Abstract
Introduction
Globally, low head circumference at birth is common and can result in suboptimal cognitive, emotional, and behavioral health, which impairs individuals’ potential to thrive in adulthood. 1 Clinicians measure failure to thrive based on head circumference (HC), which plays an important role in monitoring the growth and development of infants. HC helps us assess brain growth, as cognitive function, intracranial volume, and brain volume are closely related to the size of head circumference. 2
Microcephaly in newborns is characterized by a disproportionately small head circumference for gestational age and can be categorized as absolute (asymmetrical growth retardation, where the head circumference (HC) is reduced to a greater extent than length and weight) or relative (symmetrical growth retardation, where the HC, length, and weight are reduced to a similar degree). 3 Despite considerable advances in case ascertainment, microcephaly remains a heterogeneous group of primarily neurological deficits. 4 A smaller HC may be linked to learning difficulties and a lower intelligence quotient (IQ). This association has been observed even for HC values immediately below the mean; lower IQ is related to higher mortality, and socioeconomic position has been suggested as a mediator of this IQ-related mortality. 5
A newborn with microcephaly may develop normally, develop slowly, or, in extreme circumstances, pass away shortly after delivery.6,7 According to data from Latin America and the Caribbean, microcephaly can result in a loss of approximately 30 years of disability-adjusted life expectancy per case, as well as more than US$ 91 100 in costs per patient per year. 8 Each region has a different prevalence of microcephaly: in the U.S., it ranges from 20 to 120 cases per 100 000 live births; in Australia, it is about 55 cases per 100 000 live births; and in Europe, it is 15.3 cases per 100 000 live births.6,9,10
It is recognized that the first 2 years of life account for the bulk of brain growth, which continues to expand in volume until puberty. 11 A low head circumference (HC) value may also be used to predict a child’s preschool cognitive growth and brain development. Prospective research conducted in Southern India revealed a favorable correlation between HC and learning, as well as visuospatial abilities, in children aged 9 to 10. 12
Several factors, including maternal education, maternal intelligence quotient, maternal body mass index, socioeconomic status, 13 birth weight, exclusive breastfeeding, and maternal smoking, influence head circumference (HC) in children through complex pathways. 14
Microcephaly is frequently associated with intellectual disability and neurological abnormalities.15,16,17 The measurement of head size at birth provides insight into when growth retardation occurs during intrauterine life. However, in many impoverished nations, such as Ethiopia, head circumference (HC) is not routinely measured. Even when it is measured, the study area is often omitted, with clinical anthropometric assessments and research studies predominantly focusing on weight and length/height measurements. There is limited evidence regarding the determinants of microcephaly in Ethiopia, particularly in the study area. For this reason, the current study is imperative. Therefore, this study aims to fill the gap by providing information on the determinants of low head circumference using head circumference reference data from the World Health Organization (WHO). 16
Method and Material
Study Design, Area, and Period
A facility-based unmatched case-control study was employed in Dessie Comprehensive Specialized Hospital, South Wollo Zone, Amhara Region from December 3, 2022, to April 20, 2023. Dessie is found in the South Wollo Zone, which is located 481 km from Bahir Dar and 401 km from Addis Ababa. The total population is about 273 305. Dessie City has 1 Specialized Comprehensive Hospital, 5 general private hospitals, 32 private clinics, 5 health centers, 1 Family Guidance Association of Ethiopia (FGAE), and a Marie-Stops clinic. Dessie Comprehensive Specialized Hospital provides 200 deliveries per month (August 2014 DHIS2 report).
Source Population
✓ All mothers who delivered live births with normal head circumferences at Dessie Comprehensive Specialized Hospital were the source population for the control group, whereas those who had low head circumferences were the source population for the case group.
Study Population
All mothers with live births were paired at Dessie Comprehensive Specialized Hospital during the study period.
✓ Cases are newborns whose WHO head circumference was less than 32 cm.
✓ Controls are newborns whose WHO head circumference was greater than or equal to 32 cm.
