A systematic review of the risks of a low birthweight (LBW), preterm, and small-for-gestational-age births in relation to paternal factors was performed. Medline, Embase, Cumulative Index of Nursing and Allied Health Literature, and bibliographies of identified articles were searched for English-language studies. Study qualities were assessed according to a predefined checklist. Thirty-six studies of low-to-moderate risk of bias were reviewed for various paternal factors: age, height, weight, birthweight, occupation, education, and alcohol use. Extreme paternal age was associated with higher risk for LBW. Among infants who were born to tall fathers, birthweight was approximately 125-150 g higher compared with infants who were born to short fathers. Paternal LBW was associated with lower birthweight of the offspring. In conclusion, paternal characteristics including age, height, and birthweight are associated with LBW. Paternal occupational exposure and low levels of education may be associated with LBW; however, further studies are needed.
Low birthweight (LBW) birth and preterm births (PTBs) are public health issues with significant individual, familial, and societal impact. Familial influence in the cause of LBW/PTB births is suspected; however, the major research attention has been focused on maternal determinants. Paternal factors (such as advanced paternal age and chemical exposures) have been linked with congenital malformations. De La Rochebrochard et al, in a minireview, concluded that advanced paternal age (>40 years) was associated with miscarriages and fetal deaths. Diseases such as Alpert syndrome, Marfan syndrome, and Waardenberg syndrome are associated with advanced paternal age. Strobino et al reviewed the connection between paternal occupational exposure and effect on offspring. They reported that paternal occupation was not associated with spontaneous abortion and that there was a lack of conclusive impact on other birth outcomes.
For Editors’ Commentary, see Table of Contents
See related editorial, page 99
Studies have reported paternal factors that influence birthweight or gestational age. However, no comprehensive review of paternal determinants or factors on LBW, PTB, or small for gestational age (SGA) births has been conducted. The objective of this study was to review systematically the risk of an infant with LBW, PTB, and SGA in relation to various reported paternal factors.
Materials and Methods
The data were extracted from published articles; therefore, no ethical approval was obtained.
Criteria for consideration of studies for this review
Observational studies that explored the association of any of the paternal factors and the outcomes of LBW, PTB, and SGA births of offspring were included in this review. If the study provided adequate information on the method of ascertainment of the paternal factor and its effects on any of the outcomes of interest, the study was eligible for inclusion in the review. We included only information that was available from the publications and did not contact primary authors. Studies that were published as abstracts were excluded.
Types of studies
Observational cohort studies, case control studies, and studies of surveys or interviews were included. Reports of data from national or local vital statistics that were not published as peer-reviewed articles were not included.
Types of participants
Women who had a live birth were included. Data on reports of maternal influence on birth outcomes were not included in this review.
Assessment of exposure
Previous knowledge of the subject indicated that paternal age, anthropometry, paternal birthweight, occupation, and educational background would be probable exposures to be included in the review. We did not include paternal race as an exposure variable because race has a complex interaction with maternal race. Similarly, we excluded paternal smoking as an exposure because most studies have reported on environmental tobacco exposure, which could have been from partners or other sources, and it was difficult to differentiate. We included studies that reported a collection of ascertainment of exposure data from maternal charts, interview, and direct or indirect assessments.
Types of outcome measures
Studies that reported data on any of the following outcomes were included: (1) LBW birth defined as birthweight <2.5 kg; (2) PTB defined as gestational age <37 weeks; (3) birthweight in grams; (4) gestational age in weeks, and (5) SGA birth defined as birthweight <10th percentile for gestational age.
Search strategy for identification of studies
Electronic databases (Medline, Embase, and Cumulative Index of Nursing and Allied Health Literature) were searched, with assistance from an experienced librarian, from their inception to March 2009 for all published studies in the English language. The search terms were modified according to database requirements. The reference lists of the identified articles were reviewed to locate additional eligible studies. The articles were scanned initially on the basis of titles and abstracts. The reviewer was not blinded to authors or institution. Selected articles were retrieved in full and were assessed for eligibility. Search terms used were low birthweight; premature birth; preterm birth; small for gestational age; growth, intrauterine; growth restriction, fetal; growth restriction, intrauterine; high risk pregnancy; infant, premature; infant, newborn; pregnancy; familial factors; father, paternal factors, paternal age, paternal birthweight, occupation, education, anthropometry, weight, height, body mass , and body mass index.
