Multiparity favors same-sex partner preference in male rats.

Same-sex partner preference is present in many mammals, including rodents. Several possible causal factors have been proposed for the establishment of this preference. The Fraternal Birth Order effect refers to the observation that older brothers increase the probability of homosexuality in men, but no experiment has analyzed this possibility. In this study, partner preference (tested in a three compartments box) and female and male sexual behavior (studied in a cylindrical arena) were evaluated in young male rats (3 months) born to multiparous mothers that had 4-6 previous gestations and around 12 months of age. Control groups were young male rats born to primiparous young (4 months) or aged (12 months) mothers. In the partner preference test, the males born to multiparous dams spent less time interacting with the receptive female and more time interacting with the sexually active male, and a 39% exhibited same-sex partner preference. This high percentage seems related to multiparity of their mothers and not to maternal age, because the males born to primiparous aged females (12 months) showed a similar low proportion of same-sex partner preference than the males born to young (4 months) primiparous females (4%). In the sexual behavior tests, no male born of a multiparous dam and with same-sex preference ejaculated and 54% displayed proceptivity and lordosis. Present results suggest that the fraternal birth order effect may occur also in rats.

Distribution of estrogen receptors alpha and beta in the brain of male rats with same-sex preference.

Two distinct estrogen receptors (ERs) exist, ERα and ERß. Both receptors participate in sexual differentiation of the rat brain and likely participate in the regulation of adult sexual orientation (i.e. partner preference). This last idea was investigated herein by examining males treated with the aromatase inhibitor, letrozole, administered prenatally (0.56 µg/kg G10-22). This treatment usually provokes same-sex preference in 1-2 males per litter. Vehicle-treated males (with female preference) and females in spontaneous proestrus (with male preference) were included as controls. ERα and ERß expression was analyzed by immunohistochemistry in brain areas known to control masculine sexual behavior and partner preference, like the medial preoptic area (MPOA), bed nucleus of the stria terminalis (BNST), medial amygdala (MeA) and ventromedial hypothalamic nucleus (VMH), as well as other brain regions suspected to participate in these processes. In addition, serum levels of estradiol were determined in all male groups. Letrozole-treated male rats that preferred sexually experienced males (LPM) showed over-expressed ERα in the hippocampal cornu Ammonis (CA 1, 3, 4) and dentate gyrus. The LPM group showed up-regulated ERß expression in the CA2 and reticular thalamic nucleus. The levels of estradiol did not differ between the groups. Higher expression of ERs in these males was different than their expression in females, with male sex-preference. This suggests that males with same-sex preference showed a unique brain, this sui generis steroid receptor expression probably participates in the biological underpinnings of sexual preference.

Antenatal women's childbearing practices at the Niger Delta university teaching hospital, Okolobiri Nigeria

Background: Overpopulation in a community or a country reflects high fertility desires of its citizens. A country can only progress meaningfully if its resources and amenities can provide for all its citizens. Objectives: To examine the childbearing practices of antenatal attendees at the Niger Delta University Teaching Hospital, Okolobiri, Nigeria and whether there is any suggestion of fertility decline or transition. Materials and Methods: A cross-sectional study of two hundred and fifty-two women who had antenatal care in the hospital during the study period. Data was collected using a structured self-administered questionnaire with a reliability coefficient of 0.85. Data collected were analysed using IBM SPSS Statistics version 25. Statistical significance was a p-value <0.05. Results: The mean age of the respondents was 30.5 ± 5.9 years. More than half (53.6%) had tertiary education and 39.3% had secondary education. Only 29.4% were housewives/unemployed. The median parity was 2 and 229 women accounted for previous deliveries of 596 babies. The median desired total number of children was 4 (range 1 to 8). More than half (56.3%) did not believe in spacing after the first child. Seventy-six (30.2%) had no knowledge of modern contraceptives. There was a significant relationship (p - 0.018) between child sex preference and number of births. Conclusion: With a current median parity of two children/woman and desired total number of children of a median of four children/woman, the childbearing practices of the population studied may not result in a fertility rate far below the Nigeria national average of 5.3 children per woman. Nevertheless, a study to derive the total fertility rate in the study population is necessary to determine whether or not there is ongoing fertility transition.

Androgen receptors immunoreactivity in the rat brain of males with same-sex preference.

