A case controlled study of pregnancy complicated by severe maternal anaemia

Prospective evaluation of placental abruption in nulliparous women

INTRODUCTION

Because most data on placental abruption are derived from retrospective studies, multiple sources of bias may have affected the results. Thus, we aimed to characterize risk factors and outcomes for placental abruption in a large prospective cohort of nulliparous women.

METHODS

This was a secondary analysis of women enrolled in the Nulliparous Pregnancy Outcomes Study Monitoring-to-be (nuMom2b) study, a prospective observational cohort. Participants were recruited in their first trimester of pregnancy from 8 sites and had 4 study visits, including at delivery. Placental abruption was defined by confirmed clinical criteria. The primary analysis was restricted to abruption identified antepartum and intrapartum. As a secondary analysis, we examined antepartum and intrapartum abruptions separately. We compared risk factors (maternal demographic and clinical characteristics) and outcomes in women with and without placental abruption using univariable and multivariable analyses as appropriate.

RESULTS

9450 women were included in the primary analysis. Abruption was identified in 0.66% (n = 62), of which 35 (56%) were antepartum and 27 (44%) intrapartum. For women with abruption, the mean gestational age at delivery was 35.6 ± 4.4 weeks and 38.8 ± 2.2 weeks for women without abruption. Gravidity was associated with abruption (OR 3.1, 95% CI: 1.6-6.0). In univariate analysis, abruption was associated with cesarean delivery (OR 3.7, 95% CI: 2.2-6.0), blood transfusion (OR 3.8, 95% CI: 1.4-10.7), PPROM (OR 9.0, 95% CI: 5.4-15.1), preterm birth (OR 8.5, 95% CI: 5.1-14.2), SGA (OR 4.0, 95% CI: 2.3-6.95), RDS (OR 5.5, 95% CI: 2.6-11.2), IVH 20.2 (OR 20.2, 95% CI: 5.9-68.8) and ROP (OR 12.2, 95% CI: 2.8-52.6). However, after adjustment for confounders including gestational age, abruption was only associated with increased odds of cesarean delivery and blood transfusion. Results were similar when restricted to antepartum and intrapartum abruptions.

CONCLUSION

Abruption was identified in <1% of nulliparous women. However, few maternal risk factors were identified. Neonatal morbidities were associated with an abruption and were primarily driven by gestational age due to preterm birth.

Maternal Anemia and Low Birth Weight: A Systematic Review and Meta-Analysis

Objective: To systematically analyze the relationship between maternal anemia and low birth weight. Methods: A search of studies was conducted in the main databases (Medline, Embase, Scopus, Web of Science, SciELO, and Lilacs), the gray literature, and the reference lists of selected articles. Cohort and case-control studies that met the eligibility criteria were included in the review. There was no limitation on the language or date of publication. Article selection and data extraction were performed by two independent reviewers. Meta-analyses with random effects, subgroup analyses and meta-regressions were performed. Publication bias was measured using Egger regression and visual funnel plot inspection. Results: A total of 7243 articles were found, of which 71 comprised the systematic review and 68 were included in the meta-analyses. Maternal anemia was associated with low birth weight with an adjusted OR: 1.23 (95% CI: 1.06–1.43) and I²: 58%. The meta-regressions confirmed that the sample size and the methodological quality may partially explain the statistical heterogeneity. Conclusions: Maternal anemia was considered a risk factor for low birth weight.

Maternal Anemia and Low Birth Weight: A Systematic Review and Meta-Analysis

OBJECTIVE

To systematically analyze the relationship between maternal anemia and low birth weight.

METHODS

A search of studies was conducted in the main databases (Medline, Embase, Scopus, Web of Science, SciELO, and Lilacs), the gray literature, and the reference lists of selected articles. Cohort and case-control studies that met the eligibility criteria were included in the review. There was no limitation on the language or date of publication. Article selection and data extraction were performed by two independent reviewers. Meta-analyses with random effects, subgroup analyses and meta-regressions were performed. Publication bias was measured using Egger regression and visual funnel plot inspection.

RESULTS

A total of 7243 articles were found, of which 71 comprised the systematic review and 68 were included in the meta-analyses. Maternal anemia was associated with low birth weight with an adjusted OR: 1.23 (95% CI: 1.06⁻1.43) and I²: 58%. The meta-regressions confirmed that the sample size and the methodological quality may partially explain the statistical heterogeneity.