Methods of the review
Data extraction
Data from each eligible study were extracted into custom-made data collection forms. Minor modifications (such as combining birthweight means for male and female subjects) and the calculation of raw percentages from available data were done. Confounders that were adjusted for in the analyses in the individual studies were reported. When adjusted data were reported in the primary studies, they were extracted and noted in the results.
Assessment of quality of included studies
The methodologic quality of studies was assessed with a predefined checklist that was based on criteria for the sample selection, exposure assessment, outcome assessment, confounder, and analytical and attrition biases ( Appendix ). The classifications were applied in each category: cannot tell, no bias, low risk, moderate risk, or high risk of bias.
Data synthesis
We expected a significant degree of clinical heterogeneity among studies in each of the paternal factors and planned for a systematic review and not metaanalyses from the outset. Qualitative synthesis of the evidence was planned because of the reasons mentioned earlier.
Heterogeneity and publication bias assessment
Clinical heterogeneity was assessed and reported in the Tables.
Results
Description of studies
Thirty-eight studies were included in this review. Some of the included studies reported on >1 paternal factor. Paternal alcohol use was identified as an exposure during the literature review (which was not planned a priori). Eleven studies were excluded after detailed evaluation. Details of included studies and reasons for excluded studies are given in Figure 1 .
Methodologic quality of included studies
The results of the quality assessments of the included studies are reported in Tables 1-6 . The studies had low-to-moderate risk of biases. The major criticism of the included studies was that the assessment of exposure in many reports was indirect (such as maternal history, derived or deduced assessment method for occupational exposure). Adjustment of confounders was variable among studies; however, compared with other reports of determinants of LBW/PTB births, most of the studies in this category have accounted for common confounders. Assessment of outcomes was satisfactory in most studies. Many studies reported only incidence or percentage of outcome data and not odds ratio or relative risk and their associated confidence interval. The data in the Tables reflect what is reported in the articles. If the risk estimates are missing from a Table, the implication is that they were not reported.
| Study | Study characteristics | Assessment | Risk of bias | Results | |||
|---|---|---|---|---|---|---|---|
| Category, y | LBW, OR (95% CI) | PTB, OR (95% CI) | SGA, OR (95% CI) | ||||
| Abel et al , a | 1978-1992; Cohort study performed in North Dakota; used the statewide database; n = 154,391 | Exposure: maternal history | Selection: none | 21-26 | 1.00 | 1.00 | |
| Outcome: birth certificates | Exposure assessment: low | <20 | 1.28 (1.02–1.61) | 1.24 (1.02–1.52) | |||
| Confounders adjusted: socioeconomic status, maternal age, infant sex, race | Outcome assessment: none | 26-30 | 1.07 (0.85–1.33) | 0.89 (0.80–1.00) | |||
| Confounding factors: low | 31-35 | 1.03 (0.74–1.44) | 0.88 (0.77–1.02) | ||||
| Analytical: none | 36-40 | 1.26 (0.81–1.96) | 1.01 (0.83–1.21) | ||||
| Attrition: cannot tell | 41-45 | 1.35 (0.77–2.35) | 1.12 (0.77–1.33) | ||||
| Overall: low | >45 | 1.38 (0.71–2.68) | 1.12 (0.79–1.57) | ||||
| Astolfi et al , a | 1990-1998; Cohort study of nationwide sample from Italy; singleton, first born live births to mothers 20-29 y old and father >20 y old; n = 1,510,823 | Exposure: vital statistics dataset | Selection: none | 20-24 | 1.13 (1.01–1.25) | ||
| Outcome: birth certificates | Exposure assessment: low | 25-29 | 1.00 | ||||
