The leucocytes during pregnancy

White blood cells in pregnancy: reference intervals for before and after delivery

BACKGROUND

White blood cells (WBC) are commonly measured to investigate suspected infection and inflammation in pregnant women, but the pregnancy-specific reference interval is variably reported, increasing diagnostic uncertainty in this high-risk population. It is essential that clinicians can interpret WBC results in the context of normal pregnant physiology, given the huge global burden of infection on maternal mortality.

METHODS

We performed a longitudinal, repeated measures population study of 24,318 pregnant women in Oxford, UK, to map the trajectory of WBC between 8-40 weeks of gestation. We defined 95% reference intervals (RI) for total WBC, neutrophils, lymphocytes, eosinophils, basophils, and monocytes for the antenatal and postnatal periods.

FINDINGS

WBC were measured 80,637 times over five years. The upper reference limit for total WBC was elevated by 36% in pregnancy (RI 5.7-15.0×109/L), driven by a 55% increase in neutrophils (3.7-11.6×109/L) and 38% increase in monocytes (0.3-1.1×109/L), which remained stable between 8-40 weeks. Lymphocytes were reduced by 36% (1.0-2.9×109/L), while eosinophils and basophils were unchanged. Total WBC was elevated significantly further from the first day after birth (similar regardless of the mode of delivery), which resolved to pre-delivery levels by an average of seven days, and to pre-pregnancy levels by day 21.

INTERPRETATION

There are marked changes in WBC in pregnancy, with substantial differences between cell subtypes. WBC are measured frequently in pregnant women in obstetric and non-obstetric settings, and results should be interpreted using a pregnancy-specific RI until delivery, and between days 7-21 after childbirth.

FUNDING

None.

Integrative single-cell and cell-free plasma RNA transcriptomics elucidates placental cellular dynamics

The human placenta is a dynamic and heterogeneous organ critical in the establishment of the fetomaternal interface and the maintenance of gestational well-being. It is also the major source of cell-free fetal nucleic acids in the maternal circulation. Placental dysfunction contributes to significant complications, such as preeclampsia, a potentially lethal hypertensive disorder during pregnancy. Previous studies have identified significant changes in the expression profiles of preeclamptic placentas using whole-tissue analysis. Moreover, studies have shown increased levels of targeted RNA transcripts, overall and placental contributions in maternal cell-free nucleic acids during pregnancy progression and gestational complications, but it remains infeasible to noninvasively delineate placental cellular dynamics and dysfunction at the cellular level using maternal cell-free nucleic acid analysis. In this study, we addressed this issue by first dissecting the cellular heterogeneity of the human placenta and defined individual cell-type-specific gene signatures by analyzing more than 24,000 nonmarker selected cells from full-term and early preeclamptic placentas using large-scale microfluidic single-cell transcriptomic technology. Our dataset identified diverse cellular subtypes in the human placenta and enabled reconstruction of the trophoblast differentiation trajectory. Through integrative analysis with maternal plasma cell-free RNA, we resolved the longitudinal cellular dynamics of hematopoietic and placental cells in pregnancy progression. Furthermore, we were able to noninvasively uncover the cellular dysfunction of extravillous trophoblasts in early preeclamptic placentas. Our work showed the potential of integrating transcriptomic information derived from single cells into the interpretation of cell-free plasma RNA, enabling the noninvasive elucidation of cellular dynamics in complex pathological conditions.

Changes in blood parameters in rhesus monkeys (Macaca mulatta) during the first trimester of gestation

BACKGROUND

Regarding the good practice in the laboratory work, it is essential to have a broad spectrum of biochemical and hematological references in pregnant females to determine the health status of the colony.

OBJECTIVE

To establish reference values to reveal changes in hematology and blood chemistry in pregnant rhesus monkeys (Macaca mulatta) in their first trimester of pregnancy.

METHODS

Twenty-eight females in reproductive stage were used, divided into two groups: 14 pregnant macaques in their first trimester and 14 non-pregnant used as the control group. Blood samples were collected for the hematological test and blood chemistry.