Inclusion and Exclusion Criteria
Inclusion criteria
All mothers who gave live births with a head circumference greater than or equal to 32 cm at Dessie Comprehensive Specialized Hospital for the control group, while those newborn babies whose head circumference was less than 32 cm were for the case group.
Exclusion criteria for both cases and controls
Mothers who gave live births with signs and symptoms of hydrocephalus, and distended veins of the scalp were excluded.
Sample size determination
Epi Info, statistical software version 7.2.3.1 was used to calculate the sample size based on all the assumptions made in previous studies conducted in the semi-urban settlement of Vellore, Southern India, 1.95 odds ratio, a control-to-case ratio of 3:1, and 38% of controls among the exposed group with the primiparity variable. 11 There was also an accepted error of 5%, a power of 80%, and a 95% confidence level. Adding a 10% non-response rate, the sample size obtained considering the above assumptions was 381 (95 cases and 286 controls).
Sampling procedures
Cases were selected as all newborns with low head circumference in the delivery room during the data collection period until the required sample size was attained, and controls were selected by systematic random sampling technique (who have normal head circumference measurements). According to Dessie Comprehensive Specialized Hospital maternal and child health service data, the 6-month newly delivered babies was 2520. Since the study period is 4 months, the average number of newly delivered babies in this period was 1680. Controls were selected at every

Sampling procedure for low head circumference at birth of newborn at Dessie Comprehensive Specialized Hospital Northeast Ethiopia.
Study Variables
Dependent variables
Low head circumference at birth (Yes, No).
Independent variables
Socio-demographic variables
Maternal age, sex, residence, occupation, marital status, family size, educational level, and household monthly income
Reproductive characteristics
Mother’s height, gestational age at birth, parity, antenatal care, and mode of delivery.
Maternal disease status
Heart disease, hypertension, diabetes, anemia during pregnancy, and genital/reproductive infections.
Newborn characteristics
Sex of the neonate, birth weight, sepsis of newborn, Intrauterine growth restriction, Apgar score at 1 minute, and Apgar score at 5 minutes.
Behavioral variables
Smoking, chat chewing, alcohol intake, antenatal folic acid supplementation, and Information about Nutrition.
Operational definitions
Head circumference (HC)
Head circumference is an anthropometric measure that can be used to determine whether the head size of a baby is within the typical age range. Using a flexible fabric tape measure, HC was measured around the head, above the eyebrows, and across the occipital protuberance, to the nearest 0.1 cm. 3
Microcephaly
WHO head circumference-for-age
Data collection tools and techniques
Primary data were collected from the client by using a structured questionnaire. After face-to-face interviews, charts of these mothers’ live births were reviewed. The questionnaire was originally developed in English and was used as it is for secondary data collection and translated into Amharic for primary data collection. The questionnaire consists of 4 parts, which include: sociodemographic characteristics (age, sex of the neonate, ethnicity, religion, educational status, and occupational status of the client, maternal-related characteristics factors, newborn-related characteristics; and environmental variables.
Head circumference (HC) measurement was carried out by measuring tape within 24 hours of birth by the trained nurses. After parents or caregivers agreed to participate in the study, they were asked to remove any of the child’s hair ornaments or braids. Children were placed on their parents/caregivers’ laps to feel safe and comfortable, and a head circumference tape was placed around the child’s head so that the tape was situated across the frontal bones of the skull and immediately above the eyebrows; perpendicular to the long axis of the face; above the ears; and over the occipital prominence on the back of the head. The tape was moved up and down over the back of the head in order to always locate the maximal circumference. The tape measure was made to be neither too loose nor too tight, so that it would fit comfortably around the head, but also would be compressed to the hair and underlying soft tissues. The measurement was taken from the lateral side. The HC was measured to the nearest 0.1 cm. Since the HC tape shows both centimeters and inches, checking the metric scale was very important.
Data quality control
Equipment
A non-stretchable measurement tape was used and checked for variation when used repeatedly, getting wet, or getting warm. The measurement tape was checked against a fixed standard (metal) when we started to use it, and again after using it for a period of time.