Androgen receptors (AR) are crucial in the control of male sexual behavior and sex preference. AR are particularly concentrated in areas related with the neuroendocrine control of sex preference including the medial amygdala (MeA), the ventromedial nucleus of the hypothalamus (VMH), the bed nucleus of the stria terminalis (BNST), the medial preoptic area (MPOA), the nucleus accumbens (Acb), the suprachiasmatic (SCh) and supraoptic (SO) nuclei, but also seem to be important for the control of reproductive processes in the hippocampus (CA1-CA4 and dentate gyrus, DG). In the present study we analyzed the density of AR in these brain areas of adult male rats with sexual preference (established in a three-compartment box). Same-sex preference was produced in male rats by the prenatal administration of the aromatase inhibitor, letrozole (0.56 µg/kg/ml s.c. G10-22) that usually produces 1-2 animals per litter with same sex preference, while the others retain a female sex preference. We also included a group of proestrus females that had a clear preference for a sexually active male. AR were analyzed by immunocytochemistry using PG21 as primary antibody. We also measured total plasma testosterone concentrations by radioimmunoassay. In males with same sex preference there was a specific AR overexpression in CA3 and CA4 that suggests a feminized pattern because females in proestrus trend to show a higher density of AR in these hippocampal areas. Sex differences in AR density were found in the anterior cingulate cortex (ACg) and frontoparietal cortex (FrPa). Serum levels of testosterone did not differ between groups. Data are discussed based on the role of AR in the hippocampus.

Does sex composition of offspring relate to fertility in urban areas? The case of Ouagadougou, Burkina Faso.

With the onset of the demographic transition in sub-Saharan Africa, couples' desired number of children and the sex composition of offspring may become conflicted, with potential effects on future fertility. While intuitively expected, this effect has not been observed in studies in sub-Saharan Africa, where the level of fertility is higher than in other African regions. In this study, the hypothesis of a conflicted situation was examined by assessing the effect of sex composition of offspring on women's intentions regarding additional children and their use of modern contraceptives. A mixed-method analysis was performed using quantitative data regarding 2567 women aged 35-49 years drawn from a 2012 Demtrend retrospective longitudinal population survey, supplemented by qualitative data collected through 23 in-depth interviews of men and women in Ouagadougou. Results showed that the absence of one sex (boy or girl) in the existing offspring was associated with additional demand for children and lower contraceptive use. These results suggest that a desire for a combination of both girls and boys may be the driving factor contributing to larger family size; that is, continued fertility may not be determined by son preference, but rather by overall composition of offspring, when existing children are all girls or all boys. This could explain the stalling of the fertility decline observed in recent years in Ouagadougou.

Sensory Detection by the Vomeronasal Organ Modulates Experience-Dependent Social Behaviors in Female Mice.

In mice, social behaviors are largely controlled by the olfactory system. Pheromone detection induces naïve virgin females to retrieve isolated pups to the nest and to be sexually receptive to males, but social experience increases the performance of both types of innate behaviors. Whether animals are intrinsically sensitive to the smell of conspecifics, or the detection of olfactory cues modulates experience for the display of social responses is currently unclear. Here, we employed mice with an olfactory-specific deletion of the G protein Gαi2, which partially eliminates sensory function in the vomeronasal organ (VNO), to show that social behavior in female mice results from interactions between intrinsic mechanisms in the vomeronasal system and experience-dependent plasticity. In pup- and sexually-naïve females, Gαi2 deletion elicited a reduction in pup retrieval behavior, but not in sexual receptivity. By contrast, experienced animals showed normal maternal behavior, but the experience-dependent increase in sexual receptivity was incomplete. Further, lower receptivity was accompanied by reduced neuronal activity in the anterior accessory olfactory bulb and the rostral periventricular area of the third ventricle. Therefore, neural mechanisms utilize intrinsic sensitivity in the mouse vomeronasal system and enable plasticity to display consistent social behavior.

Recalled Parental Gender Preference in Chinese Culture: A Taiwan Birth Cohort Study.