CONCLUSIONS

Maternal anemia was considered a risk factor for low birth weight.

Placental genome and maternal-placental genetic interactions: a genome-wide and candidate gene association study of placental abruption

While available evidence supports the role of genetics in the pathogenesis of placental abruption (PA), PA-related placental genome variations and maternal-placental genetic interactions have not been investigated. Maternal blood and placental samples collected from participants in the Peruvian Abruptio Placentae Epidemiology study were genotyped using Illumina's Cardio-Metabochip platform. We examined 118,782 genome-wide SNPs and 333 SNPs in 32 candidate genes from mitochondrial biogenesis and oxidative phosphorylation pathways in placental DNA from 280 PA cases and 244 controls. We assessed maternal-placental interactions in the candidate gene SNPS and two imprinted regions (IGF2/H19 and C19MC). Univariate and penalized logistic regression models were fit to estimate odds ratios. We examined the combined effect of multiple SNPs on PA risk using weighted genetic risk scores (WGRS) with repeated ten-fold cross-validations. A multinomial model was used to investigate maternal-placental genetic interactions. In placental genome-wide and candidate gene analyses, no SNP was significant after false discovery rate correction. The top genome-wide association study (GWAS) hits were rs544201, rs1484464 (CTNNA2), rs4149570 (TNFRSF1A) and rs13055470 (ZNRF3) (p-values: 1.11e-05 to 3.54e-05). The top 200 SNPs of the GWAS overrepresented genes involved in cell cycle, growth and proliferation. The top candidate gene hits were rs16949118 (COX10) and rs7609948 (THRB) (p-values: 6.00e-03 and 8.19e-03). Participants in the highest quartile of WGRS based on cross-validations using SNPs selected from the GWAS and candidate gene analyses had a 8.40-fold (95% CI: 5.8-12.56) and a 4.46-fold (95% CI: 2.94-6.72) higher odds of PA compared to participants in the lowest quartile. We found maternal-placental genetic interactions on PA risk for two SNPs in PPARG (chr3:12313450 and chr3:12412978) and maternal imprinting effects for multiple SNPs in the C19MC and IGF2/H19 regions. Variations in the placental genome and interactions between maternal-placental genetic variations may contribute to PA risk. Larger studies may help advance our understanding of PA pathogenesis.

Intravenous iron sucrose versus oral iron in treatment of iron deficiency anemia in pregnancy: a randomized clinical trial

AIM

Iron deficiency is a leading cause of anemia in pregnancy. The present study aimed to compare the efficacy of oral and intravenous iron therapy in improving iron deficiency anemia in pregnancy and restoring iron stores, compare the obstetric outcome in the two groups and evaluate the safety of intravenous iron sucrose.

MATERIAL AND METHODS

This was a prospective study, where 100 anemic antenatal women with hemoglobin 7-9 g/dL, mean corpuscular volume <85 fL and serum ferritin <15 ng/mL, were randomized into two groups. In group A (n=50), the women received 200 mg tablets of ferrous sulphate, each containing 60 mg elemental iron, three times a day for 4 weeks. In group B (n=50), iron sucrose was given in divided doses of 200 mg each on alternate days by slow intravenous infusion. Primary outcome measure was treatment efficacy, assessed by measurement of hemoglobin, red blood cell indices and reticulocytes on days 7, 14, 21, and 30 and at delivery, and of ferritin on day 30 and at delivery. Any side-effects of treatment and the neonatal outcome were studied as secondary outcome measures.

RESULTS

There was a statistically significant difference in increase of hemoglobin levels (3.1g/dL in group A vs 5.1 g/dL in group B; P=0.002) and ferritin levels between the two groups on day 30 (P=0.005). The adverse effects from iron treatment were mild but more prominent in group A. Neonatal outcome was comparable in the two groups.

CONCLUSION

Intravenous administration of iron sucrose is a safe treatment for correction of anemia in pregnancy, without serious side-effects.

