The perinatal effects of delayed childbearing

Caesarean section in nulliparous women of advanced maternal age has been reduced in Sweden and Norway since the 1970s: a register-based study

OBJECTIVE

To investigate rates of caesarean delivery in Sweden and Norway from 1973 to 2008 in relation to advanced and very advanced maternal age.

DESIGN

Register study.

SETTING

Sweden and Norway.

SAMPLE

All nulliparous women aged over 30 years with a singleton pregnancy, with the fetus in a cephalic presentation, and delivering at term between 1973 and 2008 were evaluated. The study population comprised 329 824 women in Sweden and 127 810 women in Norway.

METHODS

Data from the national Medical Birth Registers were used to describe caesarean section rates in three age groups: 30-34 years (reference group); 35-39 years (advanced age group); and ≥ 40 years (very advanced age group). Logistic regression analyses estimated the risk in each age group over four decades, in each of the two national samples.

RESULTS

Caesarean delivery decreased from 1973-1979 to 2000-2008 in the two oldest age groups in Sweden (35-39 years, OR = 0.53, 95% CI = 0.50-0.58; ≥ 40 years, OR = 0.36, 95% CI = 0.30-0.43) and Norway (35-39 years, OR = 0.61, 95% CI = 0.54-0.68; ≥ 40 years, OR = 0.45, 95% CI = 0.34-0.58), but increased in women aged 30-34 years. The caesarean delivery rate in the two oldest groups peaked in the second half of the 1970s. Regardless of time point, the caesarean delivery rate was always highest in women aged ≥ 40 years, followed by women aged 35-39 years and lowest in women aged 30-34 years.

CONCLUSIONS

Caesarean delivery in nulliparous women of advanced and very advanced age peaked by end of the 1970s in Sweden and Norway. The subsequent reduction was contemporaneous with the introduction of electronic fetal monitoring and a more consistent use of the partogram, suggesting that more effective surveillance of labour increased the chance of a vaginal birth in these high-risk women.

Comparison of demographic and obstetric characteristics of Canadian primiparous women of advanced maternal age and younger age

OBJECTIVE

The rate of pregnancy at advanced maternal age (AMA) has increased during recent decades. The purpose of this study is to compare demographic and obstetric characteristics of Canadian primiparous women of AMA with those aged 20 to 29 years.

METHODS

We conducted a secondary analysis of data collected through the national Maternity Experiences Survey (MES) of the Canadian Perinatal Surveillance System. The sample included 301 primiparous women aged 35 years or over and 1,564 primiparous women aged 20 to 29 years. Estimates of prevalence for each group and their odds ratios were calculated using sample weights of the survey, and variances were calculated using bootstrapping methods adjusting for sampling design and weights.

RESULTS

Women of AMA were significantly more likely to be better educated, to have higher income, to be employed, and to continue to work until the end of pregnancy than younger women. They also reported having significantly more information on pregnancy, labour, and birth, and they were more likely to attend prenatal classes. They were more likely to have had a miscarriage or infertility treatment, to request or be offered a Caesarean section, and to have a higher rate of Caesarean section. There were no significant differences in rates of preterm birth, low birth weight, and small-for-gestational age infants.

CONCLUSION

Pregnant women of AMA differ from younger women in demographic characteristics, knowledge level, and some health behaviours and pregnancy outcomes. The growing number of pregnancies at AMA indicates the need for developing appropriate care plans to address the specific needs of this group.

The influence of changing post-term induction of labour patterns on severe neonatal morbidity

OBJECTIVE

To estimate the influence of changing practice patterns of post-term induction of labour on severe neonatal morbidity.

METHODS

This population-based cohort study used data from the Nova Scotia Atlee Perinatal Database to evaluate the effect of post-term induction of labour on stillbirth and neonatal mortality and severe neonatal morbidity in low-risk pregnancies. The study population included all pregnant women ≥ 40 weeks' gestation delivering in Nova Scotia from 1988 to 2008 who underwent induction of labour with a single fetus in cephalic presentation. Major congenital anomalies and pre-existing or severe gestational hypertension and diabetes were excluded. Women delivering post-term from 1994 to 2008 (after the Post-term Pregnancy Trial) were compared with women delivering from 1988 to 1992 to evaluate outcomes with changing maternal characteristics and obstetric practice patterns.

RESULTS

Evaluation and comparison of time epochs (1988 to 1992, 1994 to 1998, 1999 to 2003, and 2004 to 2008) demonstrated an increased risk for perinatal mortality or severe neonatal morbidity, especially low five-minute Apgar score, among both nulliparous and multiparous women. There were no significant differences in the risks for stillbirth or perinatal mortality over time. Comparable relationships were demonstrated in a subgroup of lower risk women.

