subsequent pregnancies was then analyzed. RESULTS: Compared with women who delivered a singleton at or beyond 35 weeks' gestation in their first pregnancy, those who delivered a singleton before 35 weeks were at a significant increased risk for recurrence (odds ratio [OR] 5.6, 95% confidence interval [CI] 4.5, 7.0), whereas those who delivered twins were not (OR 1.9, 95% CI 0.46, 8.14). The OR for recurrent spontaneous preterm birth presenting with intact membranes was 7.9 (95% CI 5.6, 11.3) compared with 5.5 (95% CI 3.2, 9.4) with ruptured membranes. Of those women with a recurrent preterm birth, 49% delivered within 1 week of the gestational age of their first delivery and 70% delivered within 2 weeks. Among 15,863 nulliparous women with singleton births at their first delivery, a history of preterm birth in that pregnancy could predict only 10% of the preterm births that ultimately occurred in the entire obstetric population. CONCLUSION: In a population-based study at our hospital, women who initially delivered preterm and thus were identified to be at risk for recurrence ultimately accounted for only 10% of the prematurity problem in the cohort.     

Restricting weight gain during pregnancy in Japan: a controversial factor in reducing perinatal complications

OBJECTIVE: To evaluate the effectiveness of restricting weight gain during pregnancy to reduce perinatal complications. STUDY DESIGN: The study was conducted in the Tokyo metropolitan area, and reviewed 3071 mothers and their infants born from singleton pregnancies retrospectively. To examine the influence of increased maternal weight gain on perinatal complications, we performed five-category stratification for weight gain: less than 8.0, 8.0-10.0, 10.1-12.0, 12.1-14.0 and over 14.0 kg. RESULTS: Total weight gains less than 8.0 kg significantly increased the risk of low birth weight (LBW) and small for gestational age (SGA) infants (OR=2.19, 95% CI; 1.36-3.52, OR=1.76, 95% CI; 1.23-2.51) and total weight gain over 14.0 kg significantly increased the risk of large for gestational age (LGA) infants and pregnancy induced hypertension (PIH) (OR=3.06, 95% CI; 1.88-4.98, OR=2.87, 95% CI; 1.86-4.42, respectively), compared with women with weight gain of 10.1-12.0 kg. The groups with weight gains of 8.0-10.0 kg and 12.1-14.0 kg did not show adverse perinatal outcomes, including gestational diabetes (GDM), cesarean delivery, postpartum hemorrhage and laceration, significantly different from the 10.1 to 12.0 kg gain group. CONCLUSION: Strict restriction of weight gain during pregnancy is not effective in reducing perinatal complications.     

Perinatal outcome of pregnancies after assisted reproduction: a case-control study.

OBJECTIVE: We conducted a case-control study of all pregnancies obtained with assisted reproduction technology in the Dutch-speaking part of Belgium from 1992 until 1997 to investigate differences in peripartum obstetric events and the perinatal outcome. STUDY DESIGN: Three thousand fifty-seven singleton and 1241 twin pregnancies were studied. About 90% of pregnancies resulted from in vitro fertilization; the remainder resulted from intracytoplasmic sperm injection. Control subjects were selected from a regional register and were matched for maternal age, parity, fetal sex, plurality, and date of delivery. The main outcome measures were duration of gestation, birth weight, perinatal death, perinatal morbidity, incidence of congenital malformations, and incidence of cesarean delivery. RESULTS: Odds ratios and 95% confidence intervals were 2.6 (1.4-4.8) for perinatal mortality, 3.5 (2.2-5.7) for birth before 33 weeks of gestation, and 1.7 (1.5-1.9) for cesarean delivery in singleton pregnancies that resulted after in vitro fertilization. Twin pregnancies obtained with in vitro fertilization, on the contrary, were similar for all outcome measures, except for the incidence of cesarean delivery (odds ratio, 1.4; 95% confidence interval, 1.2-1.7) compared with spontaneously conceived twin pregnancies. CONCLUSION: The perinatal outcome of singleton pregnancies obtained with in vitro fertilization is significantly worse than that of spontaneously conceived pregnancies, mainly because of the increased rate of preterm birth. The outcome of twin pregnancies obtained with in vitro fertilization is comparable with that of normally conceived twins. For both singleton and twin pregnancies obtained with in vitro fertilization, the incidence of cesarean delivery is increased.     