| Confounders adjusted: maternal age, infant sex, couple education, birth period | Outcome assessment: none | 30-34 | 1.03 (0.99–1.07) | ||||
| Confounding factors: low | 35-39 | 1.12 (1.08–1.15) | |||||
| Analytical: none | 40-44 | 1.23 (1.15–1.31) | |||||
| Attrition: low | 45-49 | 1.16 (0.82–1.65) | |||||
| Overall: low | ≥50 | 1.15 (0.96–1.38) | |||||
| Basso and Wilcox , a , b | 1995-2000; Cohort study of national sample from United States; married, non-Hispanic white primiparous women 20-34 y old | Exposure: birth certificate; why are the exposure and outcome the same? | Selection: low | 20-24 | 1.15 (0.94–1.39) | ||
| Outcome: birth certificates | Exposure assessment: low | 25-29 | 1.00 | ||||
| Confounders adjusted: maternal education, smoking | Outcome assessment: none | 30-34 | 0.97 (0.93–1.00) | ||||
| Confounding factors: low | 35-39 | 1.02 (0.97–1.08) | |||||
| Analytical: none | 40-44 | 1.05 (0.96–1.15) | |||||
| Attrition: low | 45-49 | 1.15 (0.98–1.34) | |||||
| Overall: low | >50 | 0.97 (0.73–1.29) | |||||
| Chen et al , a | 1995-2000; Cohort study performed with nationwide data; 20-29 y-old nulliparous mother who had singleton live birth; n = 2,520,098 | Exposure: vital statistics dataset | Selection: none | <20 | 1.13 (1.07–1.19) | 1.15 (1.10–1.20) | 1.17 (1.13–1.22) |
| Outcome: birth certificates | Exposure assessment: low | 20-29 | 1.00 | 1.00 | 1.00 | ||
| Confounders adjusted: race, maternal age, education, smoking, alcohol, infant sex, prenatal care | Outcome assessment: low | 30-34 | 1.00 (0.99–1.02) | 0.98 (0.07–0.99) | 1.03 (1.02–1.04) | ||
| Confounding factors: none | 35-39 | 0.99 (0.97–1.02) | 0.98 (0.96–1.00) | 1.02 (1.00–1.04) | |||
| Analytical: none | 40-44 | 0.96 (0.92–1.01) | 0.99 (0.95–1.03) | 1.02 (0.98–1.06) | |||
| Attrition: low | 45-49 | 1.01 (0.92–1.10) | 1.01 (0.94–1.09) | 1.06 (0.99–1.03) | |||
| Overall: low | ≥50 | 0.91 (0.79–1.05) | 0.93 (0.83–1.05) | 1.02 (0.92–1.13) | |||
| Nahum and Stanislaw , a | 1998-2000; Cohort study, private single clinic at Duke University; term, uncomplicated, singletons; n = 241 | Exposure: maternal history | Selection: low | Paternal age was not a significant predictor of birthweight if maternal age was specified ( P = .08) | |||
| Outcome: charts | Exposure assessment: low | ||||||
| Confounders adjusted: none | Outcome assessment: none | ||||||
| Confounding factors: moderate | |||||||
| Analytical: low | |||||||
| Attrition: low | |||||||
| Overall: moderate | |||||||
| Olshan et al , a | 1988-1991; Cohort study of statewide data from North Carolina; 20-34 y-old resident mothers who had singleton live birth; n = 254,892 | Exposure: birth files | Selection: low | <19 | 1.13 (0.97–1.32) | 1.23 (1.10–1.39) | 1.03 (0.88–1.20) |
| Outcome: birth files | Exposure assessment: low | 20-24 | 1.04 (0.98–1.09) | 1.09 (1.05–1.14) | 0.98 (0.93–1.04) | ||
| Confounders adjusted: maternal age, race, gravidity, smoking, marital status, education, infant sex | Outcome assessment: low | 25-29 | 1.00 | 1.00 | 1.00 | ||
| Confounding factors: none | 30-34 | 0.96 (0.91–1.01) | 0.98 (0.95–1.02) | 1.01 (0.96–1.06) | |||
| Analytical: low | 35-39 | 0.96 (0.89–1.03) | 1.03 (0.97–1.08) | 0.95 (0.89–1.03) | |||
| Attrition: low | 40-44 | 1.09 (0.97–1.21) | 1.05 (0.96–1.14) | 1.05 (0.93–1.18) | |||
| Overall: low | 45-49 | 1.00 (0.81–1.23) | 1.09 (0.93–1.28) | 1.13 (0.92–1.38) | |||
| >50 | 0.81 (0.59–1.12) | 1.08 (0.85–1.36) | 0.87 (0.63–1.19) | ||||
| Reichman and Teitler , a | 1998-2000; Cohort study of randomly selected births from 75 hospitals in the United States; >18 y-old mothers who had singleton live birth; n = 4621 | Exposure: history | Selection: moderate | <20 | 0.7 (0.5–1.0) | ||
| Outcome: charts | Exposure assessment: low | 20-34 | 1.00 | ||||
| Confounders adjusted: maternal age, race, gravidity, marital status, socioeconomic status, infant sex | Outcome assessment: none | >34 | 1.7 (1.3–2.2) | ||||