RESULTS

The results showed significant difference in the blood chemistry for the following parameters: glucose, total bilirubin, and total protein. The hematological evaluation revealed significant difference in leukocytes and neutrophils.

CONCLUSIONS

These findings offer a reference range and provide a basis for improvement in techniques and refinement of clinical processes in these specimens.

Total and differential leukocyte counts percentiles in normal pregnancy

OBJECTIVE

To establish leukocyte count and leukocyte differential percentiles in normal uncomplicated pregnancy.

STUDY DESIGN

This retrospective longitudinal study was performed in an outpatient facility for routine antenatal care. The study population comprised of 726 healthy women from the 5th to the 41st week of pregnancy. Altogether, there were 1749 complete blood count evaluations, of which 481 were in the 1st trimester, 687 in the 2nd trimester and 581 in the 3rd trimester. The total and differential leukocyte counts were determined by an automated cell counter.

RESULTS

The leukocyte and neutrophil counts gradually and significantly increased form the 1st to the 3rd trimester. The monocyte count increase became significant only during the 3rd trimester. The eosinophil count did not significantly change throughout pregnancy. The basophil count significantly decreased during the 2nd trimester and returned to 1st trimester values during the 3rd trimester.

CONCLUSION

In this study, we provide total and differential leukocyte counts' mean+/-S.D., minimal and maximal values, and the 3rd, 5th, 10th, 50th, 90th, 95th, and 99th percentiles for entire pregnancy and for each trimester separately. These reference values should prove useful for diagnostic and research purposes.

Lactation mastitis: bacterial cultivation of breast milk, symptoms, treatment, and outcome

The aim of this prospective study was to compare serum C-reactive protein (CRP) and leukocytes, hemoglobin, clinical signs, treatment, and outcome among 41 episodes of lactation mastitis grouped by the outcome of bacterial cultivation of breast milk. Group A included 25 cases with positive cultures only for bacteria normally present on skin. Group B included 16 cases in which cultures indicated the presence of potentially pathogenic bacteria. Serious complications were observed among women in group B, including protracted illness and weaning. No complications were observed in group A. Staphylococcus aureus was the most frequently isolated bacteria in group B. Mean serum leukocytes were significantly higher in group B than in group A. Although CRP levels in both groups were elevated, no significant difference was found between groups. Rest and frequent emptying of the breast were curative in group A. Further interventions were necessary for mothers in group B.

Immune alterations associated with epidural analgesia for labor and delivery

PURPOSE

Epidural analgesia is frequently used for the laboring woman and commonly regarded as safe. The association of epidural analgesia with fever, in the absence of infection, in this population can result in unnecessary sepsis workups in both neonates and mothers. Studies in other populations of patients have found that epidural anesthesia may be associated with alterations in white blood cell count parameters. This study was designed to determine if epidural analgesia is associated with alterations in immune profile or immune function in healthy afebrile postpartum women.

DESIGN

This prospective quasi-experimental study examined a convenience sample of normal afebrile postpartum women in two groups for differences in immune profile and immune function based on whether they received epidural analgesia during labor and delivery.

METHODS

Mothers who agreed to participate in the study and met inclusion criteria had blood drawn for immune profile and immune function studies within 24 hours of their delivery. This study looked at immune phenotypic profile, lymphocyte proliferative response, and NK lysis assays.

RESULTS

No differences in immune profile or immune function were found based on administration of epidural analgesia.

CLINICAL IMPLICATIONS

Nurses can be confident that the white blood cell count and other phenotypic measures of leukocytes are not affected by epidural analgesia. Thus the epidural analgesic technique appears not to alter immune measures of infection in postpartum women. In evaluating fever in postpartum mothers and neonates, nurses should consider prior receipt of epidural analgesia and measures of immune profile. In addition to fever and white blood cell counts, other signs and symptoms of infection should also be evaluated in postpartum women when infection is suspected.