CONCLUSION

The increase in post-term induction of labour with time is associated with a significant increase in severe neonatal morbidity, especially among infants born to multiparous women. Evaluation of the antepartum and intrapartum management of these low-risk pregnancies may provide additional information to reduce morbidity.

Preeclampsia complicated by advanced maternal age: a registry-based study on primiparous women in Finland 1997-2008

Background

Preeclampsia is a frequent syndrome and its cause has been linked to multiple factors, making prevention of the syndrome a continuous challenge. One of the suggested risk factors for preeclampsia is advanced maternal age. In the Western countries, maternal age at first delivery has been steadily increasing, yet few studies have examined women of advanced maternal age with preeclampsia. The purpose of this registry-based study was to compare the obstetric outcomes in primiparous and preeclamptic women younger and older than 35 years.

Methods

The registry-based study used data from three Finnish health registries: Finnish Medical Birth Register, Finnish Hospital Discharge Register and Register of Congenital Malformations. The sample contained women under 35 years of age (N = 15,437) compared with those 35 and over (N = 2,387) who were diagnosed with preeclampsia and had their first singleton birth in Finland between 1997 and 2008. In multivariate modeling, the main outcome measures were Preterm delivery (before 34 and 37 weeks), low Apgar score (5 min.), small-for-gestational-age, fetal death, asphyxia, Cesarean delivery, induction, blood transfusion and admission to a Neonatal Intensive Care Unit.

Results

Women of advanced maternal age (AMA) exhibited more preeclampsia (9.4%) than younger women (6.4%). They had more prior terminations (<0.001), were more likely to have a body mass index (BMI) >25 (<0.001), had more in vitro fertilization (IVF) (<0.001) and other fertility treatments (<0.001) and a higher incidence of maternal diabetes (<0.001) and chronic hypertension (<0.001). Multivariate logistic regression indicated that women of AMA had higher rates of: preterm delivery before 37 weeks 19.2% (OR 1.39 CI 1.24 to 1.56) and before 34 weeks 8.7% (OR 1.68 CI 1.43 to 2.00) low Apgar scores at 5 min. 7.1% (OR 1.37 CI 1.00 to 1.88), Small-for-Gestational Age (SGA) 26.5% (OR 1.42 CI 1.28 to 1.57), Asphyxia 12.1% (OR 1.54 CI 1.34 to 1.77), Caesarean delivery 50% (OR 2.02 CI 1.84 to 2.20) and admission to a Neonatal Intensive Care Unit (NICU) 31.6% (OR 1.45 CI 1.32 to 1.60).

Conclusions

Preeclampsia is more common in women with advanced maternal age. Advanced maternal age is an independent risk factor for adverse outcomes in first-time mothers with preeclampsia.

EFFECTS OF AGE, ETHNICITY AND HEALTH BEHAVIOURS ON THE PREVALENCE OF ADVERSE BIRTH OUTCOMES IN TAIWAN

This study sampled 8432 singleton first live births from Taiwan's 2005 Birth Registration Database to determine if there were more pre-term or low birth weight deliveries among aboriginal women than there were among Han Chinese women, and if the ‘weathering’ hypothesis applied to aboriginal women in Taiwan. Although the aboriginal women were socially disadvantaged and engaged in more unhealthy behaviours, including smoking, drinking, chewing betel quid and exposure to second-hand smoke, the evidence did not support the hypothesis that these teenaged minority women would have better birth outcomes, as has been demonstrated among teenage African-American women in the United States. Behaviours and not ethnicity were risk factors for teenage aboriginal mothers, who started deleterious health behaviours earlier than did their older counterparts. Teenage mothers had more adverse outcomes regardless of ethnicity and aboriginal mothers had more risky behaviours in all age groups. The prevalence of detrimental health behaviour among teenage mothers in Taiwan is of concern, particularly for aboriginal teenage mothers.

A project for future life-Swedish women's thoughts on childbearing lacking experience of giving birth and parenthood

A lifeworld hermeneutic approach was used in order to understand Swedish women's thoughts on childbearing. Nine women were interviewed, and they ranged in age from 22 to 28 years and represented diverse socioeconomic, educational, sexual, and fertility backgrounds. All women were similar in that they lacked experience of giving birth and parenthood. The analysis showed that childbearing includes dimensions of both immanence and transcendence. Immanence, as childbearing is seen as stagnant to women's freedom in present life. Transcendence, as childbearing is thought of as a project for future life, a part of female identity, and a conscious standpoint for which the woman wants to be prepared and for which she wants to create the best conditions.

Pregnancy outcomes for nulliparous women of advanced maternal age in South Australia, 1998-2008

BACKGROUND

Child bearing in the later reproductive years has become increasingly common in Australia with potential implications for clinical practice.

AIM

To examine pregnancy outcomes for nulliparous women of advanced maternal age with singleton pregnancies.