Chinese culture has long favored sons over daughters. With the development of reproductive technology, the methods can be used not only in facilitation of conception, but also in sex-selective termination of pregnancies. Therefore, this study aimed to investigate: (1) the rate of pregnant expectancy/planning of children; (2) whether the Chinese cultural influence of son preference still exists, and factors effecting sex preference; and (3) whether artificial reproductive technology plays a role in parents giving birth to a child of their preferred sex. We used the Taiwan Birth Cohort Study dataset at six-months, which included 21,248 babies born in 2005. More mothers than fathers reported this pregnancy as unexpected (29.0% vs. 20.5%). Over half of the parents showed no preference for the sex of their child (mothers: 52.6%, fathers: 55.8%). However, among those who showed a preference, significantly more preferred sons than daughters (son preference, mothers: 24.8%, fathers: 24.3%; daughter preference, mothers: 22.5%, fathers: 19.9%). Additionally, structural equation modeling found that parents who had planned their pregnancy were more likely to prefer sons and less likely to prefer daughters. Parents who used artificial reproductive technology for conception were more likely to prefer and conceive sons. A preference for male children still exists in Taiwan, contributing to the high sex ratio at birth of 110 in our 2005 birth cohort. However, over half of the parents reported being neutral in the preference of the gender of their offspring. This suggests that Taiwan is moving toward a more gender-equitable society.

Rural-urban differences in the predictive influence of sex preference on marital dissolution in Nigeria.

This study examined the influence of place of residence on sex preference as a predictor of marital dissolution in Nigeria. It also appraised the mediation of socio-demographic factors on the relationship between sex preference and marital dissolution. Data were sourced from the 2018 demographic and health survey of Nigeria. Analyses involved the use of descriptive statistics, Pearson chi-square test and binary logistic regression models. Generally, marital dissolution significantly occurred more in rural than in urban areas. While more respondents had no child sex preference, preference for boys was significantly more among the urban women compared to the rural women. Irrespective of place of residence, sex preference was not a significant predictor of marital dissolution in Nigeria as the unadjusted models of marital dissolution and sex preference indicated that preference for more boys significantly decreased the odds of marital dissolution in the rural (OR=0.84; p=0.05), urban (OR=0.67; p=0.001), and total population (OR=0.77; p=0.001). In addition, preference for more girls significantly decreased the likelihood of marital dissolution in the rural (OR=0.82; p=0.002) and total populations (OR=0.84; p=0.05). Moreover, in the full adjusted model of the total population, preference for more males (OR=0.57; p=0.002) was also significantly associated with decreased odds of marital dissolution. Conversely, other factors that significantly increased the odds of marital dissolution included educational attainment, intimate partner violence, religion, being employed, polygamous unions, and region of residence. Women should achieve higher levels of education and be engaged in income earning occupations as mitigation measures against marital dissolution. Anti-dissolution campaigns should be initiated, especially in rural areas with high levels of intimate partner violence and in regions with relatively high incidences of marital dissolution/p-/p-1.

Impaired sex preference, but not social and social novelty preferences, following systemic blockade of oxytocin receptors in adult male mice.

The hypothalamic neuropeptide oxytocin (OT) is a powerful modulator of mammalian social behavior and its administration was shown to affect various types of social interactions. However, systematic examinations of the role of endogenous OT release in social behavior have heretofore been done only using genetically modified animal models in which the genes encoding either OT or the OT receptor (OTR) were mutated. While such genetic manipulations revealed various behavioral deficits, these deficits may involve developmental or long-term processes and do not prove the participation of acute OT release in the impaired behavior. Here we used a battery of social discrimination tasks to evaluate the effects of acute systemic OTR blockade, using a non-peptide, orally active OTR antagonist (L368,899), on social behavior of adult male C57BL/6 J mice. We found no effect of the pharmacological manipulation on the social preference and social novelty preference behaviors. However, the preference of a male mouse for investigating a female conspecific more than a male (sex preference behavior), was lost by administration of the OTR antagonist. Finally, we found that blocking OTR activity before social defeat prevented the consequent loss of social preference, suggesting a role for OT in the acquisition of aversive social memory. Overall, our results suggest that OT plays a role in modulating the salience of social stimuli and facilitating their memory, as predicted by the social salience theory, rather than in regulating the internal motivation of the subject for social interactions.

Involvement of ventral pallidal vasopressin in the sex-specific regulation of sociosexual motivation in rats.

