Background
Seasonal variations greatly influence birth patterns differently from country to country. In Ghana, there is paucity of information on birth seasonal patterns. This retrospective study described the trends and seasonality of births and perinatal outcomes in Upper East Region of Ghana.

Methods
Births occurring in each month of the calendar years (2010–2014; inclusive) were extracted from the District Health Information Management System (DHIMS2) database of the Bolgatanga Municipal Health Directorate and exported into Microsoft Excel spread sheet and Epi Ifo for analysis. Analysis was carried out by calculating average number of births per month correcting for unequal month length using 30 days. A Chi-square test for trend was performed to check for statistical significance (p < 0.05) in trends and seasonality of birth and perinatal outcomes.

Results
There were 24,171 health facility deliveries, of which 97.7 % were singleton deliveries and 2.3 % were multiple (two or three) deliveries. There was a consistent rise in the annual health facility deliveries controlled for the number of fertile women, from 4169 in 2010 to 5474 in 2014 (p < 0.0001). Monthly birth distribution displayed a periodic pattern with peaks in May, September and October and troughs during the months of January, February and July (p < 0.0001). Women were likely to give birth during the raining season than the dry season. Caesarean Section (CS) rate showed a steady rise over the years (124 per 1000 births in 2010 to 185 per 1000 births in 2014 (p < 0.0001) with overall rate of 14.6 %. Stillbirth (SB) rate, however decreased slightly over the years from 29 per 1000 births to 23 per 1000 births (p = 0.197) with overall SB rate of 2.6 %. Similarly, Low Birth Weight (LBW) declined from 77 per 1000 live births to 71 per 1000 live births from 2010 to 2014 (p < 0.0001). Seasonal (rainy and dry) distributions did not show a clear difference in birth frequencies.

Conclusion
Health facility delivery was persistently high in the Bolgatanga Municipality with birth peaking in May, September and October. Despite the rising rate of caesarean section, stillbirth rate did not significantly improved over the years. A prospective study may reveal the reasons for the increasing caesarean section rate. Additionally, understanding the factors that affect the decreasing trends of low birth weight in the municipality is crucial to public health policy makers in Ghana.