METHODS

A retrospective population-based cohort study was conducted to compare the pregnancy outcomes for women aged 35-39 years and ≥40 years with women aged 25-29 years, analysing 34 695 records from the South Australian Perinatal Database between 1998 and 2008.

RESULTS

Pre-existing hypertension [relative risks (RR) 1.98 and 2.94 for women aged 35-39 years and ≥40 years, respectively], placenta praevia (RR 2.88 and 3.68), suspected intrauterine growth restriction (RR 1.33 and 1.77) and gestational diabetes (RR 1.97 and 2.53) increased with age. Women of advanced maternal age were more likely to have not laboured prior to birth (RR 2.19 and 3.28), be induced (RR 1.12 and 1.27) and have a breech presentation (RR 1.57 and 1.60). The likelihood of fetal distress increased with advancing maternal age (RR 1.15 and 1.24). Regression analyses revealed women of advanced maternal age were significantly more likely to have small for gestational age infants [adjusted odds ratios (AOR) 1.26 and 1.50], preterm birth (AOR 1.26 and 1.43), elective caesarean [relative risk ratios (RRR) 2.55 and 4.52], emergency caesarean (RRR 1.59 and 2.21) and experience a perinatal death (RRR 1.94 and 2.18).

CONCLUSIONS

The likelihood of pre-existing medical conditions, obstetric complications, adverse labour and birth outcomes and complications increased with advancing maternal age. Advanced maternal age was also independently associated with selected adverse pregnancy and infant outcomes.

Advanced maternal age and obstetric morbidity for women giving birth in Victoria, Australia: A population-based study

BACKGROUND

As the proportions of older women giving birth increase, there is a growing body of evidence on the increased risks of poorer maternal and perinatal outcomes for this group. However, the associations are not completely understood. This study aimed to establish the prevalence of selected maternal morbidities and examine whether advanced maternal age is associated with a higher risk of morbidity for women giving birth in Victoria.

METHOD

Data on all births over 20 weeks‧ gestation for 2005 and 2006 were obtained from the Victorian Perinatal Data Collection. Unadjusted and adjusted analyses were undertaken using logistic regression to examine and quantify the association between advanced maternal age (35 years and older) and selected obstetric morbidities and complications.

RESULTS

There was evidence of an association between older maternal age and selected morbidities and complications. Older nulliparous women were at highest odds of gestational diabetes (AdjOR, 1.83; 95% CI, 1.67-2.02), placenta praevia (AdjOR, 2.02; 95% CI, 1.68-2.44), multiple birth (AdjOR, 1.80; 95% CI, 1.58-2.06) and caesarean delivery (AdjOR, 1.93; 95% CI, 1.84-2.02). Older multiparous women were at highest odds of gestational diabetes (AdjOR, 2.01; 95% CI, 1.88-2.15) and placenta praevia (AdjOR, 2.11; 95% CI, 1.83-2.44).

CONCLUSIONS

Older women giving birth in Victoria are at an increased risk of a range of obstetric morbidities. Delayed childbearing for an increasing number of women has societal and public health ramifications and will potentially place greater demand on healthcare services.

Maternal age, birth order, and race: differential effects on birthweight

BACKGROUND

Studies examining the influence of maternal age and birth order on birthweight have not effectively disentangled the relative contributions of each factor to birthweight, especially as they may differ by race.

METHODS

A population-based, cross-sectional study of North Carolina births from 1999 to 2003 was performed. Analysis was restricted to 510 288 singleton births from 28 to 42 weeks' gestation with no congenital anomalies. Multivariable linear regression was used to model maternal age and birth order on birthweight, adjusting for infant sex, education, marital status, tobacco use and race.

RESULTS

Mean birthweight was lower for non-Hispanic black individuals (NHB, 3166 g) compared with non-Hispanic white individuals (NHW, 3409 g) and Hispanic individuals (3348 g). Controlling for covariates, birthweight increased with maternal age until the early 30s. Race-specific modelling showed that the upper extremes of maternal age had a significant depressive effect on birthweight for NHW and NHB (35+ years, p<0.001), but only age less than 25 years was a significant contributor to lower birthweights for Hispanic individuals, p<0.0001. Among all racial subgroups, birth order had a greater influence on birthweight than maternal age, with the largest incremental increase from first to second births. Among NHB, birth order accounted for a smaller increment in birthweight than for NHW and Hispanic women.

CONCLUSION

Birth order exerts a greater influence on birthweight than maternal age, with signficantly different effects across racial subgroups.

Donor age is a major determinant of success of oocyte donation/recipient programme

BACKGROUND

In recent years, particularly in developed countries, women have tended to delay childbirth until over 40 years of age. Our study aims to identify whether the donor's age or recipient's age influences the pregnancy and live birth rate following oocyte recipient cycles.

METHODS

A population study included 3889 fresh oocyte recipient cycles. Pregnancy and live delivery rates were compared in recipient age groups (<35, 35-39, 40-44 and ≥45 years) and donor age groups (<30, 30-34, 35-39 and ≥40 years).