To ensure the quality of the data, the questionnaires were pretested on 19 (5%) of the respondents at Kombolcha General Hospital before the actual data collection.
Four trained female health professionals (2 nurses working in the postnatal room and 2 midwives working at the labor and delivery ward of Dessie Comprehensive Specialized Hospital) participated in the data collection. Two-day training was given for data collectors. Supervision and on-the-spot checking of the data collection procedure were made by the principal investigator. For client chart review and primary data collection, a structured checklist and a structured questionnaire were used, respectively. Every day, at the end of the data collection, a discussion was held with the data collectors, problems encountered were discussed, and timely solutions were worked out from the experiences. The completeness of the questionnaire was checked before data entry.
Data management and analysis
The data were checked for completeness, and data cleaning was performed through tabulation and frequency for accuracy, consistency, and missing values. After cleaning the data, it was coded and first entered into Epi-Data version 4.6 then checked and transferred to Statistical Package for Social Science (SPSS) version 26 for analysis. Descriptive statistics were computed and reported by frequency, mean, median, standard deviation, and percentage of the independent variables. Variables with a
Ethical Approval and Informed Consent
Ethical clearance was obtained from the ethical review committee of Wollo University, College of Health Sciences with a reference number of cmHs/1754/11/22. A consent letter was obtained from Dessie City Health Department and Dessie Comprehensive Specialized Hospital. All selected participants were informed about the objective of the study to obtain their verbal informed consent and ascent, and what is more, for subjects’ newborns. Participants were informed of their full right to withdraw or refuse to participate in the study at any time. Privacy and confidentiality of information given by each respondent were guaranteed by omitting names or any personal identifiers.
Results
Socio-Demographic Characteristics of the Study Participants
A total of 368 participants on newborn babies at Dessie Comprehensive Specialized Hospital (82 cases and 286 controls) participated in this study, which accounts for a response rate of 96.59%. Among the participants, 19 (23.2%) of the case and 116 (40.6%) of the control were urban dwellers. Majority of the respondents, 308 (83.7%) were married (Table 1).
Socio-demographic Characteristics of the Study Participants in Dessie Comprehensive Specialized Hospital, Northeast Ethiopia, 2023.
Obstetric and Medical History of the Mother
From this study 328 (89.13%) of the participants were delivered through spontaneous vaginal delivery. More than half of the study participants 63.3% have less than or equal to two histories of delivery (Table 2).
Maternal Characteristics of the Study Participants at Dessie Comprehensive Specialized Hospital, 2023 (n = 368).
Maternal Disease Status
Of the study participants, 6% of them have hypertension during pregnancy. Nine percent of the study participants were diagnosed with anemia during pregnancy (Table 3).
Maternal Disease Status of the Study Participants at Dessie Comprehensive Specialized Hospital, 2023 (n = 368).
Maternal Behavioral-Related Variables
In this study, the majority of 80 (97.6%) of the study participants were smokers from cases whereas 279 (97.6%) of the study participants were smokers from controls. Of the study participants, 54 (14.7%) of them did not take folic acid supplements during pregnancy. Thirty-two (8.7%) of the study participants did not get nutritional education during pregnancy (Table 4).
Maternal Behavioral Characteristics of the Study Participants at Dessie Comprehensive Specialized Hospital, 2023.
Health-Related Characteristics of Newborn Babies
From to number of cases, 46 (56.1%) of them were male in sex and more than half 165 (57.7%) of the newborn babies were also male in sex from controls. On the other hand, from cases, the majority 72 (87.8%) of the newborn babies didn’t have congenital abnormalities and from controls, most 271 (94.8%) of the newborn babies also didn’t have congenital abnormalities (Table 5).
Health-related Characteristics of the Newborn Participating in this Study at Dessie Comprehensive Specialized Hospital, 2023.
Determinates of Low Head Circumference at the Birth of Newborn
In bi-variable analysis, 6 variables namely, residence, parity, age of the mother, anemia during pregnancy, congenital anomalies, and folic acid supplementation were candidate variables for multivariable logistic regression at a
In multivariable logistic regression, 2 of 6 variables were significantly associated with low head circumference at birth of newborns among study participants at a 5% level of significance.