Cervical pessaries for the prevention of preterm birth: a systematic review and meta-analysis

Objective: The objective of this study is to evaluate the effectiveness and safety of cervical pessaries for the prevention of preterm birth.

Methods: We searched PubMed, Embase, Web of Science, and other sources from inception to July 2016. This analysis referred to pregnant women with singleton/multiple viable fetus/fetuses, with or without cervical pessary placement.

Results: Six randomized control trials and five cohort studies involving 3911 participants were included. Overall, cervical pessary placement was slightly associated with the decrease of spontaneous delivery less than 34 weeks (relative risk 0.65 [95% CI: 0.44–0.96]) and increased gestational age at delivery (weighted mean difference 1.03 weeks [95% CI: 0.37–1.70]) in multiple pregnancies, but not with poor perinatal outcomes. Pessary placement in singleton pregnancies did not show any difference. A planned subgroup analysis showed multiple pregnancies with shorter cervical length (≤25?mm) had a longer prolongation of pregnancy (weighted mean difference 2.08 weeks [95% CI: 1.35–2.82]).

Conclusion: This meta-analysis suggested pessary placement could slightly reduce the rate of spontaneous preterm delivery before 34 weeks, and increase gestational age at delivery in multiple pregnancies, but not in singleton pregnancies. More studies of high quality with detailed records are urgent to confirm the efficacy of this procedure.     

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.     

Effect of the interpregnancy interval on perinatal outcomes in Latin America

OBJECTIVE: To estimate whether interpregnancy interval is independently associated with increased risk of perinatal death and other adverse perinatal outcomes. METHODS: We investigated the effect of interpregnancy interval on perinatal outcomes in 1,125,430 pregnancies recorded in the Perinatal Information System database of the Latin American Center for Perinatology and Human Development, Montevideo, Uruguay, between 1985 and 2004. Odds ratios (ORs) were adjusted for 16 major confounding factors using multiple logistic regression models. RESULTS: Compared with infants with interpregnancy intervals of 18-23 months, those born to women with intervals shorter than 6 months had an increased risk of early neonatal death (adjusted OR 1.49, 95% confidence interval [CI] 1.06-1.96), fetal death (adjusted OR 1.54, 95% CI 1.28-1.83), low birth weight (adjusted OR 1.88, 95% CI 1.78-1.90), very low birth weight (adjusted OR 2.01, 95% CI 1.73-2.31), preterm birth (adjusted OR 1.80, 95% CI 1.71-1.89), very preterm birth (adjusted OR 1.95, 95% CI 1.67-2.26), and small for gestational age (adjusted OR 1.30, 95% CI 1.25-1.36). Intervals of 6-11 months and 60 months and longer were also associated with a significantly greater risk for the 7 adverse perinatal outcomes. CONCLUSION: In Latin America, interpregnancy intervals shorter than 12 months and longer than 59 months are independently associated with increased risk of adverse perinatal outcomes. These data suggest that spacing pregnancies appropriately could prevent perinatal deaths and other adverse perinatal outcomes in the developing world.     

Lower risk of adverse perinatal outcomes in natural versus artificial frozen–thawed embryo transfer cycles: a systematic review and meta-analysis

This systematic review of literature and meta-analysis of observational studies reports on perinatal outcomes after frozen embryo transfer (FET). The aim was to determine whether natural cycle frozen embryo transfer (NC-FET) in singleton pregnancies conceived after IVF decreased the risk of adverse perinatal outcomes compared with artificial cycle frozen embryo transfer (AC-FET). Thirteen cohort studies, including 93,201 cycles, met the inclusion criteria. NC-FET was associated with a lower risk of hypertensive disorders in pregnancy (HDP) (RR 0.61, 95% CI 0.50 to 0.73), preeclampsia (RR 0.47, 95% CI 0.42 to 0.53), large for gestational age (LGA) (RR 0.93, 95% CI 0.90 to 0.96) and macrosomia (RR 0.82, 95% CI 0.69 to 0.97) compared with AC-FET. No significant difference was found in the risk of gestational hypertension and small for gestational age. Secondary outcomes assessed were the risk of preterm birth (RR 0.83, 95% CI 0.79 to 0.88); post-term birth (RR 0.48, 95% CI 0.29 to 0.80); low birth weight (RR 0.84, 95% CI 0.80 to 0.89); caesarean section (RR 0.84, 95% CI 0.77 to 0.91); postpartum haemorrhage (RR 0.39, 95% CI 0.35 to 0.45); placental abruption (RR 0.61, 95% CI 0.38 to 0.98); and placenta accreta (RR 0.18, 95% CI 0.10 to 0.33). All were significantly lower with NC-FET compared with AC-FET. In assessing safety, NC-FET significantly decreased the risk of HDP, preeclampsia, LGA, macrosomia, preterm birth, post-term birth, low birth weight, caesarean section, postpartum haemorrhage, placental abruption and placenta accreta. Further randomized controlled trials addressing the effect of NC-FET and AC-FET on maternal and perinatal outcomes are warranted. Clinicians should carefully monitor pregnancies achieved by FET in artificial cycles prenatally, during labour and postnatally.     