RESULTS

The highest live birth rate was of cycles in donors aged 30-34 years (25.0%), it decreased (P< 0.05) to 24.1% in donors aged <30 years, 20.7% in donors aged 35-39 years and 11.5% in donors aged ≥40 years. The multivariate analysis showed no significant differences in the success by recipient's age. Compared with cycles in donors aged 30-34 years, cycles in donors aged 35-39 years had 14 and 18% less chance to achieve a pregnancy [adjusted rate ratio (ARR) 0.86, 95% confidence interval (CI) 0.75-0.98] and a live delivery (ARR 0.82, 95% CI 0.71-0.96), while cycles in donors aged 40 years or older had 42 and 54% less chance to achieve a pregnancy (ARR 0.58, 95% CI 0.41-0.84) and a live delivery (ARR 0.46, 95% CI 0.29-0.73).

CONCLUSIONS

Older recipients with younger donors did not have a poorer pregnancy outcome compared with younger recipients with younger donors. Choosing a donor aged <35 years would increase the chance of pregnancy and live delivery for older recipients.

Positive impact of a long-running urban Aboriginal medical service midwifery program

BACKGROUND

  The Winnunga Nimmityjah Aboriginal Health Service Aboriginal Midwifery Access Program (AMAP) was established in 2001 to provide antenatal care, birth support and postnatal care to clients in the Australian Capital Territory (ACT).

AIM

  To describe the uptake and impact of AMAP services on access to antenatal care, behavioural risk factors and pregnancy outcomes and to compare the characteristics of AMAP clients with other women giving birth in the ACT.

METHODS

  A descriptive study of medical records for AMAP clients who gave birth in 2004-2008.

OUTCOME MEASURES

maternal and baby characteristics, antenatal visits, behavioural risk factors and complications. Characteristics of AMAP clients were compared with the ACT Maternal and Perinatal Collection.

RESULTS

  Of 187 women, 11.2% were aged <20 years, 50.3% presented in the first trimester and 94.7% attended five or more antenatal visits. Of 193 babies, 17.1% were born preterm and 18.1% had low birthweight. Compared with the ACT Maternal and Perinatal Collection, Aboriginal and Torres Strait Islander AMAP clients had a higher smoking rate (63.8 vs 49.0%), a lower caesarean delivery rate (20.0 vs 27.6%), a slightly lower proportion of preterm babies (18.8 vs 21.6%) and a slightly lower proportion of low-birthweight babies (18.8 vs 21.0%).

CONCLUSIONS

  Aboriginal Midwifery Access Program provides high-quality antenatal care in a trusted environment. The high rate of smoking in pregnancy needs to be addressed.

Temporal trends in neonatal outcomes following iatrogenic preterm delivery

Background

Preterm birth rates have increased substantially in the recent years mostly due to obstetric intervention. We studied the effects of increasing iatrogenic preterm birth on temporal trends in perinatal mortality and serious neonatal morbidity in the United States.

Methods

We used data on singleton and twin births in the United States, 1995-2005 (n = 36,399,333), to examine trends in stillbirths, neonatal deaths, and serious neonatal morbidity (5-minute Apgar ≤3, assisted ventilation ≥30 min and neonatal seizures). Preterm birth subtypes were identified using an algorithm that categorized live births <37 weeks into iatrogenic preterm births, births following premature rupture of membranes and spontaneous preterm births. Temporal changes were quantified using odds ratios (OR) and 95% confidence intervals (CI).

Results

Among singletons, preterm birth increased from 7.3 to 8.8 per 100 live births from 1995 to 2005, while iatrogenic preterm birth increased from 2.2 to 3.7 per 100 live births. Stillbirth rates declined from 3.4 to 3.0 per 1,000 total births from 1995-96 to 2004-05, and neonatal mortality rates declined from 2.4 to 2.1 per 1,000 live births. Temporal declines in neonatal mortality/morbidity were most pronounced at 34-36 weeks gestation and larger among iatrogenic preterm births (OR = 0.75, CI 0.73-0.77) than among spontaneous preterm births (OR = 0.82, CI 0.80-0.84); P < 0.001. Similar patterns were observed among twins, with some notable differences.

Conclusion

Increases in iatrogenic preterm birth have been accompanied by declines in perinatal mortality. The temporal decline in neonatal mortality/serious neonatal morbidity has been larger among iatrogenic preterm births as compared with spontaneous preterm births.

Difficult and failed intubation: Incident rates and maternal, obstetrical, and anesthetic predictors

BACKGROUND

Difficult and failed tracheal intubation may be more common in the obstetrical population. The objective of this study was to determine the incidence of difficult and failed tracheal intubation in a Canadian tertiary care obstetric hospital and to identify predictors.