Newborn babies who delivered from rural resident mothers [AOR = 1.95, 95% CI: 1.08, 3.52] were 2 times more likely to have low head circumference as compared to those who delivered from urban residents. On the other hand, newborn babies who delivered from an anemic pregnant mother [AOR = 2.61, 95% CI: 1.18, 5.78] were 2.6 times more likely to have low head circumference as compared to those who delivered from non-anemic pregnant mothers (Table 6).
Determinants of Low Head Circumference Newborn Among Study Participants in Dessie Comprehensive Specialized Hospital, Amhara Region, Northeast Ethiopia, 2023 (n = 368).
Abbreviations: COR, crude odds ratio; AOR, adjusted odds ratio.
Discussion
In this study, the main determinants of low head circumference among newborn babies were being rural residents and having anemia during pregnancy. The possible overestimation due to the use of the World Health Organization (WHO) growth standard for comparison, as well as the presence of healthy newborns with microcephaly in this study, could be explained by the concept of proportionality of head size and the late manifestation of abnormalities. 3 The implications of this study’s findings suggest that emotional and behavioral problems may manifest among newborn babies, which are becoming increasingly prevalent and have substantial impacts on the individual, family, and society.
The results of this study showed that reduced head circumference in newborns had a positive association with living in a rural area. Newborns delivered by rural pregnant women were 2 times more likely to have low head circumference compared to those delivered by urban pregnant women. This finding is consistent with a study conducted in southwest Nigeria. 18 The possible justification could be that pregnant women living in rural areas might not receive the same level of nutritional and disease-related education as those in urban areas, as urban resident pregnant women are more likely to attend antenatal care. Additionally, urban pregnant women may have better access to a balanced diet compared to their rural counterparts. This, in turn, could contribute to the delivery of babies with low head circumference. 15
The other important variable that showed a positive association with low head circumference among newborn babies was having anemia during pregnancy. Those who had anemia during pregnancy were 3 times more likely to have babies with low head circumference compared to those who did not have anemia during pregnancy. This study’s findings are also in line with the results of a study conducted in the semi-urban settlement of Vellore, Southern India. 11 This is due to the fact that anemic pregnant women do not provide adequate amounts of nutrients to the fetus. Consequently, the probability of low head circumference among newborn babies could be high. Additionally, iron deficiency anemia has a negative impact on the growth and development of the brain. 19
Many research articles have demonstrated that smaller infant head circumference is linked to maternal parity, advanced age, and shorter maternal height.19 -22 For instance, a cross-sectional study from Iran reported that the length and head circumference of neonates increased significantly with maternal age and parity. 20 The children of very young mothers, aged 12 to 16, were considerably smaller in all body dimensions than the children of older adolescent mothers or adult mothers, according to research by Neggers et al 23 on the birth outcomes of adolescent mothers. However, in this study, advancing age, maternal parity, and shorter maternal height were not significantly associated with smaller infant head circumference. This non-significant association observed in this study may be due to the small sample size.
Strength and Limitation of the Study
Since this study is facility-based, it is difficult to generalize the findings to all pregnant women in the community. On the other hand, recall bias is a significant concern among the study participants. Cases and controls were not categorized based on the sex-specific WHO HC charts, which may lead to inaccuracies in the case definition for identifying females with microcephaly. Additionally, this study did not account for gestational age in determining microcephaly. However, one of its most significant advantages is that it provides valuable information regarding the risk factors for low head circumference at the birth of a newborn.
Conclusion
In this study, being a rural resident and having anemia during pregnancy were determinants of low head circumference among newborn babies in Dessie Comprehensive Specialized Hospital. It’s recommended that Health facilities should address all rural pregnant women and encourage them to attend antenatal care follow-up and increase the availability of iron supplementation. Healthcare professionals should provide iron sulfate for all pregnant mothers who attend antenatal care services. Health planners should give priority to rural pregnant women.
