Association of low maternal levels of salusins with gestational diabetes mellitus and with small-for-gestational-age fetuses

Objectives

To evaluate maternal and cord serum concentrations of salusin-α and salusin-β in women with gestational diabetes mellitus (GDM) and with small-for-gestational age (SGA) fetuses.

Study design

Pregnant women with GDM (n = 25), women with SGA (n = 20) and maternal age-matched normal healthy pregnant subjects (n = 25) participated in the study. Maternal serum and cord blood salusin-α and salusin-β levels at the time of birth were measured using ELISA, and their relation with metabolic parameters was also assessed.

Results

Mean concentrations of maternal and fetal serum salusin-α in the GDM and SGA groups were significantly lower than those of the controls (P < 0.001, P < 0.001, P < 0.001 and P < 0.001, respectively). Mean concentrations of maternal and cord blood salusin-β also decreased in both the GDM and the SGA groups in comparison to the control group (P < 0.001, P < 0.001, P < 0.001 and P < 0.001, respectively). The concentrations of maternal serum salusin-α and salusin-β were strongly positively correlated with the concentrations of cord blood salusin-α and salusin-β (R = 0.92, P < 0.001 and R = 0.94, P < 0.001, respectively).

Conclusions

The low levels of maternal serum salusin-α and salusin-β may have negative impact on metabolic disorders and vascular dysfunction.     

Physiology and clinical value of glycosuria after a glucose challenge during pregnancy

Objective

Urine testing for glucose is commonly performed during pregnancy but little is known about the regulation and clinical value of glycosuria because studies are hampered by its low prevalence and intermittent nature. The aim of this study was to compare the urine and plasma response 60 min after a 50 g oral glucose challenge in the setting of gestational diabetes mellitus (GDM) screening.

Study design

Of 338 consecutively enrolled gravidas, 325 completed the study. Glycosuria was measured semi-quantitatively (0, 1, 2 or 3+) and venous plasma glucose was measured.

Results

Post-challenge glycosuria occurred in 26.2% of gravidas. Women with 2 or 3+ glycosuria showed higher plasma glucose (p < 0.001), lower height (p = 0.004) and lower body weight throughout pregnancy (p = 0.014); however, glycosuria was not related to age, parity, body mass index (BMI), highest blood pressure or newborn size at birth. The sensitivity for a GDM diagnosis was 8.2%. Comparison of pure “urine” responders (i.e., any glycosuria but glucose <130 mg/dl, n = 50) with “plasma” responders (no glycosuria but plasma glucose ≥140 mg/dl, n = 29) showed that urine responders were younger and had a lower body weight and BMI than plasma responders.

Conclusion

Glycosuria after an oral glucose challenge depends on the plasma glucose excursion, and is more pronounced in gravidas with lower height and body weight, who presumably have a smaller plasma distribution volume. Post-load glycosuria is a poor predictor of GDM, pre-eclampsia and newborn size at birth, and therefore has limited clinical benefit.     

Perinatal outcome in singletons after modified natural cycle IVF and standard IVF with ovarian stimulation

Objective

Singletons born after IVF treatment are at risk for adverse pregnancy outcome, the cause of which is unknown. The aim of the present study was to investigate the influence of ovarian stimulation on perinatal outcome.

Study design

In this single-centre retrospective study, perinatal outcome of singleton pregnancies resulting from IVF treatment with (n = 106) and without ovarian stimulation (n = 84) were compared. For IVF without ovarian stimulation, a modified natural cycle protocol was used.

Results

No differences were found in pregnancy duration, proportion of prematurity and proportion of low birth weight. Mean birth weight of modified natural cycle vs standard IVF singletons was 3485 (±527) vs 3218 (±670) g; P = 0.003. After adjustment for prognostic factors by linear regression analysis, the difference in birth weight remaining was 134 g; P = 0.045.

Conclusions

Birth weights of modified natural cycle IVF singletons found in this study are higher than standard IVF singletons, suggesting that ovarian stimulation may be a causative factor in the occurrence of low birth weight in standard IVF.     

Does gestational diabetes affect women's health-related quality of life after delivery?

Objectives

Our objective in this study was to investigate the effects of gestational diabetes (GDM) on women's health-related quality of life (HRQoL) after delivery. This study investigates the differences between a GDM group and a control group.