| Confounding factors: none | |||||||
| Analytical: low | |||||||
| Attrition: none | |||||||
| Overall: moderate | |||||||
| Selvin and Garfinkel | 1959-1967; Cohort study, singleton live births to white mothers in New York state (excluding New York City); n = 1,515,443 | Exposure: birth certificates | Selection: low | ≤19 | 8.58% | ||
| Outcome: birth certificates | Exposure assessment: low | 20-24 | 6.66% | ||||
| Confounder adjusted: maternal age | Outcome assessment: low | 25-29 | 5.77% | ||||
| Confounding factors: low | 30-34 | 5.63% | |||||
| Analytical: low | 35-39 | 6.08% | |||||
| Attrition: low | 40-44 | 6.57% | |||||
| Overall: low | 45-49 | 7.38% | |||||
| 50-54 | 7.82% | ||||||
| ≥55 | 7.99% | ||||||
| Total | 6.13% | ||||||
| Tough et al , a | 1990-1996; Cohort study, provide wide data from Alberta, Canada; mothers between 25-29 y old; n = 259,903 | Exposure: birth certificates | Selection: none | ≤19 | 1.00 | 1.00 | |
| Outcome: birth certificates | Exposure assessment: low | 20-24 | 0.84 (0.74–0.95) | 0.87 (0.77–0.97) | |||
| Confounder adjusted: maternal age | Outcome assessment: none | 25-29 | 0.82 (0.72–0.93) | 0.82 (0.73–0.93) | |||
| Confounding factors: low | 30-34 | 0.77 (0.67–0.88) | 0.77 (0.68–0.85) | ||||
| Analytical: low | 35-39 | 0.76 (0.66–0.87) | 0.75 (0.66–0.85) | ||||
| Attrition: low | 40-44 | 0.79 (0.68–0.92) | 0.81 (0.71–0.93) | ||||
| Overall: low | 45-49 | 0.93 (0.77–1.13) | 0.88 (0.74–1.05) | ||||
| ≥50 | 0.98 (0.75–1.26) | 0.96 (0.76–1.21) | |||||
| Zhu et al , a | 1980-1996; Cohort study; singleton live births in Danish fertility database; first child of couple; father <30 y old and >35 y old; n = 70,347 | Exposure: national database | Selection: low | 20-24 | 1.00 | ||
| Outcome: national database | Exposure assessment: low | 25-29 | 1.1 (0.9–1.2) | ||||
| Confounders adjusted: maternal age, parity, education, income, infant sex, year of birth | Outcome assessment: low | 35-39 | 1.1 (1.0–1.3) | ||||
| Confounding factors: none | 40-44 | 1.2 (1.0–1.4) | |||||
| Analytical: low | 45-49 | 1.2 (0.9–1.5) | |||||
| Attrition: none | ≥50 | 1.1 (0.8–1.6) | |||||
| Overall: low | |||||||
a Results mentioned here are adjusted estimates;
| Study | Study characteristics | Assessment | Risk of bias | Results | |
|---|---|---|---|---|---|
| Category, cm | Birthweight, g a | ||||
| Cawley et al | 1949-1950; Cohort study, singleton, live births and no neonatal death in 2 areas (Smethwick and Birmingham, UK); n = 1544 | Exposure: maternal history and measurement | Selection: low | <168 | 3239 |
| Outcome: charts | Exposure assessment: low | 168-173 | 3307 | ||
| Confounder adjusted: maternal height | Outcome assessment: none | 173-178 | 3325 | ||
| Confounding factors: moderate | 178-183 | 3329 | |||
| Analytical: low | >183 | 3447 | |||
| Attrition: moderate | |||||
| Overall: moderate | |||||
| Klebanoff , b | 1959-1961; Cohort study, singleton, live births from single center in Copenhagen, Denmark; n = 3130 | Exposure: maternal history | Selection: low | ≤175 | 3325 |
| Outcome: charts | Exposure assessment: low | 175-178 | 3413 | ||
| Confounders adjusted: maternal birthweight, height, weight, smoking, hypertension, education, employment, infant sex, birth order | Outcome assessment: none | 179-182 | 3413 | ||
| Confounding factors: none | ≥183 | 3421 | |||
| Analytical: low | P for trend = .088 | ||||
| Attrition: moderate | |||||
| Overall: moderate | |||||
| Magnus et al | 1967-1979; Cohort study, singleton, live births who survived neonatal period; data from Norway birth registry; n = 3130 | Exposure: national database | Selection: moderate | Results reported as mean parental height in each 500-g birthweight category; not mean birthweight in each parental height group | |