METHODS

Maternal, perinatal, and anesthetic information on all pregnant women or recently pregnant (up to three days postpartum) women undergoing general anesthesia (GA) from 1984 to 2003 at the Izaac Walton Killam Health Centre (IWK) was abstracted from the Nova Scotia Atlee Perinatal Database, and the information was augmented by chart review. The incidence and predictors of difficult and failed tracheal intubation were determined. Analyses using logistic regression were performed for the complete GA cohort and for the subgroup that had Cesarean delivery under GA.

RESULTS

There were 102,587 deliveries of ≥20 weeks gestation in the study population, with 3,107 GAs identified, 2,986 records reviewed, and 2,633 GAs (88%) retained in the complete cohort. Difficult tracheal intubation was encountered in 123 of 2,633 (4.7%) women in the complete cohort and 60 of 1,052 (5.7%) women in the Cesarean delivery subgroup. Only two failed tracheal intubations were identified (0.08%) in the complete cohort, and both occurred during GAs for postpartum tubal ligation. The combined rate of difficult/failed tracheal intubation remained stable over the 20 years reviewed despite decreasing GA rates. Amongst the complete cohort, maternal age ≥35 yr, weight at delivery 90 to 99 kg, and absence of labour predicted increased risks; while weight at delivery 90 to 99 kg and absence of labour amongst the Cesarean delivery subgroup predicted difficult/failed tracheal intubation.

CONCLUSION

Previously accepted risk factors, such as labour, pre-existing medical conditions and obstetrical disorders, did not predict an increased risk of difficult tracheal intubation, while maternal age ≥35 yr, weight 90 to 99 kg, and absence of active labour were found to predict increased risk.

Age at first birth, mode of conception and psychological wellbeing in pregnancy: findings from the parental age and transition to parenthood Australia (PATPA) study

BACKGROUND

It is increasingly common for women in high-income countries to delay childbearing. We aimed to describe the context of pregnancy for first-time mothers of different ages and examine relationships among maternal age at first birth, mode of conception and psychosocial wellbeing in pregnancy.

METHODS

Using stratified sampling, we recruited similar numbers of women conceiving through assisted reproductive technology (ART; n = 297) or spontaneously (n = 295) across three age groups: younger, ≤ 20-30 years; middle, 31-36 years; older, ≥ 37 years. Women participated in a structured interview and completed validated questionnaires assessing socio-economic status, personality, quality of partner relationship, state and trait anxiety, pregnancy-focused (P-F) anxiety and maternal-fetal attachment.

RESULTS

Older maternal age was associated with lower depression and anxiety symptoms, lower maternal-fetal attachment (P< 0.05), greater psychological hardiness (resilience) (P< 0.001) and lower ratings of control in the partner relationship (P< 0.05) at a univariate level. ART conception, but not older maternal age, was associated with more P-F anxiety. Although most main effects of age and mode of conception became non-significant after controlling for contextual/reproductive history variables, a significant association between ART conception and more intense fetal attachment emerged (P< 0.05).

CONCLUSIONS

Women having their first baby when older appear to have some psychological advantages over their younger counterparts; they are more resilient, report their partners as less controlling and report lower symptoms of depression and anxiety during pregnancy. However, women conceiving through ART have a more complex experience of pregnancy, simultaneously experiencing more P-F anxiety and more intense emotional attachment to the fetus.

Older maternal age and intervention in labor: a population-based study comparing older and younger first-time mothers in Victoria, Australia

BACKGROUND

In Australia, birth rates for women aged 35 years or more are significant and increasing and a considerable percentage are first births. This study investigated the effect of maternal age on interventions in labor and birth for primiparous women aged 35 to 44 years compared with primiparous women aged 25 to 29 years.

METHODS

All primiparous women who gave birth in Victoria, Australia, in 2005 and 2006 (n = 57,426) were included in this population-based cross-sectional study. Women were stratified by admission status (private/public). Main outcome measures were induction of labor, augmentation of labor, use of epidural analgesia, and method of birth. Multivariate logistic regression was used to explore the relationship between maternal age and cesarean adjusted for confounders.

RESULTS

Older women were more likely to give birth by cesarean section whether admitted as public or private patients. For private patients, total cesarean rates were 31.8 percent (25-29 yr), 46.0 percent (35-39 yr), and 60.0 percent (40-44 yr; p < 0.001) compared with 27.5, 41.6, and 53.4 percent for public patients (p < 0.001). Older women who experienced labor were more likely to have an instrumental vaginal birth or an emergency cesarean section than younger women. Both were more common in women admitted as private patients. Age-related trends were also seen for induction of labor and use of epidural analgesia. Rates were higher for private patients. Rates of induction were (37.8, 40.2, and 42.5%) for private patients compared with (32.1, 36.7, and 40.1%) for public patients and rates for epidural were (45.3, 49.9, and 48.1%) among private patients compared with (33.3, 38.8, and 39.3%) among public patients.