Lymphocyte, monocyte, and natural killer cell reference ranges in postpartal women

Normative values for immune-cell subsets in postpartal women, who are recovering from the relative immunosuppression of pregnancy, have not been established. Considerable differences in normative values for subsets of immune cells have been demonstrated based on sociodemographic factors, such as age and race. In order to make accurate clinical decisions about postpartal women, comparisons with normal reference ranges are necessary. Therefore, flow cytometric data for 51 healthy women at 4 months postpartum are presented and changes over the first 4 postpartal months are documented. The levels of some lymphocyte cell subsets, such as CD4+/CD45RA+ and Ia on lymphocytes, remained stable over time. The levels of other lymphocyte cell subsets, such as CD4+/CD29+, increased over the first 4 postpartal months, while those of other cell subsets, such as CD8 and CD11b, increased between delivery and 2 months postpartum and then dropped again by the fourth postpartal month. The levels of two natural killer cell subsets (CD3-/CD16+ and CD3-/CD57+) rose from delivery until 1 month postpartum and then plateaued. Comparisons were made with reference ranges of nonpostpartal groups provided in the literature and in a study of healthy women being conducted in the same laboratory, and postpartal women were found to have lower values of CD8, CD3-/CD16+, CD4+/CD45RA+, CD20, and CD11b than those reported in the literature.

Transient immunologic effects of betamethasone in human pregnancy after suppression of preterm labor

Maternal immune suppression is a potentially significant adverse effect when betamethasone is used to hasten lung maturation of the fetus at risk for preterm delivery. However, increased incidence of infection has not been observed consistently after betamethasone treatment of pregnant women. This study was designed to determine if the cellular immune response to steroids may be modified during pregnancy in a way that would diminish the infection risk associated with steroid treatment. The effect of betamethasone on immunocytes among patients with preterm labor or in nonpregnant subjects were determined following administration of 12 mg of betamethasone intramuscularly. We measured serially the circulating leukocytes, lymphocytes, T lymphocytes, and their subsets. Measurements were also made of localized leukocyte mobilization to serum-filled skin chambers covering experimental inflammatory sites. Patients in preterm labor had increased WBC counts prior to treatment with betamethasone but no additional leukocytosis was induced nor was mobilization of leukocytes to the skin chambers decreased. Lymphopenia and depression of T cells was more transient among pregnant patients compared to nonpregnant. Thus, the pregnant patients studied had diminished or more transient potentially adverse immunocyte responses to betamethasone as compared to nonpregnant subjects.

Lymphocyte subsets defined by monoclonal antibodies in human pregnancy

Using monoclonal antibodies, indirect immunofluorescence, and flow cytometry, the proportions and absolute numbers of various lymphocyte subsets in peripheral blood have been measured in normal human pregnancy. Groups of ten women were studied at 12, 28, and 36 weeks of gestation and compared with 16 nonpregnant control women. The percentage of T cells (OKT3+) was constant throughout pregnancy, and this was confirmed in three women studied serially prior to and throughout early pregnancy. A slight fall in the proportion of helper cells (OKT4+) and rise in the proportion of suppressor cells (OKT8+) was observed at 12 and 28 weeks, but these changes, and the resulting fall in helper/suppressor ratio, were not statistically significant. Absolute lymphocyte counts determined by white cell count and differential were lower during pregnancy. The absolute numbers of T cells, helper cells, suppressor cells, and Ia-bearing cells (mainly B cells) were significantly lower at 36 weeks' gestation. T cells and helper cells were significantly reduced in absolute number at 12 weeks' gestation. There was no change in the ratio of T cells to B cells at any stage of gestation. The lack of any significant change in the balance between helper and suppressor cells in peripheral blood suggests that these cells are not important in the immune adaptation to pregnancy.