Study Design

Using random sampling, 100 women who had had GDM were selected from a birth register. Glucose tolerance tests administered to these participants during pregnancy had yielded 1 or 2 abnormal values. The control group (n = 100) consisted of women who had normal glucose tolerance test during pregnancy. The informants were invited to a personal meeting, where their weight and height were measured and where they also answered the 15D questionnaire. Data were analysed with χ² – test, Mann–Whitney-test, independent samples t-test and regression analysis.

Results

The results for investigating the HRQoL indicated no significant differences on the 15D dimensions between the GDM group and the control group. The HRQoL for both groups was weakest on the dimensions of sleeping, discomfort and symptoms. Furthermore, the control group had a lower vitality score than the GDM group did. Analysis of the influence of background factors on HRQoL showed that women in a relationship experienced higher quality of life than single women.

Conclusion

This study showed no indication that women's lowered HRQoL, as measured by the 15D instrument, could be partly explained by GDM. Women's HRQoL was insignificantly decreased on the dimension of vitality only, so finding motivation for lifestyle changes and diabetes self-care may become challenging.     

Maternal obesity and rate of cesarean delivery in Djibouti

Objective

To calculate the prevalence of maternal obesity and to determine the relation between obesity and cesarean delivery in an urban hospital in Djibouti.

Methods

In an observational cohort study, all women who had a live birth or stillbirth between October 2012 and November 2013 were considered for inclusion. Body mass index (BMI, calculated as weight in kilograms divided by the square of height in meters) was calculated throughout pregnancy, and women with a BMI of at least 30.0 were deemed to be obese. Multivariate logistic regression analyses were used to evaluate the relation between cesarean and obesity.

Results

Overall, 100 (24.8%) of 404 women were obese before 14 weeks of pregnancy, as were 112 (25.2%) of 445 before 22 weeks, and 200 (43.2%) of 463 at delivery. Obesity before 22 weeks was associated with a 127% excess risk of cesarean delivery (adjusted odds ratio 2.27; 95% CI 1.07–4.82; P = 0.032). Similar trends were found when the analyses were limited to the subgroup of women without a previous cesarean delivery or primiparae.

Conclusion

Prevalence of maternal obesity is high in Djibouti City and is related to an excess risk of cesarean delivery, even after controlling for a range of medical and socioeconomic variables.     

A cohort study of Plasmodium falciparum malaria in pregnancy and associations with uteroplacental blood flow and fetal anthropometrics in Kenya

Objective

To use ultrasound to explore the impact of malaria in pregnancy on fetal growth and newborn outcomes among a cohort of women enrolled in an intermittent presumptive treatment in pregnancy (IPTp) with sulfadoxine/pyrimethamine (SP) program in coastal Kenya.

Methods

Enrolled women were tested for malaria at first prenatal care visit, and physical and ultrasound examinations were performed. In total, 477 women who had term, live births had malaria tested at delivery and their birth outcomes assessed, and were included in the study.

Results

Peripheral malaria was detected via polymerase chain reaction among 10.9% (n = 87) at first prenatal care visit and 8.8% (n = 36) at delivery. Insecticide-treated bed nets (ITNs) were used by 73.6% (n = 583) and were associated with decreased malaria risk. There was a trend for impaired fetal growth and placental blood flow in malaria-infected women in the second trimester, but not later in pregnancy. Among women with low body mass index (BMI), malaria was associated with reduced birth weight (P = 0.04); anthropometric measures were similar otherwise.

Conclusion

With IPTp-SP and ITNs, malaria in pregnancy was associated with transient differences in utero, and reduced birth weight was restricted to those with low BMI.     

Advantages of recombinant follicle-stimulating hormone over human menopausal gonadotropin for ovarian stimulation in intrauterine insemination: a randomized clinical trial in unexplained infertility

Objective

To compare two different gonadotropin preparations, human menopausal gonadotropin (hMG) and recombinant follicle-stimulating hormone (rFSH), combined with clomiphene citrate (CC) in women with unexplained infertility undergoing intrauterine insemination (IUI).

Study design

In this prospective clinical trial, couples prepared for IUI cycles were randomly allocated to two groups either to receive CC and hMG (group A, n = 127) or CC and rFSH (group B, n = 132) for ovarian stimulation. Outcomes including rates of clinical pregnancy, miscarriage, OHSS, multiple pregnancy, cancelation, and live birth were compared between groups.

