science of us

Are My Hormones Me?

I want a baby. Or do my hormones want a baby?

Photo: Andrew Ostrovsky/Getty Images/iStockphoto
Photo: Andrew Ostrovsky/Getty Images/iStockphoto
Photo: Andrew Ostrovsky/Getty Images/iStockphoto

Every so often I become preoccupied with having a baby. With pregnancy, with motherhood, with all things reproduction. Sometimes it seems to align with ovulation, sometimes not. Sometimes it arrives like a storm and leaves just as suddenly. Lately it’s been lingering, a constant simmer that occasionally tips into boiling. It’s never been like this before, but maybe it’s an age thing (I’m 36), maybe it came from getting sober and feeling behind, maybe it’s all the baby pictures I see on Instagram.

Until recently, my understanding of hormones made me want to blame this feeling on them, or credit it to them, or something like that. It was so new and overwhelming, I figured something chemical must be happening. The feeling is almost like being on a drug, or being drunk — but like being on “motherhood” instead of cocaine. Or having “pregnancy glasses” instead of beer goggles. But unlike being on a drug, the feeling is hard to discredit after the fact.

At their simplest, hormones are tiny molecules released within the body by glands and other organs. (And glands are clusters of cells that make and secrete things — for instance, there’s the thyroid and adrenal glands, and the ovaries and the pancreas, which also secrete hormones.) In Greek, “hormone” means “setting in motion,” and these signaling molecules travel in the bloodstream from the gland to wherever it is they’re headed, to pass on a directive. They’re messengers, essentially, carrying instructions for organs throughout the body. Once they arrive at their destination, they typically bind to the target organ, which absorbs their message and behaves accordingly. (I think of hormones as like little students rushing through the hallways of a school, clutching a presentation under their arm, ready to deliver a final project.)

Hormones are critical for most aspects of human function, including physical growth, puberty, hunger, metabolism, sexual function, and reproduction. Also sleep, menstruation, lactation, stress, and mood, among many others. Some well-known hormones include insulin, adrenaline, oxytocin, estrogen, testosterone, and cortisol. (And some less-well-known ones, for instance, are calcitonin, glucagon, and orexin.) The overall hormone-and-gland system is called the endocrine system, and common disorders of the endocrine system include obesity, diabetes, and thyroid diseases. Hormones seemingly control everything, in other words, and I’d started to envision them as little particles floating around my body, carrying banners that said, “Have a baby!!!” It was interesting, then, to learn that I basically had it all wrong.

While the urgent desire to have a child in one’s late 30s and early 40s is “as real as the day is long,” said Dr. David Keefe, chair of NYU Langone’s Department of Obstetrics & Gynecology, “I’m not convinced it’s hormonal.” Instead, he said, the feeling is likely “existential.” He noted, in fact, that there’s “really not much” that happens to women during this time hormonally: “There’s a consistent, gradual decline in women’s fertility around this time,” Keefe said, “but if you look at the hormonal profiles, there’s really not much that occurs.”

Another OB/GYN, Dr. Mary Jane Minkin, of Yale, told me the same thing: “To the best of my knowledge,” she said, “there isn’t a hormonal surge leading to an urge to conceive [during this phase of life]. There is some more hormonal variability as we get older — with a decline in overall estrogen and progesterone levels — but that doesn’t lead to any biological urges that I know of.” She noted that there is, instead, “a sociological issue,” namely that “educated women often know that their fertility diminishes with age, and so many do therefore feel an urge to conceive.” But this is “driven by the brain and not particularly hormonal,” she emphasized.

Maybe I shouldn’t have been so surprised, but I was. Given the popularity of companies like KindBody, which offers anti-Müllerian hormone (AMH) testing, it seemed to me that hormones must have everything to do with fertility — with the urge to conceive as well as the ability. But there is no reliable fertility test; measuring things like AMH or follicle-stimulating hormone (FSH) are “essentially ineffective,” as Keefe put it, at predicting a woman’s fertility status. To be fair, KindBody has acknowledged this. Still, I’d been under the impression that measuring my own fertility should be as easy as giving a biological sample, running numbers, and getting some kind of readout. “Unfortunately there is no good hormonal indicator of one’s fertility,” Keefe told me. “So women are left to imagine. To fear. And that’s when the sense of urgency, almost panic, can sometimes set in.”

It was both freeing and frustrating to be delivered back to the understanding that fertility is largely a mystery. The idea that wanting to have a child isn’t hormonal but existential — logical, rational — began to unloosen something within me. (I Googled what existential means, too, to make sure I knew what we were talking about: “Concerned with existence” is the general definition. Worried about the meaning of life, how to be, and what to do.)

Since the fertility window begins to close for women sooner than it does for men, whether to have children is an existential question that women must typically face at a younger age, as Keefe noted. (He described this as one of life’s “great injustices.”) In his words, the closing of the fertility window is “a time to reconcile” — a time to be honest with oneself about what one really wants, whatever that might be. Reproduction is “kind of at the core of our sense of who we are,” he said, “and so at some point we’re forced to come to terms with it.” It’s not a time of “panicking,” as he put it, but “at the same time, it’s not a time of putting one’s head in the soil to avoid having to worry.” My visuals of the little internal particles floating around in my blood, unbidden, dictating my desires as if I were their puppet (carrying that “have a baby” banner), began to dissipate.

While I was working on this story, a younger friend asked me to describe what it felt like to want to have a baby. At first I didn’t know what to say, and I was embarrassed. I want to be pregnant, I said, to go around being pregnant and googling pregnancy stuff, doing the “nesting” thing, nurturing a little creature as it grows. Eating, sitting. And then I also imagine holding a baby in my arms, against my chest, murmuring to it, nursing. I have vague ideas about intimacy, quietness, and warmth. What it might feel like to love and care for something — someone — in that way. To open my life permanently. To create a new family with another person, to embody hope and unity.

It was interesting and sort of uncomfortable, initially, to learn that the impulse toward this is existential rather than hormonal — active rather than passive, essentially. Something I’m choosing rather than something that’s happening to me. Accepting it felt like dropping a pretense: This is what I want, this is who I am. I’m not a helpless pinball, or at least not entirely.

Are My Hormones Me?