The effect of periconceptional supplementation on blood vitamin concentrations in women at recurrence risk for neural tube defect

1. We measured erythrocyte folic acid and riboflavin, serum folic acid and leucocyte vitamin C in women at high risk for neural tube defect (NTD) recurrence who were receiving periconceptional vitamin supplementation, before they received extra vitamins, after 28 d of supplementation and at the 8th week of pregnancy. Blood vitamin concentrations in unsupplemented high-risk women were also compared with the values found in unsupplemented low-risk women. 2. Vitamin supplementation with Pregnavite Forte F (Bencard) raised the mean values for all vitamins measured by the 8th week of pregnancy. Mean erythrocyte folic acid rose from 250 to 478 ng/ml; plasma folic acid from 8.4 to 26.1 ng/ml; leucocyte vitamin C from 1.82 to 3.21 micrograms/ml blood; erythrocyte riboflavin (glutathione reductase (EC 1.6.4.2) activation ratio) from 1.08 to 1.04. All women receiving supplements had increased their serum and erythrocyte folic acid levels above the highest values found in women in an earlier study, who subsequently gave birth to children with NTD. Not all women, however, increased their leucocyte ascorbic acid or erythrocyte riboflavin levels above the highest values. 3. When vitamin concentrations in unsupplemented high-risk women compared with levels in unsupplemented women at low risk for NTD, no significant differences were found in the mean values. However, a significantly higher proportion of high-risk compared with low-risk women had erythrocyte folic acid and leucocyte vitamin C values on or below the 5th percentile of the adult normal range. 4. The effectiveness of Pregnavite Forte E (Bencard) for increasing maternal vitamin reserves is discussed with a view to preventing NTD and the possibility of identifying groups at risk for NTD because of low blood vitamin levels is considered.

Plasma lactoferrin levels in pregnancy and cystic fibrosis

Plasma lactoferrin levels were determined by radioimmunoassay for the different weeks of normal pregnancy, in normal healthy adults and in children with and without cystic fibrosis. The lactoferrin levels were higher in pregnancy than in both male and female normal adults and showed a slight progressive increase up to week 29 and thereafter remained high. Five our of seven children with cystic fibrosis had markedly raised plasma lactoferrin levels from six to 16 times higher than the mean of a control group of children.

Leucocyte ascorbic acid and pregnancy

1. Leucocyte ascorbic acid concentrations have been measured in 1147 females during early pregnancy and in smaller numbers of women before conception, throughout pregnancy and at 6 months post partum. 2. The leucocyte concentration in the 1st trimester was found to be affected by season, social class and smoking. Selecting individuals by extremes of social class, season and smoking produced two small populations with almost separate ascorbic acid distributions and mean concentrations of 21.7 and 45.1 microgram/10(8) leucocytes. 3. Early pregnancy had little effect on leucocyte ascorbic acid concentrations but values decreased in the second trimester. However, this was associated with a leucocytosis so that the total leucocyte ascorbic acid content of blood was unchanged. 4. Low ascorbic acid concentrations during the 1st trimester were not associated with subsequent spontaneous abortions, still-births or neonatal deaths, but there was an increased frequency of low values in women who gave birth to infants smaller than 3250 g. 5. The adequacy of ascorbic acid reserves in early pregnancy is discussed.

Blood neutrophil response to bacterial infection in the first month of life

Serial white blood cell counts were undertaken on 100 babies who required admission to hospital in the first 4 weeks of life. Severe neutropenia was seen in 3 babies who died with overwhelming septicaemia, but a significant and early rise in the absolute polymorphonuclear neutrophil count was detected in 9 of the remaining 11 cases of septicaemia. A similar neutrophil response was seen within 24 hours of the onset of symptoms in 5 babies with meningitis, 10 babies with urinary infection, and 5 babies with pneumonia. Raised neutrophil counts were seen in only 9 of the remaining 66 babies, and all 9 had undergone major surgery. In more than 98% of healthy babies the neutrophil count is within the range 1350 to 8840 cells/mm³ after the first 4 days of life; counts outside this range nearly always occur during serious bacterial infection.