The ventral pallidum (VP) is a critical node of the mesocorticolimbic reward circuit and is known to modulate social behaviors in rodents. Arginine vasopressin (AVP) signaling via the V1A receptor (V1AR) within the VP is necessary for the expression of socially motivated affiliative behaviors in monogamous voles. However, whether the VP-AVP system regulates socially motivated behaviors in non-monogamous species remains unknown. Here, we determined the extent of AVP fiber innervation in the VP as well as the involvement of the VP-AVP system in sociosexual motivation in adult male and female rats. We found that males have nearly twice the density of AVP-immunoreactive (AVP-ir) fibers in the VP compared to females, suggesting the possibility that males experience enhanced AVP signaling in the VP. We further found that this sex difference in VP-AVP-ir fiber density likely arises from an observed sex difference (males > females) in the percentage of VP-projecting AVP-ir cell bodies located in the bed nucleus of the stria terminalis and medial amygdala. To determine the behavioral implications of this sex difference, we next blocked AVP signaling in the VP by antagonizing VP-V1ARs in male and female rats and tested their preference to investigate an unfamiliar male rat or unfamiliar estrus female rat confined to corrals located on opposite ends of a three-chamber apparatus. Under vehicle conditions, males showed a significantly greater innate preference to investigate an opposite sex over same sex conspecific than estrus females. Interestingly, VP-V1AR antagonism significantly reduced males' opposite sex preference, while enhancing estrus females' opposite sex preference. Importantly, all subjects reliably discriminated between male and female stimulus rats regardless of drug treatment, demonstrating a change in motivational state rather than a perceptual impairment induced by VP-V1AR blockade. These results provide a novel functional link between a sex difference in ventral pallidal AVP fiber density and the sex-specific regulation of a sexually motivated behavior necessary for reproductive success.

Access to Information on Family Planning and Use of Modern Contraceptives Among Married Igbo Women in Southeast, Nigeria.

This study was conducted among married Igbo women in Nigeria who have the lowest median birth interval coupled with a culture of sex preference and low use of modern contraceptives. We examined the relationship between access to information on family planning and sex preference on the use of modern contraceptive (MC). The 2013 Nigeria Demographic and Health Survey data were used. The data of 1,661 women of reproductive age were analyzed in this study. Access to information on family planning was low, and almost half (48.6%) of the women had a score of zero. Controlling for possible confounding variables, the data show that women who have good (odds ratio [ OR]= 3.92; CI [2.28, 6.75], p < .001) and poor ( OR = 2.56; CI [1.85, 3.56], p < .001) access to information on family planning were more likely to use MC than those with no access to information on family planning. Sex preference showed no relationship with the use of MC. Families where husbands want more children than their wives inhibit ( OR = 0.62, CI [0.42, 0.90], p < .05) the use of MC compared with those families where husbands and wives fertility desire is the same. Public health programs by government and donors should intensify interventions to increase access to family planning information to promote the use of MC among married Igbo women.

Changes in sex ratio at birth among immigrant groups in Sweden.

What happens when citizens from societies with strong son preference culture migrate to countries in which preference for having a child of each sex prevails? Using data from Swedish population registers, we investigate the sex ratio at birth by parity and the sex composition of previous children in Sweden. Our results showed that women with Chinese, Korean, and Indian background had a substantially elevated sex ratio at the third parity if previous children were both girls. Strikingly, this skewed ratio became less pronounced after 2000, suggesting a shift for a more neutral sex preference for children among these groups in the new century.

Factors affecting women's sex preference in multiethnic society in North Khorasan Province, Iran.

BACKGROUND: Sex preference is one of the cultural problems of countries in the field of demographic issues. It can increase the number of pregnancies, reduce the interval between births and delay in seeking prenatal care, which can threaten the health of mother, baby, child and family, especially in traditional societies. OBJECTIVES: To determine the role of ethnicity on sex preference of different ethnicities living in North Khorasan Province (Iran). METHODS: This cross-sectional study was conducted using a multistage cluster sampling method and a researcher-made questionnaire of reproductive behavior on 1,000 women from 5 ethnicities (Fars, Turk, Kurd, Turkman and Tat) in North Khorasan Province in the summer of 2016. Data were analyzed by IBM-SPSS version 21, using descriptive statistics, ANOVA, t-test, and logistic regression. A significance level of ≤0.05 was set for examining the study hypotheses. RESULTS: The results showed sex preferences among different ethnicities of North Khorasan Province. The highest level of preference for sons was seen in Turkman (66% vs. 23%). Unlike other ethnic groups, Turkman (21%) and Kurdish people (29.7%) were under pressure from the spouse's family to give birth to sons. CONCLUSION: Sex preference, especially among the Turkman ethnic group, which are different in terms of geographical, economic and social conditions, affects the fertility and reproductive behavior of the respondents; and it is necessary to reduce son preference for the health and well-being of children and women.