Impact of maternal anaemia on birth outcomes of teen twin pregnancies: a comparative analysis with mature young mothers

We investigated the impact of maternal anaemia on birth outcomes among adolescent twin pregnancies in the United States using the vital statistics records for matched multiple births covering the years 1995-1997 inclusive. The study group consisted of mothers aged 19 years or younger who had a twin pregnancy. A cohort of women aged 20-29 years with twin pregnancies served as the comparison group. The main birth outcomes of interest were: low and very low birth weight, preterm and very preterm delivery, small-for-gestational age, stillbirth, neonatal and perinatal mortality. Crude and adjusted odds ratios for the above outcomes were calculated using the generalised estimating equation framework (GEE) that captured both intra- and intercluster sources of heterogeneity. Although not statistically significant, we detected an elevated risk for stillbirth among anaemic women (20-30%) in either age cohort, a magnitude that is substantial at the population level as well as warranting further aetiological investigations.

Maternal anemia during pregnancy is an independent risk factor for low birthweight and preterm delivery

OBJECTIVE

The present study was designed to investigate the outcome of pregnancy and delivery in patients with anemia.

METHODS

A retrospective population-based study comparing all singleton pregnancies of patients with and without anemia was performed. Deliveries occurred during the years 1988-2002 in the Soroka University Medical Center. Maternal anemia was defined as hemoglobin concentration lower than 10 g/dl during pregnancy. Patients with hemoglobinopathies such as thalassemia were excluded from the analysis. Multiple logistic regression models were performed to control for confounders.

RESULTS

During the study period there were 153,396 deliveries, of which 13,204 (8.6%) occurred in patients with anemia. In a multivariable analysis, the following conditions were significantly associated with maternal anemia: placental abruption, placenta previa, labor induction, previous cesarean section (CS), non-vertex presentation and Bedouin ethnicity. Higher rates of preterm deliveries (<37 weeks gestation) and low birthweight (<2500 g) were found among patients with anemia as compared to the non-anemic women (10.7% versus 9.0%, p < 0.001 and 10.5% versus 9.4%, p < 0.001; respectively). Higher rates of CS were found among anemic women (20.4% versus 10.3%; p < 0.001). The significant association between anemia and low birthweight persisted after adjusting for gender, ethnicity and gestational age, using a multivariable analysis (OR = 1.1; 95% CI 1.0-1.2, p = 0.02). Two multivariable logistic regression models, with preterm delivery (<37 weeks gestation) and low birthweight (<2500 g) as the outcome variables, were constructed in order to control for possible confounders such as ethnicity, maternal age, placental problems, mode of delivery and non-vertex presentation. Maternal anemia was an independent risk factor for both, preterm delivery (OR = 1.2; 95% CI 1.1-1.2, p < 0.001) and low birthweight (OR = 1.1; 95% CI 1.1-1.2, p = 0.001).

CONCLUSION

Maternal anemia influences birthweight and preterm delivery, but in our population, is not associated with adverse perinatal outcome.

Postpartum hemorrhage in resource-poor settings

Despite the strong interest of international health agencies, worldwide maternal mortality has not declined substantially over the past 10 years. Postpartum hemorrhage (PPH) is the most common cause of maternal death across the world, responsible for more than 25% of deaths annually. Although effective tools for prevention and treatment of PPH are available, most are not feasible or practical for use in the developing world where many births still occur at home with untrained birth attendants. Application of many available clinical solutions in rural areas would necessitate substantial changes in government infrastructure and in local culture and customs surrounding pregnancy and childbirth. Before treatment can be administered, prompt and accurate diagnosis must be made, which requires training and appropriate blood measurement tools. After diagnosis, appropriate interventions that can be applied in remote settings are needed. Many uterotonics known to be effective in reducing PPH in tertiary care settings may not be useful in community settings because they require refrigeration and/or skilled administration. Moreover, rapid transfer to a higher level of care must be available, a challenge in many settings because of distance and lack of transportation. In light of these barriers, low-technological replacements for treatments commonly applied in the developed-world must be utilized. Community education, improvements to emergency care systems, training for birth attendants, misoprostol, and Uniject have shown promise as potential solutions. In the short term, it is expedient to capitalize on practical opportunities that utilize the existing strengths and resources in each community or region in order to implement appropriate solutions to save the lives of women during childbirth.

Maternal anaemia and its impact on perinatal outcome

OBJECTIVE

To find out the relationship between maternal anaemia and perinatal morbidity and mortality.