Results

Duration of gonadotropin therapy was significantly shorter in group B (5.1 ± 0.84 vs. 4.7 ± 0.8 days, CI = 95%, P < 0.001). The total dose of administered gonadotropin was also significantly lower in group B (386.9 ± 68.2 vs. 348.2 ± 56.3 IU, CI = 95%, P < 0.001). Dominant follicle number (>17 mm), mean follicular diameter, and endometrial thickness on the day of hCG injection were similar. Clinical pregnancy, multiple pregnancies, abortion, live birth, ovarian hyperstimulation syndrome (OHSS), and cancelation rates were not statistically different between the groups.

Conclusion

IUI cycles in which rFSH had been administered may require shorter duration and a lower total gonadotropin dose.     

Characteristics of heart,arteries, and veins in low and high cardiac output preeclampsia

Objective

To assess the feasibility of non-invasive measurements of maternal cardiac output in relation to birth weight percentile and cardiovascular physiology in preeclampsia.

Study design

In a cohort of 62 women with preeclampsia, impedance cardiography was used to measure cardiac output and to evaluate heart and arteries. Venous characteristics were assessed by combined electrocardiogram-Doppler ultrasonography. Statistical differences were evaluated by Mann–Whitney U-tests.

Results

Cardiac output correlated with birth weight percentile (P = .002), with more small for gestational age newborns in low cardiac output preeclampsia (<7.5 L/min) than in high cardiac output preeclampsia (≥8.9 L/min) (12/29 vs. 2/16, P = .044). This was associated with lower aortic flow indices and shorter venous pulse transit times in low than in high cardiac output preeclampsia.

Conclusion

Non-invasive impedance cardiography measurements of maternal cardiac output correlate with birth weight percentile and are associated with different functionality of heart, arteries, and veins in low and high cardiac output preeclampsia.     

Effectiveness of GnRH antagonist in intrauterine insemination cycles

Objective

To evaluate the effectiveness of GnRH antagonists in women undergoing controlled ovarian stimulation and intrauterine insemination cycles (COS/IUI).

Study design

Randomized controlled trial. Recruited women were randomized into two groups: GnRH antagonist and control group. The primary outcomes were incidence of premature LH surge and clinical pregnancy rates.

Results

One hundred and forty-one consecutive women were included in the study, with 70 in the antagonist group and 71 in the control arm. The baseline clinical characteristics were similar in both groups. The incidence of premature LH surge and premature luteinization was lower in the antagonist group as compared to the control group (5% vs. 10.3%, P = 0.45 and 5% vs. 13.8, P = 0.31) but not statistically significant. The clinical pregnancy rates were lower in the antagonist group (2.8% vs. 10%, P = 0.12), which was also not statistically significant.

Conclusion

The addition of GnRH antagonist during controlled ovarian stimulation and intrauterine insemination cycles does not lead to improvement in clinical pregnancy rates.     

Body Mass Index and spontaneous miscarriage

Objective

We compared the incidence of spontaneous miscarriage in women categorised as obese, based on a Body Mass Index (BMI) >29.9 kg/m², with women in other BMI categories.

Study design

In a prospective observational study conducted in a university teaching hospital, women were enrolled at their convenience in the first trimester after a sonogram confirmed an ongoing singleton pregnancy with fetal heart activity present. Maternal height and weight were measured digitally and BMI calculated. Maternal body composition was measured by advanced bioelectrical impedance analysis.

Results

In 1200 women, the overall miscarriage rate was 2.8% (n = 33). The mean gestational age at enrolment was 9.9 weeks. In the obese category (n = 217), the miscarriage rate was 2.3% compared with 3.3% in the overweight category (n = 329), and 2.3% in the normal BMI group (n = 621). There was no difference in the mean body composition parameters, particularly fat mass parameters, between those women who miscarried and those who did not.

Conclusions

In women with sonographic evidence of fetal heart activity in the first trimester, the rate of spontaneous miscarriage is low and is not increased in women with BMI > 29.9 kg/m² compared to women in the normal BMI category.     

