Portraying Pregnancy​: From Holbein to Social Media (until 26 April; temporarily closed) opens with images of the Visitation, the encounter in St Luke’s Gospel between the expectant Virgin Mary and her sixty-year-old cousin Elizabeth, improbably pregnant, in the days before IVF, with John the Baptist. The Visitation is the Second Joyful Mystery of the rosary. For those who grew up in Catholic Ireland, it was also a cautionary tale: if it happened to them, it could happen to you. Later in the exhibition, which includes paintings, prints, photographs, objects and clothing relating to pregnancy from the 15th century to the present, Edward Burne-Jones’s Annunciation (1876-79) shows the Virgin receiving news of her pregnancy from the Angel Gabriel. This (the First Joyful Mystery) preoccupied me from the age of nine or ten. I may not have got my period, I may have been years from letting any of the lads from school put a hand up my skirt in the handball alley, but the anxiety persisted. Gabriel might show up at any moment and announce that the Holy Spirit, in the shape of a dove, had descended in the dead of the night and knocked me up. (‘My mother’s a Jew, my father’s a bird,’ Buck Mulligan sings in Ulysses.)

Pregnancy begins as speculation. This exhibition reminds us that for most of history – before it was possible to pee on a stick and wait for a pink line, or to see a foetus via ultrasound – doctors had no failsafe way of confirming gestation. It wasn’t until 1927 that scientists detected HCG, a hormone produced by the placenta after implantation, in pregnant women’s urine. The first pregnancy test involved injecting baby rats with a sample: if HCG was present, the rats, despite their immaturity, started to behave as though they were on heat. Before this, diagnosis depended on patient testimony and medical guesswork. ‘Quickening’, movement in the womb during the second trimester, was ‘confirmatory evidence’ of gestation.

But bodies can be unreliable narrators. When Mary Tudor met the pope’s emissary on 29 November 1554, she felt the child stir inside her, as St Elizabeth had when the Virgin touched her stomach. ‘Exultavit infans in utero pius,’ the queen exclaimed to Cardinal Pole, directly referencing the Visitation. The previous day, Mary had sat in the great chamber at Whitehall Palace ‘richly apparelled, and her belly laid out, that all men might see that she was with child’. What was it these men saw? It was reported to Charles V that his daughter-in-law was exhibiting the ‘customary symptoms’ of pregnancy: her colouring, ‘the state of her breasts’, the fact that her dresses no longer did up. She was expected to give birth in May 1555; a nursery was prepared and a cradle carved. By the end of summer, hope was lost: the Venetian ambassador wrote that Mary’s pregnancy was more likely to ‘end in wind rather than anything else’. Another source claimed that she had given birth to a monkey.

Anthonis Mor’s portrait from 1554 depicts Mary in the throes of this phantom pregnancy, shortly after her marriage to Philip II. The queen is shown seated rather than standing, in the tradition of portraits of Habsburg brides, and the partlet concealing her shoulders and neck follows the conservative fashion of contemporary Spain. She is 37. What’s striking is her witheredness, her brittle grasp of the rose in her hand – a symbol of subservience to her Spanish consort. This is Bloody Mary drained of life, as in Victorian photographs where the subject seems to regard you from beyond the grave.