METHOD

A cohort of 629 pregnant women was studied from October 2001 to October 2002. Of these, 313 were anaemic (haemoglobin <11 g/dl in labour and on two previous occasions in current pregnancy). A total of 316 women had haemoglobin >11 g/dl at all times in pregnancy and were labelled as non-anaemic. Perinatal outcomes included preterm delivery, low birth weight (LBW) at delivery, intrauterine growth restriction, perinatal mortality, APGAR score at 1 and 5 min, intrauterine foetal demise (IUD).

RESULTS

The risk of preterm delivery and LBW among exposed group was 4 and 1.9 times higher among anaemic women, respectively. Newborns of anaemic mothers had 1.8 times increased risk of having an APGAR score of <5 at 1 min and the risk of IUD was 3.7 times higher for anaemic women.

CONCLUSION

Low maternal haemoglobin levels are associated with increased risk of preterm delivery, LBW babies, APGAR score <5 at 1 min and IUD.

Iron therapy in iron deficiency anemia in pregnancy: intravenous route versus oral route

OBJECTIVE

The aim of this study was to compare intravenous iron sucrose versus oral iron sulfate in anemia at 6 months of pregnancy.

STUDY DESIGN

A random, prospective, open study with individual benefit was performed involving 50 patients with hemoglobin levels between 8 and 10 g/dL and a ferritin value of <50 microg/L. In the intravenous group (IV group), the iron dose was calculated from the following formula: Weight before pregnancy (kg) x (120 g/L - Actual hemoglobin [g/L]) x 0.24 + 500 mg. The oral group (PO group) received 240 mg of iron sulfate per day for 4 weeks. Treatment efficacy was assessed by measurement of hemoglobin and reticulocytes on days 8, 15, 21, and 30 and at delivery and of ferritin on day 30 and at delivery. The baby's birth weight and iron stores were noted. Results were expressed as median +/- interquartile range. Mann-Whitney and Wilcoxon tests were used for the analysis, with P <.05 considered significant.

RESULTS

An increase in hemoglobin was observed, rising from 9.6 +/- 0.79 g/dL to 11.11 +/- 1.3 g/dL on day 30 in the IV group and from 9.7 +/- 0.5 g/dL to 11 +/- 1.25 g/dL on day 30 in the PO group (not significant). On day 30 (P <.0001) and at delivery (P =.01) ferritin was higher in the IV group. A mean higher birth weight of 250 g was noted in the IV group (not significant).

CONCLUSION

Iron sucrose appears to be a treatment without serious side effects indicated in correction of pregnancy anemia or iron stores depletion.

[Antipublic antibodies and pregnancy: use of iron sucrose in autologous blood donation with cryopreservation]

An autologous blood donation with cryopreservation in a pregnant woman with natural antibody against a high frequency alloantigen is reported. A natural anti Gerbich antibody and a rare erythrocyte phenotype at high risk of polyimmunization was discovered during the third month of pregnancy. This leads to recommend the constitution of an autologous blood reserve. Before first sampling a moderate iron deficiency anaemia (10.3 g.dL-1) was treated with 600 mg of intravenous iron sucrose. Four blood packs of 350 mL were taken; after every sampling 200 mg of iron sucrose were injected intravenously. No maternal or foetal adverse effects occurred. Five weeks before delivery, an autologous blood reserve consisting in 4 cryopreserved red cells packs and 4 fresh frozen plasma was constituted. Epidural analgesia was used for delivery. No haemorrhage occurred. The reserve was not used and remained available for future use (one year for fresh frozen plasma and without limit for red cells).

Is There a Causal Relationship between Iron Deficiency or Iron-Deficiency Anemia and Weight at Birth, Length of Gestation and Perinatal Mortality?

An extensive literature review was conducted to identify whether iron deficiency, iron-deficiency anemia and anemia from any cause are causally related to low birth weight, preterm birth or perinatal mortality. Strong evidence exists for an association between maternal hemoglobin concentration and birth weight as well as between maternal hemoglobin concentration and preterm birth. It was not possible to determine how much of this association is attributable to iron-deficiency anemia in particular. Minimal values for both low birth weight and preterm birth occurred at maternal hemoglobin concentrations below the current cut-off value for anemia during pregnancy (110 g/L) in a number of studies, particularly those in which maternal hemoglobin values were not controlled for the duration of gestation. Supplementation of anemic or nonanemic pregnant women with iron, folic acid or both does not appear to increase either birth weight or the duration of gestation. However, these studies must be interpreted cautiously because most are subject to a bias toward false-negative findings. Thus, although there may be other reasons to offer women supplemental iron during pregnancy, the currently available evidence from studies with designs appropriate to establish a causal relationship is insufficient to support or reject this practice for the specific purposes of raising birth weight or lowering the rate of preterm birth.