Maternal polycystic ovary syndrome may be associated with adverse pregnancy outcomes

Objective

To determine whether maternal polycystic ovary syndrome (PCOS) is associated with adverse pregnancy outcomes in a population of Italian parturients.

Study design

Retrospective study carried out in an academic hospital in Bologna, Italy, including 516 consecutive Italian women who delivered between January and April 2006. PCOS women, women with hyperandrogenic features not configuring PCOS (Intermediate group) and non-hyperandrogenic controls were identified by a telephone survey of 229 women. Statistical analysis was performed using ANOVA or chi-square.

Results

PCOS women, accounted for 6.6% of our cohort. Gestational diabetes mellitus (GDM) was significantly more frequent in the PCOS group than in the other groups (20% vs. 3.6% and 4%; P < 0.01). The association of GDM and pregnancy-induced hypertension occurred in one subject in the PCOS group but in none of the other groups (P < 0.001). Preterm birth was more frequent in the PCOS group than in control group (20% vs. 6.9%; P < 0.05), whereas mean length of gestation was not different. The higher occurrence of adverse outcomes may be, at least partly, related to a higher weight gain during pregnancy in PCOS group with respect to the other groups (P < 0.05).

Conclusions

Women affected by PCOS carry an increased risk of adverse pregnancy outcomes.     

Altered CD16 expression on vaginal neutrophils from women with vaginitis

Objective

Reduced CD16 expression is associated with neutrophil apoptosis. This study aimed to compare CD16 expression on neutrophils in the vagina from women with normal bacterial flora and with vaginitis.

Study design

Vaginal lavages were sampled from volunteers diagnosed with bacterial vaginosis (BV, n = 34), vulvovaginal candidiasis (VC, n = 43), BV plus VC (BV + VC, n = 14), and normal flora (NF, n = 51). Neutrophils were identified by expression of CD15, CD16 and CD24 surface markers as assessed by flow cytometry.

Results

CD16 expression was elevated in neutrophils from women with vaginitis (BV p < 0.0001; VC p = 0.01; BV + VC p = 0.0027) as compared to women with NF.

Conclusion

The reduction in CD16 down-regulation is consistent with prolonged neutrophil viability and activity in the vagina of women with vaginitis. This may contribute to greater microbial clearance and, conversely, with inflammation-associated pathology.     

Maternal body mass index and duration of labor

Objective

To evaluate whether the duration of the active phase of labor is associated with maternal body mass index (BMI), in nulliparous women with spontaneous onset of labor.

Study design

Historical prospective cohort study including 63,829 nulliparous women with a singleton pregnancy and a spontaneous onset of labor, who delivered between January 1, 1995 and December 31, 2009. Data were collected from the Perinatal Revision South registry, a regional perinatal database in Southern Sweden. Women were categorized into six classes of BMI. Overweight and obese women were compared to normal weight women regarding duration of active labor. Adjustments were made for year of delivery, maternal age and infant birth weight.

Results

The median duration of labor was significantly longer in obese women (class I obesity (BMI 30–34.9) = 9.1 h, class II obesity (BMI 35–39.9) = 9.2 h and class III obesity (BMI > 40) = 9.8 h) compared to normal-weight women (BMI 18.5–24.9) = 8.8 h (p < 0.001). The risk of labor lasting more than 12 h increased with increasing maternal BMI: OR 1.04 (1.01–1.06) (OR per 5-units BMI-increase).The risk of labor lasting more than 12 h or emergency cesarean section within 12 h, compared to vaginal deliveries within 12 h, increased with increasing maternal BMI. Duration of the second stage of labor was significantly shorter in obese women: in class III obesity the median value was 0.45 h compared to normal weight women, 0.55 h (p < 0.001).

Conclusion

In nulliparous women with a spontaneous onset of labor, duration of the active phase of labor increased significantly with increasing maternal BMI. Once obese women reach the second stage they deliver more quickly than normal weight women, which implies that the risk of prolonged labor is restricted to the first stage of labor. It is clinically important to consider the prolonged first stage of labor in obese women, for example when diagnosing first stage labor arrest, in order to optimize management of this rapidly growing at-risk group of women. Thus, it might be reasonable to adapt the considered upper limit for duration of labor, according to maternal BMI.     

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.     