Parental investment in Tibetan populations does not reflect stated cultural norms.

In this paper, we examined both stated norms of sex preference and actual sex-biases in parental investment in a Tibetan pastoralist society. We collected detailed demographic data on infant mortality, infant feeding, the length of interbirth intervals, and a decision when giving gifts, to examine sex-biased parental investment. Our results indicate a mismatch between self-reported son preference and measures of actual parental investment that favor daughters. We interpret this female-biased parental investment as a possible response to daughters generating more economic resources. However, the stated sex preferences of both sexes reflect cultural norms that appear to have remained unchanged over a long period, which may reflect the importance of male roles in the past. Our behavioral measures of parental investment are those most likely to be in the control of women (such as breastfeeding and interbirth interval), so this mismatch between stated and actual investment may be especially true of women.

Child Desire Among Men and Women Living with HIV/AIDS in the Traditional Culture of Vietnam.

In various settings, heterogeneity in fertility rates among HIV-affected couples highlights the importance of understanding contextual factors to inform program planning and implementation. We interviewed 1016 patients with HIV/AIDS at seven clinics in Vietnam to assess their desire to have a(nother) child and willingness to pay (WTP) for prevention of mother to child transmission (PMTCT) services. One-fifth of participants reported their desire for a(another) child and this was slightly higher among men than women. Factors associated with the desire to have a(nother) child of HIV/AIDS patients included (1) not yet have a child or a son, (2) provincial and district-level service, (3) income per capita, (4) marital status and (5) history of drug injection. The average WTP for PMTCT service was US $179 (95% CI 161-197). The study highlights the need for interventions on social, cultural barriers, improved accessibility and outcomes of counseling, and better care and treatment services for couples and child affected by HIV/AIDS.

Is There a Change in Patient Preference for a Female Colonoscopist during the Last Decade in Korea?

BACKGROUND/AIMS: Patients may feel embarrassed during colonoscopy. Our study aimed to assess changes in patient preference, over the past decade, for the sex of their colonoscopist. METHODS: Prospective studies were performed at a single health center from July to September 2008, and from July to September 2016. Subjects included colonoscopy patients (2008: 354, 2016: 304) who were asked to complete a questionnaire before colonoscopy. RESULTS: In 2016, 69 patients (24.9%) expressed a sex preference, compared with 46 patients (14.6%) in 2008. By 2016, female patient preference for a female colonoscopist had significantly increased to 95% (odds ratio [OR], 2.678; 95% confidence interval [CI], 1.418- 5.057; P=0.002). In multivariate analysis, patient sex (OR, 4.404; P=0.000), patient age (OR, 0.977; 95% CI, 0.961-0.992; P=0.004), and year of procedure (OR, 1.674; 95% CI, 1.028-2.752) were statistically significant factors in sex preference. Between 2008 and 2016, female patients preferred a female colonoscopist because of embarrassment. Male patients also preferred a male colonoscopist, and the primary reason shifted from expertise to patient embarrassment (2008: 29%, 2016: 63%). CONCLUSIONS: Patients have an increased gender preference for the colonoscopist because of embarrassment. Taking this into account can increase patient satisfaction during colonoscopy.

Is There a Change in Patient Preference for a Female Colonoscopist during the Last Decade in Korea?

BACKGROUND/AIMS: Patients may feel embarrassed during colonoscopy. Our study aimed to assess changes in patient preference, over the past decade, for the sex of their colonoscopist. METHODS: Prospective studies were performed at a single health center from July to September 2008, and from July to September 2016. Subjects included colonoscopy patients (2008: 354, 2016: 304) who were asked to complete a questionnaire before colonoscopy. RESULTS: In 2016, 69 patients (24.9%) expressed a sex preference, compared with 46 patients (14.6%) in 2008. By 2016, female patient preference for a female colonoscopist had significantly increased to 95% (odds ratio [OR], 2.678; 95% confidence interval [CI], 1.418– 5.057; P=0.002). In multivariate analysis, patient sex (OR, 4.404; P=0.000), patient age (OR, 0.977; 95% CI, 0.961–0.992; P=0.004), and year of procedure (OR, 1.674; 95% CI, 1.028–2.752) were statistically significant factors in sex preference. Between 2008 and 2016, female patients preferred a female colonoscopist because of embarrassment. Male patients also preferred a male colonoscopist, and the primary reason shifted from expertise to patient embarrassment (2008: 29%, 2016: 63%). CONCLUSIONS: Patients have an increased gender preference for the colonoscopist because of embarrassment. Taking this into account can increase patient satisfaction during colonoscopy.