CONCLUSIONS

Interventions in labor and birth increased with maternal age, and this effect was seen particularly for cesarean section among women admitted privately. These findings were not fully explained by the complications we considered.

Effect of older maternal age on birth outcomes in twin pregnancies: a population-based study

OBJECTIVE

We compared perinatal mortality, preterm birth (<37, <33 and <28 weeks), small for gestational age (SGA), Apgar score (<4), mechanical ventilation (1 days) and prolonged neonatal intensive care unit (NICU) hospitalization (13 days) between twins of 25 to 34 and >35-year-old women. Further, we examined whether older maternal age effects were modified by parity or otherwise affected by chorionicity.

STUDY DESIGN

We carried out a population-based retrospective cohort study including all twin births in British Columbia (BC), Canada, from 1999 to 2003. The BC perinatal database registry was used to obtain clinical, behavioral and demographic data. Adjusted odds ratios (OR) with 95% confidence intervals (CI) were calculated using generalized estimating equation models.

RESULT

Overall, twins of older women were more likely to be born preterm (<37 weeks), but not very or extremely preterm (<33 weeks). These twins were not at increased risk of perinatal death, mechanical ventilation or were not SGA compared with twins of younger women. Twins of older primiparous women did not have an elevated risk of NICU hospitalization; twins born to older multiparous women had higher risk (OR=1.8; 95% CI: 1.2 to 2.6). Analyses restricted to opposite-sex (dichorionic) twins showed that perinatal death, mechanical ventilation and very preterm birth occur less likely among older women (OR=0.2 (95% CI: 0.0 to 0.8), OR=0.3 (95% CI: 0.1 to 0.7) and OR=0.4 (95% CI: 0.2 to 0.7), respectively). Further, the risk of late preterm birth was increased and NICU hospitalization was reduced among opposite-sex twins born to older compared with younger primiparous women (OR=1.9 (95% CI: 1.3 to 2.8) and OR=0.2 (95% CI: 0.1 to 0.5), respectively).

CONCLUSION

Twins of older mothers did not have an elevated risk for most adverse birth outcomes, except for late preterm birth. Risks of neonatal care admission may be elevated among older multiparous women.

Delayed childbearing: effects on fertility and the outcome of pregnancy

In modern societies, the proportion of women who delay childbearing beyond the age of 35 years has greatly increased in recent decades. They are falsely reassured by popular beliefs that advances in new reproductive technologies can compensate for the age-related decline in fertility. Yet age remains the single most important determinant of male and female fertility, either natural or treated. The consequences of advancing maternal age are not only relevant for the risk of natural and assisted conception, but also for the outcome of pregnancy. Although the absolute rate of poor pregnancy outcomes may be low from an individual standpoint, the impact of delaying childbearing from a public health perspective cannot be overestimated and should be in the agenda of public health policies for the years to come. This review summarizes available evidence regarding the impact of delaying childbearing on fertility and pregnancy outcomes.

Desenvolvimento de um Questionário Quantitativo de Freqüência Alimentar (QQFA) para gestantes usuárias de Unidades Básicas de Saúde de Ribeirão Preto, São Paulo, Brasil

O objetivo do presente estudo foi desenvolver um questionário quantitativo de freqüência alimentar para gestantes adultas usuárias do Sistema Único de Saúde de Ribeirão Preto, São Paulo, Brasil. Um inquérito recordatório de 24 horas (IR24h) foi obtido de 150 gestantes, 50 em cada trimestre gestacional, com idade entre 18 e 35 anos. Um segundo IR24h foi obtido de 90 gestantes, 30 em cada trimestre gestacional, entre 7 e 15 dias após o primeiro inquérito. Uma lista de 85 alimentos foi estabelecida por regressão linear múltipla stepwise, estimando-se a contribuição percentual para a variabilidade interindividual da estimativa de energia e 28 nutrientes de interesse, com contribuição de 74,2 a 98,8% para os nutrientes de interesse selecionados. As porções alimentares foram determinadas de acordo com a distribuição percentual dos pesos relatados e descritas nos percentis 25, 50, 75 e 100. Desconhecemos a existência de questionário quantitativo de freqüência alimentar desenvolvido para gestantes no Brasil.

The effect of maternal age on adverse birth outcomes: does parity matter?

OBJECTIVES

To examine the effect of parity on the association between older maternal age and adverse birth outcomes, specifically stillbirth, neonatal death, preterm birth, small for gestational age, and neonatal intensive care unit admission.

METHODS

We conducted a retrospective cohort study of singleton births in British Columbia between 1999 and 2004. In the cohort, 69 023 women were aged 20 to 29, 25 058 were aged 35 to 39, and 4816 were aged 40 and over. Perinatal risk factors, obstetric history, and birth outcomes were abstracted from the British Columbia Perinatal Database Registry. Logistic regression was used to calculate adjusted odds ratios (aOR) and 95% confidence intervals for adverse outcomes in the two older age groups compared with the young control subjects.