| Outcome: national database | Exposure assessment: low | ||||
| Confounders adjusted: none | Outcome assessment: none | ||||
| Confounding factors: moderate | |||||
| Analytical: low | |||||
| Attrition: cannot tell | |||||
| Overall: moderate | |||||
| Miletic et al | 2002; Cohort study of all births in the county of Sibenik-Knin, Croatia; n = 550 | Exposure: survey in prenatal clinic | Selection: none | Paternal height correlated significantly with the neonate birthweight ( P = .01) | |
| Outcome: hospital record | Exposure assessment: low | ||||
| Confounders adjusted: none | Outcome assessment: none | ||||
| Confounding factors: moderate | |||||
| Analytical: low | |||||
| Attrition: cannot tell | |||||
| Overall: moderate | |||||
| Morrison et al | 1980-1996; Cohort study, singleton, live births, term, without anomalies in Queensland University single center study; n = 8556 | Exposure: maternal history | Selection: low | Paternal height was significantly correlated with birthweight ( P < .0007) | |
| Outcome: charts | Exposure assessment: low | ||||
| Confounder adjusted: maternal body mass index | Outcome assessment: none | ||||
| Confounding factors: moderate | |||||
| Analytical: low | |||||
| Attrition: cannot tell | |||||
| Overall: moderate | |||||
| Nahum and Stanislaw , b | See Table 1 for details | Fathers with height >2 SD above and below the mean had 125-g difference in birthweight of index child | |||
| Pritchard et al | 1967-1971; Cohort study, singleton, live births in Aberdeen, UK, hospital and associated nursing homes of 32-43 weeks’ gestational age; n = 5834 | Exposure: direct measurement | Selection: low | SD scores for birthweight were 0.29 higher (approximate correlation of 115-g birthweight) for taller men compared with shorter men | |
| Outcome: charts | Exposure assessment: moderate | ||||
| Confounder adjusted: maternal height | Outcome assessment: low | ||||
| Confounding factors: moderate | |||||
| Analytical: low | |||||
| Attrition: low | |||||
| Overall: moderate | |||||
| To et al | 1995-1996; Cohort study, singleton, live births of Chinese parents from single center in Hong Kong; >36 weeks’ gestational age; n = 355 | Exposure: direct measurement | Selection: low | Paternal height divided in 5 strata (5 cm for 160-180 cm), significantly correlated with birthweight ( P < .01) | |
| Outcome: charts | Exposure assessment: none | ||||
| Confounders adjusted: maternal prepregnancy weight and height | Outcome assessment: none | ||||
| Confounding factors: low | |||||
| Analytical: low | |||||
| Attrition: moderate | |||||
| Overall: moderate | |||||
| Wilcox et al , b | 1992-1993; Cohort study, singleton, term, live births without congenital anomaly from single center in Nottingham, UK; n = 571 | Exposure: direct measurement | Selection: low | <170 | 3322 ± 396 |
| Outcome: charts | Exposure assessment: none | 170-174 | 3406 ± 473 | ||
| Confounders adjusted: smoking, maternal height, paternal weight | Outcome assessment: none | 175-179 | 3465 ± 432 | ||
| Confounding factors: low | 180-184 | 3474 ± 470 | |||
| Analytical: low | 185-189 | 3503 ± 351 | |||
| Attrition: low | >190 | 3585 ± 378 | |||
| Overall: low | |||||
| Winikoff and Debrovner | 1992-1993; Cohort study, singleton primiparous, term live births; uncomplicated pregnancies from a single clinic in New York; n = 259 | Exposure: maternal history | Selection: moderate | Paternal height was significantly associated with variations in birthweight ( P < .05) | |
| Outcome: charts | Exposure assessment: low | ||||
| Confounders adjusted: maternal height, paternal weight, maternal prepregnancy weight, weight gain during pregnancy | Outcome assessment: none | ||||
| Confounding factors: low | |||||
| Analytical: low | |||||
| Attrition: cannot tell | |||||
| Overall: moderate | |||||
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