Maternal smoking and gestational age in twin pregnancies

BACKGROUND: A twin pregnancy imposes greater demands on maternal physiology and smoking may thus be associated theoretically with a greater risk of preterm delivery than in singleton pregnancies. POPULATION AND METHODS: From 1989 to 1996 all women who booked for antenatal care at the Department of Gynecology and Obstetrics, Aarhus University Hospital, Denmark were asked to fill in two questionnaires. Apart from smoking habits, these questionnaires provided information on medical and obstetric history together with information on sociodemographic and other lifestyle variables. Gestational age at delivery was calculated from ultrasonographically determined fetal biparietal diameter and information about the last menstrual period. Only women carrying twins were included in the present study (n=401). RESULTS: Mean gestational age was 5 days (95% CI 1-9 days) shorter among smokers compared with non-smokers. Among non-smokers mean gestational age was 261 days (+/-18), among women who smoked 1-9 and 10+ cigarettes per day 257 days (+/-23) and 255 days (+/-20), respectively. The overall risk of preterm delivery (< 37 weeks) and delivery before 34 completed weeks was 1.3 (95% CI 0.9-2.2) and 1.4 (95% CI 0.8-2.4), respectively. Primiparous women had shorter gestational age than did multiparous women. Still, among primiparous as well as among multiparous women gestational age decreased with smoking. Adjustment for maternal age, height and prepregnancy weight, alcohol and caffeine intake, marital status, education, occupational status, preterm birth in previous pregnancies, and in vitro fertilization in the present pregnancy did not change the results. CONCLUSIONS: Smoking has a substantial effect on mean gestational age in twin pregnancies, and a dose response like relationship is present.     

Infant and Maternal Outcomes for Women Who Experience Imprisonment in Ontario,Canada: A Retrospective Cohort Study

ObjectiveTo describe the population-level risk of infant and maternal outcomes for women who experience imprisonment and compare outcomes with the general population.MethodsWe conducted a retrospective cohort study. We used linked correctional and health data for women released from provincial prisons in 2010. We defined three exposure groups for Ontario singleton deliveries from 2005-2015: deliveries to women who were in prison during pregnancy but not necessarily for delivery, prison pregnancies; deliveries to women who had been in prison but not while pregnant, prison controls; and general population deliveries. We compared groups using generalized estimating equations. Primary outcomes were preterm birth, low birth weight, and small for gestational age birth weight. Secondary outcomes included NICU admission, neonatal abstinence syndrome, placental abruption, and preterm prelabour rupture of membranes.ResultsIn prison pregnancies (n = 544) and prison controls (n = 2156), respectively, preterm birth risk was 15.5% and 12.5%, low birth weight risk was 13.0% and 11.6%, and small for gestational age birth weight risk was 18.1% and 19.2%. Adjusted for maternal age and parity and compared with general population deliveries (N = 1 284 949), odds ratios were increased for prison pregnancies and prison controls, respectively, at 2.7 (95% CI 2.2–3.4) and 2.1 (95% CI 1.9–2.4) for preterm birth, 3.1 (95% CI 2.4–3.9) and 2.7 (95% CI 2.3–3.1) for low birth weight, and 1.6 (95% CI 1.3–2.1) and 1.8 (95% CI 1.6–2.0) for small for gestational age birth weight.ConclusionThere is an increased risk of adverse infant outcomes in women who experience imprisonment compared with the general population, whether they are in prison during pregnancy or not.     

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.