RESULTS

Compared with younger control subjects, women aged 35 to 39 years had an aOR of stillbirth of 1.5 (95% CI 1.2 to 1.9) and women aged >or= 40 years also had an aOR of 1.5 (95% CI 1.0 to 2.4). The aOR for NICU admission was 1.2 (95% CI 1.0 to 1.3) in women aged 35 to 39 years and 1.4 (95% CI 1.1 to 17) in women aged >or= 40 years compared with younger control subjects. The risk of preterm birth and SGA differed by parity. The aOR for preterm birth compared with younger primiparas was 1.5 (95% CI 1.4 to 1.7) for women aged 35 to 39 years and 1.6 (95% CI 1.3 to 2.0) for women aged >or= 40 years. In multiparas the aOR for preterm birth was 1.1 (95% CI 1.1 to 1.2) in women aged 35 to 39 and 1.3 (95% CI 1.1 to 1.5) in women >or= 40 years. The aOR for SGA in primiparas was 1.2 (95% CI 1.1 to 1.4) for women aged 35 to 39 and 1.4 (95% CI 1.1 to 1.7) for women aged >or= 40 years. The risk of neonatal death was not significantly different between groups.

CONCLUSION

Older women were at elevated risk of stillbirth, preterm birth, and NICU admission regardless of parity. Parity modified the effect of maternal age on preterm birth and SGA. Older primiparas were at elevated risk for SGA, but no association between age and SGA was found in multiparas. Older primiparas were at higher risk of preterm birth than older multiparas compared with younger women.

Birth outcomes among older mothers in rural versus urban areas: a residence-based approach

PURPOSE

We examined the association between rural residence and birth outcomes in older mothers, the effect of parity on this association, and the trend in adverse birth outcomes in relation to the distance to the nearest hospital with cesarean-section capacity.

METHODS

A population-based retrospective cohort study, including all singleton births to 35+ year-old women in British Columbia (Canada), 1999-2003. We compared birth outcomes in rural versus urban areas, and between 3 distance categories to a hospital (<50, 50-150, >150 km). Outcomes included labor induction, cesarean section, stillbirth, perinatal death, preterm birth (<37 weeks), small-for-gestational-age, large-for-gestational-age, and neonatal intensive care unit admission. We used multivariate regression to obtain adjusted odds ratios (ORs) and 95% confidence intervals (CIs).

FINDINGS

Among the 29,698 subjects, 11.5% lived in rural areas; 5% lived within 50-150 km; and 1.1% lived >150 km from a hospital. Rural women were at lower risk of primary and repeat cesarean section (OR = 0.9, CI: 0.9-1.0; OR = 0.7, CI: 0.6-0.9) and small-for-gestational-age (OR = 0.8, CI: 0.7-0.9) births; they were at increased risk for perinatal death (OR = 1.5, CI: 1.1-2.1) and large-for-gestational-age (OR = 1.1, CI: 1.1-1.2) births. The association was stronger among multiparous versus primiparous women. No differences in emergency cesarean section, preterm birth, or neonatal intensive care admission were found, regardless of parity. Perinatal mortality increased with distance from hospital; OR = 1.5 (CI: 1.1-2.1) per distance category.

CONCLUSIONS

Older women in rural versus urban areas had a lower rate of cesarean section and increased risk of perinatal death. The risk of perinatal death increased with the distance to hospital. Further studies need to evaluate the contribution of underlying perinatal risks, access to care, and decision making regarding referral and transport.

Advanced maternal age and the risk of cesarean birth: a systematic review

BACKGROUND

The increasing pregnancy rate at advanced maternal age is contemporaneous with the increasing rate of cesarean birth. Several studies have found that advanced maternal age is a risk factor for cesarean birth. The objective of this systematic review was to assess the relationship between advanced maternal age and cesarean birth among nulliparous and multiparous women.

METHODS

To identify relevant studies, we searched the literature for articles published from January 1, 1995 to March 1, 2008, using Medline, EMBASE, PsychINFO, and CINAHL. We also hand-searched the bibliographies of retrieved articles to identify additional related studies. We included all cohort studies and all case-control studies that examined this association in developed countries. The Cochrane Collaboration's Review Manager software (5.0) was used to summarize the data.

RESULTS

Twenty-one studies met the inclusion criteria and were included in the review. All studies demonstrated an increased risk of cesarean birth among women at advanced maternal age compared with younger women, for both nulliparas and multiparas (relative risk varied from 1.39 to 2.76). Because we found extreme heterogeneity (both statistical and clinical) among the included studies, we did not provide a pooled estimate of the risk of cesarean birth.