Anaemia in pregnancy--is the current definition meaningful?

OBJECTIVE

To determine if the current definition of antenatal anaemia (haemoglobin < 10 g/dl) has any clinical significance.

STUDY DESIGN

A retrospective study on all singleton deliveries over a 3-year period in two teaching hospitals under one university department was conducted by the extraction of data from a computer database. The major pregnancy complications and perinatal outcome were compared between mothers with and without anaemia and adjusted for parity.

RESULTS

The incidence of multiparity was significantly higher in the 817 anaemia patients compared to the 10125 non-anaemia patients, but there was no difference in the incidence of other major antenatal complications, type of labour or mode of delivery, incidence of preterm delivery, or perinatal mortality or morbidity, after adjusting for parity. Among the anaemia patients, those with thalassaemia trait (54.8%) had a significantly higher incidence of gestational glucose intolerance but the incidences of other complications and the perinatal outcome were similar to the iron deficiency patients.

CONCLUSION

Antenatal anaemia, defined as a maternal haemoglobin of < 10 g/dl, does not adversely affect pregnancy outcome. This raises the question of whether the diagnosis of anaemia should be redefined.

Relationship between birth weight and biochemical measures of maternal nutritional status at delivery in Bangladeshi urban poors

A cross-sectional study was carried out to investigate relationship of birth weight with selected biochemical indices of nutritional status of mothers at delivery in poor urban population of Dhaka, Bangladesh. One hundred and fifty one pregnant women of known gestational length, aged 20-30 years, who attended a local maternity hospital for delivery participated in this study. All of them were free from any pregnancy complications or diseases, and delivered a singleton fullterm baby. Socio-economic and obstetric history were taken by interview. Anthropometric data and blood samples were collected on the same day. Twenty per cent of the participants were anaemic (Hb < 11.0 g dl-1), 49% had subnormal (< 4.0 g dl-1) serum albumin and 32.5% had serum vitamin A lower than adequate level (< 30.0 micrograms dl-1). Mothers who gave birth to low birth weight babies had lower levels of haemoglobin (P = 0.06), serum albumin (P = 0.02) and serum vitamin A (P = 0.05) at delivery compared with the mothers who gave birth to normal weight babies. After adjustment for various confounding factors, only serum albumin level remained significantly lower in the mothers of low birth weight babies. Using multiple regression analysis for birth weight, the overall F-ratio was calculated to be 12.5 and was highly significant (P = 0.0000). The adjusted R2 was 0.32. Gestational age, father's occupation, mother's body weight and serum albumin level were found to have significant independent effect on birth weight.

Postpartum anaemia is not related to maternal iron status in the third trimester

OBJECTIVE

To determine whether the maternal haemoglobin and iron stores of non-anaemic mothers (haemoglobin > or = 10 g/dl) who developed postpartum anaemia were lower compared to mothers who did not develop postpartum anaemia.

STUDY DESIGN

A prospective study was conducted in a teaching hospital on 467 low-risk mothers recruited from the antenatal clinic over a 3-month period, who were given only low dose iron supplement and delivered in the same hospital. Blood was drawn at 28-30 weeks for the measurement of haemoglobin, mean cell volume, serum ferritin, serum iron and total iron binding capacity. These results were compared between mothers with a postpartum day 3 haemoglobin of > or = 10 g/dl and those < 10 g/dl. Statistical analysis was performed with parametric and non-parametric methods as appropriate.

RESULTS

Mothers with postpartum anaemia had a higher incidence of postpartum haemorrhage (19.6% vs. 3.9%, P < 0.001) as well as heavier mean intrapartum blood loss (444 ml vs. 304 ml, P < 0.001), but there was no difference in the haemoglobin, mean cell volume, serum ferritin, serum iron and total iron binding capacity.

CONCLUSIONS

In mothers without antenatal anaemia, the development of postpartum anaemia is not related to the maternal iron status in the third trimester.