Do women prefer a female breast surgeon?

BACKGROUND: Patient preferences regarding the gender of their physicians is a highly sensitive issue, which can be particularly salient in intimate medical situations. Previously published studies found that women tend to prefer female physicians, especially in the case of obstetricians and gynecologists. Data regarding other intimate specialties, such as breast surgery, are scarce. The present study was undertaken to assess gender preferences of women regarding their choice of a breast surgeon. METHODS: Five hundred and fifteen consecutive women who attended breast clinics in two university-affiliated tertiary hospitals were prospectively enrolled. A 25-item anonymous questionnaire was completed by women independently and used to assess their preferences in selecting their breast surgeon. Of the 515 women, 500 (97 % response rate; mean age 50.6 ± 15.4 years) completed the anonymous questionnaire. RESULTS: Overall, 160 (32 %) women preferred to undergo breast examination by a female breast surgeon, 296 (59 %) had no preference, and only 44 (9 %) preferred a male surgeon. A same-gender preference was significantly and independently associated with younger age of the patients (Odds Ratio = 0.978, 95 % Confidence Interval 0.962-0.994, P = 0.007) and being married (Odds Ratio = 0.563, 95 % Confidence Interval 0.347-0.916, P = 0.021). However, only small and equal numbers of patients preferred to undergo breast surgery by a female (14 %) or a male (13 %) surgeon, and most patients (73 %) had no gender preferences. Furthermore, the three most important factors, which affected in general the actual selection, were surgical ability (93 %), experience (91.2 %) and knowledge (78.6 %), rather than physician gender per se. CONCLUSIONS: Overall, about a third of women prefer a female breast surgeon for their breast examination. Embarrassment during the examination was the major reason for same-gender preference. In contrast, when it comes to breast operations, preference for a female surgeon is less pronounced, with the professional skills of the surgeons becoming the predominant consideration. The fact that almost a third of the potential patients prefer female surgeons with regard to their breast examinations emphasizes the need to increase the number of female surgeons. Such an increase can be achieved through academic and economic changes that will enable more women to specialize in general surgery. TRIAL REGISTRATION: Trial registration is not required for this type of research.

Male rats with same sex preference show high experimental anxiety and lack of anxiogenic-like effect of fluoxetine in the plus maze test.

Homosexual men show a 2-4 higher risk to suffer anxiety in comparison with heterosexuals. It is unknown if biological factors collaborate to increase such incidence. Fluoxetine produces differential brain activation in homosexuals as compared with heterosexuals, suggesting that it may produce a divergent behavioral effect dependant on sex-preference. The first aim was to evaluate experimental anxiety in male rats that show same-sex preference in the elevated plus maze (EPM). The second goal explored the putative differential effect of fluoxetine (10mg/kg) in male rats with female and same-sex preference in the EPM. To induce same-sex preference males were prenatally treated with letrozole (0.56µg/kg, 10-20 gestation days), while controls were males prenatally treated with letrozole that retain female-preference or which mothers received oil. In both groups we found animals with male preference, but the proportion was higher in males that prenatally received letrozole (10 vs. 27%). Males with same-sex preference spent less time and showed lower number of entries to the open arms of the EPM than males that prefer females, regardless of the prenatal treatment. In males with female preference, fluoxetine reduced the time spent and number of entries to the open arms that was absent in males with same-sex preference. These data suggest that biological factors contribute to the high levels of anxiety in subjects with same-sex preference and that fluoxetine in men may produce a divergent action depending on sexual orientation.

Sex preference for children in German villages during the fertility transition.

In the past, parents' sex preferences for their children have proved difficult to verify. This study used John Knodel's German village genealogies of couples married between 1815 and 1899 to investigate sex preferences for children during the fertility transition. Event history analyses of couples' propensity to progress to a fifth parity was used to test whether the probability of having additional children was influenced by the sex composition of surviving children. It appears that son preference influenced reproductive behaviour: couples having only girls experienced significantly higher transition rates than those having only boys or a mixed sibset. However, couples who married after about 1870 began to exhibit fertility behaviour consistent with the choice to have at least one surviving boy and girl. This result represents a surprisingly early move towards the symmetrical sex preference typical of modern European populations.