Pregnancy outcomes of expectant management of stable mild to moderate chronic hypertension as compared with planned delivery

Objective

To compare outcomes between elective delivery at 37 weeks of pregnancy and expectant management among pregnant women with mild to moderate chronic hypertension.

Methods

In a two-center study, 76 women with mild to moderate chronic hypertension were randomly allocated to planned delivery at 37 completed weeks (group A) or expectant management for spontaneous onset of labor or reaching 41 weeks (group B) between April 2012 and October 2013. Differences were compared by t test, χ² test, or Fisher exact test. Odds ratios (ORs) with 95% confidence interval (CIs) were determined.

Results

There were no differences in superimposed pre-eclampsia (SPE), severe hypertension, preterm delivery, placental abruption, oligohydramnios, intrauterine growth restriction, or perinatal mortality between the groups. Group B had higher gestational age at delivery (P = 0.001) and birth weight (P = 0.01), but lower cesarean (OR 3.4; 95% CI, 1.2–10.3; P = 0.03) and neonatal care unit admission (OR 5.4; 95% CI, 1.4–21.0; P = 0.01) rates. More women with SPE were diagnosed before than after 37 weeks in group B (P = 0.01). Overall, patients who developed SPE had more adverse pregnancy outcomes than those who did not.

Conclusion

Mild to moderate chronic hypertension could be managed expectantly up to 41 weeks if SPE did not develop.     

Evaluation of FAS and caspase-3 in the endometrial tissue of patients with idiopathic infertility and recurrent pregnancy loss

Objective

To investigate expression of BcL-2, FAS, FAS ligand (FASL) and cleaved caspase-3 in the endometrial tissue of women with idiopathic infertility (with two consecutive failed cycles of in vitro fertilization) and women with idiopathic recurrent pregnancy loss. The control group consisted of fertile women.

Study design

Endometrial tissue samples from fertile women (n = 25), women with idiopathic infertility (n = 25) and women with idiopathic recurrent pregnancy loss (n = 25) were collected on the seventh or eighth postovulatory day of their menstrual cycles for evaluation. Expression of BcL-2, FAS, FASL and cleaved caspase-3 was assessed using immunohistochemical methods.

Results

Expression of BcL-2 and FAS was significantly higher and lower, respectively, in the women with idiopathic infertility than in the other groups (p < 0.01). Expression of cleaved caspase-3 was significantly lower in the women with idiopathic infertility than in the other groups (p < 0.01). Expression of FASL was similar in all three groups.

Conclusion

Disturbances in endometrial apoptosis may be a contributing factor in patients with idiopathic infertility and recurrent pregnancy loss.     

Association between delivery of a small-for-gestational-age neonate and long-term maternal cardiovascular morbidity

Objective

To investigate whether delivering a small-for-gestational-age (SGA) newborn is a risk factor for subsequent long-term maternal cardiovascular morbidity.

Methods

Data were analyzed from consecutive pregnant women who delivered at Soroka University Medical Center, Beer-Sheva, Israel, between 1988 and 1999, and were followed-up retrospectively until 2010. Long-term cardiovascular morbidity was compared among women with and without SGA neonates.

Results

During the study period, 47 612 deliveries met the inclusion criteria, and 4411 (9.3%) women delivered an SGA neonate. Delivery of an SGA neonate was a risk factor for long-term complex cardiovascular events, including congestive heart failure, hypertensive heart and kidney disease, and acute cor pulmonale (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.3–4.4; P = 0.006); and long-term cardiovascular mortality (OR, 3.4; 95% CI, 1.5–7.6; P = 0.006). Women who delivered an SGA neonate had a significantly higher risk for cardiovascular mortality during the follow-up period (Kaplan–Meier survival analysis, P = 0.002). Delivery of an SGA neonate remained an independent risk factor for long-term maternal cardiovascular mortality (Cox multivariable regression: adjusted hazard ratio, 3.5; 95% CI, 1.5–8.2; P = 0.004).

Conclusion

Delivery of an SGA neonate is an independent risk factor for long-term cardiovascular morbidity in a follow-up period of more than 10 years.     

Idiopathic urinary findings and fetal growth restriction in low risk pregnancy

Objective

To determine whether maternal urinary findings in the first trimester of pregnancy are associated with fetal growth restriction.

Study design

The prevalence of urinary findings in singleton pregnancies complicated by fetal growth restriction were compared with a low-risk control group of pregnancies who gave birth to normal weight babies, in the same condition.