CONCLUSIONS

All included studies illustrated an increased risk of cesarean birth among older women. Fifteen studies adjusted this association for potential confounders, which suggests that a valid and independent association is likely to exist between advanced maternal age and cesarean birth. However, the associated factors for this increased risk are not totally understood in the literature.

Third party reproduction and the aging couple

The average age of childbearing has been increasing in industrialized nations, including the United States. As a result, more women in their late 30s to early 40s are seeking their first pregnancy than ever before. Unfortunately, fertility declines with increasing female age. In addition, success of infertility treatments including those using assisted reproductive technologies (ART) decreases as the age of the female partner advances. Third party reproduction involves using gametes or the uterus of a third person to achieve pregnancy. Oocyte donation is a common form of third party reproduction, associated with significant success rates, which gives aging couples an opportunity to bear children. For safety and success, all the participants must be extensively screened medically and psychologically. In addition, a detailed understanding of the process by all parties involved should be achieved. While third party reproduction through oocyte donation is a long and labor intensive process with a significant amount of emotional, financial, and physical involvement from all parties, it is quite often a gratifying experience for everyone involved which include, oocyte donors, recipients, social workers, nurses and physicians.

A significant linear association exists between advanced maternal age and adverse perinatal outcome

OBJECTIVE

The present study was aimed to investigate perinatal outcome of elderly nulliparous patients.

STUDY DESIGN

A retrospective study was performed comparing pregnancy outcomes of nulliparous patients at three age groups: less than 35 years (reference group), 35-40 years, and above 40 years. The linear-by-linear association test was used to examine linear association between advanced maternal age and adverse pregnancy outcomes. A multiple logistic regression model was used to control for confounders.

RESULTS

Out of 45,033 nulliparous women with singleton gestations, 1,036 were of women over the age of 35, and 188 over 40. A significant linear association was documented between advanced maternal age and adverse outcomes, such as intra uterine growth restriction, low birth weight, congenital malformations, and perinatal mortality. Using a multiple logistic regression model, controlling for gestational age, IUGR and malformations, advanced maternal age was not found to be an independent risk factor for perinatal mortality (adjusted odds ratio = 1.04, 95% confidence interval 0.7-1.4).

CONCLUSION

A significant linear association exists between advanced maternal age and adverse maternal and perinatal outcomes. Nevertheless, in our population, advanced maternal age is not an independent risk factor for perinatal mortality.

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.

Neonatal intensive care utilization and neonatal outcome of infants born to women aged 40 years and over in New Zealand

BACKGROUND

Increased maternal age is associated with pregnancy complications and there are few data available on neonatal outcome and utilization of neonatal resources. Our first aim was to use national New Zealand data to determine if the outcomes following admission to NICU are different for infants born to women aged 40 years and over, compared with those born to women under 40 years of age. The second aim was to document trends in the requirement of neonatal intensive care in infants born to women aged 40 years and older.

METHOD

Eligible infants were identified from registration with the Australian and New Zealand Neonatal Network for 1995-2004 inclusive. The relationship between maternal age and neonatal outcome was tested using univariate and multivariate analysis, and trends in the number of infants in maternal age groups below 35 years, 35-39 years and over 40 years were determined.

RESULTS

On multivariate analysis using logistic regression, maternal age over 40 years was not found to be associated with a significant increase in the odds ratio for the composite poor outcome. However, over the 10-year period, there was an increase in the number of admissions and the percentage of admissions of infants born to women over 40 years of age.

CONCLUSION

Although the number of infants admitted for neonatal care following birth to women over 40 years of age has increased, these infants do not appear to have an increased risk of severe abnormal outcome.

Maternal weathering and risk of preterm delivery

OBJECTIVES

We compared the association between advancing maternal age and risk of preterm delivery across 4 groups (Black smokers, Black nonsmokers, White smokers, White nonsmokers) and within the context of neighborhood deprivation levels.

METHODS

We obtained data from linked census and birth records for singletons (n = 182 938) delivered by women aged 20 to 39 years in Philadelphia, Pennsylvania; Baltimore, Maryland; 16 Michigan cities; 3 Maryland counties; and 2 North Carolina counties. Results from area-specific multilevel logistic regression models were combined to obtain pooled estimates of relations between maternal age and risk of preterm delivery. We repeated the models after categorizing women by neighborhood deprivation level (low, medium, and high).

RESULTS

Among multiparous women, there was a significant age-related increase in preterm delivery in 3 of the 4 groups. The adjusted odds ratio per 5-year age increase was 1.31 in Black smokers, 1.11 in Black nonsmokers, and 1.16 in White smokers. In each group, the odds ratio increased as neighborhood deprivation increased.

CONCLUSIONS

These results support the "weathering" hypothesis, suggesting that Black women, women with high-risk behaviors, and women living in high-deprivation neighborhoods may develop "accelerated aging" that increases preterm delivery risk.