Results

There were significant statistical differences in the mean gestational age (p < 0.001), isolated asymptomatic bacteriuria (p < 0.001), hematuria (p = 0.002, OR = 6.6, CI = 1.8–24.2) and proteinuria (p = 0.016, OR = 4.1, CI = 1.2–13.3). There was no recognizable relation between ketonuria and fetal growth restriction.

Conclusion

Our data showed a relation between the increase of adverse pregnancy outcomes, including fetal growth restriction, and hematuria, proteinuria and asymptomatic bacteriuria. Appropriate monitoring of pregnant women using these findings may be helpful in the identification of more complications.     

Risk factors and adverse pregnancy outcomes among births affected by velamentous umbilical cord insertion: a retrospective population-based register study

Objective

To identify risk factors associated with velamentous cord insertion (VCI) and to evaluate the association between adverse pregnancy outcomes and VCI in singleton pregnancies.

Study design

The total population of women (n = 26,849) with singleton pregnancies delivered in Kuopio University Hospital during the study period between 2000 and 2011 was reviewed. Risk factors and the risk of adverse pregnancy outcomes (admission to a neonatal unit, fetal death, preterm delivery, low birth weight (LBW < 2500 g), the infant being small for its gestation age (SGA), low Apgar scores (<7) at 1 and 5 min and fetal venous pH < 7.15) were evaluated separately among women with and without VCI by means of logistic regression analyses.

Results

The incidence of VCI among women with singleton pregnancies was 2.4% (n = 633 of 26,849). Independent risk factors for VCI were nulliparity, obesity, fertility problems, placenta previa and maternal smoking. VCI was associated with a 1.38-, 2.01-, 3.93- and 1.39-fold increased risk of admission to a neonatal unit, preterm delivery (<37 gestation weeks), LBW and SGA, respectively compared to pregnancies involving normal cord insertion. Of the women with VCI, 15.3% underwent non-elective cesarean section compared to 8.3% (p ≤ 0.001) of women without VCI.

Conclusions

The results suggest that the incidence of VCI increases along with an increase in fertility problems and maternal obesity. VCI is a moderate risk condition increasing the risks of prematurity and impaired fetal growth.     

Factors influencing delivery mode for nulliparous women with a singleton pregnancy and cephalic presentation during a 17-year period

Objective

To evaluate the effects of maternal age, induction of labour, epidural analgesia and birth weight on mode of delivery in nulliparous women with a singleton pregnancy and cephalic presentation at ≥36 weeks gestation, and to describe how these factors and their influence have changed over a 17-year period from 1989 to 2005.

Study design

The study was conducted in the obstetric department of a university teaching hospital in Ireland. Of 45,647 women delivered, 14,867 were nulliparous with a singleton pregnancy and cephalic presentation and undergoing labour at ≥36 weeks gestation, and were included in the study. The main outcome measures were the influence of maternal age, induction of labour, epidural analgesia and birth weight on the mode of delivery. Multinomial logistic regression analysis for type of delivery and the associated explanatory variables and trend analysis of these variables were performed.

Results

There was a significant progressive increase in both unplanned abdominal delivery and instrumental vaginal delivery, with advancing maternal age. Induction of labour increased the risk of unplanned abdominal delivery (OR 1.92; 95% CI 1.73–2.14). Epidural analgesia was associated with an increased risk of instrumental vaginal delivery (OR 4.68; 95% CI 4.18–5.25), and unplanned abdominal delivery (OR 2.29; 95% CI 1.98–2.66). Mothers of infants with birth weight ≥4.5 kg were less likely to be delivered by instrumental vaginal delivery (OR 0.60; 95% CI 0.41–0.88), than mothers delivering infants in the 2.50–4.49 kg birth weight category. Between 1989 and 2005 there was a significant increase in maternal age (P = 0.0001), birth weight (P = 0.042) and unplanned abdominal delivery rates (P = 0.0004), and a reduction in instrumental vaginal delivery rates (P = 0.0013).

Conclusions

These data demonstrate that the increasing trend of unplanned abdominal delivery in nulliparous women with a singleton pregnancy and cephalic presentation may be partially explained by advancing maternal age, and other obstetric factors also play a significant role.